xref: /freebsd/contrib/llvm-project/llvm/lib/Target/ARM/ARMISelLowering.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===- ARMISelLowering.cpp - ARM DAG Lowering Implementation --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that ARM uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ARMISelLowering.h"
15 #include "ARMBaseInstrInfo.h"
16 #include "ARMBaseRegisterInfo.h"
17 #include "ARMCallingConv.h"
18 #include "ARMConstantPoolValue.h"
19 #include "ARMMachineFunctionInfo.h"
20 #include "ARMPerfectShuffle.h"
21 #include "ARMRegisterInfo.h"
22 #include "ARMSelectionDAGInfo.h"
23 #include "ARMSubtarget.h"
24 #include "ARMTargetTransformInfo.h"
25 #include "MCTargetDesc/ARMAddressingModes.h"
26 #include "MCTargetDesc/ARMBaseInfo.h"
27 #include "Utils/ARMBaseInfo.h"
28 #include "llvm/ADT/APFloat.h"
29 #include "llvm/ADT/APInt.h"
30 #include "llvm/ADT/ArrayRef.h"
31 #include "llvm/ADT/BitVector.h"
32 #include "llvm/ADT/DenseMap.h"
33 #include "llvm/ADT/STLExtras.h"
34 #include "llvm/ADT/SmallPtrSet.h"
35 #include "llvm/ADT/SmallVector.h"
36 #include "llvm/ADT/Statistic.h"
37 #include "llvm/ADT/StringExtras.h"
38 #include "llvm/ADT/StringRef.h"
39 #include "llvm/ADT/StringSwitch.h"
40 #include "llvm/ADT/Twine.h"
41 #include "llvm/Analysis/VectorUtils.h"
42 #include "llvm/CodeGen/CallingConvLower.h"
43 #include "llvm/CodeGen/ComplexDeinterleavingPass.h"
44 #include "llvm/CodeGen/ISDOpcodes.h"
45 #include "llvm/CodeGen/IntrinsicLowering.h"
46 #include "llvm/CodeGen/MachineBasicBlock.h"
47 #include "llvm/CodeGen/MachineConstantPool.h"
48 #include "llvm/CodeGen/MachineFrameInfo.h"
49 #include "llvm/CodeGen/MachineFunction.h"
50 #include "llvm/CodeGen/MachineInstr.h"
51 #include "llvm/CodeGen/MachineInstrBuilder.h"
52 #include "llvm/CodeGen/MachineJumpTableInfo.h"
53 #include "llvm/CodeGen/MachineMemOperand.h"
54 #include "llvm/CodeGen/MachineOperand.h"
55 #include "llvm/CodeGen/MachineRegisterInfo.h"
56 #include "llvm/CodeGen/RuntimeLibcallUtil.h"
57 #include "llvm/CodeGen/SelectionDAG.h"
58 #include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
59 #include "llvm/CodeGen/SelectionDAGNodes.h"
60 #include "llvm/CodeGen/TargetInstrInfo.h"
61 #include "llvm/CodeGen/TargetLowering.h"
62 #include "llvm/CodeGen/TargetOpcodes.h"
63 #include "llvm/CodeGen/TargetRegisterInfo.h"
64 #include "llvm/CodeGen/TargetSubtargetInfo.h"
65 #include "llvm/CodeGen/ValueTypes.h"
66 #include "llvm/CodeGenTypes/MachineValueType.h"
67 #include "llvm/IR/Attributes.h"
68 #include "llvm/IR/CallingConv.h"
69 #include "llvm/IR/Constant.h"
70 #include "llvm/IR/Constants.h"
71 #include "llvm/IR/DataLayout.h"
72 #include "llvm/IR/DebugLoc.h"
73 #include "llvm/IR/DerivedTypes.h"
74 #include "llvm/IR/Function.h"
75 #include "llvm/IR/GlobalAlias.h"
76 #include "llvm/IR/GlobalValue.h"
77 #include "llvm/IR/GlobalVariable.h"
78 #include "llvm/IR/IRBuilder.h"
79 #include "llvm/IR/InlineAsm.h"
80 #include "llvm/IR/Instruction.h"
81 #include "llvm/IR/Instructions.h"
82 #include "llvm/IR/IntrinsicInst.h"
83 #include "llvm/IR/Intrinsics.h"
84 #include "llvm/IR/IntrinsicsARM.h"
85 #include "llvm/IR/Module.h"
86 #include "llvm/IR/PatternMatch.h"
87 #include "llvm/IR/Type.h"
88 #include "llvm/IR/User.h"
89 #include "llvm/IR/Value.h"
90 #include "llvm/MC/MCInstrDesc.h"
91 #include "llvm/MC/MCInstrItineraries.h"
92 #include "llvm/MC/MCRegisterInfo.h"
93 #include "llvm/MC/MCSchedule.h"
94 #include "llvm/Support/AtomicOrdering.h"
95 #include "llvm/Support/BranchProbability.h"
96 #include "llvm/Support/Casting.h"
97 #include "llvm/Support/CodeGen.h"
98 #include "llvm/Support/CommandLine.h"
99 #include "llvm/Support/Compiler.h"
100 #include "llvm/Support/Debug.h"
101 #include "llvm/Support/ErrorHandling.h"
102 #include "llvm/Support/KnownBits.h"
103 #include "llvm/Support/MathExtras.h"
104 #include "llvm/Support/raw_ostream.h"
105 #include "llvm/Target/TargetMachine.h"
106 #include "llvm/Target/TargetOptions.h"
107 #include "llvm/TargetParser/Triple.h"
108 #include <algorithm>
109 #include <cassert>
110 #include <cstdint>
111 #include <cstdlib>
112 #include <iterator>
113 #include <limits>
114 #include <optional>
115 #include <tuple>
116 #include <utility>
117 #include <vector>
118 
119 using namespace llvm;
120 using namespace llvm::PatternMatch;
121 
122 #define DEBUG_TYPE "arm-isel"
123 
124 STATISTIC(NumTailCalls, "Number of tail calls");
125 STATISTIC(NumMovwMovt, "Number of GAs materialized with movw + movt");
126 STATISTIC(NumLoopByVals, "Number of loops generated for byval arguments");
127 STATISTIC(NumConstpoolPromoted,
128   "Number of constants with their storage promoted into constant pools");
129 
130 static cl::opt<bool>
131 ARMInterworking("arm-interworking", cl::Hidden,
132   cl::desc("Enable / disable ARM interworking (for debugging only)"),
133   cl::init(true));
134 
135 static cl::opt<bool> EnableConstpoolPromotion(
136     "arm-promote-constant", cl::Hidden,
137     cl::desc("Enable / disable promotion of unnamed_addr constants into "
138              "constant pools"),
139     cl::init(false)); // FIXME: set to true by default once PR32780 is fixed
140 static cl::opt<unsigned> ConstpoolPromotionMaxSize(
141     "arm-promote-constant-max-size", cl::Hidden,
142     cl::desc("Maximum size of constant to promote into a constant pool"),
143     cl::init(64));
144 static cl::opt<unsigned> ConstpoolPromotionMaxTotal(
145     "arm-promote-constant-max-total", cl::Hidden,
146     cl::desc("Maximum size of ALL constants to promote into a constant pool"),
147     cl::init(128));
148 
149 cl::opt<unsigned>
150 MVEMaxSupportedInterleaveFactor("mve-max-interleave-factor", cl::Hidden,
151   cl::desc("Maximum interleave factor for MVE VLDn to generate."),
152   cl::init(2));
153 
154 // The APCS parameter registers.
155 static const MCPhysReg GPRArgRegs[] = {
156   ARM::R0, ARM::R1, ARM::R2, ARM::R3
157 };
158 
handleCMSEValue(const SDValue & Value,const ISD::InputArg & Arg,SelectionDAG & DAG,const SDLoc & DL)159 static SDValue handleCMSEValue(const SDValue &Value, const ISD::InputArg &Arg,
160                                SelectionDAG &DAG, const SDLoc &DL) {
161   assert(Arg.ArgVT.isScalarInteger());
162   assert(Arg.ArgVT.bitsLT(MVT::i32));
163   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, Arg.ArgVT, Value);
164   SDValue Ext =
165       DAG.getNode(Arg.Flags.isSExt() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND, DL,
166                   MVT::i32, Trunc);
167   return Ext;
168 }
169 
addTypeForNEON(MVT VT,MVT PromotedLdStVT)170 void ARMTargetLowering::addTypeForNEON(MVT VT, MVT PromotedLdStVT) {
171   if (VT != PromotedLdStVT) {
172     setOperationAction(ISD::LOAD, VT, Promote);
173     AddPromotedToType (ISD::LOAD, VT, PromotedLdStVT);
174 
175     setOperationAction(ISD::STORE, VT, Promote);
176     AddPromotedToType (ISD::STORE, VT, PromotedLdStVT);
177   }
178 
179   MVT ElemTy = VT.getVectorElementType();
180   if (ElemTy != MVT::f64)
181     setOperationAction(ISD::SETCC, VT, Custom);
182   setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
183   setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
184   if (ElemTy == MVT::i32) {
185     setOperationAction(ISD::SINT_TO_FP, VT, Custom);
186     setOperationAction(ISD::UINT_TO_FP, VT, Custom);
187     setOperationAction(ISD::FP_TO_SINT, VT, Custom);
188     setOperationAction(ISD::FP_TO_UINT, VT, Custom);
189   } else {
190     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
191     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
192     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
193     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
194   }
195   setOperationAction(ISD::BUILD_VECTOR,      VT, Custom);
196   setOperationAction(ISD::VECTOR_SHUFFLE,    VT, Custom);
197   setOperationAction(ISD::CONCAT_VECTORS,    VT, Legal);
198   setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Legal);
199   setOperationAction(ISD::SELECT,            VT, Expand);
200   setOperationAction(ISD::SELECT_CC,         VT, Expand);
201   setOperationAction(ISD::VSELECT,           VT, Expand);
202   setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Expand);
203   if (VT.isInteger()) {
204     setOperationAction(ISD::SHL, VT, Custom);
205     setOperationAction(ISD::SRA, VT, Custom);
206     setOperationAction(ISD::SRL, VT, Custom);
207   }
208 
209   // Neon does not support vector divide/remainder operations.
210   setOperationAction(ISD::SDIV, VT, Expand);
211   setOperationAction(ISD::UDIV, VT, Expand);
212   setOperationAction(ISD::FDIV, VT, Expand);
213   setOperationAction(ISD::SREM, VT, Expand);
214   setOperationAction(ISD::UREM, VT, Expand);
215   setOperationAction(ISD::FREM, VT, Expand);
216   setOperationAction(ISD::SDIVREM, VT, Expand);
217   setOperationAction(ISD::UDIVREM, VT, Expand);
218 
219   if (!VT.isFloatingPoint() && VT != MVT::v2i64 && VT != MVT::v1i64)
220     for (auto Opcode : {ISD::ABS, ISD::ABDS, ISD::ABDU, ISD::SMIN, ISD::SMAX,
221                         ISD::UMIN, ISD::UMAX})
222       setOperationAction(Opcode, VT, Legal);
223   if (!VT.isFloatingPoint())
224     for (auto Opcode : {ISD::SADDSAT, ISD::UADDSAT, ISD::SSUBSAT, ISD::USUBSAT})
225       setOperationAction(Opcode, VT, Legal);
226 }
227 
addDRTypeForNEON(MVT VT)228 void ARMTargetLowering::addDRTypeForNEON(MVT VT) {
229   addRegisterClass(VT, &ARM::DPRRegClass);
230   addTypeForNEON(VT, MVT::f64);
231 }
232 
addQRTypeForNEON(MVT VT)233 void ARMTargetLowering::addQRTypeForNEON(MVT VT) {
234   addRegisterClass(VT, &ARM::DPairRegClass);
235   addTypeForNEON(VT, MVT::v2f64);
236 }
237 
setAllExpand(MVT VT)238 void ARMTargetLowering::setAllExpand(MVT VT) {
239   for (unsigned Opc = 0; Opc < ISD::BUILTIN_OP_END; ++Opc)
240     setOperationAction(Opc, VT, Expand);
241 
242   // We support these really simple operations even on types where all
243   // the actual arithmetic has to be broken down into simpler
244   // operations or turned into library calls.
245   setOperationAction(ISD::BITCAST, VT, Legal);
246   setOperationAction(ISD::LOAD, VT, Legal);
247   setOperationAction(ISD::STORE, VT, Legal);
248   setOperationAction(ISD::UNDEF, VT, Legal);
249 }
250 
addAllExtLoads(const MVT From,const MVT To,LegalizeAction Action)251 void ARMTargetLowering::addAllExtLoads(const MVT From, const MVT To,
252                                        LegalizeAction Action) {
253   setLoadExtAction(ISD::EXTLOAD,  From, To, Action);
254   setLoadExtAction(ISD::ZEXTLOAD, From, To, Action);
255   setLoadExtAction(ISD::SEXTLOAD, From, To, Action);
256 }
257 
addMVEVectorTypes(bool HasMVEFP)258 void ARMTargetLowering::addMVEVectorTypes(bool HasMVEFP) {
259   const MVT IntTypes[] = { MVT::v16i8, MVT::v8i16, MVT::v4i32 };
260 
261   for (auto VT : IntTypes) {
262     addRegisterClass(VT, &ARM::MQPRRegClass);
263     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
264     setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
265     setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
266     setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
267     setOperationAction(ISD::SHL, VT, Custom);
268     setOperationAction(ISD::SRA, VT, Custom);
269     setOperationAction(ISD::SRL, VT, Custom);
270     setOperationAction(ISD::SMIN, VT, Legal);
271     setOperationAction(ISD::SMAX, VT, Legal);
272     setOperationAction(ISD::UMIN, VT, Legal);
273     setOperationAction(ISD::UMAX, VT, Legal);
274     setOperationAction(ISD::ABS, VT, Legal);
275     setOperationAction(ISD::SETCC, VT, Custom);
276     setOperationAction(ISD::MLOAD, VT, Custom);
277     setOperationAction(ISD::MSTORE, VT, Legal);
278     setOperationAction(ISD::CTLZ, VT, Legal);
279     setOperationAction(ISD::CTTZ, VT, Custom);
280     setOperationAction(ISD::BITREVERSE, VT, Legal);
281     setOperationAction(ISD::BSWAP, VT, Legal);
282     setOperationAction(ISD::SADDSAT, VT, Legal);
283     setOperationAction(ISD::UADDSAT, VT, Legal);
284     setOperationAction(ISD::SSUBSAT, VT, Legal);
285     setOperationAction(ISD::USUBSAT, VT, Legal);
286     setOperationAction(ISD::ABDS, VT, Legal);
287     setOperationAction(ISD::ABDU, VT, Legal);
288     setOperationAction(ISD::AVGFLOORS, VT, Legal);
289     setOperationAction(ISD::AVGFLOORU, VT, Legal);
290     setOperationAction(ISD::AVGCEILS, VT, Legal);
291     setOperationAction(ISD::AVGCEILU, VT, Legal);
292 
293     // No native support for these.
294     setOperationAction(ISD::UDIV, VT, Expand);
295     setOperationAction(ISD::SDIV, VT, Expand);
296     setOperationAction(ISD::UREM, VT, Expand);
297     setOperationAction(ISD::SREM, VT, Expand);
298     setOperationAction(ISD::UDIVREM, VT, Expand);
299     setOperationAction(ISD::SDIVREM, VT, Expand);
300     setOperationAction(ISD::CTPOP, VT, Expand);
301     setOperationAction(ISD::SELECT, VT, Expand);
302     setOperationAction(ISD::SELECT_CC, VT, Expand);
303 
304     // Vector reductions
305     setOperationAction(ISD::VECREDUCE_ADD, VT, Legal);
306     setOperationAction(ISD::VECREDUCE_SMAX, VT, Legal);
307     setOperationAction(ISD::VECREDUCE_UMAX, VT, Legal);
308     setOperationAction(ISD::VECREDUCE_SMIN, VT, Legal);
309     setOperationAction(ISD::VECREDUCE_UMIN, VT, Legal);
310     setOperationAction(ISD::VECREDUCE_MUL, VT, Custom);
311     setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
312     setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
313     setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
314 
315     if (!HasMVEFP) {
316       setOperationAction(ISD::SINT_TO_FP, VT, Expand);
317       setOperationAction(ISD::UINT_TO_FP, VT, Expand);
318       setOperationAction(ISD::FP_TO_SINT, VT, Expand);
319       setOperationAction(ISD::FP_TO_UINT, VT, Expand);
320     } else {
321       setOperationAction(ISD::FP_TO_SINT_SAT, VT, Custom);
322       setOperationAction(ISD::FP_TO_UINT_SAT, VT, Custom);
323     }
324 
325     // Pre and Post inc are supported on loads and stores
326     for (unsigned im = (unsigned)ISD::PRE_INC;
327          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
328       setIndexedLoadAction(im, VT, Legal);
329       setIndexedStoreAction(im, VT, Legal);
330       setIndexedMaskedLoadAction(im, VT, Legal);
331       setIndexedMaskedStoreAction(im, VT, Legal);
332     }
333   }
334 
335   const MVT FloatTypes[] = { MVT::v8f16, MVT::v4f32 };
336   for (auto VT : FloatTypes) {
337     addRegisterClass(VT, &ARM::MQPRRegClass);
338     if (!HasMVEFP)
339       setAllExpand(VT);
340 
341     // These are legal or custom whether we have MVE.fp or not
342     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
343     setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
344     setOperationAction(ISD::INSERT_VECTOR_ELT, VT.getVectorElementType(), Custom);
345     setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
346     setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
347     setOperationAction(ISD::BUILD_VECTOR, VT.getVectorElementType(), Custom);
348     setOperationAction(ISD::SCALAR_TO_VECTOR, VT, Legal);
349     setOperationAction(ISD::SETCC, VT, Custom);
350     setOperationAction(ISD::MLOAD, VT, Custom);
351     setOperationAction(ISD::MSTORE, VT, Legal);
352     setOperationAction(ISD::SELECT, VT, Expand);
353     setOperationAction(ISD::SELECT_CC, VT, Expand);
354 
355     // Pre and Post inc are supported on loads and stores
356     for (unsigned im = (unsigned)ISD::PRE_INC;
357          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
358       setIndexedLoadAction(im, VT, Legal);
359       setIndexedStoreAction(im, VT, Legal);
360       setIndexedMaskedLoadAction(im, VT, Legal);
361       setIndexedMaskedStoreAction(im, VT, Legal);
362     }
363 
364     if (HasMVEFP) {
365       setOperationAction(ISD::FMINNUM, VT, Legal);
366       setOperationAction(ISD::FMAXNUM, VT, Legal);
367       setOperationAction(ISD::FROUND, VT, Legal);
368       setOperationAction(ISD::VECREDUCE_FADD, VT, Custom);
369       setOperationAction(ISD::VECREDUCE_FMUL, VT, Custom);
370       setOperationAction(ISD::VECREDUCE_FMIN, VT, Custom);
371       setOperationAction(ISD::VECREDUCE_FMAX, VT, Custom);
372 
373       // No native support for these.
374       setOperationAction(ISD::FDIV, VT, Expand);
375       setOperationAction(ISD::FREM, VT, Expand);
376       setOperationAction(ISD::FSQRT, VT, Expand);
377       setOperationAction(ISD::FSIN, VT, Expand);
378       setOperationAction(ISD::FCOS, VT, Expand);
379       setOperationAction(ISD::FTAN, VT, Expand);
380       setOperationAction(ISD::FPOW, VT, Expand);
381       setOperationAction(ISD::FLOG, VT, Expand);
382       setOperationAction(ISD::FLOG2, VT, Expand);
383       setOperationAction(ISD::FLOG10, VT, Expand);
384       setOperationAction(ISD::FEXP, VT, Expand);
385       setOperationAction(ISD::FEXP2, VT, Expand);
386       setOperationAction(ISD::FEXP10, VT, Expand);
387       setOperationAction(ISD::FNEARBYINT, VT, Expand);
388     }
389   }
390 
391   // Custom Expand smaller than legal vector reductions to prevent false zero
392   // items being added.
393   setOperationAction(ISD::VECREDUCE_FADD, MVT::v4f16, Custom);
394   setOperationAction(ISD::VECREDUCE_FMUL, MVT::v4f16, Custom);
395   setOperationAction(ISD::VECREDUCE_FMIN, MVT::v4f16, Custom);
396   setOperationAction(ISD::VECREDUCE_FMAX, MVT::v4f16, Custom);
397   setOperationAction(ISD::VECREDUCE_FADD, MVT::v2f16, Custom);
398   setOperationAction(ISD::VECREDUCE_FMUL, MVT::v2f16, Custom);
399   setOperationAction(ISD::VECREDUCE_FMIN, MVT::v2f16, Custom);
400   setOperationAction(ISD::VECREDUCE_FMAX, MVT::v2f16, Custom);
401 
402   // We 'support' these types up to bitcast/load/store level, regardless of
403   // MVE integer-only / float support. Only doing FP data processing on the FP
404   // vector types is inhibited at integer-only level.
405   const MVT LongTypes[] = { MVT::v2i64, MVT::v2f64 };
406   for (auto VT : LongTypes) {
407     addRegisterClass(VT, &ARM::MQPRRegClass);
408     setAllExpand(VT);
409     setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
410     setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
411     setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
412     setOperationAction(ISD::VSELECT, VT, Legal);
413     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
414   }
415   setOperationAction(ISD::SCALAR_TO_VECTOR, MVT::v2f64, Legal);
416 
417   // We can do bitwise operations on v2i64 vectors
418   setOperationAction(ISD::AND, MVT::v2i64, Legal);
419   setOperationAction(ISD::OR, MVT::v2i64, Legal);
420   setOperationAction(ISD::XOR, MVT::v2i64, Legal);
421 
422   // It is legal to extload from v4i8 to v4i16 or v4i32.
423   addAllExtLoads(MVT::v8i16, MVT::v8i8, Legal);
424   addAllExtLoads(MVT::v4i32, MVT::v4i16, Legal);
425   addAllExtLoads(MVT::v4i32, MVT::v4i8, Legal);
426 
427   // It is legal to sign extend from v4i8/v4i16 to v4i32 or v8i8 to v8i16.
428   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::v4i8,  Legal);
429   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::v4i16, Legal);
430   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::v4i32, Legal);
431   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::v8i8,  Legal);
432   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::v8i16, Legal);
433 
434   // Some truncating stores are legal too.
435   setTruncStoreAction(MVT::v4i32, MVT::v4i16, Legal);
436   setTruncStoreAction(MVT::v4i32, MVT::v4i8,  Legal);
437   setTruncStoreAction(MVT::v8i16, MVT::v8i8,  Legal);
438 
439   // Pre and Post inc on these are legal, given the correct extends
440   for (unsigned im = (unsigned)ISD::PRE_INC;
441        im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
442     for (auto VT : {MVT::v8i8, MVT::v4i8, MVT::v4i16}) {
443       setIndexedLoadAction(im, VT, Legal);
444       setIndexedStoreAction(im, VT, Legal);
445       setIndexedMaskedLoadAction(im, VT, Legal);
446       setIndexedMaskedStoreAction(im, VT, Legal);
447     }
448   }
449 
450   // Predicate types
451   const MVT pTypes[] = {MVT::v16i1, MVT::v8i1, MVT::v4i1, MVT::v2i1};
452   for (auto VT : pTypes) {
453     addRegisterClass(VT, &ARM::VCCRRegClass);
454     setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
455     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
456     setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
457     setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
458     setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
459     setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
460     setOperationAction(ISD::SETCC, VT, Custom);
461     setOperationAction(ISD::SCALAR_TO_VECTOR, VT, Expand);
462     setOperationAction(ISD::LOAD, VT, Custom);
463     setOperationAction(ISD::STORE, VT, Custom);
464     setOperationAction(ISD::TRUNCATE, VT, Custom);
465     setOperationAction(ISD::VSELECT, VT, Expand);
466     setOperationAction(ISD::SELECT, VT, Expand);
467     setOperationAction(ISD::SELECT_CC, VT, Expand);
468 
469     if (!HasMVEFP) {
470       setOperationAction(ISD::SINT_TO_FP, VT, Expand);
471       setOperationAction(ISD::UINT_TO_FP, VT, Expand);
472       setOperationAction(ISD::FP_TO_SINT, VT, Expand);
473       setOperationAction(ISD::FP_TO_UINT, VT, Expand);
474     }
475   }
476   setOperationAction(ISD::SETCC, MVT::v2i1, Expand);
477   setOperationAction(ISD::TRUNCATE, MVT::v2i1, Expand);
478   setOperationAction(ISD::AND, MVT::v2i1, Expand);
479   setOperationAction(ISD::OR, MVT::v2i1, Expand);
480   setOperationAction(ISD::XOR, MVT::v2i1, Expand);
481   setOperationAction(ISD::SINT_TO_FP, MVT::v2i1, Expand);
482   setOperationAction(ISD::UINT_TO_FP, MVT::v2i1, Expand);
483   setOperationAction(ISD::FP_TO_SINT, MVT::v2i1, Expand);
484   setOperationAction(ISD::FP_TO_UINT, MVT::v2i1, Expand);
485 
486   setOperationAction(ISD::SIGN_EXTEND, MVT::v8i32, Custom);
487   setOperationAction(ISD::SIGN_EXTEND, MVT::v16i16, Custom);
488   setOperationAction(ISD::SIGN_EXTEND, MVT::v16i32, Custom);
489   setOperationAction(ISD::ZERO_EXTEND, MVT::v8i32, Custom);
490   setOperationAction(ISD::ZERO_EXTEND, MVT::v16i16, Custom);
491   setOperationAction(ISD::ZERO_EXTEND, MVT::v16i32, Custom);
492   setOperationAction(ISD::TRUNCATE, MVT::v8i32, Custom);
493   setOperationAction(ISD::TRUNCATE, MVT::v16i16, Custom);
494 }
495 
ARMTargetLowering(const TargetMachine & TM,const ARMSubtarget & STI)496 ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
497                                      const ARMSubtarget &STI)
498     : TargetLowering(TM), Subtarget(&STI) {
499   RegInfo = Subtarget->getRegisterInfo();
500   Itins = Subtarget->getInstrItineraryData();
501 
502   setBooleanContents(ZeroOrOneBooleanContent);
503   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
504 
505   if (!Subtarget->isTargetDarwin() && !Subtarget->isTargetIOS() &&
506       !Subtarget->isTargetWatchOS() && !Subtarget->isTargetDriverKit()) {
507     bool IsHFTarget = TM.Options.FloatABIType == FloatABI::Hard;
508     for (int LCID = 0; LCID < RTLIB::UNKNOWN_LIBCALL; ++LCID)
509       setLibcallCallingConv(static_cast<RTLIB::Libcall>(LCID),
510                             IsHFTarget ? CallingConv::ARM_AAPCS_VFP
511                                        : CallingConv::ARM_AAPCS);
512   }
513 
514   if (Subtarget->isTargetMachO()) {
515     // Uses VFP for Thumb libfuncs if available.
516     if (Subtarget->isThumb() && Subtarget->hasVFP2Base() &&
517         Subtarget->hasARMOps() && !Subtarget->useSoftFloat()) {
518       static const struct {
519         const RTLIB::Libcall Op;
520         const char * const Name;
521         const ISD::CondCode Cond;
522       } LibraryCalls[] = {
523         // Single-precision floating-point arithmetic.
524         { RTLIB::ADD_F32, "__addsf3vfp", ISD::SETCC_INVALID },
525         { RTLIB::SUB_F32, "__subsf3vfp", ISD::SETCC_INVALID },
526         { RTLIB::MUL_F32, "__mulsf3vfp", ISD::SETCC_INVALID },
527         { RTLIB::DIV_F32, "__divsf3vfp", ISD::SETCC_INVALID },
528 
529         // Double-precision floating-point arithmetic.
530         { RTLIB::ADD_F64, "__adddf3vfp", ISD::SETCC_INVALID },
531         { RTLIB::SUB_F64, "__subdf3vfp", ISD::SETCC_INVALID },
532         { RTLIB::MUL_F64, "__muldf3vfp", ISD::SETCC_INVALID },
533         { RTLIB::DIV_F64, "__divdf3vfp", ISD::SETCC_INVALID },
534 
535         // Single-precision comparisons.
536         { RTLIB::OEQ_F32, "__eqsf2vfp",    ISD::SETNE },
537         { RTLIB::UNE_F32, "__nesf2vfp",    ISD::SETNE },
538         { RTLIB::OLT_F32, "__ltsf2vfp",    ISD::SETNE },
539         { RTLIB::OLE_F32, "__lesf2vfp",    ISD::SETNE },
540         { RTLIB::OGE_F32, "__gesf2vfp",    ISD::SETNE },
541         { RTLIB::OGT_F32, "__gtsf2vfp",    ISD::SETNE },
542         { RTLIB::UO_F32,  "__unordsf2vfp", ISD::SETNE },
543 
544         // Double-precision comparisons.
545         { RTLIB::OEQ_F64, "__eqdf2vfp",    ISD::SETNE },
546         { RTLIB::UNE_F64, "__nedf2vfp",    ISD::SETNE },
547         { RTLIB::OLT_F64, "__ltdf2vfp",    ISD::SETNE },
548         { RTLIB::OLE_F64, "__ledf2vfp",    ISD::SETNE },
549         { RTLIB::OGE_F64, "__gedf2vfp",    ISD::SETNE },
550         { RTLIB::OGT_F64, "__gtdf2vfp",    ISD::SETNE },
551         { RTLIB::UO_F64,  "__unorddf2vfp", ISD::SETNE },
552 
553         // Floating-point to integer conversions.
554         // i64 conversions are done via library routines even when generating VFP
555         // instructions, so use the same ones.
556         { RTLIB::FPTOSINT_F64_I32, "__fixdfsivfp",    ISD::SETCC_INVALID },
557         { RTLIB::FPTOUINT_F64_I32, "__fixunsdfsivfp", ISD::SETCC_INVALID },
558         { RTLIB::FPTOSINT_F32_I32, "__fixsfsivfp",    ISD::SETCC_INVALID },
559         { RTLIB::FPTOUINT_F32_I32, "__fixunssfsivfp", ISD::SETCC_INVALID },
560 
561         // Conversions between floating types.
562         { RTLIB::FPROUND_F64_F32, "__truncdfsf2vfp",  ISD::SETCC_INVALID },
563         { RTLIB::FPEXT_F32_F64,   "__extendsfdf2vfp", ISD::SETCC_INVALID },
564 
565         // Integer to floating-point conversions.
566         // i64 conversions are done via library routines even when generating VFP
567         // instructions, so use the same ones.
568         // FIXME: There appears to be some naming inconsistency in ARM libgcc:
569         // e.g., __floatunsidf vs. __floatunssidfvfp.
570         { RTLIB::SINTTOFP_I32_F64, "__floatsidfvfp",    ISD::SETCC_INVALID },
571         { RTLIB::UINTTOFP_I32_F64, "__floatunssidfvfp", ISD::SETCC_INVALID },
572         { RTLIB::SINTTOFP_I32_F32, "__floatsisfvfp",    ISD::SETCC_INVALID },
573         { RTLIB::UINTTOFP_I32_F32, "__floatunssisfvfp", ISD::SETCC_INVALID },
574       };
575 
576       for (const auto &LC : LibraryCalls) {
577         setLibcallName(LC.Op, LC.Name);
578         if (LC.Cond != ISD::SETCC_INVALID)
579           setCmpLibcallCC(LC.Op, LC.Cond);
580       }
581     }
582   }
583 
584   // RTLIB
585   if (Subtarget->isAAPCS_ABI() &&
586       (Subtarget->isTargetAEABI() || Subtarget->isTargetGNUAEABI() ||
587        Subtarget->isTargetMuslAEABI() || Subtarget->isTargetAndroid())) {
588     static const struct {
589       const RTLIB::Libcall Op;
590       const char * const Name;
591       const CallingConv::ID CC;
592       const ISD::CondCode Cond;
593     } LibraryCalls[] = {
594       // Double-precision floating-point arithmetic helper functions
595       // RTABI chapter 4.1.2, Table 2
596       { RTLIB::ADD_F64, "__aeabi_dadd", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
597       { RTLIB::DIV_F64, "__aeabi_ddiv", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
598       { RTLIB::MUL_F64, "__aeabi_dmul", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
599       { RTLIB::SUB_F64, "__aeabi_dsub", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
600 
601       // Double-precision floating-point comparison helper functions
602       // RTABI chapter 4.1.2, Table 3
603       { RTLIB::OEQ_F64, "__aeabi_dcmpeq", CallingConv::ARM_AAPCS, ISD::SETNE },
604       { RTLIB::UNE_F64, "__aeabi_dcmpeq", CallingConv::ARM_AAPCS, ISD::SETEQ },
605       { RTLIB::OLT_F64, "__aeabi_dcmplt", CallingConv::ARM_AAPCS, ISD::SETNE },
606       { RTLIB::OLE_F64, "__aeabi_dcmple", CallingConv::ARM_AAPCS, ISD::SETNE },
607       { RTLIB::OGE_F64, "__aeabi_dcmpge", CallingConv::ARM_AAPCS, ISD::SETNE },
608       { RTLIB::OGT_F64, "__aeabi_dcmpgt", CallingConv::ARM_AAPCS, ISD::SETNE },
609       { RTLIB::UO_F64,  "__aeabi_dcmpun", CallingConv::ARM_AAPCS, ISD::SETNE },
610 
611       // Single-precision floating-point arithmetic helper functions
612       // RTABI chapter 4.1.2, Table 4
613       { RTLIB::ADD_F32, "__aeabi_fadd", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
614       { RTLIB::DIV_F32, "__aeabi_fdiv", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
615       { RTLIB::MUL_F32, "__aeabi_fmul", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
616       { RTLIB::SUB_F32, "__aeabi_fsub", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
617 
618       // Single-precision floating-point comparison helper functions
619       // RTABI chapter 4.1.2, Table 5
620       { RTLIB::OEQ_F32, "__aeabi_fcmpeq", CallingConv::ARM_AAPCS, ISD::SETNE },
621       { RTLIB::UNE_F32, "__aeabi_fcmpeq", CallingConv::ARM_AAPCS, ISD::SETEQ },
622       { RTLIB::OLT_F32, "__aeabi_fcmplt", CallingConv::ARM_AAPCS, ISD::SETNE },
623       { RTLIB::OLE_F32, "__aeabi_fcmple", CallingConv::ARM_AAPCS, ISD::SETNE },
624       { RTLIB::OGE_F32, "__aeabi_fcmpge", CallingConv::ARM_AAPCS, ISD::SETNE },
625       { RTLIB::OGT_F32, "__aeabi_fcmpgt", CallingConv::ARM_AAPCS, ISD::SETNE },
626       { RTLIB::UO_F32,  "__aeabi_fcmpun", CallingConv::ARM_AAPCS, ISD::SETNE },
627 
628       // Floating-point to integer conversions.
629       // RTABI chapter 4.1.2, Table 6
630       { RTLIB::FPTOSINT_F64_I32, "__aeabi_d2iz",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
631       { RTLIB::FPTOUINT_F64_I32, "__aeabi_d2uiz", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
632       { RTLIB::FPTOSINT_F64_I64, "__aeabi_d2lz",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
633       { RTLIB::FPTOUINT_F64_I64, "__aeabi_d2ulz", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
634       { RTLIB::FPTOSINT_F32_I32, "__aeabi_f2iz",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
635       { RTLIB::FPTOUINT_F32_I32, "__aeabi_f2uiz", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
636       { RTLIB::FPTOSINT_F32_I64, "__aeabi_f2lz",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
637       { RTLIB::FPTOUINT_F32_I64, "__aeabi_f2ulz", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
638 
639       // Conversions between floating types.
640       // RTABI chapter 4.1.2, Table 7
641       { RTLIB::FPROUND_F64_F32, "__aeabi_d2f", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
642       { RTLIB::FPROUND_F64_F16, "__aeabi_d2h", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
643       { RTLIB::FPEXT_F32_F64,   "__aeabi_f2d", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
644 
645       // Integer to floating-point conversions.
646       // RTABI chapter 4.1.2, Table 8
647       { RTLIB::SINTTOFP_I32_F64, "__aeabi_i2d",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
648       { RTLIB::UINTTOFP_I32_F64, "__aeabi_ui2d", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
649       { RTLIB::SINTTOFP_I64_F64, "__aeabi_l2d",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
650       { RTLIB::UINTTOFP_I64_F64, "__aeabi_ul2d", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
651       { RTLIB::SINTTOFP_I32_F32, "__aeabi_i2f",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
652       { RTLIB::UINTTOFP_I32_F32, "__aeabi_ui2f", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
653       { RTLIB::SINTTOFP_I64_F32, "__aeabi_l2f",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
654       { RTLIB::UINTTOFP_I64_F32, "__aeabi_ul2f", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
655 
656       // Long long helper functions
657       // RTABI chapter 4.2, Table 9
658       { RTLIB::MUL_I64, "__aeabi_lmul", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
659       { RTLIB::SHL_I64, "__aeabi_llsl", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
660       { RTLIB::SRL_I64, "__aeabi_llsr", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
661       { RTLIB::SRA_I64, "__aeabi_lasr", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
662 
663       // Integer division functions
664       // RTABI chapter 4.3.1
665       { RTLIB::SDIV_I8,  "__aeabi_idiv",     CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
666       { RTLIB::SDIV_I16, "__aeabi_idiv",     CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
667       { RTLIB::SDIV_I32, "__aeabi_idiv",     CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
668       { RTLIB::SDIV_I64, "__aeabi_ldivmod",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
669       { RTLIB::UDIV_I8,  "__aeabi_uidiv",    CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
670       { RTLIB::UDIV_I16, "__aeabi_uidiv",    CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
671       { RTLIB::UDIV_I32, "__aeabi_uidiv",    CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
672       { RTLIB::UDIV_I64, "__aeabi_uldivmod", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
673     };
674 
675     for (const auto &LC : LibraryCalls) {
676       setLibcallName(LC.Op, LC.Name);
677       setLibcallCallingConv(LC.Op, LC.CC);
678       if (LC.Cond != ISD::SETCC_INVALID)
679         setCmpLibcallCC(LC.Op, LC.Cond);
680     }
681 
682     // EABI dependent RTLIB
683     if (TM.Options.EABIVersion == EABI::EABI4 ||
684         TM.Options.EABIVersion == EABI::EABI5) {
685       static const struct {
686         const RTLIB::Libcall Op;
687         const char *const Name;
688         const CallingConv::ID CC;
689         const ISD::CondCode Cond;
690       } MemOpsLibraryCalls[] = {
691         // Memory operations
692         // RTABI chapter 4.3.4
693         { RTLIB::MEMCPY,  "__aeabi_memcpy",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
694         { RTLIB::MEMMOVE, "__aeabi_memmove", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
695         { RTLIB::MEMSET,  "__aeabi_memset",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
696       };
697 
698       for (const auto &LC : MemOpsLibraryCalls) {
699         setLibcallName(LC.Op, LC.Name);
700         setLibcallCallingConv(LC.Op, LC.CC);
701         if (LC.Cond != ISD::SETCC_INVALID)
702           setCmpLibcallCC(LC.Op, LC.Cond);
703       }
704     }
705   }
706 
707   if (Subtarget->isTargetWindows()) {
708     static const struct {
709       const RTLIB::Libcall Op;
710       const char * const Name;
711       const CallingConv::ID CC;
712     } LibraryCalls[] = {
713       { RTLIB::FPTOSINT_F32_I64, "__stoi64", CallingConv::ARM_AAPCS_VFP },
714       { RTLIB::FPTOSINT_F64_I64, "__dtoi64", CallingConv::ARM_AAPCS_VFP },
715       { RTLIB::FPTOUINT_F32_I64, "__stou64", CallingConv::ARM_AAPCS_VFP },
716       { RTLIB::FPTOUINT_F64_I64, "__dtou64", CallingConv::ARM_AAPCS_VFP },
717       { RTLIB::SINTTOFP_I64_F32, "__i64tos", CallingConv::ARM_AAPCS_VFP },
718       { RTLIB::SINTTOFP_I64_F64, "__i64tod", CallingConv::ARM_AAPCS_VFP },
719       { RTLIB::UINTTOFP_I64_F32, "__u64tos", CallingConv::ARM_AAPCS_VFP },
720       { RTLIB::UINTTOFP_I64_F64, "__u64tod", CallingConv::ARM_AAPCS_VFP },
721     };
722 
723     for (const auto &LC : LibraryCalls) {
724       setLibcallName(LC.Op, LC.Name);
725       setLibcallCallingConv(LC.Op, LC.CC);
726     }
727   }
728 
729   // Use divmod compiler-rt calls for iOS 5.0 and later.
730   if (Subtarget->isTargetMachO() &&
731       !(Subtarget->isTargetIOS() &&
732         Subtarget->getTargetTriple().isOSVersionLT(5, 0))) {
733     setLibcallName(RTLIB::SDIVREM_I32, "__divmodsi4");
734     setLibcallName(RTLIB::UDIVREM_I32, "__udivmodsi4");
735   }
736 
737   // The half <-> float conversion functions are always soft-float on
738   // non-watchos platforms, but are needed for some targets which use a
739   // hard-float calling convention by default.
740   if (!Subtarget->isTargetWatchABI()) {
741     if (Subtarget->isAAPCS_ABI()) {
742       setLibcallCallingConv(RTLIB::FPROUND_F32_F16, CallingConv::ARM_AAPCS);
743       setLibcallCallingConv(RTLIB::FPROUND_F64_F16, CallingConv::ARM_AAPCS);
744       setLibcallCallingConv(RTLIB::FPEXT_F16_F32, CallingConv::ARM_AAPCS);
745     } else {
746       setLibcallCallingConv(RTLIB::FPROUND_F32_F16, CallingConv::ARM_APCS);
747       setLibcallCallingConv(RTLIB::FPROUND_F64_F16, CallingConv::ARM_APCS);
748       setLibcallCallingConv(RTLIB::FPEXT_F16_F32, CallingConv::ARM_APCS);
749     }
750   }
751 
752   // In EABI, these functions have an __aeabi_ prefix, but in GNUEABI they have
753   // a __gnu_ prefix (which is the default).
754   if (Subtarget->isTargetAEABI()) {
755     static const struct {
756       const RTLIB::Libcall Op;
757       const char * const Name;
758       const CallingConv::ID CC;
759     } LibraryCalls[] = {
760       { RTLIB::FPROUND_F32_F16, "__aeabi_f2h", CallingConv::ARM_AAPCS },
761       { RTLIB::FPROUND_F64_F16, "__aeabi_d2h", CallingConv::ARM_AAPCS },
762       { RTLIB::FPEXT_F16_F32, "__aeabi_h2f", CallingConv::ARM_AAPCS },
763     };
764 
765     for (const auto &LC : LibraryCalls) {
766       setLibcallName(LC.Op, LC.Name);
767       setLibcallCallingConv(LC.Op, LC.CC);
768     }
769   }
770 
771   if (Subtarget->isThumb1Only())
772     addRegisterClass(MVT::i32, &ARM::tGPRRegClass);
773   else
774     addRegisterClass(MVT::i32, &ARM::GPRRegClass);
775 
776   if (!Subtarget->useSoftFloat() && !Subtarget->isThumb1Only() &&
777       Subtarget->hasFPRegs()) {
778     addRegisterClass(MVT::f32, &ARM::SPRRegClass);
779     addRegisterClass(MVT::f64, &ARM::DPRRegClass);
780 
781     setOperationAction(ISD::FP_TO_SINT_SAT, MVT::i32, Custom);
782     setOperationAction(ISD::FP_TO_UINT_SAT, MVT::i32, Custom);
783     setOperationAction(ISD::FP_TO_SINT_SAT, MVT::i64, Custom);
784     setOperationAction(ISD::FP_TO_UINT_SAT, MVT::i64, Custom);
785 
786     if (!Subtarget->hasVFP2Base())
787       setAllExpand(MVT::f32);
788     if (!Subtarget->hasFP64())
789       setAllExpand(MVT::f64);
790   }
791 
792   if (Subtarget->hasFullFP16()) {
793     addRegisterClass(MVT::f16, &ARM::HPRRegClass);
794     setOperationAction(ISD::BITCAST, MVT::i16, Custom);
795     setOperationAction(ISD::BITCAST, MVT::f16, Custom);
796 
797     setOperationAction(ISD::FMINNUM, MVT::f16, Legal);
798     setOperationAction(ISD::FMAXNUM, MVT::f16, Legal);
799   }
800 
801   if (Subtarget->hasBF16()) {
802     addRegisterClass(MVT::bf16, &ARM::HPRRegClass);
803     setAllExpand(MVT::bf16);
804     if (!Subtarget->hasFullFP16())
805       setOperationAction(ISD::BITCAST, MVT::bf16, Custom);
806   }
807 
808   for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
809     for (MVT InnerVT : MVT::fixedlen_vector_valuetypes()) {
810       setTruncStoreAction(VT, InnerVT, Expand);
811       addAllExtLoads(VT, InnerVT, Expand);
812     }
813 
814     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
815     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
816 
817     setOperationAction(ISD::BSWAP, VT, Expand);
818   }
819 
820   setOperationAction(ISD::ConstantFP, MVT::f32, Custom);
821   setOperationAction(ISD::ConstantFP, MVT::f64, Custom);
822 
823   setOperationAction(ISD::READ_REGISTER, MVT::i64, Custom);
824   setOperationAction(ISD::WRITE_REGISTER, MVT::i64, Custom);
825 
826   if (Subtarget->hasMVEIntegerOps())
827     addMVEVectorTypes(Subtarget->hasMVEFloatOps());
828 
829   // Combine low-overhead loop intrinsics so that we can lower i1 types.
830   if (Subtarget->hasLOB()) {
831     setTargetDAGCombine({ISD::BRCOND, ISD::BR_CC});
832   }
833 
834   if (Subtarget->hasNEON()) {
835     addDRTypeForNEON(MVT::v2f32);
836     addDRTypeForNEON(MVT::v8i8);
837     addDRTypeForNEON(MVT::v4i16);
838     addDRTypeForNEON(MVT::v2i32);
839     addDRTypeForNEON(MVT::v1i64);
840 
841     addQRTypeForNEON(MVT::v4f32);
842     addQRTypeForNEON(MVT::v2f64);
843     addQRTypeForNEON(MVT::v16i8);
844     addQRTypeForNEON(MVT::v8i16);
845     addQRTypeForNEON(MVT::v4i32);
846     addQRTypeForNEON(MVT::v2i64);
847 
848     if (Subtarget->hasFullFP16()) {
849       addQRTypeForNEON(MVT::v8f16);
850       addDRTypeForNEON(MVT::v4f16);
851     }
852 
853     if (Subtarget->hasBF16()) {
854       addQRTypeForNEON(MVT::v8bf16);
855       addDRTypeForNEON(MVT::v4bf16);
856     }
857   }
858 
859   if (Subtarget->hasMVEIntegerOps() || Subtarget->hasNEON()) {
860     // v2f64 is legal so that QR subregs can be extracted as f64 elements, but
861     // none of Neon, MVE or VFP supports any arithmetic operations on it.
862     setOperationAction(ISD::FADD, MVT::v2f64, Expand);
863     setOperationAction(ISD::FSUB, MVT::v2f64, Expand);
864     setOperationAction(ISD::FMUL, MVT::v2f64, Expand);
865     // FIXME: Code duplication: FDIV and FREM are expanded always, see
866     // ARMTargetLowering::addTypeForNEON method for details.
867     setOperationAction(ISD::FDIV, MVT::v2f64, Expand);
868     setOperationAction(ISD::FREM, MVT::v2f64, Expand);
869     // FIXME: Create unittest.
870     // In another words, find a way when "copysign" appears in DAG with vector
871     // operands.
872     setOperationAction(ISD::FCOPYSIGN, MVT::v2f64, Expand);
873     // FIXME: Code duplication: SETCC has custom operation action, see
874     // ARMTargetLowering::addTypeForNEON method for details.
875     setOperationAction(ISD::SETCC, MVT::v2f64, Expand);
876     // FIXME: Create unittest for FNEG and for FABS.
877     setOperationAction(ISD::FNEG, MVT::v2f64, Expand);
878     setOperationAction(ISD::FABS, MVT::v2f64, Expand);
879     setOperationAction(ISD::FSQRT, MVT::v2f64, Expand);
880     setOperationAction(ISD::FSIN, MVT::v2f64, Expand);
881     setOperationAction(ISD::FCOS, MVT::v2f64, Expand);
882     setOperationAction(ISD::FTAN, MVT::v2f64, Expand);
883     setOperationAction(ISD::FPOW, MVT::v2f64, Expand);
884     setOperationAction(ISD::FLOG, MVT::v2f64, Expand);
885     setOperationAction(ISD::FLOG2, MVT::v2f64, Expand);
886     setOperationAction(ISD::FLOG10, MVT::v2f64, Expand);
887     setOperationAction(ISD::FEXP, MVT::v2f64, Expand);
888     setOperationAction(ISD::FEXP2, MVT::v2f64, Expand);
889     setOperationAction(ISD::FEXP10, MVT::v2f64, Expand);
890     // FIXME: Create unittest for FCEIL, FTRUNC, FRINT, FNEARBYINT, FFLOOR.
891     setOperationAction(ISD::FCEIL, MVT::v2f64, Expand);
892     setOperationAction(ISD::FTRUNC, MVT::v2f64, Expand);
893     setOperationAction(ISD::FRINT, MVT::v2f64, Expand);
894     setOperationAction(ISD::FNEARBYINT, MVT::v2f64, Expand);
895     setOperationAction(ISD::FFLOOR, MVT::v2f64, Expand);
896     setOperationAction(ISD::FMA, MVT::v2f64, Expand);
897   }
898 
899   if (Subtarget->hasNEON()) {
900     // The same with v4f32. But keep in mind that vadd, vsub, vmul are natively
901     // supported for v4f32.
902     setOperationAction(ISD::FSQRT, MVT::v4f32, Expand);
903     setOperationAction(ISD::FSIN, MVT::v4f32, Expand);
904     setOperationAction(ISD::FCOS, MVT::v4f32, Expand);
905     setOperationAction(ISD::FTAN, MVT::v4f32, Expand);
906     setOperationAction(ISD::FPOW, MVT::v4f32, Expand);
907     setOperationAction(ISD::FLOG, MVT::v4f32, Expand);
908     setOperationAction(ISD::FLOG2, MVT::v4f32, Expand);
909     setOperationAction(ISD::FLOG10, MVT::v4f32, Expand);
910     setOperationAction(ISD::FEXP, MVT::v4f32, Expand);
911     setOperationAction(ISD::FEXP2, MVT::v4f32, Expand);
912     setOperationAction(ISD::FEXP10, MVT::v4f32, Expand);
913     setOperationAction(ISD::FCEIL, MVT::v4f32, Expand);
914     setOperationAction(ISD::FTRUNC, MVT::v4f32, Expand);
915     setOperationAction(ISD::FRINT, MVT::v4f32, Expand);
916     setOperationAction(ISD::FNEARBYINT, MVT::v4f32, Expand);
917     setOperationAction(ISD::FFLOOR, MVT::v4f32, Expand);
918 
919     // Mark v2f32 intrinsics.
920     setOperationAction(ISD::FSQRT, MVT::v2f32, Expand);
921     setOperationAction(ISD::FSIN, MVT::v2f32, Expand);
922     setOperationAction(ISD::FCOS, MVT::v2f32, Expand);
923     setOperationAction(ISD::FTAN, MVT::v2f32, Expand);
924     setOperationAction(ISD::FPOW, MVT::v2f32, Expand);
925     setOperationAction(ISD::FLOG, MVT::v2f32, Expand);
926     setOperationAction(ISD::FLOG2, MVT::v2f32, Expand);
927     setOperationAction(ISD::FLOG10, MVT::v2f32, Expand);
928     setOperationAction(ISD::FEXP, MVT::v2f32, Expand);
929     setOperationAction(ISD::FEXP2, MVT::v2f32, Expand);
930     setOperationAction(ISD::FEXP10, MVT::v2f32, Expand);
931     setOperationAction(ISD::FCEIL, MVT::v2f32, Expand);
932     setOperationAction(ISD::FTRUNC, MVT::v2f32, Expand);
933     setOperationAction(ISD::FRINT, MVT::v2f32, Expand);
934     setOperationAction(ISD::FNEARBYINT, MVT::v2f32, Expand);
935     setOperationAction(ISD::FFLOOR, MVT::v2f32, Expand);
936 
937     // Neon does not support some operations on v1i64 and v2i64 types.
938     setOperationAction(ISD::MUL, MVT::v1i64, Expand);
939     // Custom handling for some quad-vector types to detect VMULL.
940     setOperationAction(ISD::MUL, MVT::v8i16, Custom);
941     setOperationAction(ISD::MUL, MVT::v4i32, Custom);
942     setOperationAction(ISD::MUL, MVT::v2i64, Custom);
943     // Custom handling for some vector types to avoid expensive expansions
944     setOperationAction(ISD::SDIV, MVT::v4i16, Custom);
945     setOperationAction(ISD::SDIV, MVT::v8i8, Custom);
946     setOperationAction(ISD::UDIV, MVT::v4i16, Custom);
947     setOperationAction(ISD::UDIV, MVT::v8i8, Custom);
948     // Neon does not have single instruction SINT_TO_FP and UINT_TO_FP with
949     // a destination type that is wider than the source, and nor does
950     // it have a FP_TO_[SU]INT instruction with a narrower destination than
951     // source.
952     setOperationAction(ISD::SINT_TO_FP, MVT::v4i16, Custom);
953     setOperationAction(ISD::SINT_TO_FP, MVT::v8i16, Custom);
954     setOperationAction(ISD::UINT_TO_FP, MVT::v4i16, Custom);
955     setOperationAction(ISD::UINT_TO_FP, MVT::v8i16, Custom);
956     setOperationAction(ISD::FP_TO_UINT, MVT::v4i16, Custom);
957     setOperationAction(ISD::FP_TO_UINT, MVT::v8i16, Custom);
958     setOperationAction(ISD::FP_TO_SINT, MVT::v4i16, Custom);
959     setOperationAction(ISD::FP_TO_SINT, MVT::v8i16, Custom);
960 
961     setOperationAction(ISD::FP_ROUND,   MVT::v2f32, Expand);
962     setOperationAction(ISD::FP_EXTEND,  MVT::v2f64, Expand);
963 
964     // NEON does not have single instruction CTPOP for vectors with element
965     // types wider than 8-bits.  However, custom lowering can leverage the
966     // v8i8/v16i8 vcnt instruction.
967     setOperationAction(ISD::CTPOP,      MVT::v2i32, Custom);
968     setOperationAction(ISD::CTPOP,      MVT::v4i32, Custom);
969     setOperationAction(ISD::CTPOP,      MVT::v4i16, Custom);
970     setOperationAction(ISD::CTPOP,      MVT::v8i16, Custom);
971     setOperationAction(ISD::CTPOP,      MVT::v1i64, Custom);
972     setOperationAction(ISD::CTPOP,      MVT::v2i64, Custom);
973 
974     setOperationAction(ISD::CTLZ,       MVT::v1i64, Expand);
975     setOperationAction(ISD::CTLZ,       MVT::v2i64, Expand);
976 
977     // NEON does not have single instruction CTTZ for vectors.
978     setOperationAction(ISD::CTTZ, MVT::v8i8, Custom);
979     setOperationAction(ISD::CTTZ, MVT::v4i16, Custom);
980     setOperationAction(ISD::CTTZ, MVT::v2i32, Custom);
981     setOperationAction(ISD::CTTZ, MVT::v1i64, Custom);
982 
983     setOperationAction(ISD::CTTZ, MVT::v16i8, Custom);
984     setOperationAction(ISD::CTTZ, MVT::v8i16, Custom);
985     setOperationAction(ISD::CTTZ, MVT::v4i32, Custom);
986     setOperationAction(ISD::CTTZ, MVT::v2i64, Custom);
987 
988     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v8i8, Custom);
989     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v4i16, Custom);
990     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v2i32, Custom);
991     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v1i64, Custom);
992 
993     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v16i8, Custom);
994     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v8i16, Custom);
995     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v4i32, Custom);
996     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::v2i64, Custom);
997 
998     for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
999       setOperationAction(ISD::MULHS, VT, Expand);
1000       setOperationAction(ISD::MULHU, VT, Expand);
1001     }
1002 
1003     // NEON only has FMA instructions as of VFP4.
1004     if (!Subtarget->hasVFP4Base()) {
1005       setOperationAction(ISD::FMA, MVT::v2f32, Expand);
1006       setOperationAction(ISD::FMA, MVT::v4f32, Expand);
1007     }
1008 
1009     setTargetDAGCombine({ISD::SHL, ISD::SRL, ISD::SRA, ISD::FP_TO_SINT,
1010                          ISD::FP_TO_UINT, ISD::FMUL, ISD::LOAD});
1011 
1012     // It is legal to extload from v4i8 to v4i16 or v4i32.
1013     for (MVT Ty : {MVT::v8i8, MVT::v4i8, MVT::v2i8, MVT::v4i16, MVT::v2i16,
1014                    MVT::v2i32}) {
1015       for (MVT VT : MVT::integer_fixedlen_vector_valuetypes()) {
1016         setLoadExtAction(ISD::EXTLOAD, VT, Ty, Legal);
1017         setLoadExtAction(ISD::ZEXTLOAD, VT, Ty, Legal);
1018         setLoadExtAction(ISD::SEXTLOAD, VT, Ty, Legal);
1019       }
1020     }
1021 
1022     for (auto VT : {MVT::v8i8, MVT::v4i16, MVT::v2i32, MVT::v16i8, MVT::v8i16,
1023                     MVT::v4i32}) {
1024       setOperationAction(ISD::VECREDUCE_SMAX, VT, Custom);
1025       setOperationAction(ISD::VECREDUCE_UMAX, VT, Custom);
1026       setOperationAction(ISD::VECREDUCE_SMIN, VT, Custom);
1027       setOperationAction(ISD::VECREDUCE_UMIN, VT, Custom);
1028     }
1029   }
1030 
1031   if (Subtarget->hasNEON() || Subtarget->hasMVEIntegerOps()) {
1032     setTargetDAGCombine(
1033         {ISD::BUILD_VECTOR, ISD::VECTOR_SHUFFLE, ISD::INSERT_SUBVECTOR,
1034          ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT,
1035          ISD::SIGN_EXTEND_INREG, ISD::STORE, ISD::SIGN_EXTEND, ISD::ZERO_EXTEND,
1036          ISD::ANY_EXTEND, ISD::INTRINSIC_WO_CHAIN, ISD::INTRINSIC_W_CHAIN,
1037          ISD::INTRINSIC_VOID, ISD::VECREDUCE_ADD, ISD::ADD, ISD::BITCAST});
1038   }
1039   if (Subtarget->hasMVEIntegerOps()) {
1040     setTargetDAGCombine({ISD::SMIN, ISD::UMIN, ISD::SMAX, ISD::UMAX,
1041                          ISD::FP_EXTEND, ISD::SELECT, ISD::SELECT_CC,
1042                          ISD::SETCC});
1043   }
1044   if (Subtarget->hasMVEFloatOps()) {
1045     setTargetDAGCombine(ISD::FADD);
1046   }
1047 
1048   if (!Subtarget->hasFP64()) {
1049     // When targeting a floating-point unit with only single-precision
1050     // operations, f64 is legal for the few double-precision instructions which
1051     // are present However, no double-precision operations other than moves,
1052     // loads and stores are provided by the hardware.
1053     setOperationAction(ISD::FADD,       MVT::f64, Expand);
1054     setOperationAction(ISD::FSUB,       MVT::f64, Expand);
1055     setOperationAction(ISD::FMUL,       MVT::f64, Expand);
1056     setOperationAction(ISD::FMA,        MVT::f64, Expand);
1057     setOperationAction(ISD::FDIV,       MVT::f64, Expand);
1058     setOperationAction(ISD::FREM,       MVT::f64, Expand);
1059     setOperationAction(ISD::FCOPYSIGN,  MVT::f64, Expand);
1060     setOperationAction(ISD::FGETSIGN,   MVT::f64, Expand);
1061     setOperationAction(ISD::FNEG,       MVT::f64, Expand);
1062     setOperationAction(ISD::FABS,       MVT::f64, Expand);
1063     setOperationAction(ISD::FSQRT,      MVT::f64, Expand);
1064     setOperationAction(ISD::FSIN,       MVT::f64, Expand);
1065     setOperationAction(ISD::FCOS,       MVT::f64, Expand);
1066     setOperationAction(ISD::FPOW,       MVT::f64, Expand);
1067     setOperationAction(ISD::FLOG,       MVT::f64, Expand);
1068     setOperationAction(ISD::FLOG2,      MVT::f64, Expand);
1069     setOperationAction(ISD::FLOG10,     MVT::f64, Expand);
1070     setOperationAction(ISD::FEXP,       MVT::f64, Expand);
1071     setOperationAction(ISD::FEXP2,      MVT::f64, Expand);
1072     setOperationAction(ISD::FEXP10,      MVT::f64, Expand);
1073     setOperationAction(ISD::FCEIL,      MVT::f64, Expand);
1074     setOperationAction(ISD::FTRUNC,     MVT::f64, Expand);
1075     setOperationAction(ISD::FRINT,      MVT::f64, Expand);
1076     setOperationAction(ISD::FNEARBYINT, MVT::f64, Expand);
1077     setOperationAction(ISD::FFLOOR,     MVT::f64, Expand);
1078     setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
1079     setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
1080     setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
1081     setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
1082     setOperationAction(ISD::FP_TO_SINT, MVT::f64, Custom);
1083     setOperationAction(ISD::FP_TO_UINT, MVT::f64, Custom);
1084     setOperationAction(ISD::FP_ROUND,   MVT::f32, Custom);
1085     setOperationAction(ISD::STRICT_FP_TO_SINT, MVT::i32, Custom);
1086     setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::i32, Custom);
1087     setOperationAction(ISD::STRICT_FP_TO_SINT, MVT::f64, Custom);
1088     setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::f64, Custom);
1089     setOperationAction(ISD::STRICT_FP_ROUND,   MVT::f32, Custom);
1090   }
1091 
1092   if (!Subtarget->hasFP64() || !Subtarget->hasFPARMv8Base()) {
1093     setOperationAction(ISD::FP_EXTEND,  MVT::f64, Custom);
1094     setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f64, Custom);
1095     if (Subtarget->hasFullFP16()) {
1096       setOperationAction(ISD::FP_ROUND,  MVT::f16, Custom);
1097       setOperationAction(ISD::STRICT_FP_ROUND, MVT::f16, Custom);
1098     }
1099   }
1100 
1101   if (!Subtarget->hasFP16()) {
1102     setOperationAction(ISD::FP_EXTEND,  MVT::f32, Custom);
1103     setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f32, Custom);
1104   }
1105 
1106   computeRegisterProperties(Subtarget->getRegisterInfo());
1107 
1108   // ARM does not have floating-point extending loads.
1109   for (MVT VT : MVT::fp_valuetypes()) {
1110     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
1111     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
1112   }
1113 
1114   // ... or truncating stores
1115   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
1116   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
1117   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
1118 
1119   // ARM does not have i1 sign extending load.
1120   for (MVT VT : MVT::integer_valuetypes())
1121     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
1122 
1123   // ARM supports all 4 flavors of integer indexed load / store.
1124   if (!Subtarget->isThumb1Only()) {
1125     for (unsigned im = (unsigned)ISD::PRE_INC;
1126          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
1127       setIndexedLoadAction(im,  MVT::i1,  Legal);
1128       setIndexedLoadAction(im,  MVT::i8,  Legal);
1129       setIndexedLoadAction(im,  MVT::i16, Legal);
1130       setIndexedLoadAction(im,  MVT::i32, Legal);
1131       setIndexedStoreAction(im, MVT::i1,  Legal);
1132       setIndexedStoreAction(im, MVT::i8,  Legal);
1133       setIndexedStoreAction(im, MVT::i16, Legal);
1134       setIndexedStoreAction(im, MVT::i32, Legal);
1135     }
1136   } else {
1137     // Thumb-1 has limited post-inc load/store support - LDM r0!, {r1}.
1138     setIndexedLoadAction(ISD::POST_INC, MVT::i32,  Legal);
1139     setIndexedStoreAction(ISD::POST_INC, MVT::i32,  Legal);
1140   }
1141 
1142   setOperationAction(ISD::SADDO, MVT::i32, Custom);
1143   setOperationAction(ISD::UADDO, MVT::i32, Custom);
1144   setOperationAction(ISD::SSUBO, MVT::i32, Custom);
1145   setOperationAction(ISD::USUBO, MVT::i32, Custom);
1146 
1147   setOperationAction(ISD::UADDO_CARRY, MVT::i32, Custom);
1148   setOperationAction(ISD::USUBO_CARRY, MVT::i32, Custom);
1149   if (Subtarget->hasDSP()) {
1150     setOperationAction(ISD::SADDSAT, MVT::i8, Custom);
1151     setOperationAction(ISD::SSUBSAT, MVT::i8, Custom);
1152     setOperationAction(ISD::SADDSAT, MVT::i16, Custom);
1153     setOperationAction(ISD::SSUBSAT, MVT::i16, Custom);
1154     setOperationAction(ISD::UADDSAT, MVT::i8, Custom);
1155     setOperationAction(ISD::USUBSAT, MVT::i8, Custom);
1156     setOperationAction(ISD::UADDSAT, MVT::i16, Custom);
1157     setOperationAction(ISD::USUBSAT, MVT::i16, Custom);
1158   }
1159   if (Subtarget->hasBaseDSP()) {
1160     setOperationAction(ISD::SADDSAT, MVT::i32, Legal);
1161     setOperationAction(ISD::SSUBSAT, MVT::i32, Legal);
1162   }
1163 
1164   // i64 operation support.
1165   setOperationAction(ISD::MUL,     MVT::i64, Expand);
1166   setOperationAction(ISD::MULHU,   MVT::i32, Expand);
1167   if (Subtarget->isThumb1Only()) {
1168     setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
1169     setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
1170   }
1171   if (Subtarget->isThumb1Only() || !Subtarget->hasV6Ops()
1172       || (Subtarget->isThumb2() && !Subtarget->hasDSP()))
1173     setOperationAction(ISD::MULHS, MVT::i32, Expand);
1174 
1175   setOperationAction(ISD::SHL_PARTS, MVT::i32, Custom);
1176   setOperationAction(ISD::SRA_PARTS, MVT::i32, Custom);
1177   setOperationAction(ISD::SRL_PARTS, MVT::i32, Custom);
1178   setOperationAction(ISD::SRL,       MVT::i64, Custom);
1179   setOperationAction(ISD::SRA,       MVT::i64, Custom);
1180   setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
1181   setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i64, Custom);
1182   setOperationAction(ISD::LOAD, MVT::i64, Custom);
1183   setOperationAction(ISD::STORE, MVT::i64, Custom);
1184 
1185   // MVE lowers 64 bit shifts to lsll and lsrl
1186   // assuming that ISD::SRL and SRA of i64 are already marked custom
1187   if (Subtarget->hasMVEIntegerOps())
1188     setOperationAction(ISD::SHL, MVT::i64, Custom);
1189 
1190   // Expand to __aeabi_l{lsl,lsr,asr} calls for Thumb1.
1191   if (Subtarget->isThumb1Only()) {
1192     setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
1193     setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
1194     setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
1195   }
1196 
1197   if (!Subtarget->isThumb1Only() && Subtarget->hasV6T2Ops())
1198     setOperationAction(ISD::BITREVERSE, MVT::i32, Legal);
1199 
1200   // ARM does not have ROTL.
1201   setOperationAction(ISD::ROTL, MVT::i32, Expand);
1202   for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
1203     setOperationAction(ISD::ROTL, VT, Expand);
1204     setOperationAction(ISD::ROTR, VT, Expand);
1205   }
1206   setOperationAction(ISD::CTTZ,  MVT::i32, Custom);
1207   setOperationAction(ISD::CTPOP, MVT::i32, Expand);
1208   if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only()) {
1209     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
1210     setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, LibCall);
1211   }
1212 
1213   // @llvm.readcyclecounter requires the Performance Monitors extension.
1214   // Default to the 0 expansion on unsupported platforms.
1215   // FIXME: Technically there are older ARM CPUs that have
1216   // implementation-specific ways of obtaining this information.
1217   if (Subtarget->hasPerfMon())
1218     setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Custom);
1219 
1220   // Only ARMv6 has BSWAP.
1221   if (!Subtarget->hasV6Ops())
1222     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
1223 
1224   bool hasDivide = Subtarget->isThumb() ? Subtarget->hasDivideInThumbMode()
1225                                         : Subtarget->hasDivideInARMMode();
1226   if (!hasDivide) {
1227     // These are expanded into libcalls if the cpu doesn't have HW divider.
1228     setOperationAction(ISD::SDIV,  MVT::i32, LibCall);
1229     setOperationAction(ISD::UDIV,  MVT::i32, LibCall);
1230   }
1231 
1232   if (Subtarget->isTargetWindows() && !Subtarget->hasDivideInThumbMode()) {
1233     setOperationAction(ISD::SDIV, MVT::i32, Custom);
1234     setOperationAction(ISD::UDIV, MVT::i32, Custom);
1235 
1236     setOperationAction(ISD::SDIV, MVT::i64, Custom);
1237     setOperationAction(ISD::UDIV, MVT::i64, Custom);
1238   }
1239 
1240   setOperationAction(ISD::SREM,  MVT::i32, Expand);
1241   setOperationAction(ISD::UREM,  MVT::i32, Expand);
1242 
1243   // Register based DivRem for AEABI (RTABI 4.2)
1244   if (Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid() ||
1245       Subtarget->isTargetGNUAEABI() || Subtarget->isTargetMuslAEABI() ||
1246       Subtarget->isTargetWindows()) {
1247     setOperationAction(ISD::SREM, MVT::i64, Custom);
1248     setOperationAction(ISD::UREM, MVT::i64, Custom);
1249     HasStandaloneRem = false;
1250 
1251     if (Subtarget->isTargetWindows()) {
1252       const struct {
1253         const RTLIB::Libcall Op;
1254         const char * const Name;
1255         const CallingConv::ID CC;
1256       } LibraryCalls[] = {
1257         { RTLIB::SDIVREM_I8, "__rt_sdiv", CallingConv::ARM_AAPCS },
1258         { RTLIB::SDIVREM_I16, "__rt_sdiv", CallingConv::ARM_AAPCS },
1259         { RTLIB::SDIVREM_I32, "__rt_sdiv", CallingConv::ARM_AAPCS },
1260         { RTLIB::SDIVREM_I64, "__rt_sdiv64", CallingConv::ARM_AAPCS },
1261 
1262         { RTLIB::UDIVREM_I8, "__rt_udiv", CallingConv::ARM_AAPCS },
1263         { RTLIB::UDIVREM_I16, "__rt_udiv", CallingConv::ARM_AAPCS },
1264         { RTLIB::UDIVREM_I32, "__rt_udiv", CallingConv::ARM_AAPCS },
1265         { RTLIB::UDIVREM_I64, "__rt_udiv64", CallingConv::ARM_AAPCS },
1266       };
1267 
1268       for (const auto &LC : LibraryCalls) {
1269         setLibcallName(LC.Op, LC.Name);
1270         setLibcallCallingConv(LC.Op, LC.CC);
1271       }
1272     } else {
1273       const struct {
1274         const RTLIB::Libcall Op;
1275         const char * const Name;
1276         const CallingConv::ID CC;
1277       } LibraryCalls[] = {
1278         { RTLIB::SDIVREM_I8, "__aeabi_idivmod", CallingConv::ARM_AAPCS },
1279         { RTLIB::SDIVREM_I16, "__aeabi_idivmod", CallingConv::ARM_AAPCS },
1280         { RTLIB::SDIVREM_I32, "__aeabi_idivmod", CallingConv::ARM_AAPCS },
1281         { RTLIB::SDIVREM_I64, "__aeabi_ldivmod", CallingConv::ARM_AAPCS },
1282 
1283         { RTLIB::UDIVREM_I8, "__aeabi_uidivmod", CallingConv::ARM_AAPCS },
1284         { RTLIB::UDIVREM_I16, "__aeabi_uidivmod", CallingConv::ARM_AAPCS },
1285         { RTLIB::UDIVREM_I32, "__aeabi_uidivmod", CallingConv::ARM_AAPCS },
1286         { RTLIB::UDIVREM_I64, "__aeabi_uldivmod", CallingConv::ARM_AAPCS },
1287       };
1288 
1289       for (const auto &LC : LibraryCalls) {
1290         setLibcallName(LC.Op, LC.Name);
1291         setLibcallCallingConv(LC.Op, LC.CC);
1292       }
1293     }
1294 
1295     setOperationAction(ISD::SDIVREM, MVT::i32, Custom);
1296     setOperationAction(ISD::UDIVREM, MVT::i32, Custom);
1297     setOperationAction(ISD::SDIVREM, MVT::i64, Custom);
1298     setOperationAction(ISD::UDIVREM, MVT::i64, Custom);
1299   } else {
1300     setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
1301     setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
1302   }
1303 
1304   setOperationAction(ISD::GlobalAddress, MVT::i32,   Custom);
1305   setOperationAction(ISD::ConstantPool,  MVT::i32,   Custom);
1306   setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
1307   setOperationAction(ISD::BlockAddress, MVT::i32, Custom);
1308 
1309   setOperationAction(ISD::TRAP, MVT::Other, Legal);
1310   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
1311 
1312   // Use the default implementation.
1313   setOperationAction(ISD::VASTART,            MVT::Other, Custom);
1314   setOperationAction(ISD::VAARG,              MVT::Other, Expand);
1315   setOperationAction(ISD::VACOPY,             MVT::Other, Expand);
1316   setOperationAction(ISD::VAEND,              MVT::Other, Expand);
1317   setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
1318   setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
1319 
1320   if (Subtarget->isTargetWindows())
1321     setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
1322   else
1323     setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
1324 
1325   // ARMv6 Thumb1 (except for CPUs that support dmb / dsb) and earlier use
1326   // the default expansion.
1327   InsertFencesForAtomic = false;
1328   if (Subtarget->hasAnyDataBarrier() &&
1329       (!Subtarget->isThumb() || Subtarget->hasV8MBaselineOps())) {
1330     // ATOMIC_FENCE needs custom lowering; the others should have been expanded
1331     // to ldrex/strex loops already.
1332     setOperationAction(ISD::ATOMIC_FENCE,     MVT::Other, Custom);
1333     if (!Subtarget->isThumb() || !Subtarget->isMClass())
1334       setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i64, Custom);
1335 
1336     // On v8, we have particularly efficient implementations of atomic fences
1337     // if they can be combined with nearby atomic loads and stores.
1338     if (!Subtarget->hasAcquireRelease() ||
1339         getTargetMachine().getOptLevel() == CodeGenOptLevel::None) {
1340       // Automatically insert fences (dmb ish) around ATOMIC_SWAP etc.
1341       InsertFencesForAtomic = true;
1342     }
1343   } else {
1344     // If there's anything we can use as a barrier, go through custom lowering
1345     // for ATOMIC_FENCE.
1346     // If target has DMB in thumb, Fences can be inserted.
1347     if (Subtarget->hasDataBarrier())
1348       InsertFencesForAtomic = true;
1349 
1350     setOperationAction(ISD::ATOMIC_FENCE,   MVT::Other,
1351                        Subtarget->hasAnyDataBarrier() ? Custom : Expand);
1352 
1353     // Set them all for libcall, which will force libcalls.
1354     setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i32, LibCall);
1355     setOperationAction(ISD::ATOMIC_SWAP, MVT::i32, LibCall);
1356     setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i32, LibCall);
1357     setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i32, LibCall);
1358     setOperationAction(ISD::ATOMIC_LOAD_AND, MVT::i32, LibCall);
1359     setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i32, LibCall);
1360     setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i32, LibCall);
1361     setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i32, LibCall);
1362     setOperationAction(ISD::ATOMIC_LOAD_MIN, MVT::i32, LibCall);
1363     setOperationAction(ISD::ATOMIC_LOAD_MAX, MVT::i32, LibCall);
1364     setOperationAction(ISD::ATOMIC_LOAD_UMIN, MVT::i32, LibCall);
1365     setOperationAction(ISD::ATOMIC_LOAD_UMAX, MVT::i32, LibCall);
1366     // Mark ATOMIC_LOAD and ATOMIC_STORE custom so we can handle the
1367     // Unordered/Monotonic case.
1368     if (!InsertFencesForAtomic) {
1369       setOperationAction(ISD::ATOMIC_LOAD, MVT::i32, Custom);
1370       setOperationAction(ISD::ATOMIC_STORE, MVT::i32, Custom);
1371     }
1372   }
1373 
1374   // Compute supported atomic widths.
1375   if (Subtarget->isTargetLinux() ||
1376       (!Subtarget->isMClass() && Subtarget->hasV6Ops())) {
1377     // For targets where __sync_* routines are reliably available, we use them
1378     // if necessary.
1379     //
1380     // ARM Linux always supports 64-bit atomics through kernel-assisted atomic
1381     // routines (kernel 3.1 or later). FIXME: Not with compiler-rt?
1382     //
1383     // ARMv6 targets have native instructions in ARM mode. For Thumb mode,
1384     // such targets should provide __sync_* routines, which use the ARM mode
1385     // instructions. (ARMv6 doesn't have dmb, but it has an equivalent
1386     // encoding; see ARMISD::MEMBARRIER_MCR.)
1387     setMaxAtomicSizeInBitsSupported(64);
1388   } else if ((Subtarget->isMClass() && Subtarget->hasV8MBaselineOps()) ||
1389              Subtarget->hasForced32BitAtomics()) {
1390     // Cortex-M (besides Cortex-M0) have 32-bit atomics.
1391     setMaxAtomicSizeInBitsSupported(32);
1392   } else {
1393     // We can't assume anything about other targets; just use libatomic
1394     // routines.
1395     setMaxAtomicSizeInBitsSupported(0);
1396   }
1397 
1398   setMaxDivRemBitWidthSupported(64);
1399 
1400   setOperationAction(ISD::PREFETCH,         MVT::Other, Custom);
1401 
1402   // Requires SXTB/SXTH, available on v6 and up in both ARM and Thumb modes.
1403   if (!Subtarget->hasV6Ops()) {
1404     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
1405     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
1406   }
1407   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
1408 
1409   if (!Subtarget->useSoftFloat() && Subtarget->hasFPRegs() &&
1410       !Subtarget->isThumb1Only()) {
1411     // Turn f64->i64 into VMOVRRD, i64 -> f64 to VMOVDRR
1412     // iff target supports vfp2.
1413     setOperationAction(ISD::BITCAST, MVT::i64, Custom);
1414     setOperationAction(ISD::GET_ROUNDING, MVT::i32, Custom);
1415     setOperationAction(ISD::SET_ROUNDING, MVT::Other, Custom);
1416     setOperationAction(ISD::GET_FPENV, MVT::i32, Legal);
1417     setOperationAction(ISD::SET_FPENV, MVT::i32, Legal);
1418     setOperationAction(ISD::RESET_FPENV, MVT::Other, Legal);
1419     setOperationAction(ISD::GET_FPMODE, MVT::i32, Legal);
1420     setOperationAction(ISD::SET_FPMODE, MVT::i32, Custom);
1421     setOperationAction(ISD::RESET_FPMODE, MVT::Other, Custom);
1422   }
1423 
1424   // We want to custom lower some of our intrinsics.
1425   setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
1426   setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom);
1427   setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom);
1428   setOperationAction(ISD::EH_SJLJ_SETUP_DISPATCH, MVT::Other, Custom);
1429   if (Subtarget->useSjLjEH())
1430     setLibcallName(RTLIB::UNWIND_RESUME, "_Unwind_SjLj_Resume");
1431 
1432   setOperationAction(ISD::SETCC,     MVT::i32, Expand);
1433   setOperationAction(ISD::SETCC,     MVT::f32, Expand);
1434   setOperationAction(ISD::SETCC,     MVT::f64, Expand);
1435   setOperationAction(ISD::SELECT,    MVT::i32, Custom);
1436   setOperationAction(ISD::SELECT,    MVT::f32, Custom);
1437   setOperationAction(ISD::SELECT,    MVT::f64, Custom);
1438   setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
1439   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
1440   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
1441   if (Subtarget->hasFullFP16()) {
1442     setOperationAction(ISD::SETCC,     MVT::f16, Expand);
1443     setOperationAction(ISD::SELECT,    MVT::f16, Custom);
1444     setOperationAction(ISD::SELECT_CC, MVT::f16, Custom);
1445   }
1446 
1447   setOperationAction(ISD::SETCCCARRY, MVT::i32, Custom);
1448 
1449   setOperationAction(ISD::BRCOND,    MVT::Other, Custom);
1450   setOperationAction(ISD::BR_CC,     MVT::i32,   Custom);
1451   if (Subtarget->hasFullFP16())
1452       setOperationAction(ISD::BR_CC, MVT::f16,   Custom);
1453   setOperationAction(ISD::BR_CC,     MVT::f32,   Custom);
1454   setOperationAction(ISD::BR_CC,     MVT::f64,   Custom);
1455   setOperationAction(ISD::BR_JT,     MVT::Other, Custom);
1456 
1457   // We don't support sin/cos/fmod/copysign/pow
1458   setOperationAction(ISD::FSIN,      MVT::f64, Expand);
1459   setOperationAction(ISD::FSIN,      MVT::f32, Expand);
1460   setOperationAction(ISD::FCOS,      MVT::f32, Expand);
1461   setOperationAction(ISD::FCOS,      MVT::f64, Expand);
1462   setOperationAction(ISD::FSINCOS,   MVT::f64, Expand);
1463   setOperationAction(ISD::FSINCOS,   MVT::f32, Expand);
1464   setOperationAction(ISD::FREM,      MVT::f64, Expand);
1465   setOperationAction(ISD::FREM,      MVT::f32, Expand);
1466   if (!Subtarget->useSoftFloat() && Subtarget->hasVFP2Base() &&
1467       !Subtarget->isThumb1Only()) {
1468     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
1469     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
1470   }
1471   setOperationAction(ISD::FPOW,      MVT::f64, Expand);
1472   setOperationAction(ISD::FPOW,      MVT::f32, Expand);
1473 
1474   if (!Subtarget->hasVFP4Base()) {
1475     setOperationAction(ISD::FMA, MVT::f64, Expand);
1476     setOperationAction(ISD::FMA, MVT::f32, Expand);
1477   }
1478 
1479   // Various VFP goodness
1480   if (!Subtarget->useSoftFloat() && !Subtarget->isThumb1Only()) {
1481     // FP-ARMv8 adds f64 <-> f16 conversion. Before that it should be expanded.
1482     if (!Subtarget->hasFPARMv8Base() || !Subtarget->hasFP64()) {
1483       setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
1484       setOperationAction(ISD::FP_TO_FP16, MVT::f64, Expand);
1485     }
1486 
1487     // fp16 is a special v7 extension that adds f16 <-> f32 conversions.
1488     if (!Subtarget->hasFP16()) {
1489       setOperationAction(ISD::FP16_TO_FP, MVT::f32, Expand);
1490       setOperationAction(ISD::FP_TO_FP16, MVT::f32, Expand);
1491     }
1492 
1493     // Strict floating-point comparisons need custom lowering.
1494     setOperationAction(ISD::STRICT_FSETCC,  MVT::f16, Custom);
1495     setOperationAction(ISD::STRICT_FSETCCS, MVT::f16, Custom);
1496     setOperationAction(ISD::STRICT_FSETCC,  MVT::f32, Custom);
1497     setOperationAction(ISD::STRICT_FSETCCS, MVT::f32, Custom);
1498     setOperationAction(ISD::STRICT_FSETCC,  MVT::f64, Custom);
1499     setOperationAction(ISD::STRICT_FSETCCS, MVT::f64, Custom);
1500   }
1501 
1502   // Use __sincos_stret if available.
1503   if (getLibcallName(RTLIB::SINCOS_STRET_F32) != nullptr &&
1504       getLibcallName(RTLIB::SINCOS_STRET_F64) != nullptr) {
1505     setOperationAction(ISD::FSINCOS, MVT::f64, Custom);
1506     setOperationAction(ISD::FSINCOS, MVT::f32, Custom);
1507   }
1508 
1509   // FP-ARMv8 implements a lot of rounding-like FP operations.
1510   if (Subtarget->hasFPARMv8Base()) {
1511     setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
1512     setOperationAction(ISD::FCEIL, MVT::f32, Legal);
1513     setOperationAction(ISD::FROUND, MVT::f32, Legal);
1514     setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
1515     setOperationAction(ISD::FNEARBYINT, MVT::f32, Legal);
1516     setOperationAction(ISD::FRINT, MVT::f32, Legal);
1517     setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
1518     setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
1519     if (Subtarget->hasNEON()) {
1520       setOperationAction(ISD::FMINNUM, MVT::v2f32, Legal);
1521       setOperationAction(ISD::FMAXNUM, MVT::v2f32, Legal);
1522       setOperationAction(ISD::FMINNUM, MVT::v4f32, Legal);
1523       setOperationAction(ISD::FMAXNUM, MVT::v4f32, Legal);
1524     }
1525 
1526     if (Subtarget->hasFP64()) {
1527       setOperationAction(ISD::FFLOOR, MVT::f64, Legal);
1528       setOperationAction(ISD::FCEIL, MVT::f64, Legal);
1529       setOperationAction(ISD::FROUND, MVT::f64, Legal);
1530       setOperationAction(ISD::FTRUNC, MVT::f64, Legal);
1531       setOperationAction(ISD::FNEARBYINT, MVT::f64, Legal);
1532       setOperationAction(ISD::FRINT, MVT::f64, Legal);
1533       setOperationAction(ISD::FMINNUM, MVT::f64, Legal);
1534       setOperationAction(ISD::FMAXNUM, MVT::f64, Legal);
1535     }
1536   }
1537 
1538   // FP16 often need to be promoted to call lib functions
1539   if (Subtarget->hasFullFP16()) {
1540     setOperationAction(ISD::FREM, MVT::f16, Promote);
1541     setOperationAction(ISD::FCOPYSIGN, MVT::f16, Expand);
1542     setOperationAction(ISD::FSIN, MVT::f16, Promote);
1543     setOperationAction(ISD::FCOS, MVT::f16, Promote);
1544     setOperationAction(ISD::FTAN, MVT::f16, Promote);
1545     setOperationAction(ISD::FSINCOS, MVT::f16, Promote);
1546     setOperationAction(ISD::FPOWI, MVT::f16, Promote);
1547     setOperationAction(ISD::FPOW, MVT::f16, Promote);
1548     setOperationAction(ISD::FEXP, MVT::f16, Promote);
1549     setOperationAction(ISD::FEXP2, MVT::f16, Promote);
1550     setOperationAction(ISD::FEXP10, MVT::f16, Promote);
1551     setOperationAction(ISD::FLOG, MVT::f16, Promote);
1552     setOperationAction(ISD::FLOG10, MVT::f16, Promote);
1553     setOperationAction(ISD::FLOG2, MVT::f16, Promote);
1554 
1555     setOperationAction(ISD::FROUND, MVT::f16, Legal);
1556   }
1557 
1558   if (Subtarget->hasNEON()) {
1559     // vmin and vmax aren't available in a scalar form, so we can use
1560     // a NEON instruction with an undef lane instead.
1561     setOperationAction(ISD::FMINIMUM, MVT::f32, Legal);
1562     setOperationAction(ISD::FMAXIMUM, MVT::f32, Legal);
1563     setOperationAction(ISD::FMINIMUM, MVT::f16, Legal);
1564     setOperationAction(ISD::FMAXIMUM, MVT::f16, Legal);
1565     setOperationAction(ISD::FMINIMUM, MVT::v2f32, Legal);
1566     setOperationAction(ISD::FMAXIMUM, MVT::v2f32, Legal);
1567     setOperationAction(ISD::FMINIMUM, MVT::v4f32, Legal);
1568     setOperationAction(ISD::FMAXIMUM, MVT::v4f32, Legal);
1569 
1570     if (Subtarget->hasFullFP16()) {
1571       setOperationAction(ISD::FMINNUM, MVT::v4f16, Legal);
1572       setOperationAction(ISD::FMAXNUM, MVT::v4f16, Legal);
1573       setOperationAction(ISD::FMINNUM, MVT::v8f16, Legal);
1574       setOperationAction(ISD::FMAXNUM, MVT::v8f16, Legal);
1575 
1576       setOperationAction(ISD::FMINIMUM, MVT::v4f16, Legal);
1577       setOperationAction(ISD::FMAXIMUM, MVT::v4f16, Legal);
1578       setOperationAction(ISD::FMINIMUM, MVT::v8f16, Legal);
1579       setOperationAction(ISD::FMAXIMUM, MVT::v8f16, Legal);
1580     }
1581   }
1582 
1583   // On MSVC, both 32-bit and 64-bit, ldexpf(f32) is not defined.  MinGW has
1584   // it, but it's just a wrapper around ldexp.
1585   if (Subtarget->isTargetWindows()) {
1586     for (ISD::NodeType Op : {ISD::FLDEXP, ISD::STRICT_FLDEXP, ISD::FFREXP})
1587       if (isOperationExpand(Op, MVT::f32))
1588         setOperationAction(Op, MVT::f32, Promote);
1589   }
1590 
1591   // LegalizeDAG currently can't expand fp16 LDEXP/FREXP on targets where i16
1592   // isn't legal.
1593   for (ISD::NodeType Op : {ISD::FLDEXP, ISD::STRICT_FLDEXP, ISD::FFREXP})
1594     if (isOperationExpand(Op, MVT::f16))
1595       setOperationAction(Op, MVT::f16, Promote);
1596 
1597   // We have target-specific dag combine patterns for the following nodes:
1598   // ARMISD::VMOVRRD  - No need to call setTargetDAGCombine
1599   setTargetDAGCombine(
1600       {ISD::ADD, ISD::SUB, ISD::MUL, ISD::AND, ISD::OR, ISD::XOR});
1601 
1602   if (Subtarget->hasMVEIntegerOps())
1603     setTargetDAGCombine(ISD::VSELECT);
1604 
1605   if (Subtarget->hasV6Ops())
1606     setTargetDAGCombine(ISD::SRL);
1607   if (Subtarget->isThumb1Only())
1608     setTargetDAGCombine(ISD::SHL);
1609   // Attempt to lower smin/smax to ssat/usat
1610   if ((!Subtarget->isThumb() && Subtarget->hasV6Ops()) ||
1611       Subtarget->isThumb2()) {
1612     setTargetDAGCombine({ISD::SMIN, ISD::SMAX});
1613   }
1614 
1615   setStackPointerRegisterToSaveRestore(ARM::SP);
1616 
1617   if (Subtarget->useSoftFloat() || Subtarget->isThumb1Only() ||
1618       !Subtarget->hasVFP2Base() || Subtarget->hasMinSize())
1619     setSchedulingPreference(Sched::RegPressure);
1620   else
1621     setSchedulingPreference(Sched::Hybrid);
1622 
1623   //// temporary - rewrite interface to use type
1624   MaxStoresPerMemset = 8;
1625   MaxStoresPerMemsetOptSize = 4;
1626   MaxStoresPerMemcpy = 4; // For @llvm.memcpy -> sequence of stores
1627   MaxStoresPerMemcpyOptSize = 2;
1628   MaxStoresPerMemmove = 4; // For @llvm.memmove -> sequence of stores
1629   MaxStoresPerMemmoveOptSize = 2;
1630 
1631   // On ARM arguments smaller than 4 bytes are extended, so all arguments
1632   // are at least 4 bytes aligned.
1633   setMinStackArgumentAlignment(Align(4));
1634 
1635   // Prefer likely predicted branches to selects on out-of-order cores.
1636   PredictableSelectIsExpensive = Subtarget->getSchedModel().isOutOfOrder();
1637 
1638   setPrefLoopAlignment(Align(1ULL << Subtarget->getPrefLoopLogAlignment()));
1639   setPrefFunctionAlignment(Align(1ULL << Subtarget->getPrefLoopLogAlignment()));
1640 
1641   setMinFunctionAlignment(Subtarget->isThumb() ? Align(2) : Align(4));
1642 }
1643 
useSoftFloat() const1644 bool ARMTargetLowering::useSoftFloat() const {
1645   return Subtarget->useSoftFloat();
1646 }
1647 
1648 // FIXME: It might make sense to define the representative register class as the
1649 // nearest super-register that has a non-null superset. For example, DPR_VFP2 is
1650 // a super-register of SPR, and DPR is a superset if DPR_VFP2. Consequently,
1651 // SPR's representative would be DPR_VFP2. This should work well if register
1652 // pressure tracking were modified such that a register use would increment the
1653 // pressure of the register class's representative and all of it's super
1654 // classes' representatives transitively. We have not implemented this because
1655 // of the difficulty prior to coalescing of modeling operand register classes
1656 // due to the common occurrence of cross class copies and subregister insertions
1657 // and extractions.
1658 std::pair<const TargetRegisterClass *, uint8_t>
findRepresentativeClass(const TargetRegisterInfo * TRI,MVT VT) const1659 ARMTargetLowering::findRepresentativeClass(const TargetRegisterInfo *TRI,
1660                                            MVT VT) const {
1661   const TargetRegisterClass *RRC = nullptr;
1662   uint8_t Cost = 1;
1663   switch (VT.SimpleTy) {
1664   default:
1665     return TargetLowering::findRepresentativeClass(TRI, VT);
1666   // Use DPR as representative register class for all floating point
1667   // and vector types. Since there are 32 SPR registers and 32 DPR registers so
1668   // the cost is 1 for both f32 and f64.
1669   case MVT::f32: case MVT::f64: case MVT::v8i8: case MVT::v4i16:
1670   case MVT::v2i32: case MVT::v1i64: case MVT::v2f32:
1671     RRC = &ARM::DPRRegClass;
1672     // When NEON is used for SP, only half of the register file is available
1673     // because operations that define both SP and DP results will be constrained
1674     // to the VFP2 class (D0-D15). We currently model this constraint prior to
1675     // coalescing by double-counting the SP regs. See the FIXME above.
1676     if (Subtarget->useNEONForSinglePrecisionFP())
1677       Cost = 2;
1678     break;
1679   case MVT::v16i8: case MVT::v8i16: case MVT::v4i32: case MVT::v2i64:
1680   case MVT::v4f32: case MVT::v2f64:
1681     RRC = &ARM::DPRRegClass;
1682     Cost = 2;
1683     break;
1684   case MVT::v4i64:
1685     RRC = &ARM::DPRRegClass;
1686     Cost = 4;
1687     break;
1688   case MVT::v8i64:
1689     RRC = &ARM::DPRRegClass;
1690     Cost = 8;
1691     break;
1692   }
1693   return std::make_pair(RRC, Cost);
1694 }
1695 
getTargetNodeName(unsigned Opcode) const1696 const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
1697 #define MAKE_CASE(V)                                                           \
1698   case V:                                                                      \
1699     return #V;
1700   switch ((ARMISD::NodeType)Opcode) {
1701   case ARMISD::FIRST_NUMBER:
1702     break;
1703     MAKE_CASE(ARMISD::Wrapper)
1704     MAKE_CASE(ARMISD::WrapperPIC)
1705     MAKE_CASE(ARMISD::WrapperJT)
1706     MAKE_CASE(ARMISD::COPY_STRUCT_BYVAL)
1707     MAKE_CASE(ARMISD::CALL)
1708     MAKE_CASE(ARMISD::CALL_PRED)
1709     MAKE_CASE(ARMISD::CALL_NOLINK)
1710     MAKE_CASE(ARMISD::tSECALL)
1711     MAKE_CASE(ARMISD::t2CALL_BTI)
1712     MAKE_CASE(ARMISD::BRCOND)
1713     MAKE_CASE(ARMISD::BR_JT)
1714     MAKE_CASE(ARMISD::BR2_JT)
1715     MAKE_CASE(ARMISD::RET_GLUE)
1716     MAKE_CASE(ARMISD::SERET_GLUE)
1717     MAKE_CASE(ARMISD::INTRET_GLUE)
1718     MAKE_CASE(ARMISD::PIC_ADD)
1719     MAKE_CASE(ARMISD::CMP)
1720     MAKE_CASE(ARMISD::CMN)
1721     MAKE_CASE(ARMISD::CMPZ)
1722     MAKE_CASE(ARMISD::CMPFP)
1723     MAKE_CASE(ARMISD::CMPFPE)
1724     MAKE_CASE(ARMISD::CMPFPw0)
1725     MAKE_CASE(ARMISD::CMPFPEw0)
1726     MAKE_CASE(ARMISD::BCC_i64)
1727     MAKE_CASE(ARMISD::FMSTAT)
1728     MAKE_CASE(ARMISD::CMOV)
1729     MAKE_CASE(ARMISD::SSAT)
1730     MAKE_CASE(ARMISD::USAT)
1731     MAKE_CASE(ARMISD::ASRL)
1732     MAKE_CASE(ARMISD::LSRL)
1733     MAKE_CASE(ARMISD::LSLL)
1734     MAKE_CASE(ARMISD::SRL_GLUE)
1735     MAKE_CASE(ARMISD::SRA_GLUE)
1736     MAKE_CASE(ARMISD::RRX)
1737     MAKE_CASE(ARMISD::ADDC)
1738     MAKE_CASE(ARMISD::ADDE)
1739     MAKE_CASE(ARMISD::SUBC)
1740     MAKE_CASE(ARMISD::SUBE)
1741     MAKE_CASE(ARMISD::LSLS)
1742     MAKE_CASE(ARMISD::VMOVRRD)
1743     MAKE_CASE(ARMISD::VMOVDRR)
1744     MAKE_CASE(ARMISD::VMOVhr)
1745     MAKE_CASE(ARMISD::VMOVrh)
1746     MAKE_CASE(ARMISD::VMOVSR)
1747     MAKE_CASE(ARMISD::EH_SJLJ_SETJMP)
1748     MAKE_CASE(ARMISD::EH_SJLJ_LONGJMP)
1749     MAKE_CASE(ARMISD::EH_SJLJ_SETUP_DISPATCH)
1750     MAKE_CASE(ARMISD::TC_RETURN)
1751     MAKE_CASE(ARMISD::THREAD_POINTER)
1752     MAKE_CASE(ARMISD::DYN_ALLOC)
1753     MAKE_CASE(ARMISD::MEMBARRIER_MCR)
1754     MAKE_CASE(ARMISD::PRELOAD)
1755     MAKE_CASE(ARMISD::LDRD)
1756     MAKE_CASE(ARMISD::STRD)
1757     MAKE_CASE(ARMISD::WIN__CHKSTK)
1758     MAKE_CASE(ARMISD::WIN__DBZCHK)
1759     MAKE_CASE(ARMISD::PREDICATE_CAST)
1760     MAKE_CASE(ARMISD::VECTOR_REG_CAST)
1761     MAKE_CASE(ARMISD::MVESEXT)
1762     MAKE_CASE(ARMISD::MVEZEXT)
1763     MAKE_CASE(ARMISD::MVETRUNC)
1764     MAKE_CASE(ARMISD::VCMP)
1765     MAKE_CASE(ARMISD::VCMPZ)
1766     MAKE_CASE(ARMISD::VTST)
1767     MAKE_CASE(ARMISD::VSHLs)
1768     MAKE_CASE(ARMISD::VSHLu)
1769     MAKE_CASE(ARMISD::VSHLIMM)
1770     MAKE_CASE(ARMISD::VSHRsIMM)
1771     MAKE_CASE(ARMISD::VSHRuIMM)
1772     MAKE_CASE(ARMISD::VRSHRsIMM)
1773     MAKE_CASE(ARMISD::VRSHRuIMM)
1774     MAKE_CASE(ARMISD::VRSHRNIMM)
1775     MAKE_CASE(ARMISD::VQSHLsIMM)
1776     MAKE_CASE(ARMISD::VQSHLuIMM)
1777     MAKE_CASE(ARMISD::VQSHLsuIMM)
1778     MAKE_CASE(ARMISD::VQSHRNsIMM)
1779     MAKE_CASE(ARMISD::VQSHRNuIMM)
1780     MAKE_CASE(ARMISD::VQSHRNsuIMM)
1781     MAKE_CASE(ARMISD::VQRSHRNsIMM)
1782     MAKE_CASE(ARMISD::VQRSHRNuIMM)
1783     MAKE_CASE(ARMISD::VQRSHRNsuIMM)
1784     MAKE_CASE(ARMISD::VSLIIMM)
1785     MAKE_CASE(ARMISD::VSRIIMM)
1786     MAKE_CASE(ARMISD::VGETLANEu)
1787     MAKE_CASE(ARMISD::VGETLANEs)
1788     MAKE_CASE(ARMISD::VMOVIMM)
1789     MAKE_CASE(ARMISD::VMVNIMM)
1790     MAKE_CASE(ARMISD::VMOVFPIMM)
1791     MAKE_CASE(ARMISD::VDUP)
1792     MAKE_CASE(ARMISD::VDUPLANE)
1793     MAKE_CASE(ARMISD::VEXT)
1794     MAKE_CASE(ARMISD::VREV64)
1795     MAKE_CASE(ARMISD::VREV32)
1796     MAKE_CASE(ARMISD::VREV16)
1797     MAKE_CASE(ARMISD::VZIP)
1798     MAKE_CASE(ARMISD::VUZP)
1799     MAKE_CASE(ARMISD::VTRN)
1800     MAKE_CASE(ARMISD::VTBL1)
1801     MAKE_CASE(ARMISD::VTBL2)
1802     MAKE_CASE(ARMISD::VMOVN)
1803     MAKE_CASE(ARMISD::VQMOVNs)
1804     MAKE_CASE(ARMISD::VQMOVNu)
1805     MAKE_CASE(ARMISD::VCVTN)
1806     MAKE_CASE(ARMISD::VCVTL)
1807     MAKE_CASE(ARMISD::VIDUP)
1808     MAKE_CASE(ARMISD::VMULLs)
1809     MAKE_CASE(ARMISD::VMULLu)
1810     MAKE_CASE(ARMISD::VQDMULH)
1811     MAKE_CASE(ARMISD::VADDVs)
1812     MAKE_CASE(ARMISD::VADDVu)
1813     MAKE_CASE(ARMISD::VADDVps)
1814     MAKE_CASE(ARMISD::VADDVpu)
1815     MAKE_CASE(ARMISD::VADDLVs)
1816     MAKE_CASE(ARMISD::VADDLVu)
1817     MAKE_CASE(ARMISD::VADDLVAs)
1818     MAKE_CASE(ARMISD::VADDLVAu)
1819     MAKE_CASE(ARMISD::VADDLVps)
1820     MAKE_CASE(ARMISD::VADDLVpu)
1821     MAKE_CASE(ARMISD::VADDLVAps)
1822     MAKE_CASE(ARMISD::VADDLVApu)
1823     MAKE_CASE(ARMISD::VMLAVs)
1824     MAKE_CASE(ARMISD::VMLAVu)
1825     MAKE_CASE(ARMISD::VMLAVps)
1826     MAKE_CASE(ARMISD::VMLAVpu)
1827     MAKE_CASE(ARMISD::VMLALVs)
1828     MAKE_CASE(ARMISD::VMLALVu)
1829     MAKE_CASE(ARMISD::VMLALVps)
1830     MAKE_CASE(ARMISD::VMLALVpu)
1831     MAKE_CASE(ARMISD::VMLALVAs)
1832     MAKE_CASE(ARMISD::VMLALVAu)
1833     MAKE_CASE(ARMISD::VMLALVAps)
1834     MAKE_CASE(ARMISD::VMLALVApu)
1835     MAKE_CASE(ARMISD::VMINVu)
1836     MAKE_CASE(ARMISD::VMINVs)
1837     MAKE_CASE(ARMISD::VMAXVu)
1838     MAKE_CASE(ARMISD::VMAXVs)
1839     MAKE_CASE(ARMISD::UMAAL)
1840     MAKE_CASE(ARMISD::UMLAL)
1841     MAKE_CASE(ARMISD::SMLAL)
1842     MAKE_CASE(ARMISD::SMLALBB)
1843     MAKE_CASE(ARMISD::SMLALBT)
1844     MAKE_CASE(ARMISD::SMLALTB)
1845     MAKE_CASE(ARMISD::SMLALTT)
1846     MAKE_CASE(ARMISD::SMULWB)
1847     MAKE_CASE(ARMISD::SMULWT)
1848     MAKE_CASE(ARMISD::SMLALD)
1849     MAKE_CASE(ARMISD::SMLALDX)
1850     MAKE_CASE(ARMISD::SMLSLD)
1851     MAKE_CASE(ARMISD::SMLSLDX)
1852     MAKE_CASE(ARMISD::SMMLAR)
1853     MAKE_CASE(ARMISD::SMMLSR)
1854     MAKE_CASE(ARMISD::QADD16b)
1855     MAKE_CASE(ARMISD::QSUB16b)
1856     MAKE_CASE(ARMISD::QADD8b)
1857     MAKE_CASE(ARMISD::QSUB8b)
1858     MAKE_CASE(ARMISD::UQADD16b)
1859     MAKE_CASE(ARMISD::UQSUB16b)
1860     MAKE_CASE(ARMISD::UQADD8b)
1861     MAKE_CASE(ARMISD::UQSUB8b)
1862     MAKE_CASE(ARMISD::BUILD_VECTOR)
1863     MAKE_CASE(ARMISD::BFI)
1864     MAKE_CASE(ARMISD::VORRIMM)
1865     MAKE_CASE(ARMISD::VBICIMM)
1866     MAKE_CASE(ARMISD::VBSP)
1867     MAKE_CASE(ARMISD::MEMCPY)
1868     MAKE_CASE(ARMISD::VLD1DUP)
1869     MAKE_CASE(ARMISD::VLD2DUP)
1870     MAKE_CASE(ARMISD::VLD3DUP)
1871     MAKE_CASE(ARMISD::VLD4DUP)
1872     MAKE_CASE(ARMISD::VLD1_UPD)
1873     MAKE_CASE(ARMISD::VLD2_UPD)
1874     MAKE_CASE(ARMISD::VLD3_UPD)
1875     MAKE_CASE(ARMISD::VLD4_UPD)
1876     MAKE_CASE(ARMISD::VLD1x2_UPD)
1877     MAKE_CASE(ARMISD::VLD1x3_UPD)
1878     MAKE_CASE(ARMISD::VLD1x4_UPD)
1879     MAKE_CASE(ARMISD::VLD2LN_UPD)
1880     MAKE_CASE(ARMISD::VLD3LN_UPD)
1881     MAKE_CASE(ARMISD::VLD4LN_UPD)
1882     MAKE_CASE(ARMISD::VLD1DUP_UPD)
1883     MAKE_CASE(ARMISD::VLD2DUP_UPD)
1884     MAKE_CASE(ARMISD::VLD3DUP_UPD)
1885     MAKE_CASE(ARMISD::VLD4DUP_UPD)
1886     MAKE_CASE(ARMISD::VST1_UPD)
1887     MAKE_CASE(ARMISD::VST2_UPD)
1888     MAKE_CASE(ARMISD::VST3_UPD)
1889     MAKE_CASE(ARMISD::VST4_UPD)
1890     MAKE_CASE(ARMISD::VST1x2_UPD)
1891     MAKE_CASE(ARMISD::VST1x3_UPD)
1892     MAKE_CASE(ARMISD::VST1x4_UPD)
1893     MAKE_CASE(ARMISD::VST2LN_UPD)
1894     MAKE_CASE(ARMISD::VST3LN_UPD)
1895     MAKE_CASE(ARMISD::VST4LN_UPD)
1896     MAKE_CASE(ARMISD::WLS)
1897     MAKE_CASE(ARMISD::WLSSETUP)
1898     MAKE_CASE(ARMISD::LE)
1899     MAKE_CASE(ARMISD::LOOP_DEC)
1900     MAKE_CASE(ARMISD::CSINV)
1901     MAKE_CASE(ARMISD::CSNEG)
1902     MAKE_CASE(ARMISD::CSINC)
1903     MAKE_CASE(ARMISD::MEMCPYLOOP)
1904     MAKE_CASE(ARMISD::MEMSETLOOP)
1905 #undef MAKE_CASE
1906   }
1907   return nullptr;
1908 }
1909 
getSetCCResultType(const DataLayout & DL,LLVMContext &,EVT VT) const1910 EVT ARMTargetLowering::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1911                                           EVT VT) const {
1912   if (!VT.isVector())
1913     return getPointerTy(DL);
1914 
1915   // MVE has a predicate register.
1916   if ((Subtarget->hasMVEIntegerOps() &&
1917        (VT == MVT::v2i64 || VT == MVT::v4i32 || VT == MVT::v8i16 ||
1918         VT == MVT::v16i8)) ||
1919       (Subtarget->hasMVEFloatOps() &&
1920        (VT == MVT::v2f64 || VT == MVT::v4f32 || VT == MVT::v8f16)))
1921     return MVT::getVectorVT(MVT::i1, VT.getVectorElementCount());
1922   return VT.changeVectorElementTypeToInteger();
1923 }
1924 
1925 /// getRegClassFor - Return the register class that should be used for the
1926 /// specified value type.
1927 const TargetRegisterClass *
getRegClassFor(MVT VT,bool isDivergent) const1928 ARMTargetLowering::getRegClassFor(MVT VT, bool isDivergent) const {
1929   (void)isDivergent;
1930   // Map v4i64 to QQ registers but do not make the type legal. Similarly map
1931   // v8i64 to QQQQ registers. v4i64 and v8i64 are only used for REG_SEQUENCE to
1932   // load / store 4 to 8 consecutive NEON D registers, or 2 to 4 consecutive
1933   // MVE Q registers.
1934   if (Subtarget->hasNEON()) {
1935     if (VT == MVT::v4i64)
1936       return &ARM::QQPRRegClass;
1937     if (VT == MVT::v8i64)
1938       return &ARM::QQQQPRRegClass;
1939   }
1940   if (Subtarget->hasMVEIntegerOps()) {
1941     if (VT == MVT::v4i64)
1942       return &ARM::MQQPRRegClass;
1943     if (VT == MVT::v8i64)
1944       return &ARM::MQQQQPRRegClass;
1945   }
1946   return TargetLowering::getRegClassFor(VT);
1947 }
1948 
1949 // memcpy, and other memory intrinsics, typically tries to use LDM/STM if the
1950 // source/dest is aligned and the copy size is large enough. We therefore want
1951 // to align such objects passed to memory intrinsics.
shouldAlignPointerArgs(CallInst * CI,unsigned & MinSize,Align & PrefAlign) const1952 bool ARMTargetLowering::shouldAlignPointerArgs(CallInst *CI, unsigned &MinSize,
1953                                                Align &PrefAlign) const {
1954   if (!isa<MemIntrinsic>(CI))
1955     return false;
1956   MinSize = 8;
1957   // On ARM11 onwards (excluding M class) 8-byte aligned LDM is typically 1
1958   // cycle faster than 4-byte aligned LDM.
1959   PrefAlign =
1960       (Subtarget->hasV6Ops() && !Subtarget->isMClass() ? Align(8) : Align(4));
1961   return true;
1962 }
1963 
1964 // Create a fast isel object.
1965 FastISel *
createFastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo) const1966 ARMTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
1967                                   const TargetLibraryInfo *libInfo) const {
1968   return ARM::createFastISel(funcInfo, libInfo);
1969 }
1970 
getSchedulingPreference(SDNode * N) const1971 Sched::Preference ARMTargetLowering::getSchedulingPreference(SDNode *N) const {
1972   unsigned NumVals = N->getNumValues();
1973   if (!NumVals)
1974     return Sched::RegPressure;
1975 
1976   for (unsigned i = 0; i != NumVals; ++i) {
1977     EVT VT = N->getValueType(i);
1978     if (VT == MVT::Glue || VT == MVT::Other)
1979       continue;
1980     if (VT.isFloatingPoint() || VT.isVector())
1981       return Sched::ILP;
1982   }
1983 
1984   if (!N->isMachineOpcode())
1985     return Sched::RegPressure;
1986 
1987   // Load are scheduled for latency even if there instruction itinerary
1988   // is not available.
1989   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
1990   const MCInstrDesc &MCID = TII->get(N->getMachineOpcode());
1991 
1992   if (MCID.getNumDefs() == 0)
1993     return Sched::RegPressure;
1994   if (!Itins->isEmpty() &&
1995       Itins->getOperandCycle(MCID.getSchedClass(), 0) > 2U)
1996     return Sched::ILP;
1997 
1998   return Sched::RegPressure;
1999 }
2000 
2001 //===----------------------------------------------------------------------===//
2002 // Lowering Code
2003 //===----------------------------------------------------------------------===//
2004 
isSRL16(const SDValue & Op)2005 static bool isSRL16(const SDValue &Op) {
2006   if (Op.getOpcode() != ISD::SRL)
2007     return false;
2008   if (auto Const = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
2009     return Const->getZExtValue() == 16;
2010   return false;
2011 }
2012 
isSRA16(const SDValue & Op)2013 static bool isSRA16(const SDValue &Op) {
2014   if (Op.getOpcode() != ISD::SRA)
2015     return false;
2016   if (auto Const = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
2017     return Const->getZExtValue() == 16;
2018   return false;
2019 }
2020 
isSHL16(const SDValue & Op)2021 static bool isSHL16(const SDValue &Op) {
2022   if (Op.getOpcode() != ISD::SHL)
2023     return false;
2024   if (auto Const = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
2025     return Const->getZExtValue() == 16;
2026   return false;
2027 }
2028 
2029 // Check for a signed 16-bit value. We special case SRA because it makes it
2030 // more simple when also looking for SRAs that aren't sign extending a
2031 // smaller value. Without the check, we'd need to take extra care with
2032 // checking order for some operations.
isS16(const SDValue & Op,SelectionDAG & DAG)2033 static bool isS16(const SDValue &Op, SelectionDAG &DAG) {
2034   if (isSRA16(Op))
2035     return isSHL16(Op.getOperand(0));
2036   return DAG.ComputeNumSignBits(Op) == 17;
2037 }
2038 
2039 /// IntCCToARMCC - Convert a DAG integer condition code to an ARM CC
IntCCToARMCC(ISD::CondCode CC)2040 static ARMCC::CondCodes IntCCToARMCC(ISD::CondCode CC) {
2041   switch (CC) {
2042   default: llvm_unreachable("Unknown condition code!");
2043   case ISD::SETNE:  return ARMCC::NE;
2044   case ISD::SETEQ:  return ARMCC::EQ;
2045   case ISD::SETGT:  return ARMCC::GT;
2046   case ISD::SETGE:  return ARMCC::GE;
2047   case ISD::SETLT:  return ARMCC::LT;
2048   case ISD::SETLE:  return ARMCC::LE;
2049   case ISD::SETUGT: return ARMCC::HI;
2050   case ISD::SETUGE: return ARMCC::HS;
2051   case ISD::SETULT: return ARMCC::LO;
2052   case ISD::SETULE: return ARMCC::LS;
2053   }
2054 }
2055 
2056 /// FPCCToARMCC - Convert a DAG fp condition code to an ARM CC.
FPCCToARMCC(ISD::CondCode CC,ARMCC::CondCodes & CondCode,ARMCC::CondCodes & CondCode2)2057 static void FPCCToARMCC(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
2058                         ARMCC::CondCodes &CondCode2) {
2059   CondCode2 = ARMCC::AL;
2060   switch (CC) {
2061   default: llvm_unreachable("Unknown FP condition!");
2062   case ISD::SETEQ:
2063   case ISD::SETOEQ: CondCode = ARMCC::EQ; break;
2064   case ISD::SETGT:
2065   case ISD::SETOGT: CondCode = ARMCC::GT; break;
2066   case ISD::SETGE:
2067   case ISD::SETOGE: CondCode = ARMCC::GE; break;
2068   case ISD::SETOLT: CondCode = ARMCC::MI; break;
2069   case ISD::SETOLE: CondCode = ARMCC::LS; break;
2070   case ISD::SETONE: CondCode = ARMCC::MI; CondCode2 = ARMCC::GT; break;
2071   case ISD::SETO:   CondCode = ARMCC::VC; break;
2072   case ISD::SETUO:  CondCode = ARMCC::VS; break;
2073   case ISD::SETUEQ: CondCode = ARMCC::EQ; CondCode2 = ARMCC::VS; break;
2074   case ISD::SETUGT: CondCode = ARMCC::HI; break;
2075   case ISD::SETUGE: CondCode = ARMCC::PL; break;
2076   case ISD::SETLT:
2077   case ISD::SETULT: CondCode = ARMCC::LT; break;
2078   case ISD::SETLE:
2079   case ISD::SETULE: CondCode = ARMCC::LE; break;
2080   case ISD::SETNE:
2081   case ISD::SETUNE: CondCode = ARMCC::NE; break;
2082   }
2083 }
2084 
2085 //===----------------------------------------------------------------------===//
2086 //                      Calling Convention Implementation
2087 //===----------------------------------------------------------------------===//
2088 
2089 /// getEffectiveCallingConv - Get the effective calling convention, taking into
2090 /// account presence of floating point hardware and calling convention
2091 /// limitations, such as support for variadic functions.
2092 CallingConv::ID
getEffectiveCallingConv(CallingConv::ID CC,bool isVarArg) const2093 ARMTargetLowering::getEffectiveCallingConv(CallingConv::ID CC,
2094                                            bool isVarArg) const {
2095   switch (CC) {
2096   default:
2097     report_fatal_error("Unsupported calling convention");
2098   case CallingConv::ARM_AAPCS:
2099   case CallingConv::ARM_APCS:
2100   case CallingConv::GHC:
2101   case CallingConv::CFGuard_Check:
2102     return CC;
2103   case CallingConv::PreserveMost:
2104     return CallingConv::PreserveMost;
2105   case CallingConv::PreserveAll:
2106     return CallingConv::PreserveAll;
2107   case CallingConv::ARM_AAPCS_VFP:
2108   case CallingConv::Swift:
2109   case CallingConv::SwiftTail:
2110     return isVarArg ? CallingConv::ARM_AAPCS : CallingConv::ARM_AAPCS_VFP;
2111   case CallingConv::C:
2112   case CallingConv::Tail:
2113     if (!Subtarget->isAAPCS_ABI())
2114       return CallingConv::ARM_APCS;
2115     else if (Subtarget->hasFPRegs() && !Subtarget->isThumb1Only() &&
2116              getTargetMachine().Options.FloatABIType == FloatABI::Hard &&
2117              !isVarArg)
2118       return CallingConv::ARM_AAPCS_VFP;
2119     else
2120       return CallingConv::ARM_AAPCS;
2121   case CallingConv::Fast:
2122   case CallingConv::CXX_FAST_TLS:
2123     if (!Subtarget->isAAPCS_ABI()) {
2124       if (Subtarget->hasVFP2Base() && !Subtarget->isThumb1Only() && !isVarArg)
2125         return CallingConv::Fast;
2126       return CallingConv::ARM_APCS;
2127     } else if (Subtarget->hasVFP2Base() &&
2128                !Subtarget->isThumb1Only() && !isVarArg)
2129       return CallingConv::ARM_AAPCS_VFP;
2130     else
2131       return CallingConv::ARM_AAPCS;
2132   }
2133 }
2134 
CCAssignFnForCall(CallingConv::ID CC,bool isVarArg) const2135 CCAssignFn *ARMTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
2136                                                  bool isVarArg) const {
2137   return CCAssignFnForNode(CC, false, isVarArg);
2138 }
2139 
CCAssignFnForReturn(CallingConv::ID CC,bool isVarArg) const2140 CCAssignFn *ARMTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
2141                                                    bool isVarArg) const {
2142   return CCAssignFnForNode(CC, true, isVarArg);
2143 }
2144 
2145 /// CCAssignFnForNode - Selects the correct CCAssignFn for the given
2146 /// CallingConvention.
CCAssignFnForNode(CallingConv::ID CC,bool Return,bool isVarArg) const2147 CCAssignFn *ARMTargetLowering::CCAssignFnForNode(CallingConv::ID CC,
2148                                                  bool Return,
2149                                                  bool isVarArg) const {
2150   switch (getEffectiveCallingConv(CC, isVarArg)) {
2151   default:
2152     report_fatal_error("Unsupported calling convention");
2153   case CallingConv::ARM_APCS:
2154     return (Return ? RetCC_ARM_APCS : CC_ARM_APCS);
2155   case CallingConv::ARM_AAPCS:
2156     return (Return ? RetCC_ARM_AAPCS : CC_ARM_AAPCS);
2157   case CallingConv::ARM_AAPCS_VFP:
2158     return (Return ? RetCC_ARM_AAPCS_VFP : CC_ARM_AAPCS_VFP);
2159   case CallingConv::Fast:
2160     return (Return ? RetFastCC_ARM_APCS : FastCC_ARM_APCS);
2161   case CallingConv::GHC:
2162     return (Return ? RetCC_ARM_APCS : CC_ARM_APCS_GHC);
2163   case CallingConv::PreserveMost:
2164     return (Return ? RetCC_ARM_AAPCS : CC_ARM_AAPCS);
2165   case CallingConv::PreserveAll:
2166     return (Return ? RetCC_ARM_AAPCS : CC_ARM_AAPCS);
2167   case CallingConv::CFGuard_Check:
2168     return (Return ? RetCC_ARM_AAPCS : CC_ARM_Win32_CFGuard_Check);
2169   }
2170 }
2171 
MoveToHPR(const SDLoc & dl,SelectionDAG & DAG,MVT LocVT,MVT ValVT,SDValue Val) const2172 SDValue ARMTargetLowering::MoveToHPR(const SDLoc &dl, SelectionDAG &DAG,
2173                                      MVT LocVT, MVT ValVT, SDValue Val) const {
2174   Val = DAG.getNode(ISD::BITCAST, dl, MVT::getIntegerVT(LocVT.getSizeInBits()),
2175                     Val);
2176   if (Subtarget->hasFullFP16()) {
2177     Val = DAG.getNode(ARMISD::VMOVhr, dl, ValVT, Val);
2178   } else {
2179     Val = DAG.getNode(ISD::TRUNCATE, dl,
2180                       MVT::getIntegerVT(ValVT.getSizeInBits()), Val);
2181     Val = DAG.getNode(ISD::BITCAST, dl, ValVT, Val);
2182   }
2183   return Val;
2184 }
2185 
MoveFromHPR(const SDLoc & dl,SelectionDAG & DAG,MVT LocVT,MVT ValVT,SDValue Val) const2186 SDValue ARMTargetLowering::MoveFromHPR(const SDLoc &dl, SelectionDAG &DAG,
2187                                        MVT LocVT, MVT ValVT,
2188                                        SDValue Val) const {
2189   if (Subtarget->hasFullFP16()) {
2190     Val = DAG.getNode(ARMISD::VMOVrh, dl,
2191                       MVT::getIntegerVT(LocVT.getSizeInBits()), Val);
2192   } else {
2193     Val = DAG.getNode(ISD::BITCAST, dl,
2194                       MVT::getIntegerVT(ValVT.getSizeInBits()), Val);
2195     Val = DAG.getNode(ISD::ZERO_EXTEND, dl,
2196                       MVT::getIntegerVT(LocVT.getSizeInBits()), Val);
2197   }
2198   return DAG.getNode(ISD::BITCAST, dl, LocVT, Val);
2199 }
2200 
2201 /// LowerCallResult - Lower the result values of a call into the
2202 /// appropriate copies out of appropriate physical registers.
LowerCallResult(SDValue Chain,SDValue InGlue,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,const SDLoc & dl,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals,bool isThisReturn,SDValue ThisVal,bool isCmseNSCall) const2203 SDValue ARMTargetLowering::LowerCallResult(
2204     SDValue Chain, SDValue InGlue, CallingConv::ID CallConv, bool isVarArg,
2205     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
2206     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
2207     SDValue ThisVal, bool isCmseNSCall) const {
2208   // Assign locations to each value returned by this call.
2209   SmallVector<CCValAssign, 16> RVLocs;
2210   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs,
2211                  *DAG.getContext());
2212   CCInfo.AnalyzeCallResult(Ins, CCAssignFnForReturn(CallConv, isVarArg));
2213 
2214   // Copy all of the result registers out of their specified physreg.
2215   for (unsigned i = 0; i != RVLocs.size(); ++i) {
2216     CCValAssign VA = RVLocs[i];
2217 
2218     // Pass 'this' value directly from the argument to return value, to avoid
2219     // reg unit interference
2220     if (i == 0 && isThisReturn) {
2221       assert(!VA.needsCustom() && VA.getLocVT() == MVT::i32 &&
2222              "unexpected return calling convention register assignment");
2223       InVals.push_back(ThisVal);
2224       continue;
2225     }
2226 
2227     SDValue Val;
2228     if (VA.needsCustom() &&
2229         (VA.getLocVT() == MVT::f64 || VA.getLocVT() == MVT::v2f64)) {
2230       // Handle f64 or half of a v2f64.
2231       SDValue Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
2232                                       InGlue);
2233       Chain = Lo.getValue(1);
2234       InGlue = Lo.getValue(2);
2235       VA = RVLocs[++i]; // skip ahead to next loc
2236       SDValue Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
2237                                       InGlue);
2238       Chain = Hi.getValue(1);
2239       InGlue = Hi.getValue(2);
2240       if (!Subtarget->isLittle())
2241         std::swap (Lo, Hi);
2242       Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
2243 
2244       if (VA.getLocVT() == MVT::v2f64) {
2245         SDValue Vec = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
2246         Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
2247                           DAG.getConstant(0, dl, MVT::i32));
2248 
2249         VA = RVLocs[++i]; // skip ahead to next loc
2250         Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InGlue);
2251         Chain = Lo.getValue(1);
2252         InGlue = Lo.getValue(2);
2253         VA = RVLocs[++i]; // skip ahead to next loc
2254         Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InGlue);
2255         Chain = Hi.getValue(1);
2256         InGlue = Hi.getValue(2);
2257         if (!Subtarget->isLittle())
2258           std::swap (Lo, Hi);
2259         Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
2260         Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
2261                           DAG.getConstant(1, dl, MVT::i32));
2262       }
2263     } else {
2264       Val = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), VA.getLocVT(),
2265                                InGlue);
2266       Chain = Val.getValue(1);
2267       InGlue = Val.getValue(2);
2268     }
2269 
2270     switch (VA.getLocInfo()) {
2271     default: llvm_unreachable("Unknown loc info!");
2272     case CCValAssign::Full: break;
2273     case CCValAssign::BCvt:
2274       Val = DAG.getNode(ISD::BITCAST, dl, VA.getValVT(), Val);
2275       break;
2276     }
2277 
2278     // f16 arguments have their size extended to 4 bytes and passed as if they
2279     // had been copied to the LSBs of a 32-bit register.
2280     // For that, it's passed extended to i32 (soft ABI) or to f32 (hard ABI)
2281     if (VA.needsCustom() &&
2282         (VA.getValVT() == MVT::f16 || VA.getValVT() == MVT::bf16))
2283       Val = MoveToHPR(dl, DAG, VA.getLocVT(), VA.getValVT(), Val);
2284 
2285     // On CMSE Non-secure Calls, call results (returned values) whose bitwidth
2286     // is less than 32 bits must be sign- or zero-extended after the call for
2287     // security reasons. Although the ABI mandates an extension done by the
2288     // callee, the latter cannot be trusted to follow the rules of the ABI.
2289     const ISD::InputArg &Arg = Ins[VA.getValNo()];
2290     if (isCmseNSCall && Arg.ArgVT.isScalarInteger() &&
2291         VA.getLocVT().isScalarInteger() && Arg.ArgVT.bitsLT(MVT::i32))
2292       Val = handleCMSEValue(Val, Arg, DAG, dl);
2293 
2294     InVals.push_back(Val);
2295   }
2296 
2297   return Chain;
2298 }
2299 
computeAddrForCallArg(const SDLoc & dl,SelectionDAG & DAG,const CCValAssign & VA,SDValue StackPtr,bool IsTailCall,int SPDiff) const2300 std::pair<SDValue, MachinePointerInfo> ARMTargetLowering::computeAddrForCallArg(
2301     const SDLoc &dl, SelectionDAG &DAG, const CCValAssign &VA, SDValue StackPtr,
2302     bool IsTailCall, int SPDiff) const {
2303   SDValue DstAddr;
2304   MachinePointerInfo DstInfo;
2305   int32_t Offset = VA.getLocMemOffset();
2306   MachineFunction &MF = DAG.getMachineFunction();
2307 
2308   if (IsTailCall) {
2309         Offset += SPDiff;
2310         auto PtrVT = getPointerTy(DAG.getDataLayout());
2311         int Size = VA.getLocVT().getFixedSizeInBits() / 8;
2312         int FI = MF.getFrameInfo().CreateFixedObject(Size, Offset, true);
2313         DstAddr = DAG.getFrameIndex(FI, PtrVT);
2314         DstInfo =
2315             MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
2316   } else {
2317         SDValue PtrOff = DAG.getIntPtrConstant(Offset, dl);
2318         DstAddr = DAG.getNode(ISD::ADD, dl, getPointerTy(DAG.getDataLayout()),
2319                               StackPtr, PtrOff);
2320         DstInfo =
2321             MachinePointerInfo::getStack(DAG.getMachineFunction(), Offset);
2322   }
2323 
2324   return std::make_pair(DstAddr, DstInfo);
2325 }
2326 
PassF64ArgInRegs(const SDLoc & dl,SelectionDAG & DAG,SDValue Chain,SDValue & Arg,RegsToPassVector & RegsToPass,CCValAssign & VA,CCValAssign & NextVA,SDValue & StackPtr,SmallVectorImpl<SDValue> & MemOpChains,bool IsTailCall,int SPDiff) const2327 void ARMTargetLowering::PassF64ArgInRegs(const SDLoc &dl, SelectionDAG &DAG,
2328                                          SDValue Chain, SDValue &Arg,
2329                                          RegsToPassVector &RegsToPass,
2330                                          CCValAssign &VA, CCValAssign &NextVA,
2331                                          SDValue &StackPtr,
2332                                          SmallVectorImpl<SDValue> &MemOpChains,
2333                                          bool IsTailCall,
2334                                          int SPDiff) const {
2335   SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
2336                               DAG.getVTList(MVT::i32, MVT::i32), Arg);
2337   unsigned id = Subtarget->isLittle() ? 0 : 1;
2338   RegsToPass.push_back(std::make_pair(VA.getLocReg(), fmrrd.getValue(id)));
2339 
2340   if (NextVA.isRegLoc())
2341     RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), fmrrd.getValue(1-id)));
2342   else {
2343     assert(NextVA.isMemLoc());
2344     if (!StackPtr.getNode())
2345       StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP,
2346                                     getPointerTy(DAG.getDataLayout()));
2347 
2348     SDValue DstAddr;
2349     MachinePointerInfo DstInfo;
2350     std::tie(DstAddr, DstInfo) =
2351         computeAddrForCallArg(dl, DAG, NextVA, StackPtr, IsTailCall, SPDiff);
2352     MemOpChains.push_back(
2353         DAG.getStore(Chain, dl, fmrrd.getValue(1 - id), DstAddr, DstInfo));
2354   }
2355 }
2356 
canGuaranteeTCO(CallingConv::ID CC,bool GuaranteeTailCalls)2357 static bool canGuaranteeTCO(CallingConv::ID CC, bool GuaranteeTailCalls) {
2358   return (CC == CallingConv::Fast && GuaranteeTailCalls) ||
2359          CC == CallingConv::Tail || CC == CallingConv::SwiftTail;
2360 }
2361 
2362 /// LowerCall - Lowering a call into a callseq_start <-
2363 /// ARMISD:CALL <- callseq_end chain. Also add input and output parameter
2364 /// nodes.
2365 SDValue
LowerCall(TargetLowering::CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const2366 ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
2367                              SmallVectorImpl<SDValue> &InVals) const {
2368   SelectionDAG &DAG                     = CLI.DAG;
2369   SDLoc &dl                             = CLI.DL;
2370   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
2371   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
2372   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
2373   SDValue Chain                         = CLI.Chain;
2374   SDValue Callee                        = CLI.Callee;
2375   bool &isTailCall                      = CLI.IsTailCall;
2376   CallingConv::ID CallConv              = CLI.CallConv;
2377   bool doesNotRet                       = CLI.DoesNotReturn;
2378   bool isVarArg                         = CLI.IsVarArg;
2379 
2380   MachineFunction &MF = DAG.getMachineFunction();
2381   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
2382   MachineFunction::CallSiteInfo CSInfo;
2383   bool isStructRet = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
2384   bool isThisReturn = false;
2385   bool isCmseNSCall   = false;
2386   bool isSibCall = false;
2387   bool PreferIndirect = false;
2388   bool GuardWithBTI = false;
2389 
2390   // Analyze operands of the call, assigning locations to each operand.
2391   SmallVector<CCValAssign, 16> ArgLocs;
2392   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs,
2393                  *DAG.getContext());
2394   CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForCall(CallConv, isVarArg));
2395 
2396   // Lower 'returns_twice' calls to a pseudo-instruction.
2397   if (CLI.CB && CLI.CB->getAttributes().hasFnAttr(Attribute::ReturnsTwice) &&
2398       !Subtarget->noBTIAtReturnTwice())
2399     GuardWithBTI = AFI->branchTargetEnforcement();
2400 
2401   // Determine whether this is a non-secure function call.
2402   if (CLI.CB && CLI.CB->getAttributes().hasFnAttr("cmse_nonsecure_call"))
2403     isCmseNSCall = true;
2404 
2405   // Disable tail calls if they're not supported.
2406   if (!Subtarget->supportsTailCall())
2407     isTailCall = false;
2408 
2409   // For both the non-secure calls and the returns from a CMSE entry function,
2410   // the function needs to do some extra work afte r the call, or before the
2411   // return, respectively, thus it cannot end with atail call
2412   if (isCmseNSCall || AFI->isCmseNSEntryFunction())
2413     isTailCall = false;
2414 
2415   if (isa<GlobalAddressSDNode>(Callee)) {
2416     // If we're optimizing for minimum size and the function is called three or
2417     // more times in this block, we can improve codesize by calling indirectly
2418     // as BLXr has a 16-bit encoding.
2419     auto *GV = cast<GlobalAddressSDNode>(Callee)->getGlobal();
2420     if (CLI.CB) {
2421       auto *BB = CLI.CB->getParent();
2422       PreferIndirect = Subtarget->isThumb() && Subtarget->hasMinSize() &&
2423                        count_if(GV->users(), [&BB](const User *U) {
2424                          return isa<Instruction>(U) &&
2425                                 cast<Instruction>(U)->getParent() == BB;
2426                        }) > 2;
2427     }
2428   }
2429   if (isTailCall) {
2430     // Check if it's really possible to do a tail call.
2431     isTailCall =
2432         IsEligibleForTailCallOptimization(CLI, CCInfo, ArgLocs, PreferIndirect);
2433 
2434     if (isTailCall && !getTargetMachine().Options.GuaranteedTailCallOpt &&
2435         CallConv != CallingConv::Tail && CallConv != CallingConv::SwiftTail)
2436       isSibCall = true;
2437 
2438     // We don't support GuaranteedTailCallOpt for ARM, only automatically
2439     // detected sibcalls.
2440     if (isTailCall)
2441       ++NumTailCalls;
2442   }
2443 
2444   if (!isTailCall && CLI.CB && CLI.CB->isMustTailCall())
2445     report_fatal_error("failed to perform tail call elimination on a call "
2446                        "site marked musttail");
2447 
2448   // Get a count of how many bytes are to be pushed on the stack.
2449   unsigned NumBytes = CCInfo.getStackSize();
2450 
2451   // SPDiff is the byte offset of the call's argument area from the callee's.
2452   // Stores to callee stack arguments will be placed in FixedStackSlots offset
2453   // by this amount for a tail call. In a sibling call it must be 0 because the
2454   // caller will deallocate the entire stack and the callee still expects its
2455   // arguments to begin at SP+0. Completely unused for non-tail calls.
2456   int SPDiff = 0;
2457 
2458   if (isTailCall && !isSibCall) {
2459     auto FuncInfo = MF.getInfo<ARMFunctionInfo>();
2460     unsigned NumReusableBytes = FuncInfo->getArgumentStackSize();
2461 
2462     // Since callee will pop argument stack as a tail call, we must keep the
2463     // popped size 16-byte aligned.
2464     Align StackAlign = DAG.getDataLayout().getStackAlignment();
2465     NumBytes = alignTo(NumBytes, StackAlign);
2466 
2467     // SPDiff will be negative if this tail call requires more space than we
2468     // would automatically have in our incoming argument space. Positive if we
2469     // can actually shrink the stack.
2470     SPDiff = NumReusableBytes - NumBytes;
2471 
2472     // If this call requires more stack than we have available from
2473     // LowerFormalArguments, tell FrameLowering to reserve space for it.
2474     if (SPDiff < 0 && AFI->getArgRegsSaveSize() < (unsigned)-SPDiff)
2475       AFI->setArgRegsSaveSize(-SPDiff);
2476   }
2477 
2478   if (isSibCall) {
2479     // For sibling tail calls, memory operands are available in our caller's stack.
2480     NumBytes = 0;
2481   } else {
2482     // Adjust the stack pointer for the new arguments...
2483     // These operations are automatically eliminated by the prolog/epilog pass
2484     Chain = DAG.getCALLSEQ_START(Chain, isTailCall ? 0 : NumBytes, 0, dl);
2485   }
2486 
2487   SDValue StackPtr =
2488       DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy(DAG.getDataLayout()));
2489 
2490   RegsToPassVector RegsToPass;
2491   SmallVector<SDValue, 8> MemOpChains;
2492 
2493   // During a tail call, stores to the argument area must happen after all of
2494   // the function's incoming arguments have been loaded because they may alias.
2495   // This is done by folding in a TokenFactor from LowerFormalArguments, but
2496   // there's no point in doing so repeatedly so this tracks whether that's
2497   // happened yet.
2498   bool AfterFormalArgLoads = false;
2499 
2500   // Walk the register/memloc assignments, inserting copies/loads.  In the case
2501   // of tail call optimization, arguments are handled later.
2502   for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
2503        i != e;
2504        ++i, ++realArgIdx) {
2505     CCValAssign &VA = ArgLocs[i];
2506     SDValue Arg = OutVals[realArgIdx];
2507     ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
2508     bool isByVal = Flags.isByVal();
2509 
2510     // Promote the value if needed.
2511     switch (VA.getLocInfo()) {
2512     default: llvm_unreachable("Unknown loc info!");
2513     case CCValAssign::Full: break;
2514     case CCValAssign::SExt:
2515       Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
2516       break;
2517     case CCValAssign::ZExt:
2518       Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
2519       break;
2520     case CCValAssign::AExt:
2521       Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
2522       break;
2523     case CCValAssign::BCvt:
2524       Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
2525       break;
2526     }
2527 
2528     if (isTailCall && VA.isMemLoc() && !AfterFormalArgLoads) {
2529       Chain = DAG.getStackArgumentTokenFactor(Chain);
2530       AfterFormalArgLoads = true;
2531     }
2532 
2533     // f16 arguments have their size extended to 4 bytes and passed as if they
2534     // had been copied to the LSBs of a 32-bit register.
2535     // For that, it's passed extended to i32 (soft ABI) or to f32 (hard ABI)
2536     if (VA.needsCustom() &&
2537         (VA.getValVT() == MVT::f16 || VA.getValVT() == MVT::bf16)) {
2538       Arg = MoveFromHPR(dl, DAG, VA.getLocVT(), VA.getValVT(), Arg);
2539     } else {
2540       // f16 arguments could have been extended prior to argument lowering.
2541       // Mask them arguments if this is a CMSE nonsecure call.
2542       auto ArgVT = Outs[realArgIdx].ArgVT;
2543       if (isCmseNSCall && (ArgVT == MVT::f16)) {
2544         auto LocBits = VA.getLocVT().getSizeInBits();
2545         auto MaskValue = APInt::getLowBitsSet(LocBits, ArgVT.getSizeInBits());
2546         SDValue Mask =
2547             DAG.getConstant(MaskValue, dl, MVT::getIntegerVT(LocBits));
2548         Arg = DAG.getNode(ISD::BITCAST, dl, MVT::getIntegerVT(LocBits), Arg);
2549         Arg = DAG.getNode(ISD::AND, dl, MVT::getIntegerVT(LocBits), Arg, Mask);
2550         Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
2551       }
2552     }
2553 
2554     // f64 and v2f64 might be passed in i32 pairs and must be split into pieces
2555     if (VA.needsCustom() && VA.getLocVT() == MVT::v2f64) {
2556       SDValue Op0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
2557                                 DAG.getConstant(0, dl, MVT::i32));
2558       SDValue Op1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
2559                                 DAG.getConstant(1, dl, MVT::i32));
2560 
2561       PassF64ArgInRegs(dl, DAG, Chain, Op0, RegsToPass, VA, ArgLocs[++i],
2562                        StackPtr, MemOpChains, isTailCall, SPDiff);
2563 
2564       VA = ArgLocs[++i]; // skip ahead to next loc
2565       if (VA.isRegLoc()) {
2566         PassF64ArgInRegs(dl, DAG, Chain, Op1, RegsToPass, VA, ArgLocs[++i],
2567                          StackPtr, MemOpChains, isTailCall, SPDiff);
2568       } else {
2569         assert(VA.isMemLoc());
2570         SDValue DstAddr;
2571         MachinePointerInfo DstInfo;
2572         std::tie(DstAddr, DstInfo) =
2573             computeAddrForCallArg(dl, DAG, VA, StackPtr, isTailCall, SPDiff);
2574         MemOpChains.push_back(DAG.getStore(Chain, dl, Op1, DstAddr, DstInfo));
2575       }
2576     } else if (VA.needsCustom() && VA.getLocVT() == MVT::f64) {
2577       PassF64ArgInRegs(dl, DAG, Chain, Arg, RegsToPass, VA, ArgLocs[++i],
2578                        StackPtr, MemOpChains, isTailCall, SPDiff);
2579     } else if (VA.isRegLoc()) {
2580       if (realArgIdx == 0 && Flags.isReturned() && !Flags.isSwiftSelf() &&
2581           Outs[0].VT == MVT::i32) {
2582         assert(VA.getLocVT() == MVT::i32 &&
2583                "unexpected calling convention register assignment");
2584         assert(!Ins.empty() && Ins[0].VT == MVT::i32 &&
2585                "unexpected use of 'returned'");
2586         isThisReturn = true;
2587       }
2588       const TargetOptions &Options = DAG.getTarget().Options;
2589       if (Options.EmitCallSiteInfo)
2590         CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
2591       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
2592     } else if (isByVal) {
2593       assert(VA.isMemLoc());
2594       unsigned offset = 0;
2595 
2596       // True if this byval aggregate will be split between registers
2597       // and memory.
2598       unsigned ByValArgsCount = CCInfo.getInRegsParamsCount();
2599       unsigned CurByValIdx = CCInfo.getInRegsParamsProcessed();
2600 
2601       if (CurByValIdx < ByValArgsCount) {
2602 
2603         unsigned RegBegin, RegEnd;
2604         CCInfo.getInRegsParamInfo(CurByValIdx, RegBegin, RegEnd);
2605 
2606         EVT PtrVT =
2607             DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
2608         unsigned int i, j;
2609         for (i = 0, j = RegBegin; j < RegEnd; i++, j++) {
2610           SDValue Const = DAG.getConstant(4*i, dl, MVT::i32);
2611           SDValue AddArg = DAG.getNode(ISD::ADD, dl, PtrVT, Arg, Const);
2612           SDValue Load =
2613               DAG.getLoad(PtrVT, dl, Chain, AddArg, MachinePointerInfo(),
2614                           DAG.InferPtrAlign(AddArg));
2615           MemOpChains.push_back(Load.getValue(1));
2616           RegsToPass.push_back(std::make_pair(j, Load));
2617         }
2618 
2619         // If parameter size outsides register area, "offset" value
2620         // helps us to calculate stack slot for remained part properly.
2621         offset = RegEnd - RegBegin;
2622 
2623         CCInfo.nextInRegsParam();
2624       }
2625 
2626       if (Flags.getByValSize() > 4*offset) {
2627         auto PtrVT = getPointerTy(DAG.getDataLayout());
2628         SDValue Dst;
2629         MachinePointerInfo DstInfo;
2630         std::tie(Dst, DstInfo) =
2631             computeAddrForCallArg(dl, DAG, VA, StackPtr, isTailCall, SPDiff);
2632         SDValue SrcOffset = DAG.getIntPtrConstant(4*offset, dl);
2633         SDValue Src = DAG.getNode(ISD::ADD, dl, PtrVT, Arg, SrcOffset);
2634         SDValue SizeNode = DAG.getConstant(Flags.getByValSize() - 4*offset, dl,
2635                                            MVT::i32);
2636         SDValue AlignNode =
2637             DAG.getConstant(Flags.getNonZeroByValAlign().value(), dl, MVT::i32);
2638 
2639         SDVTList VTs = DAG.getVTList(MVT::Other, MVT::Glue);
2640         SDValue Ops[] = { Chain, Dst, Src, SizeNode, AlignNode};
2641         MemOpChains.push_back(DAG.getNode(ARMISD::COPY_STRUCT_BYVAL, dl, VTs,
2642                                           Ops));
2643       }
2644     } else {
2645       assert(VA.isMemLoc());
2646       SDValue DstAddr;
2647       MachinePointerInfo DstInfo;
2648       std::tie(DstAddr, DstInfo) =
2649           computeAddrForCallArg(dl, DAG, VA, StackPtr, isTailCall, SPDiff);
2650 
2651       SDValue Store = DAG.getStore(Chain, dl, Arg, DstAddr, DstInfo);
2652       MemOpChains.push_back(Store);
2653     }
2654   }
2655 
2656   if (!MemOpChains.empty())
2657     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains);
2658 
2659   // Build a sequence of copy-to-reg nodes chained together with token chain
2660   // and flag operands which copy the outgoing args into the appropriate regs.
2661   SDValue InGlue;
2662   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2663     Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
2664                              RegsToPass[i].second, InGlue);
2665     InGlue = Chain.getValue(1);
2666   }
2667 
2668   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
2669   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
2670   // node so that legalize doesn't hack it.
2671   bool isDirect = false;
2672 
2673   const TargetMachine &TM = getTargetMachine();
2674   const GlobalValue *GVal = nullptr;
2675   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
2676     GVal = G->getGlobal();
2677   bool isStub = !TM.shouldAssumeDSOLocal(GVal) && Subtarget->isTargetMachO();
2678 
2679   bool isARMFunc = !Subtarget->isThumb() || (isStub && !Subtarget->isMClass());
2680   bool isLocalARMFunc = false;
2681   auto PtrVt = getPointerTy(DAG.getDataLayout());
2682 
2683   if (Subtarget->genLongCalls()) {
2684     assert((!isPositionIndependent() || Subtarget->isTargetWindows()) &&
2685            "long-calls codegen is not position independent!");
2686     // Handle a global address or an external symbol. If it's not one of
2687     // those, the target's already in a register, so we don't need to do
2688     // anything extra.
2689     if (isa<GlobalAddressSDNode>(Callee)) {
2690       if (Subtarget->genExecuteOnly()) {
2691         if (Subtarget->useMovt())
2692           ++NumMovwMovt;
2693         Callee = DAG.getNode(ARMISD::Wrapper, dl, PtrVt,
2694                              DAG.getTargetGlobalAddress(GVal, dl, PtrVt));
2695       } else {
2696         // Create a constant pool entry for the callee address
2697         unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
2698         ARMConstantPoolValue *CPV = ARMConstantPoolConstant::Create(
2699             GVal, ARMPCLabelIndex, ARMCP::CPValue, 0);
2700 
2701         // Get the address of the callee into a register
2702         SDValue Addr = DAG.getTargetConstantPool(CPV, PtrVt, Align(4));
2703         Addr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Addr);
2704         Callee = DAG.getLoad(
2705             PtrVt, dl, DAG.getEntryNode(), Addr,
2706             MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
2707       }
2708     } else if (ExternalSymbolSDNode *S=dyn_cast<ExternalSymbolSDNode>(Callee)) {
2709       const char *Sym = S->getSymbol();
2710 
2711       if (Subtarget->genExecuteOnly()) {
2712         if (Subtarget->useMovt())
2713           ++NumMovwMovt;
2714         Callee = DAG.getNode(ARMISD::Wrapper, dl, PtrVt,
2715                              DAG.getTargetGlobalAddress(GVal, dl, PtrVt));
2716       } else {
2717         // Create a constant pool entry for the callee address
2718         unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
2719         ARMConstantPoolValue *CPV = ARMConstantPoolSymbol::Create(
2720             *DAG.getContext(), Sym, ARMPCLabelIndex, 0);
2721 
2722         // Get the address of the callee into a register
2723         SDValue Addr = DAG.getTargetConstantPool(CPV, PtrVt, Align(4));
2724         Addr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Addr);
2725         Callee = DAG.getLoad(
2726             PtrVt, dl, DAG.getEntryNode(), Addr,
2727             MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
2728       }
2729     }
2730   } else if (isa<GlobalAddressSDNode>(Callee)) {
2731     if (!PreferIndirect) {
2732       isDirect = true;
2733       bool isDef = GVal->isStrongDefinitionForLinker();
2734 
2735       // ARM call to a local ARM function is predicable.
2736       isLocalARMFunc = !Subtarget->isThumb() && (isDef || !ARMInterworking);
2737       // tBX takes a register source operand.
2738       if (isStub && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
2739         assert(Subtarget->isTargetMachO() && "WrapperPIC use on non-MachO?");
2740         Callee = DAG.getNode(
2741             ARMISD::WrapperPIC, dl, PtrVt,
2742             DAG.getTargetGlobalAddress(GVal, dl, PtrVt, 0, ARMII::MO_NONLAZY));
2743         Callee = DAG.getLoad(
2744             PtrVt, dl, DAG.getEntryNode(), Callee,
2745             MachinePointerInfo::getGOT(DAG.getMachineFunction()), MaybeAlign(),
2746             MachineMemOperand::MODereferenceable |
2747                 MachineMemOperand::MOInvariant);
2748       } else if (Subtarget->isTargetCOFF()) {
2749         assert(Subtarget->isTargetWindows() &&
2750                "Windows is the only supported COFF target");
2751         unsigned TargetFlags = ARMII::MO_NO_FLAG;
2752         if (GVal->hasDLLImportStorageClass())
2753           TargetFlags = ARMII::MO_DLLIMPORT;
2754         else if (!TM.shouldAssumeDSOLocal(GVal))
2755           TargetFlags = ARMII::MO_COFFSTUB;
2756         Callee = DAG.getTargetGlobalAddress(GVal, dl, PtrVt, /*offset=*/0,
2757                                             TargetFlags);
2758         if (TargetFlags & (ARMII::MO_DLLIMPORT | ARMII::MO_COFFSTUB))
2759           Callee =
2760               DAG.getLoad(PtrVt, dl, DAG.getEntryNode(),
2761                           DAG.getNode(ARMISD::Wrapper, dl, PtrVt, Callee),
2762                           MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2763       } else {
2764         Callee = DAG.getTargetGlobalAddress(GVal, dl, PtrVt, 0, 0);
2765       }
2766     }
2767   } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
2768     isDirect = true;
2769     // tBX takes a register source operand.
2770     const char *Sym = S->getSymbol();
2771     if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
2772       unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
2773       ARMConstantPoolValue *CPV =
2774         ARMConstantPoolSymbol::Create(*DAG.getContext(), Sym,
2775                                       ARMPCLabelIndex, 4);
2776       SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVt, Align(4));
2777       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
2778       Callee = DAG.getLoad(
2779           PtrVt, dl, DAG.getEntryNode(), CPAddr,
2780           MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
2781       SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, dl, MVT::i32);
2782       Callee = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVt, Callee, PICLabel);
2783     } else {
2784       Callee = DAG.getTargetExternalSymbol(Sym, PtrVt, 0);
2785     }
2786   }
2787 
2788   if (isCmseNSCall) {
2789     assert(!isARMFunc && !isDirect &&
2790            "Cannot handle call to ARM function or direct call");
2791     if (NumBytes > 0) {
2792       DiagnosticInfoUnsupported Diag(DAG.getMachineFunction().getFunction(),
2793                                      "call to non-secure function would "
2794                                      "require passing arguments on stack",
2795                                      dl.getDebugLoc());
2796       DAG.getContext()->diagnose(Diag);
2797     }
2798     if (isStructRet) {
2799       DiagnosticInfoUnsupported Diag(
2800           DAG.getMachineFunction().getFunction(),
2801           "call to non-secure function would return value through pointer",
2802           dl.getDebugLoc());
2803       DAG.getContext()->diagnose(Diag);
2804     }
2805   }
2806 
2807   // FIXME: handle tail calls differently.
2808   unsigned CallOpc;
2809   if (Subtarget->isThumb()) {
2810     if (GuardWithBTI)
2811       CallOpc = ARMISD::t2CALL_BTI;
2812     else if (isCmseNSCall)
2813       CallOpc = ARMISD::tSECALL;
2814     else if ((!isDirect || isARMFunc) && !Subtarget->hasV5TOps())
2815       CallOpc = ARMISD::CALL_NOLINK;
2816     else
2817       CallOpc = ARMISD::CALL;
2818   } else {
2819     if (!isDirect && !Subtarget->hasV5TOps())
2820       CallOpc = ARMISD::CALL_NOLINK;
2821     else if (doesNotRet && isDirect && Subtarget->hasRetAddrStack() &&
2822              // Emit regular call when code size is the priority
2823              !Subtarget->hasMinSize())
2824       // "mov lr, pc; b _foo" to avoid confusing the RSP
2825       CallOpc = ARMISD::CALL_NOLINK;
2826     else
2827       CallOpc = isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL;
2828   }
2829 
2830   // We don't usually want to end the call-sequence here because we would tidy
2831   // the frame up *after* the call, however in the ABI-changing tail-call case
2832   // we've carefully laid out the parameters so that when sp is reset they'll be
2833   // in the correct location.
2834   if (isTailCall && !isSibCall) {
2835     Chain = DAG.getCALLSEQ_END(Chain, 0, 0, InGlue, dl);
2836     InGlue = Chain.getValue(1);
2837   }
2838 
2839   std::vector<SDValue> Ops;
2840   Ops.push_back(Chain);
2841   Ops.push_back(Callee);
2842 
2843   if (isTailCall) {
2844     Ops.push_back(DAG.getTargetConstant(SPDiff, dl, MVT::i32));
2845   }
2846 
2847   // Add argument registers to the end of the list so that they are known live
2848   // into the call.
2849   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2850     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
2851                                   RegsToPass[i].second.getValueType()));
2852 
2853   // Add a register mask operand representing the call-preserved registers.
2854   const uint32_t *Mask;
2855   const ARMBaseRegisterInfo *ARI = Subtarget->getRegisterInfo();
2856   if (isThisReturn) {
2857     // For 'this' returns, use the R0-preserving mask if applicable
2858     Mask = ARI->getThisReturnPreservedMask(MF, CallConv);
2859     if (!Mask) {
2860       // Set isThisReturn to false if the calling convention is not one that
2861       // allows 'returned' to be modeled in this way, so LowerCallResult does
2862       // not try to pass 'this' straight through
2863       isThisReturn = false;
2864       Mask = ARI->getCallPreservedMask(MF, CallConv);
2865     }
2866   } else
2867     Mask = ARI->getCallPreservedMask(MF, CallConv);
2868 
2869   assert(Mask && "Missing call preserved mask for calling convention");
2870   Ops.push_back(DAG.getRegisterMask(Mask));
2871 
2872   if (InGlue.getNode())
2873     Ops.push_back(InGlue);
2874 
2875   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2876   if (isTailCall) {
2877     MF.getFrameInfo().setHasTailCall();
2878     SDValue Ret = DAG.getNode(ARMISD::TC_RETURN, dl, NodeTys, Ops);
2879     DAG.addNoMergeSiteInfo(Ret.getNode(), CLI.NoMerge);
2880     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
2881     return Ret;
2882   }
2883 
2884   // Returns a chain and a flag for retval copy to use.
2885   Chain = DAG.getNode(CallOpc, dl, NodeTys, Ops);
2886   DAG.addNoMergeSiteInfo(Chain.getNode(), CLI.NoMerge);
2887   InGlue = Chain.getValue(1);
2888   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
2889 
2890   // If we're guaranteeing tail-calls will be honoured, the callee must
2891   // pop its own argument stack on return. But this call is *not* a tail call so
2892   // we need to undo that after it returns to restore the status-quo.
2893   bool TailCallOpt = getTargetMachine().Options.GuaranteedTailCallOpt;
2894   uint64_t CalleePopBytes =
2895       canGuaranteeTCO(CallConv, TailCallOpt) ? alignTo(NumBytes, 16) : -1ULL;
2896 
2897   Chain = DAG.getCALLSEQ_END(Chain, NumBytes, CalleePopBytes, InGlue, dl);
2898   if (!Ins.empty())
2899     InGlue = Chain.getValue(1);
2900 
2901   // Handle result values, copying them out of physregs into vregs that we
2902   // return.
2903   return LowerCallResult(Chain, InGlue, CallConv, isVarArg, Ins, dl, DAG,
2904                          InVals, isThisReturn,
2905                          isThisReturn ? OutVals[0] : SDValue(), isCmseNSCall);
2906 }
2907 
2908 /// HandleByVal - Every parameter *after* a byval parameter is passed
2909 /// on the stack.  Remember the next parameter register to allocate,
2910 /// and then confiscate the rest of the parameter registers to insure
2911 /// this.
HandleByVal(CCState * State,unsigned & Size,Align Alignment) const2912 void ARMTargetLowering::HandleByVal(CCState *State, unsigned &Size,
2913                                     Align Alignment) const {
2914   // Byval (as with any stack) slots are always at least 4 byte aligned.
2915   Alignment = std::max(Alignment, Align(4));
2916 
2917   unsigned Reg = State->AllocateReg(GPRArgRegs);
2918   if (!Reg)
2919     return;
2920 
2921   unsigned AlignInRegs = Alignment.value() / 4;
2922   unsigned Waste = (ARM::R4 - Reg) % AlignInRegs;
2923   for (unsigned i = 0; i < Waste; ++i)
2924     Reg = State->AllocateReg(GPRArgRegs);
2925 
2926   if (!Reg)
2927     return;
2928 
2929   unsigned Excess = 4 * (ARM::R4 - Reg);
2930 
2931   // Special case when NSAA != SP and parameter size greater than size of
2932   // all remained GPR regs. In that case we can't split parameter, we must
2933   // send it to stack. We also must set NCRN to R4, so waste all
2934   // remained registers.
2935   const unsigned NSAAOffset = State->getStackSize();
2936   if (NSAAOffset != 0 && Size > Excess) {
2937     while (State->AllocateReg(GPRArgRegs))
2938       ;
2939     return;
2940   }
2941 
2942   // First register for byval parameter is the first register that wasn't
2943   // allocated before this method call, so it would be "reg".
2944   // If parameter is small enough to be saved in range [reg, r4), then
2945   // the end (first after last) register would be reg + param-size-in-regs,
2946   // else parameter would be splitted between registers and stack,
2947   // end register would be r4 in this case.
2948   unsigned ByValRegBegin = Reg;
2949   unsigned ByValRegEnd = std::min<unsigned>(Reg + Size / 4, ARM::R4);
2950   State->addInRegsParamInfo(ByValRegBegin, ByValRegEnd);
2951   // Note, first register is allocated in the beginning of function already,
2952   // allocate remained amount of registers we need.
2953   for (unsigned i = Reg + 1; i != ByValRegEnd; ++i)
2954     State->AllocateReg(GPRArgRegs);
2955   // A byval parameter that is split between registers and memory needs its
2956   // size truncated here.
2957   // In the case where the entire structure fits in registers, we set the
2958   // size in memory to zero.
2959   Size = std::max<int>(Size - Excess, 0);
2960 }
2961 
2962 /// MatchingStackOffset - Return true if the given stack call argument is
2963 /// already available in the same position (relatively) of the caller's
2964 /// incoming argument stack.
2965 static
MatchingStackOffset(SDValue Arg,unsigned Offset,ISD::ArgFlagsTy Flags,MachineFrameInfo & MFI,const MachineRegisterInfo * MRI,const TargetInstrInfo * TII)2966 bool MatchingStackOffset(SDValue Arg, unsigned Offset, ISD::ArgFlagsTy Flags,
2967                          MachineFrameInfo &MFI, const MachineRegisterInfo *MRI,
2968                          const TargetInstrInfo *TII) {
2969   unsigned Bytes = Arg.getValueSizeInBits() / 8;
2970   int FI = std::numeric_limits<int>::max();
2971   if (Arg.getOpcode() == ISD::CopyFromReg) {
2972     Register VR = cast<RegisterSDNode>(Arg.getOperand(1))->getReg();
2973     if (!VR.isVirtual())
2974       return false;
2975     MachineInstr *Def = MRI->getVRegDef(VR);
2976     if (!Def)
2977       return false;
2978     if (!Flags.isByVal()) {
2979       if (!TII->isLoadFromStackSlot(*Def, FI))
2980         return false;
2981     } else {
2982       return false;
2983     }
2984   } else if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Arg)) {
2985     if (Flags.isByVal())
2986       // ByVal argument is passed in as a pointer but it's now being
2987       // dereferenced. e.g.
2988       // define @foo(%struct.X* %A) {
2989       //   tail call @bar(%struct.X* byval %A)
2990       // }
2991       return false;
2992     SDValue Ptr = Ld->getBasePtr();
2993     FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr);
2994     if (!FINode)
2995       return false;
2996     FI = FINode->getIndex();
2997   } else
2998     return false;
2999 
3000   assert(FI != std::numeric_limits<int>::max());
3001   if (!MFI.isFixedObjectIndex(FI))
3002     return false;
3003   return Offset == MFI.getObjectOffset(FI) && Bytes == MFI.getObjectSize(FI);
3004 }
3005 
3006 /// IsEligibleForTailCallOptimization - Check whether the call is eligible
3007 /// for tail call optimization. Targets which want to do tail call
3008 /// optimization should implement this function. Note that this function also
3009 /// processes musttail calls, so when this function returns false on a valid
3010 /// musttail call, a fatal backend error occurs.
IsEligibleForTailCallOptimization(TargetLowering::CallLoweringInfo & CLI,CCState & CCInfo,SmallVectorImpl<CCValAssign> & ArgLocs,const bool isIndirect) const3011 bool ARMTargetLowering::IsEligibleForTailCallOptimization(
3012     TargetLowering::CallLoweringInfo &CLI, CCState &CCInfo,
3013     SmallVectorImpl<CCValAssign> &ArgLocs, const bool isIndirect) const {
3014   CallingConv::ID CalleeCC = CLI.CallConv;
3015   SDValue Callee = CLI.Callee;
3016   bool isVarArg = CLI.IsVarArg;
3017   const SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3018   const SmallVectorImpl<SDValue> &OutVals = CLI.OutVals;
3019   const SmallVectorImpl<ISD::InputArg> &Ins = CLI.Ins;
3020   const SelectionDAG &DAG = CLI.DAG;
3021   MachineFunction &MF = DAG.getMachineFunction();
3022   const Function &CallerF = MF.getFunction();
3023   CallingConv::ID CallerCC = CallerF.getCallingConv();
3024 
3025   assert(Subtarget->supportsTailCall());
3026 
3027   // Indirect tail calls cannot be optimized for Thumb1 if the args
3028   // to the call take up r0-r3. The reason is that there are no legal registers
3029   // left to hold the pointer to the function to be called.
3030   // Similarly, if the function uses return address sign and authentication,
3031   // r12 is needed to hold the PAC and is not available to hold the callee
3032   // address.
3033   if (Outs.size() >= 4 &&
3034       (!isa<GlobalAddressSDNode>(Callee.getNode()) || isIndirect)) {
3035     if (Subtarget->isThumb1Only())
3036       return false;
3037     // Conservatively assume the function spills LR.
3038     if (MF.getInfo<ARMFunctionInfo>()->shouldSignReturnAddress(true))
3039       return false;
3040   }
3041 
3042   // Look for obvious safe cases to perform tail call optimization that do not
3043   // require ABI changes. This is what gcc calls sibcall.
3044 
3045   // Exception-handling functions need a special set of instructions to indicate
3046   // a return to the hardware. Tail-calling another function would probably
3047   // break this.
3048   if (CallerF.hasFnAttribute("interrupt"))
3049     return false;
3050 
3051   if (canGuaranteeTCO(CalleeCC, getTargetMachine().Options.GuaranteedTailCallOpt))
3052     return CalleeCC == CallerCC;
3053 
3054   // Also avoid sibcall optimization if either caller or callee uses struct
3055   // return semantics.
3056   bool isCalleeStructRet = Outs.empty() ? false : Outs[0].Flags.isSRet();
3057   bool isCallerStructRet = MF.getFunction().hasStructRetAttr();
3058   if (isCalleeStructRet || isCallerStructRet)
3059     return false;
3060 
3061   // Externally-defined functions with weak linkage should not be
3062   // tail-called on ARM when the OS does not support dynamic
3063   // pre-emption of symbols, as the AAELF spec requires normal calls
3064   // to undefined weak functions to be replaced with a NOP or jump to the
3065   // next instruction. The behaviour of branch instructions in this
3066   // situation (as used for tail calls) is implementation-defined, so we
3067   // cannot rely on the linker replacing the tail call with a return.
3068   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3069     const GlobalValue *GV = G->getGlobal();
3070     const Triple &TT = getTargetMachine().getTargetTriple();
3071     if (GV->hasExternalWeakLinkage() &&
3072         (!TT.isOSWindows() || TT.isOSBinFormatELF() || TT.isOSBinFormatMachO()))
3073       return false;
3074   }
3075 
3076   // Check that the call results are passed in the same way.
3077   LLVMContext &C = *DAG.getContext();
3078   if (!CCState::resultsCompatible(
3079           getEffectiveCallingConv(CalleeCC, isVarArg),
3080           getEffectiveCallingConv(CallerCC, CallerF.isVarArg()), MF, C, Ins,
3081           CCAssignFnForReturn(CalleeCC, isVarArg),
3082           CCAssignFnForReturn(CallerCC, CallerF.isVarArg())))
3083     return false;
3084   // The callee has to preserve all registers the caller needs to preserve.
3085   const ARMBaseRegisterInfo *TRI = Subtarget->getRegisterInfo();
3086   const uint32_t *CallerPreserved = TRI->getCallPreservedMask(MF, CallerCC);
3087   if (CalleeCC != CallerCC) {
3088     const uint32_t *CalleePreserved = TRI->getCallPreservedMask(MF, CalleeCC);
3089     if (!TRI->regmaskSubsetEqual(CallerPreserved, CalleePreserved))
3090       return false;
3091   }
3092 
3093   // If Caller's vararg or byval argument has been split between registers and
3094   // stack, do not perform tail call, since part of the argument is in caller's
3095   // local frame.
3096   const ARMFunctionInfo *AFI_Caller = MF.getInfo<ARMFunctionInfo>();
3097   if (AFI_Caller->getArgRegsSaveSize())
3098     return false;
3099 
3100   // If the callee takes no arguments then go on to check the results of the
3101   // call.
3102   if (!Outs.empty()) {
3103     if (CCInfo.getStackSize()) {
3104       // Check if the arguments are already laid out in the right way as
3105       // the caller's fixed stack objects.
3106       MachineFrameInfo &MFI = MF.getFrameInfo();
3107       const MachineRegisterInfo *MRI = &MF.getRegInfo();
3108       const TargetInstrInfo *TII = Subtarget->getInstrInfo();
3109       for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
3110            i != e;
3111            ++i, ++realArgIdx) {
3112         CCValAssign &VA = ArgLocs[i];
3113         EVT RegVT = VA.getLocVT();
3114         SDValue Arg = OutVals[realArgIdx];
3115         ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
3116         if (VA.getLocInfo() == CCValAssign::Indirect)
3117           return false;
3118         if (VA.needsCustom() && (RegVT == MVT::f64 || RegVT == MVT::v2f64)) {
3119           // f64 and vector types are split into multiple registers or
3120           // register/stack-slot combinations.  The types will not match
3121           // the registers; give up on memory f64 refs until we figure
3122           // out what to do about this.
3123           if (!VA.isRegLoc())
3124             return false;
3125           if (!ArgLocs[++i].isRegLoc())
3126             return false;
3127           if (RegVT == MVT::v2f64) {
3128             if (!ArgLocs[++i].isRegLoc())
3129               return false;
3130             if (!ArgLocs[++i].isRegLoc())
3131               return false;
3132           }
3133         } else if (!VA.isRegLoc()) {
3134           if (!MatchingStackOffset(Arg, VA.getLocMemOffset(), Flags,
3135                                    MFI, MRI, TII))
3136             return false;
3137         }
3138       }
3139     }
3140 
3141     const MachineRegisterInfo &MRI = MF.getRegInfo();
3142     if (!parametersInCSRMatch(MRI, CallerPreserved, ArgLocs, OutVals))
3143       return false;
3144   }
3145 
3146   return true;
3147 }
3148 
3149 bool
CanLowerReturn(CallingConv::ID CallConv,MachineFunction & MF,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,LLVMContext & Context) const3150 ARMTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3151                                   MachineFunction &MF, bool isVarArg,
3152                                   const SmallVectorImpl<ISD::OutputArg> &Outs,
3153                                   LLVMContext &Context) const {
3154   SmallVector<CCValAssign, 16> RVLocs;
3155   CCState CCInfo(CallConv, isVarArg, MF, RVLocs, Context);
3156   return CCInfo.CheckReturn(Outs, CCAssignFnForReturn(CallConv, isVarArg));
3157 }
3158 
LowerInterruptReturn(SmallVectorImpl<SDValue> & RetOps,const SDLoc & DL,SelectionDAG & DAG)3159 static SDValue LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3160                                     const SDLoc &DL, SelectionDAG &DAG) {
3161   const MachineFunction &MF = DAG.getMachineFunction();
3162   const Function &F = MF.getFunction();
3163 
3164   StringRef IntKind = F.getFnAttribute("interrupt").getValueAsString();
3165 
3166   // See ARM ARM v7 B1.8.3. On exception entry LR is set to a possibly offset
3167   // version of the "preferred return address". These offsets affect the return
3168   // instruction if this is a return from PL1 without hypervisor extensions.
3169   //    IRQ/FIQ: +4     "subs pc, lr, #4"
3170   //    SWI:     0      "subs pc, lr, #0"
3171   //    ABORT:   +4     "subs pc, lr, #4"
3172   //    UNDEF:   +4/+2  "subs pc, lr, #0"
3173   // UNDEF varies depending on where the exception came from ARM or Thumb
3174   // mode. Alongside GCC, we throw our hands up in disgust and pretend it's 0.
3175 
3176   int64_t LROffset;
3177   if (IntKind == "" || IntKind == "IRQ" || IntKind == "FIQ" ||
3178       IntKind == "ABORT")
3179     LROffset = 4;
3180   else if (IntKind == "SWI" || IntKind == "UNDEF")
3181     LROffset = 0;
3182   else
3183     report_fatal_error("Unsupported interrupt attribute. If present, value "
3184                        "must be one of: IRQ, FIQ, SWI, ABORT or UNDEF");
3185 
3186   RetOps.insert(RetOps.begin() + 1,
3187                 DAG.getConstant(LROffset, DL, MVT::i32, false));
3188 
3189   return DAG.getNode(ARMISD::INTRET_GLUE, DL, MVT::Other, RetOps);
3190 }
3191 
3192 SDValue
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,const SDLoc & dl,SelectionDAG & DAG) const3193 ARMTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3194                                bool isVarArg,
3195                                const SmallVectorImpl<ISD::OutputArg> &Outs,
3196                                const SmallVectorImpl<SDValue> &OutVals,
3197                                const SDLoc &dl, SelectionDAG &DAG) const {
3198   // CCValAssign - represent the assignment of the return value to a location.
3199   SmallVector<CCValAssign, 16> RVLocs;
3200 
3201   // CCState - Info about the registers and stack slots.
3202   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs,
3203                  *DAG.getContext());
3204 
3205   // Analyze outgoing return values.
3206   CCInfo.AnalyzeReturn(Outs, CCAssignFnForReturn(CallConv, isVarArg));
3207 
3208   SDValue Glue;
3209   SmallVector<SDValue, 4> RetOps;
3210   RetOps.push_back(Chain); // Operand #0 = Chain (updated below)
3211   bool isLittleEndian = Subtarget->isLittle();
3212 
3213   MachineFunction &MF = DAG.getMachineFunction();
3214   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
3215   AFI->setReturnRegsCount(RVLocs.size());
3216 
3217  // Report error if cmse entry function returns structure through first ptr arg.
3218   if (AFI->isCmseNSEntryFunction() && MF.getFunction().hasStructRetAttr()) {
3219     // Note: using an empty SDLoc(), as the first line of the function is a
3220     // better place to report than the last line.
3221     DiagnosticInfoUnsupported Diag(
3222         DAG.getMachineFunction().getFunction(),
3223         "secure entry function would return value through pointer",
3224         SDLoc().getDebugLoc());
3225     DAG.getContext()->diagnose(Diag);
3226   }
3227 
3228   // Copy the result values into the output registers.
3229   for (unsigned i = 0, realRVLocIdx = 0;
3230        i != RVLocs.size();
3231        ++i, ++realRVLocIdx) {
3232     CCValAssign &VA = RVLocs[i];
3233     assert(VA.isRegLoc() && "Can only return in registers!");
3234 
3235     SDValue Arg = OutVals[realRVLocIdx];
3236     bool ReturnF16 = false;
3237 
3238     if (Subtarget->hasFullFP16() && Subtarget->isTargetHardFloat()) {
3239       // Half-precision return values can be returned like this:
3240       //
3241       // t11 f16 = fadd ...
3242       // t12: i16 = bitcast t11
3243       //   t13: i32 = zero_extend t12
3244       // t14: f32 = bitcast t13  <~~~~~~~ Arg
3245       //
3246       // to avoid code generation for bitcasts, we simply set Arg to the node
3247       // that produces the f16 value, t11 in this case.
3248       //
3249       if (Arg.getValueType() == MVT::f32 && Arg.getOpcode() == ISD::BITCAST) {
3250         SDValue ZE = Arg.getOperand(0);
3251         if (ZE.getOpcode() == ISD::ZERO_EXTEND && ZE.getValueType() == MVT::i32) {
3252           SDValue BC = ZE.getOperand(0);
3253           if (BC.getOpcode() == ISD::BITCAST && BC.getValueType() == MVT::i16) {
3254             Arg = BC.getOperand(0);
3255             ReturnF16 = true;
3256           }
3257         }
3258       }
3259     }
3260 
3261     switch (VA.getLocInfo()) {
3262     default: llvm_unreachable("Unknown loc info!");
3263     case CCValAssign::Full: break;
3264     case CCValAssign::BCvt:
3265       if (!ReturnF16)
3266         Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
3267       break;
3268     }
3269 
3270     // Mask f16 arguments if this is a CMSE nonsecure entry.
3271     auto RetVT = Outs[realRVLocIdx].ArgVT;
3272     if (AFI->isCmseNSEntryFunction() && (RetVT == MVT::f16)) {
3273       if (VA.needsCustom() && VA.getValVT() == MVT::f16) {
3274         Arg = MoveFromHPR(dl, DAG, VA.getLocVT(), VA.getValVT(), Arg);
3275       } else {
3276         auto LocBits = VA.getLocVT().getSizeInBits();
3277         auto MaskValue = APInt::getLowBitsSet(LocBits, RetVT.getSizeInBits());
3278         SDValue Mask =
3279             DAG.getConstant(MaskValue, dl, MVT::getIntegerVT(LocBits));
3280         Arg = DAG.getNode(ISD::BITCAST, dl, MVT::getIntegerVT(LocBits), Arg);
3281         Arg = DAG.getNode(ISD::AND, dl, MVT::getIntegerVT(LocBits), Arg, Mask);
3282         Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
3283       }
3284     }
3285 
3286     if (VA.needsCustom() &&
3287         (VA.getLocVT() == MVT::v2f64 || VA.getLocVT() == MVT::f64)) {
3288       if (VA.getLocVT() == MVT::v2f64) {
3289         // Extract the first half and return it in two registers.
3290         SDValue Half = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
3291                                    DAG.getConstant(0, dl, MVT::i32));
3292         SDValue HalfGPRs = DAG.getNode(ARMISD::VMOVRRD, dl,
3293                                        DAG.getVTList(MVT::i32, MVT::i32), Half);
3294 
3295         Chain =
3296             DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
3297                              HalfGPRs.getValue(isLittleEndian ? 0 : 1), Glue);
3298         Glue = Chain.getValue(1);
3299         RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3300         VA = RVLocs[++i]; // skip ahead to next loc
3301         Chain =
3302             DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
3303                              HalfGPRs.getValue(isLittleEndian ? 1 : 0), Glue);
3304         Glue = Chain.getValue(1);
3305         RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3306         VA = RVLocs[++i]; // skip ahead to next loc
3307 
3308         // Extract the 2nd half and fall through to handle it as an f64 value.
3309         Arg = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
3310                           DAG.getConstant(1, dl, MVT::i32));
3311       }
3312       // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
3313       // available.
3314       SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
3315                                   DAG.getVTList(MVT::i32, MVT::i32), Arg);
3316       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
3317                                fmrrd.getValue(isLittleEndian ? 0 : 1), Glue);
3318       Glue = Chain.getValue(1);
3319       RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3320       VA = RVLocs[++i]; // skip ahead to next loc
3321       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
3322                                fmrrd.getValue(isLittleEndian ? 1 : 0), Glue);
3323     } else
3324       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Arg, Glue);
3325 
3326     // Guarantee that all emitted copies are
3327     // stuck together, avoiding something bad.
3328     Glue = Chain.getValue(1);
3329     RetOps.push_back(DAG.getRegister(
3330         VA.getLocReg(), ReturnF16 ? Arg.getValueType() : VA.getLocVT()));
3331   }
3332   const ARMBaseRegisterInfo *TRI = Subtarget->getRegisterInfo();
3333   const MCPhysReg *I =
3334       TRI->getCalleeSavedRegsViaCopy(&DAG.getMachineFunction());
3335   if (I) {
3336     for (; *I; ++I) {
3337       if (ARM::GPRRegClass.contains(*I))
3338         RetOps.push_back(DAG.getRegister(*I, MVT::i32));
3339       else if (ARM::DPRRegClass.contains(*I))
3340         RetOps.push_back(DAG.getRegister(*I, MVT::getFloatingPointVT(64)));
3341       else
3342         llvm_unreachable("Unexpected register class in CSRsViaCopy!");
3343     }
3344   }
3345 
3346   // Update chain and glue.
3347   RetOps[0] = Chain;
3348   if (Glue.getNode())
3349     RetOps.push_back(Glue);
3350 
3351   // CPUs which aren't M-class use a special sequence to return from
3352   // exceptions (roughly, any instruction setting pc and cpsr simultaneously,
3353   // though we use "subs pc, lr, #N").
3354   //
3355   // M-class CPUs actually use a normal return sequence with a special
3356   // (hardware-provided) value in LR, so the normal code path works.
3357   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt") &&
3358       !Subtarget->isMClass()) {
3359     if (Subtarget->isThumb1Only())
3360       report_fatal_error("interrupt attribute is not supported in Thumb1");
3361     return LowerInterruptReturn(RetOps, dl, DAG);
3362   }
3363 
3364   ARMISD::NodeType RetNode = AFI->isCmseNSEntryFunction() ? ARMISD::SERET_GLUE :
3365                                                             ARMISD::RET_GLUE;
3366   return DAG.getNode(RetNode, dl, MVT::Other, RetOps);
3367 }
3368 
isUsedByReturnOnly(SDNode * N,SDValue & Chain) const3369 bool ARMTargetLowering::isUsedByReturnOnly(SDNode *N, SDValue &Chain) const {
3370   if (N->getNumValues() != 1)
3371     return false;
3372   if (!N->hasNUsesOfValue(1, 0))
3373     return false;
3374 
3375   SDValue TCChain = Chain;
3376   SDNode *Copy = *N->use_begin();
3377   if (Copy->getOpcode() == ISD::CopyToReg) {
3378     // If the copy has a glue operand, we conservatively assume it isn't safe to
3379     // perform a tail call.
3380     if (Copy->getOperand(Copy->getNumOperands()-1).getValueType() == MVT::Glue)
3381       return false;
3382     TCChain = Copy->getOperand(0);
3383   } else if (Copy->getOpcode() == ARMISD::VMOVRRD) {
3384     SDNode *VMov = Copy;
3385     // f64 returned in a pair of GPRs.
3386     SmallPtrSet<SDNode*, 2> Copies;
3387     for (SDNode *U : VMov->uses()) {
3388       if (U->getOpcode() != ISD::CopyToReg)
3389         return false;
3390       Copies.insert(U);
3391     }
3392     if (Copies.size() > 2)
3393       return false;
3394 
3395     for (SDNode *U : VMov->uses()) {
3396       SDValue UseChain = U->getOperand(0);
3397       if (Copies.count(UseChain.getNode()))
3398         // Second CopyToReg
3399         Copy = U;
3400       else {
3401         // We are at the top of this chain.
3402         // If the copy has a glue operand, we conservatively assume it
3403         // isn't safe to perform a tail call.
3404         if (U->getOperand(U->getNumOperands() - 1).getValueType() == MVT::Glue)
3405           return false;
3406         // First CopyToReg
3407         TCChain = UseChain;
3408       }
3409     }
3410   } else if (Copy->getOpcode() == ISD::BITCAST) {
3411     // f32 returned in a single GPR.
3412     if (!Copy->hasOneUse())
3413       return false;
3414     Copy = *Copy->use_begin();
3415     if (Copy->getOpcode() != ISD::CopyToReg || !Copy->hasNUsesOfValue(1, 0))
3416       return false;
3417     // If the copy has a glue operand, we conservatively assume it isn't safe to
3418     // perform a tail call.
3419     if (Copy->getOperand(Copy->getNumOperands()-1).getValueType() == MVT::Glue)
3420       return false;
3421     TCChain = Copy->getOperand(0);
3422   } else {
3423     return false;
3424   }
3425 
3426   bool HasRet = false;
3427   for (const SDNode *U : Copy->uses()) {
3428     if (U->getOpcode() != ARMISD::RET_GLUE &&
3429         U->getOpcode() != ARMISD::INTRET_GLUE)
3430       return false;
3431     HasRet = true;
3432   }
3433 
3434   if (!HasRet)
3435     return false;
3436 
3437   Chain = TCChain;
3438   return true;
3439 }
3440 
mayBeEmittedAsTailCall(const CallInst * CI) const3441 bool ARMTargetLowering::mayBeEmittedAsTailCall(const CallInst *CI) const {
3442   if (!Subtarget->supportsTailCall())
3443     return false;
3444 
3445   if (!CI->isTailCall())
3446     return false;
3447 
3448   return true;
3449 }
3450 
3451 // Trying to write a 64 bit value so need to split into two 32 bit values first,
3452 // and pass the lower and high parts through.
LowerWRITE_REGISTER(SDValue Op,SelectionDAG & DAG)3453 static SDValue LowerWRITE_REGISTER(SDValue Op, SelectionDAG &DAG) {
3454   SDLoc DL(Op);
3455   SDValue WriteValue = Op->getOperand(2);
3456 
3457   // This function is only supposed to be called for i64 type argument.
3458   assert(WriteValue.getValueType() == MVT::i64
3459           && "LowerWRITE_REGISTER called for non-i64 type argument.");
3460 
3461   SDValue Lo, Hi;
3462   std::tie(Lo, Hi) = DAG.SplitScalar(WriteValue, DL, MVT::i32, MVT::i32);
3463   SDValue Ops[] = { Op->getOperand(0), Op->getOperand(1), Lo, Hi };
3464   return DAG.getNode(ISD::WRITE_REGISTER, DL, MVT::Other, Ops);
3465 }
3466 
3467 // ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
3468 // their target counterpart wrapped in the ARMISD::Wrapper node. Suppose N is
3469 // one of the above mentioned nodes. It has to be wrapped because otherwise
3470 // Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
3471 // be used to form addressing mode. These wrapped nodes will be selected
3472 // into MOVi.
LowerConstantPool(SDValue Op,SelectionDAG & DAG) const3473 SDValue ARMTargetLowering::LowerConstantPool(SDValue Op,
3474                                              SelectionDAG &DAG) const {
3475   EVT PtrVT = Op.getValueType();
3476   // FIXME there is no actual debug info here
3477   SDLoc dl(Op);
3478   ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
3479   SDValue Res;
3480 
3481   // When generating execute-only code Constant Pools must be promoted to the
3482   // global data section. It's a bit ugly that we can't share them across basic
3483   // blocks, but this way we guarantee that execute-only behaves correct with
3484   // position-independent addressing modes.
3485   if (Subtarget->genExecuteOnly()) {
3486     auto AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
3487     auto T = const_cast<Type*>(CP->getType());
3488     auto C = const_cast<Constant*>(CP->getConstVal());
3489     auto M = const_cast<Module*>(DAG.getMachineFunction().
3490                                  getFunction().getParent());
3491     auto GV = new GlobalVariable(
3492                     *M, T, /*isConstant=*/true, GlobalVariable::InternalLinkage, C,
3493                     Twine(DAG.getDataLayout().getPrivateGlobalPrefix()) + "CP" +
3494                     Twine(DAG.getMachineFunction().getFunctionNumber()) + "_" +
3495                     Twine(AFI->createPICLabelUId())
3496                   );
3497     SDValue GA = DAG.getTargetGlobalAddress(dyn_cast<GlobalValue>(GV),
3498                                             dl, PtrVT);
3499     return LowerGlobalAddress(GA, DAG);
3500   }
3501 
3502   // The 16-bit ADR instruction can only encode offsets that are multiples of 4,
3503   // so we need to align to at least 4 bytes when we don't have 32-bit ADR.
3504   Align CPAlign = CP->getAlign();
3505   if (Subtarget->isThumb1Only())
3506     CPAlign = std::max(CPAlign, Align(4));
3507   if (CP->isMachineConstantPoolEntry())
3508     Res =
3509         DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT, CPAlign);
3510   else
3511     Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CPAlign);
3512   return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Res);
3513 }
3514 
getJumpTableEncoding() const3515 unsigned ARMTargetLowering::getJumpTableEncoding() const {
3516   // If we don't have a 32-bit pc-relative branch instruction then the jump
3517   // table consists of block addresses. Usually this is inline, but for
3518   // execute-only it must be placed out-of-line.
3519   if (Subtarget->genExecuteOnly() && !Subtarget->hasV8MBaselineOps())
3520     return MachineJumpTableInfo::EK_BlockAddress;
3521   return MachineJumpTableInfo::EK_Inline;
3522 }
3523 
LowerBlockAddress(SDValue Op,SelectionDAG & DAG) const3524 SDValue ARMTargetLowering::LowerBlockAddress(SDValue Op,
3525                                              SelectionDAG &DAG) const {
3526   MachineFunction &MF = DAG.getMachineFunction();
3527   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
3528   unsigned ARMPCLabelIndex = 0;
3529   SDLoc DL(Op);
3530   EVT PtrVT = getPointerTy(DAG.getDataLayout());
3531   const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
3532   SDValue CPAddr;
3533   bool IsPositionIndependent = isPositionIndependent() || Subtarget->isROPI();
3534   if (!IsPositionIndependent) {
3535     CPAddr = DAG.getTargetConstantPool(BA, PtrVT, Align(4));
3536   } else {
3537     unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
3538     ARMPCLabelIndex = AFI->createPICLabelUId();
3539     ARMConstantPoolValue *CPV =
3540       ARMConstantPoolConstant::Create(BA, ARMPCLabelIndex,
3541                                       ARMCP::CPBlockAddress, PCAdj);
3542     CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
3543   }
3544   CPAddr = DAG.getNode(ARMISD::Wrapper, DL, PtrVT, CPAddr);
3545   SDValue Result = DAG.getLoad(
3546       PtrVT, DL, DAG.getEntryNode(), CPAddr,
3547       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3548   if (!IsPositionIndependent)
3549     return Result;
3550   SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, DL, MVT::i32);
3551   return DAG.getNode(ARMISD::PIC_ADD, DL, PtrVT, Result, PICLabel);
3552 }
3553 
3554 /// Convert a TLS address reference into the correct sequence of loads
3555 /// and calls to compute the variable's address for Darwin, and return an
3556 /// SDValue containing the final node.
3557 
3558 /// Darwin only has one TLS scheme which must be capable of dealing with the
3559 /// fully general situation, in the worst case. This means:
3560 ///     + "extern __thread" declaration.
3561 ///     + Defined in a possibly unknown dynamic library.
3562 ///
3563 /// The general system is that each __thread variable has a [3 x i32] descriptor
3564 /// which contains information used by the runtime to calculate the address. The
3565 /// only part of this the compiler needs to know about is the first word, which
3566 /// contains a function pointer that must be called with the address of the
3567 /// entire descriptor in "r0".
3568 ///
3569 /// Since this descriptor may be in a different unit, in general access must
3570 /// proceed along the usual ARM rules. A common sequence to produce is:
3571 ///
3572 ///     movw rT1, :lower16:_var$non_lazy_ptr
3573 ///     movt rT1, :upper16:_var$non_lazy_ptr
3574 ///     ldr r0, [rT1]
3575 ///     ldr rT2, [r0]
3576 ///     blx rT2
3577 ///     [...address now in r0...]
3578 SDValue
LowerGlobalTLSAddressDarwin(SDValue Op,SelectionDAG & DAG) const3579 ARMTargetLowering::LowerGlobalTLSAddressDarwin(SDValue Op,
3580                                                SelectionDAG &DAG) const {
3581   assert(Subtarget->isTargetDarwin() &&
3582          "This function expects a Darwin target");
3583   SDLoc DL(Op);
3584 
3585   // First step is to get the address of the actua global symbol. This is where
3586   // the TLS descriptor lives.
3587   SDValue DescAddr = LowerGlobalAddressDarwin(Op, DAG);
3588 
3589   // The first entry in the descriptor is a function pointer that we must call
3590   // to obtain the address of the variable.
3591   SDValue Chain = DAG.getEntryNode();
3592   SDValue FuncTLVGet = DAG.getLoad(
3593       MVT::i32, DL, Chain, DescAddr,
3594       MachinePointerInfo::getGOT(DAG.getMachineFunction()), Align(4),
3595       MachineMemOperand::MONonTemporal | MachineMemOperand::MODereferenceable |
3596           MachineMemOperand::MOInvariant);
3597   Chain = FuncTLVGet.getValue(1);
3598 
3599   MachineFunction &F = DAG.getMachineFunction();
3600   MachineFrameInfo &MFI = F.getFrameInfo();
3601   MFI.setAdjustsStack(true);
3602 
3603   // TLS calls preserve all registers except those that absolutely must be
3604   // trashed: R0 (it takes an argument), LR (it's a call) and CPSR (let's not be
3605   // silly).
3606   auto TRI =
3607       getTargetMachine().getSubtargetImpl(F.getFunction())->getRegisterInfo();
3608   auto ARI = static_cast<const ARMRegisterInfo *>(TRI);
3609   const uint32_t *Mask = ARI->getTLSCallPreservedMask(DAG.getMachineFunction());
3610 
3611   // Finally, we can make the call. This is just a degenerate version of a
3612   // normal AArch64 call node: r0 takes the address of the descriptor, and
3613   // returns the address of the variable in this thread.
3614   Chain = DAG.getCopyToReg(Chain, DL, ARM::R0, DescAddr, SDValue());
3615   Chain =
3616       DAG.getNode(ARMISD::CALL, DL, DAG.getVTList(MVT::Other, MVT::Glue),
3617                   Chain, FuncTLVGet, DAG.getRegister(ARM::R0, MVT::i32),
3618                   DAG.getRegisterMask(Mask), Chain.getValue(1));
3619   return DAG.getCopyFromReg(Chain, DL, ARM::R0, MVT::i32, Chain.getValue(1));
3620 }
3621 
3622 SDValue
LowerGlobalTLSAddressWindows(SDValue Op,SelectionDAG & DAG) const3623 ARMTargetLowering::LowerGlobalTLSAddressWindows(SDValue Op,
3624                                                 SelectionDAG &DAG) const {
3625   assert(Subtarget->isTargetWindows() && "Windows specific TLS lowering");
3626 
3627   SDValue Chain = DAG.getEntryNode();
3628   EVT PtrVT = getPointerTy(DAG.getDataLayout());
3629   SDLoc DL(Op);
3630 
3631   // Load the current TEB (thread environment block)
3632   SDValue Ops[] = {Chain,
3633                    DAG.getTargetConstant(Intrinsic::arm_mrc, DL, MVT::i32),
3634                    DAG.getTargetConstant(15, DL, MVT::i32),
3635                    DAG.getTargetConstant(0, DL, MVT::i32),
3636                    DAG.getTargetConstant(13, DL, MVT::i32),
3637                    DAG.getTargetConstant(0, DL, MVT::i32),
3638                    DAG.getTargetConstant(2, DL, MVT::i32)};
3639   SDValue CurrentTEB = DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL,
3640                                    DAG.getVTList(MVT::i32, MVT::Other), Ops);
3641 
3642   SDValue TEB = CurrentTEB.getValue(0);
3643   Chain = CurrentTEB.getValue(1);
3644 
3645   // Load the ThreadLocalStoragePointer from the TEB
3646   // A pointer to the TLS array is located at offset 0x2c from the TEB.
3647   SDValue TLSArray =
3648       DAG.getNode(ISD::ADD, DL, PtrVT, TEB, DAG.getIntPtrConstant(0x2c, DL));
3649   TLSArray = DAG.getLoad(PtrVT, DL, Chain, TLSArray, MachinePointerInfo());
3650 
3651   // The pointer to the thread's TLS data area is at the TLS Index scaled by 4
3652   // offset into the TLSArray.
3653 
3654   // Load the TLS index from the C runtime
3655   SDValue TLSIndex =
3656       DAG.getTargetExternalSymbol("_tls_index", PtrVT, ARMII::MO_NO_FLAG);
3657   TLSIndex = DAG.getNode(ARMISD::Wrapper, DL, PtrVT, TLSIndex);
3658   TLSIndex = DAG.getLoad(PtrVT, DL, Chain, TLSIndex, MachinePointerInfo());
3659 
3660   SDValue Slot = DAG.getNode(ISD::SHL, DL, PtrVT, TLSIndex,
3661                               DAG.getConstant(2, DL, MVT::i32));
3662   SDValue TLS = DAG.getLoad(PtrVT, DL, Chain,
3663                             DAG.getNode(ISD::ADD, DL, PtrVT, TLSArray, Slot),
3664                             MachinePointerInfo());
3665 
3666   // Get the offset of the start of the .tls section (section base)
3667   const auto *GA = cast<GlobalAddressSDNode>(Op);
3668   auto *CPV = ARMConstantPoolConstant::Create(GA->getGlobal(), ARMCP::SECREL);
3669   SDValue Offset = DAG.getLoad(
3670       PtrVT, DL, Chain,
3671       DAG.getNode(ARMISD::Wrapper, DL, MVT::i32,
3672                   DAG.getTargetConstantPool(CPV, PtrVT, Align(4))),
3673       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3674 
3675   return DAG.getNode(ISD::ADD, DL, PtrVT, TLS, Offset);
3676 }
3677 
3678 // Lower ISD::GlobalTLSAddress using the "general dynamic" model
3679 SDValue
LowerToTLSGeneralDynamicModel(GlobalAddressSDNode * GA,SelectionDAG & DAG) const3680 ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
3681                                                  SelectionDAG &DAG) const {
3682   SDLoc dl(GA);
3683   EVT PtrVT = getPointerTy(DAG.getDataLayout());
3684   unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
3685   MachineFunction &MF = DAG.getMachineFunction();
3686   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
3687   unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
3688   ARMConstantPoolValue *CPV =
3689     ARMConstantPoolConstant::Create(GA->getGlobal(), ARMPCLabelIndex,
3690                                     ARMCP::CPValue, PCAdj, ARMCP::TLSGD, true);
3691   SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
3692   Argument = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Argument);
3693   Argument = DAG.getLoad(
3694       PtrVT, dl, DAG.getEntryNode(), Argument,
3695       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3696   SDValue Chain = Argument.getValue(1);
3697 
3698   SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, dl, MVT::i32);
3699   Argument = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Argument, PICLabel);
3700 
3701   // call __tls_get_addr.
3702   ArgListTy Args;
3703   ArgListEntry Entry;
3704   Entry.Node = Argument;
3705   Entry.Ty = (Type *) Type::getInt32Ty(*DAG.getContext());
3706   Args.push_back(Entry);
3707 
3708   // FIXME: is there useful debug info available here?
3709   TargetLowering::CallLoweringInfo CLI(DAG);
3710   CLI.setDebugLoc(dl).setChain(Chain).setLibCallee(
3711       CallingConv::C, Type::getInt32Ty(*DAG.getContext()),
3712       DAG.getExternalSymbol("__tls_get_addr", PtrVT), std::move(Args));
3713 
3714   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
3715   return CallResult.first;
3716 }
3717 
3718 // Lower ISD::GlobalTLSAddress using the "initial exec" or
3719 // "local exec" model.
3720 SDValue
LowerToTLSExecModels(GlobalAddressSDNode * GA,SelectionDAG & DAG,TLSModel::Model model) const3721 ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
3722                                         SelectionDAG &DAG,
3723                                         TLSModel::Model model) const {
3724   const GlobalValue *GV = GA->getGlobal();
3725   SDLoc dl(GA);
3726   SDValue Offset;
3727   SDValue Chain = DAG.getEntryNode();
3728   EVT PtrVT = getPointerTy(DAG.getDataLayout());
3729   // Get the Thread Pointer
3730   SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
3731 
3732   if (model == TLSModel::InitialExec) {
3733     MachineFunction &MF = DAG.getMachineFunction();
3734     ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
3735     unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
3736     // Initial exec model.
3737     unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
3738     ARMConstantPoolValue *CPV =
3739       ARMConstantPoolConstant::Create(GA->getGlobal(), ARMPCLabelIndex,
3740                                       ARMCP::CPValue, PCAdj, ARMCP::GOTTPOFF,
3741                                       true);
3742     Offset = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
3743     Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
3744     Offset = DAG.getLoad(
3745         PtrVT, dl, Chain, Offset,
3746         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3747     Chain = Offset.getValue(1);
3748 
3749     SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, dl, MVT::i32);
3750     Offset = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Offset, PICLabel);
3751 
3752     Offset = DAG.getLoad(
3753         PtrVT, dl, Chain, Offset,
3754         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3755   } else {
3756     // local exec model
3757     assert(model == TLSModel::LocalExec);
3758     ARMConstantPoolValue *CPV =
3759       ARMConstantPoolConstant::Create(GV, ARMCP::TPOFF);
3760     Offset = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
3761     Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
3762     Offset = DAG.getLoad(
3763         PtrVT, dl, Chain, Offset,
3764         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3765   }
3766 
3767   // The address of the thread local variable is the add of the thread
3768   // pointer with the offset of the variable.
3769   return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
3770 }
3771 
3772 SDValue
LowerGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const3773 ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
3774   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
3775   if (DAG.getTarget().useEmulatedTLS())
3776     return LowerToTLSEmulatedModel(GA, DAG);
3777 
3778   if (Subtarget->isTargetDarwin())
3779     return LowerGlobalTLSAddressDarwin(Op, DAG);
3780 
3781   if (Subtarget->isTargetWindows())
3782     return LowerGlobalTLSAddressWindows(Op, DAG);
3783 
3784   // TODO: implement the "local dynamic" model
3785   assert(Subtarget->isTargetELF() && "Only ELF implemented here");
3786   TLSModel::Model model = getTargetMachine().getTLSModel(GA->getGlobal());
3787 
3788   switch (model) {
3789     case TLSModel::GeneralDynamic:
3790     case TLSModel::LocalDynamic:
3791       return LowerToTLSGeneralDynamicModel(GA, DAG);
3792     case TLSModel::InitialExec:
3793     case TLSModel::LocalExec:
3794       return LowerToTLSExecModels(GA, DAG, model);
3795   }
3796   llvm_unreachable("bogus TLS model");
3797 }
3798 
3799 /// Return true if all users of V are within function F, looking through
3800 /// ConstantExprs.
allUsersAreInFunction(const Value * V,const Function * F)3801 static bool allUsersAreInFunction(const Value *V, const Function *F) {
3802   SmallVector<const User*,4> Worklist(V->users());
3803   while (!Worklist.empty()) {
3804     auto *U = Worklist.pop_back_val();
3805     if (isa<ConstantExpr>(U)) {
3806       append_range(Worklist, U->users());
3807       continue;
3808     }
3809 
3810     auto *I = dyn_cast<Instruction>(U);
3811     if (!I || I->getParent()->getParent() != F)
3812       return false;
3813   }
3814   return true;
3815 }
3816 
promoteToConstantPool(const ARMTargetLowering * TLI,const GlobalValue * GV,SelectionDAG & DAG,EVT PtrVT,const SDLoc & dl)3817 static SDValue promoteToConstantPool(const ARMTargetLowering *TLI,
3818                                      const GlobalValue *GV, SelectionDAG &DAG,
3819                                      EVT PtrVT, const SDLoc &dl) {
3820   // If we're creating a pool entry for a constant global with unnamed address,
3821   // and the global is small enough, we can emit it inline into the constant pool
3822   // to save ourselves an indirection.
3823   //
3824   // This is a win if the constant is only used in one function (so it doesn't
3825   // need to be duplicated) or duplicating the constant wouldn't increase code
3826   // size (implying the constant is no larger than 4 bytes).
3827   const Function &F = DAG.getMachineFunction().getFunction();
3828 
3829   // We rely on this decision to inline being idemopotent and unrelated to the
3830   // use-site. We know that if we inline a variable at one use site, we'll
3831   // inline it elsewhere too (and reuse the constant pool entry). Fast-isel
3832   // doesn't know about this optimization, so bail out if it's enabled else
3833   // we could decide to inline here (and thus never emit the GV) but require
3834   // the GV from fast-isel generated code.
3835   if (!EnableConstpoolPromotion ||
3836       DAG.getMachineFunction().getTarget().Options.EnableFastISel)
3837       return SDValue();
3838 
3839   auto *GVar = dyn_cast<GlobalVariable>(GV);
3840   if (!GVar || !GVar->hasInitializer() ||
3841       !GVar->isConstant() || !GVar->hasGlobalUnnamedAddr() ||
3842       !GVar->hasLocalLinkage())
3843     return SDValue();
3844 
3845   // If we inline a value that contains relocations, we move the relocations
3846   // from .data to .text. This is not allowed in position-independent code.
3847   auto *Init = GVar->getInitializer();
3848   if ((TLI->isPositionIndependent() || TLI->getSubtarget()->isROPI()) &&
3849       Init->needsDynamicRelocation())
3850     return SDValue();
3851 
3852   // The constant islands pass can only really deal with alignment requests
3853   // <= 4 bytes and cannot pad constants itself. Therefore we cannot promote
3854   // any type wanting greater alignment requirements than 4 bytes. We also
3855   // can only promote constants that are multiples of 4 bytes in size or
3856   // are paddable to a multiple of 4. Currently we only try and pad constants
3857   // that are strings for simplicity.
3858   auto *CDAInit = dyn_cast<ConstantDataArray>(Init);
3859   unsigned Size = DAG.getDataLayout().getTypeAllocSize(Init->getType());
3860   Align PrefAlign = DAG.getDataLayout().getPreferredAlign(GVar);
3861   unsigned RequiredPadding = 4 - (Size % 4);
3862   bool PaddingPossible =
3863     RequiredPadding == 4 || (CDAInit && CDAInit->isString());
3864   if (!PaddingPossible || PrefAlign > 4 || Size > ConstpoolPromotionMaxSize ||
3865       Size == 0)
3866     return SDValue();
3867 
3868   unsigned PaddedSize = Size + ((RequiredPadding == 4) ? 0 : RequiredPadding);
3869   MachineFunction &MF = DAG.getMachineFunction();
3870   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
3871 
3872   // We can't bloat the constant pool too much, else the ConstantIslands pass
3873   // may fail to converge. If we haven't promoted this global yet (it may have
3874   // multiple uses), and promoting it would increase the constant pool size (Sz
3875   // > 4), ensure we have space to do so up to MaxTotal.
3876   if (!AFI->getGlobalsPromotedToConstantPool().count(GVar) && Size > 4)
3877     if (AFI->getPromotedConstpoolIncrease() + PaddedSize - 4 >=
3878         ConstpoolPromotionMaxTotal)
3879       return SDValue();
3880 
3881   // This is only valid if all users are in a single function; we can't clone
3882   // the constant in general. The LLVM IR unnamed_addr allows merging
3883   // constants, but not cloning them.
3884   //
3885   // We could potentially allow cloning if we could prove all uses of the
3886   // constant in the current function don't care about the address, like
3887   // printf format strings. But that isn't implemented for now.
3888   if (!allUsersAreInFunction(GVar, &F))
3889     return SDValue();
3890 
3891   // We're going to inline this global. Pad it out if needed.
3892   if (RequiredPadding != 4) {
3893     StringRef S = CDAInit->getAsString();
3894 
3895     SmallVector<uint8_t,16> V(S.size());
3896     std::copy(S.bytes_begin(), S.bytes_end(), V.begin());
3897     while (RequiredPadding--)
3898       V.push_back(0);
3899     Init = ConstantDataArray::get(*DAG.getContext(), V);
3900   }
3901 
3902   auto CPVal = ARMConstantPoolConstant::Create(GVar, Init);
3903   SDValue CPAddr = DAG.getTargetConstantPool(CPVal, PtrVT, Align(4));
3904   if (!AFI->getGlobalsPromotedToConstantPool().count(GVar)) {
3905     AFI->markGlobalAsPromotedToConstantPool(GVar);
3906     AFI->setPromotedConstpoolIncrease(AFI->getPromotedConstpoolIncrease() +
3907                                       PaddedSize - 4);
3908   }
3909   ++NumConstpoolPromoted;
3910   return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
3911 }
3912 
isReadOnly(const GlobalValue * GV) const3913 bool ARMTargetLowering::isReadOnly(const GlobalValue *GV) const {
3914   if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
3915     if (!(GV = GA->getAliaseeObject()))
3916       return false;
3917   if (const auto *V = dyn_cast<GlobalVariable>(GV))
3918     return V->isConstant();
3919   return isa<Function>(GV);
3920 }
3921 
LowerGlobalAddress(SDValue Op,SelectionDAG & DAG) const3922 SDValue ARMTargetLowering::LowerGlobalAddress(SDValue Op,
3923                                               SelectionDAG &DAG) const {
3924   switch (Subtarget->getTargetTriple().getObjectFormat()) {
3925   default: llvm_unreachable("unknown object format");
3926   case Triple::COFF:
3927     return LowerGlobalAddressWindows(Op, DAG);
3928   case Triple::ELF:
3929     return LowerGlobalAddressELF(Op, DAG);
3930   case Triple::MachO:
3931     return LowerGlobalAddressDarwin(Op, DAG);
3932   }
3933 }
3934 
LowerGlobalAddressELF(SDValue Op,SelectionDAG & DAG) const3935 SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
3936                                                  SelectionDAG &DAG) const {
3937   EVT PtrVT = getPointerTy(DAG.getDataLayout());
3938   SDLoc dl(Op);
3939   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
3940   bool IsRO = isReadOnly(GV);
3941 
3942   // promoteToConstantPool only if not generating XO text section
3943   if (GV->isDSOLocal() && !Subtarget->genExecuteOnly())
3944     if (SDValue V = promoteToConstantPool(this, GV, DAG, PtrVT, dl))
3945       return V;
3946 
3947   if (isPositionIndependent()) {
3948     SDValue G = DAG.getTargetGlobalAddress(
3949         GV, dl, PtrVT, 0, GV->isDSOLocal() ? 0 : ARMII::MO_GOT);
3950     SDValue Result = DAG.getNode(ARMISD::WrapperPIC, dl, PtrVT, G);
3951     if (!GV->isDSOLocal())
3952       Result =
3953           DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Result,
3954                       MachinePointerInfo::getGOT(DAG.getMachineFunction()));
3955     return Result;
3956   } else if (Subtarget->isROPI() && IsRO) {
3957     // PC-relative.
3958     SDValue G = DAG.getTargetGlobalAddress(GV, dl, PtrVT);
3959     SDValue Result = DAG.getNode(ARMISD::WrapperPIC, dl, PtrVT, G);
3960     return Result;
3961   } else if (Subtarget->isRWPI() && !IsRO) {
3962     // SB-relative.
3963     SDValue RelAddr;
3964     if (Subtarget->useMovt()) {
3965       ++NumMovwMovt;
3966       SDValue G = DAG.getTargetGlobalAddress(GV, dl, PtrVT, 0, ARMII::MO_SBREL);
3967       RelAddr = DAG.getNode(ARMISD::Wrapper, dl, PtrVT, G);
3968     } else { // use literal pool for address constant
3969       ARMConstantPoolValue *CPV =
3970         ARMConstantPoolConstant::Create(GV, ARMCP::SBREL);
3971       SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
3972       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
3973       RelAddr = DAG.getLoad(
3974           PtrVT, dl, DAG.getEntryNode(), CPAddr,
3975           MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3976     }
3977     SDValue SB = DAG.getCopyFromReg(DAG.getEntryNode(), dl, ARM::R9, PtrVT);
3978     SDValue Result = DAG.getNode(ISD::ADD, dl, PtrVT, SB, RelAddr);
3979     return Result;
3980   }
3981 
3982   // If we have T2 ops, we can materialize the address directly via movt/movw
3983   // pair. This is always cheaper. If need to generate Execute Only code, and we
3984   // only have Thumb1 available, we can't use a constant pool and are forced to
3985   // use immediate relocations.
3986   if (Subtarget->useMovt() || Subtarget->genExecuteOnly()) {
3987     if (Subtarget->useMovt())
3988       ++NumMovwMovt;
3989     // FIXME: Once remat is capable of dealing with instructions with register
3990     // operands, expand this into two nodes.
3991     return DAG.getNode(ARMISD::Wrapper, dl, PtrVT,
3992                        DAG.getTargetGlobalAddress(GV, dl, PtrVT));
3993   } else {
3994     SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, Align(4));
3995     CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
3996     return DAG.getLoad(
3997         PtrVT, dl, DAG.getEntryNode(), CPAddr,
3998         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
3999   }
4000 }
4001 
LowerGlobalAddressDarwin(SDValue Op,SelectionDAG & DAG) const4002 SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
4003                                                     SelectionDAG &DAG) const {
4004   assert(!Subtarget->isROPI() && !Subtarget->isRWPI() &&
4005          "ROPI/RWPI not currently supported for Darwin");
4006   EVT PtrVT = getPointerTy(DAG.getDataLayout());
4007   SDLoc dl(Op);
4008   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
4009 
4010   if (Subtarget->useMovt())
4011     ++NumMovwMovt;
4012 
4013   // FIXME: Once remat is capable of dealing with instructions with register
4014   // operands, expand this into multiple nodes
4015   unsigned Wrapper =
4016       isPositionIndependent() ? ARMISD::WrapperPIC : ARMISD::Wrapper;
4017 
4018   SDValue G = DAG.getTargetGlobalAddress(GV, dl, PtrVT, 0, ARMII::MO_NONLAZY);
4019   SDValue Result = DAG.getNode(Wrapper, dl, PtrVT, G);
4020 
4021   if (Subtarget->isGVIndirectSymbol(GV))
4022     Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Result,
4023                          MachinePointerInfo::getGOT(DAG.getMachineFunction()));
4024   return Result;
4025 }
4026 
LowerGlobalAddressWindows(SDValue Op,SelectionDAG & DAG) const4027 SDValue ARMTargetLowering::LowerGlobalAddressWindows(SDValue Op,
4028                                                      SelectionDAG &DAG) const {
4029   assert(Subtarget->isTargetWindows() && "non-Windows COFF is not supported");
4030   assert(Subtarget->useMovt() &&
4031          "Windows on ARM expects to use movw/movt");
4032   assert(!Subtarget->isROPI() && !Subtarget->isRWPI() &&
4033          "ROPI/RWPI not currently supported for Windows");
4034 
4035   const TargetMachine &TM = getTargetMachine();
4036   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
4037   ARMII::TOF TargetFlags = ARMII::MO_NO_FLAG;
4038   if (GV->hasDLLImportStorageClass())
4039     TargetFlags = ARMII::MO_DLLIMPORT;
4040   else if (!TM.shouldAssumeDSOLocal(GV))
4041     TargetFlags = ARMII::MO_COFFSTUB;
4042   EVT PtrVT = getPointerTy(DAG.getDataLayout());
4043   SDValue Result;
4044   SDLoc DL(Op);
4045 
4046   ++NumMovwMovt;
4047 
4048   // FIXME: Once remat is capable of dealing with instructions with register
4049   // operands, expand this into two nodes.
4050   Result = DAG.getNode(ARMISD::Wrapper, DL, PtrVT,
4051                        DAG.getTargetGlobalAddress(GV, DL, PtrVT, /*offset=*/0,
4052                                                   TargetFlags));
4053   if (TargetFlags & (ARMII::MO_DLLIMPORT | ARMII::MO_COFFSTUB))
4054     Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), Result,
4055                          MachinePointerInfo::getGOT(DAG.getMachineFunction()));
4056   return Result;
4057 }
4058 
4059 SDValue
LowerEH_SJLJ_SETJMP(SDValue Op,SelectionDAG & DAG) const4060 ARMTargetLowering::LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const {
4061   SDLoc dl(Op);
4062   SDValue Val = DAG.getConstant(0, dl, MVT::i32);
4063   return DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl,
4064                      DAG.getVTList(MVT::i32, MVT::Other), Op.getOperand(0),
4065                      Op.getOperand(1), Val);
4066 }
4067 
4068 SDValue
LowerEH_SJLJ_LONGJMP(SDValue Op,SelectionDAG & DAG) const4069 ARMTargetLowering::LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const {
4070   SDLoc dl(Op);
4071   return DAG.getNode(ARMISD::EH_SJLJ_LONGJMP, dl, MVT::Other, Op.getOperand(0),
4072                      Op.getOperand(1), DAG.getConstant(0, dl, MVT::i32));
4073 }
4074 
LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op,SelectionDAG & DAG) const4075 SDValue ARMTargetLowering::LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op,
4076                                                       SelectionDAG &DAG) const {
4077   SDLoc dl(Op);
4078   return DAG.getNode(ARMISD::EH_SJLJ_SETUP_DISPATCH, dl, MVT::Other,
4079                      Op.getOperand(0));
4080 }
4081 
LowerINTRINSIC_VOID(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget) const4082 SDValue ARMTargetLowering::LowerINTRINSIC_VOID(
4083     SDValue Op, SelectionDAG &DAG, const ARMSubtarget *Subtarget) const {
4084   unsigned IntNo =
4085       Op.getConstantOperandVal(Op.getOperand(0).getValueType() == MVT::Other);
4086   switch (IntNo) {
4087     default:
4088       return SDValue();  // Don't custom lower most intrinsics.
4089     case Intrinsic::arm_gnu_eabi_mcount: {
4090       MachineFunction &MF = DAG.getMachineFunction();
4091       EVT PtrVT = getPointerTy(DAG.getDataLayout());
4092       SDLoc dl(Op);
4093       SDValue Chain = Op.getOperand(0);
4094       // call "\01__gnu_mcount_nc"
4095       const ARMBaseRegisterInfo *ARI = Subtarget->getRegisterInfo();
4096       const uint32_t *Mask =
4097           ARI->getCallPreservedMask(DAG.getMachineFunction(), CallingConv::C);
4098       assert(Mask && "Missing call preserved mask for calling convention");
4099       // Mark LR an implicit live-in.
4100       Register Reg = MF.addLiveIn(ARM::LR, getRegClassFor(MVT::i32));
4101       SDValue ReturnAddress =
4102           DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, PtrVT);
4103       constexpr EVT ResultTys[] = {MVT::Other, MVT::Glue};
4104       SDValue Callee =
4105           DAG.getTargetExternalSymbol("\01__gnu_mcount_nc", PtrVT, 0);
4106       SDValue RegisterMask = DAG.getRegisterMask(Mask);
4107       if (Subtarget->isThumb())
4108         return SDValue(
4109             DAG.getMachineNode(
4110                 ARM::tBL_PUSHLR, dl, ResultTys,
4111                 {ReturnAddress, DAG.getTargetConstant(ARMCC::AL, dl, PtrVT),
4112                  DAG.getRegister(0, PtrVT), Callee, RegisterMask, Chain}),
4113             0);
4114       return SDValue(
4115           DAG.getMachineNode(ARM::BL_PUSHLR, dl, ResultTys,
4116                              {ReturnAddress, Callee, RegisterMask, Chain}),
4117           0);
4118     }
4119   }
4120 }
4121 
4122 SDValue
LowerINTRINSIC_WO_CHAIN(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget) const4123 ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
4124                                           const ARMSubtarget *Subtarget) const {
4125   unsigned IntNo = Op.getConstantOperandVal(0);
4126   SDLoc dl(Op);
4127   switch (IntNo) {
4128   default: return SDValue();    // Don't custom lower most intrinsics.
4129   case Intrinsic::thread_pointer: {
4130     EVT PtrVT = getPointerTy(DAG.getDataLayout());
4131     return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
4132   }
4133   case Intrinsic::arm_cls: {
4134     const SDValue &Operand = Op.getOperand(1);
4135     const EVT VTy = Op.getValueType();
4136     SDValue SRA =
4137         DAG.getNode(ISD::SRA, dl, VTy, Operand, DAG.getConstant(31, dl, VTy));
4138     SDValue XOR = DAG.getNode(ISD::XOR, dl, VTy, SRA, Operand);
4139     SDValue SHL =
4140         DAG.getNode(ISD::SHL, dl, VTy, XOR, DAG.getConstant(1, dl, VTy));
4141     SDValue OR =
4142         DAG.getNode(ISD::OR, dl, VTy, SHL, DAG.getConstant(1, dl, VTy));
4143     SDValue Result = DAG.getNode(ISD::CTLZ, dl, VTy, OR);
4144     return Result;
4145   }
4146   case Intrinsic::arm_cls64: {
4147     // cls(x) = if cls(hi(x)) != 31 then cls(hi(x))
4148     //          else 31 + clz(if hi(x) == 0 then lo(x) else not(lo(x)))
4149     const SDValue &Operand = Op.getOperand(1);
4150     const EVT VTy = Op.getValueType();
4151     SDValue Lo, Hi;
4152     std::tie(Lo, Hi) = DAG.SplitScalar(Operand, dl, VTy, VTy);
4153     SDValue Constant0 = DAG.getConstant(0, dl, VTy);
4154     SDValue Constant1 = DAG.getConstant(1, dl, VTy);
4155     SDValue Constant31 = DAG.getConstant(31, dl, VTy);
4156     SDValue SRAHi = DAG.getNode(ISD::SRA, dl, VTy, Hi, Constant31);
4157     SDValue XORHi = DAG.getNode(ISD::XOR, dl, VTy, SRAHi, Hi);
4158     SDValue SHLHi = DAG.getNode(ISD::SHL, dl, VTy, XORHi, Constant1);
4159     SDValue ORHi = DAG.getNode(ISD::OR, dl, VTy, SHLHi, Constant1);
4160     SDValue CLSHi = DAG.getNode(ISD::CTLZ, dl, VTy, ORHi);
4161     SDValue CheckLo =
4162         DAG.getSetCC(dl, MVT::i1, CLSHi, Constant31, ISD::CondCode::SETEQ);
4163     SDValue HiIsZero =
4164         DAG.getSetCC(dl, MVT::i1, Hi, Constant0, ISD::CondCode::SETEQ);
4165     SDValue AdjustedLo =
4166         DAG.getSelect(dl, VTy, HiIsZero, Lo, DAG.getNOT(dl, Lo, VTy));
4167     SDValue CLZAdjustedLo = DAG.getNode(ISD::CTLZ, dl, VTy, AdjustedLo);
4168     SDValue Result =
4169         DAG.getSelect(dl, VTy, CheckLo,
4170                       DAG.getNode(ISD::ADD, dl, VTy, CLZAdjustedLo, Constant31), CLSHi);
4171     return Result;
4172   }
4173   case Intrinsic::eh_sjlj_lsda: {
4174     MachineFunction &MF = DAG.getMachineFunction();
4175     ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
4176     unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
4177     EVT PtrVT = getPointerTy(DAG.getDataLayout());
4178     SDValue CPAddr;
4179     bool IsPositionIndependent = isPositionIndependent();
4180     unsigned PCAdj = IsPositionIndependent ? (Subtarget->isThumb() ? 4 : 8) : 0;
4181     ARMConstantPoolValue *CPV =
4182       ARMConstantPoolConstant::Create(&MF.getFunction(), ARMPCLabelIndex,
4183                                       ARMCP::CPLSDA, PCAdj);
4184     CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, Align(4));
4185     CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
4186     SDValue Result = DAG.getLoad(
4187         PtrVT, dl, DAG.getEntryNode(), CPAddr,
4188         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()));
4189 
4190     if (IsPositionIndependent) {
4191       SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, dl, MVT::i32);
4192       Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
4193     }
4194     return Result;
4195   }
4196   case Intrinsic::arm_neon_vabs:
4197     return DAG.getNode(ISD::ABS, SDLoc(Op), Op.getValueType(),
4198                        Op.getOperand(1));
4199   case Intrinsic::arm_neon_vabds:
4200     if (Op.getValueType().isInteger())
4201       return DAG.getNode(ISD::ABDS, SDLoc(Op), Op.getValueType(),
4202                          Op.getOperand(1), Op.getOperand(2));
4203     return SDValue();
4204   case Intrinsic::arm_neon_vabdu:
4205     return DAG.getNode(ISD::ABDU, SDLoc(Op), Op.getValueType(),
4206                        Op.getOperand(1), Op.getOperand(2));
4207   case Intrinsic::arm_neon_vmulls:
4208   case Intrinsic::arm_neon_vmullu: {
4209     unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vmulls)
4210       ? ARMISD::VMULLs : ARMISD::VMULLu;
4211     return DAG.getNode(NewOpc, SDLoc(Op), Op.getValueType(),
4212                        Op.getOperand(1), Op.getOperand(2));
4213   }
4214   case Intrinsic::arm_neon_vminnm:
4215   case Intrinsic::arm_neon_vmaxnm: {
4216     unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vminnm)
4217       ? ISD::FMINNUM : ISD::FMAXNUM;
4218     return DAG.getNode(NewOpc, SDLoc(Op), Op.getValueType(),
4219                        Op.getOperand(1), Op.getOperand(2));
4220   }
4221   case Intrinsic::arm_neon_vminu:
4222   case Intrinsic::arm_neon_vmaxu: {
4223     if (Op.getValueType().isFloatingPoint())
4224       return SDValue();
4225     unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vminu)
4226       ? ISD::UMIN : ISD::UMAX;
4227     return DAG.getNode(NewOpc, SDLoc(Op), Op.getValueType(),
4228                          Op.getOperand(1), Op.getOperand(2));
4229   }
4230   case Intrinsic::arm_neon_vmins:
4231   case Intrinsic::arm_neon_vmaxs: {
4232     // v{min,max}s is overloaded between signed integers and floats.
4233     if (!Op.getValueType().isFloatingPoint()) {
4234       unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vmins)
4235         ? ISD::SMIN : ISD::SMAX;
4236       return DAG.getNode(NewOpc, SDLoc(Op), Op.getValueType(),
4237                          Op.getOperand(1), Op.getOperand(2));
4238     }
4239     unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vmins)
4240       ? ISD::FMINIMUM : ISD::FMAXIMUM;
4241     return DAG.getNode(NewOpc, SDLoc(Op), Op.getValueType(),
4242                        Op.getOperand(1), Op.getOperand(2));
4243   }
4244   case Intrinsic::arm_neon_vtbl1:
4245     return DAG.getNode(ARMISD::VTBL1, SDLoc(Op), Op.getValueType(),
4246                        Op.getOperand(1), Op.getOperand(2));
4247   case Intrinsic::arm_neon_vtbl2:
4248     return DAG.getNode(ARMISD::VTBL2, SDLoc(Op), Op.getValueType(),
4249                        Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
4250   case Intrinsic::arm_mve_pred_i2v:
4251   case Intrinsic::arm_mve_pred_v2i:
4252     return DAG.getNode(ARMISD::PREDICATE_CAST, SDLoc(Op), Op.getValueType(),
4253                        Op.getOperand(1));
4254   case Intrinsic::arm_mve_vreinterpretq:
4255     return DAG.getNode(ARMISD::VECTOR_REG_CAST, SDLoc(Op), Op.getValueType(),
4256                        Op.getOperand(1));
4257   case Intrinsic::arm_mve_lsll:
4258     return DAG.getNode(ARMISD::LSLL, SDLoc(Op), Op->getVTList(),
4259                        Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
4260   case Intrinsic::arm_mve_asrl:
4261     return DAG.getNode(ARMISD::ASRL, SDLoc(Op), Op->getVTList(),
4262                        Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
4263   }
4264 }
4265 
LowerATOMIC_FENCE(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)4266 static SDValue LowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG,
4267                                  const ARMSubtarget *Subtarget) {
4268   SDLoc dl(Op);
4269   auto SSID = static_cast<SyncScope::ID>(Op.getConstantOperandVal(2));
4270   if (SSID == SyncScope::SingleThread)
4271     return Op;
4272 
4273   if (!Subtarget->hasDataBarrier()) {
4274     // Some ARMv6 cpus can support data barriers with an mcr instruction.
4275     // Thumb1 and pre-v6 ARM mode use a libcall instead and should never get
4276     // here.
4277     assert(Subtarget->hasV6Ops() && !Subtarget->isThumb() &&
4278            "Unexpected ISD::ATOMIC_FENCE encountered. Should be libcall!");
4279     return DAG.getNode(ARMISD::MEMBARRIER_MCR, dl, MVT::Other, Op.getOperand(0),
4280                        DAG.getConstant(0, dl, MVT::i32));
4281   }
4282 
4283   AtomicOrdering Ord =
4284       static_cast<AtomicOrdering>(Op.getConstantOperandVal(1));
4285   ARM_MB::MemBOpt Domain = ARM_MB::ISH;
4286   if (Subtarget->isMClass()) {
4287     // Only a full system barrier exists in the M-class architectures.
4288     Domain = ARM_MB::SY;
4289   } else if (Subtarget->preferISHSTBarriers() &&
4290              Ord == AtomicOrdering::Release) {
4291     // Swift happens to implement ISHST barriers in a way that's compatible with
4292     // Release semantics but weaker than ISH so we'd be fools not to use
4293     // it. Beware: other processors probably don't!
4294     Domain = ARM_MB::ISHST;
4295   }
4296 
4297   return DAG.getNode(ISD::INTRINSIC_VOID, dl, MVT::Other, Op.getOperand(0),
4298                      DAG.getConstant(Intrinsic::arm_dmb, dl, MVT::i32),
4299                      DAG.getConstant(Domain, dl, MVT::i32));
4300 }
4301 
LowerPREFETCH(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)4302 static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG,
4303                              const ARMSubtarget *Subtarget) {
4304   // ARM pre v5TE and Thumb1 does not have preload instructions.
4305   if (!(Subtarget->isThumb2() ||
4306         (!Subtarget->isThumb1Only() && Subtarget->hasV5TEOps())))
4307     // Just preserve the chain.
4308     return Op.getOperand(0);
4309 
4310   SDLoc dl(Op);
4311   unsigned isRead = ~Op.getConstantOperandVal(2) & 1;
4312   if (!isRead &&
4313       (!Subtarget->hasV7Ops() || !Subtarget->hasMPExtension()))
4314     // ARMv7 with MP extension has PLDW.
4315     return Op.getOperand(0);
4316 
4317   unsigned isData = Op.getConstantOperandVal(4);
4318   if (Subtarget->isThumb()) {
4319     // Invert the bits.
4320     isRead = ~isRead & 1;
4321     isData = ~isData & 1;
4322   }
4323 
4324   return DAG.getNode(ARMISD::PRELOAD, dl, MVT::Other, Op.getOperand(0),
4325                      Op.getOperand(1), DAG.getConstant(isRead, dl, MVT::i32),
4326                      DAG.getConstant(isData, dl, MVT::i32));
4327 }
4328 
LowerVASTART(SDValue Op,SelectionDAG & DAG)4329 static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) {
4330   MachineFunction &MF = DAG.getMachineFunction();
4331   ARMFunctionInfo *FuncInfo = MF.getInfo<ARMFunctionInfo>();
4332 
4333   // vastart just stores the address of the VarArgsFrameIndex slot into the
4334   // memory location argument.
4335   SDLoc dl(Op);
4336   EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
4337   SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
4338   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
4339   return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1),
4340                       MachinePointerInfo(SV));
4341 }
4342 
GetF64FormalArgument(CCValAssign & VA,CCValAssign & NextVA,SDValue & Root,SelectionDAG & DAG,const SDLoc & dl) const4343 SDValue ARMTargetLowering::GetF64FormalArgument(CCValAssign &VA,
4344                                                 CCValAssign &NextVA,
4345                                                 SDValue &Root,
4346                                                 SelectionDAG &DAG,
4347                                                 const SDLoc &dl) const {
4348   MachineFunction &MF = DAG.getMachineFunction();
4349   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
4350 
4351   const TargetRegisterClass *RC;
4352   if (AFI->isThumb1OnlyFunction())
4353     RC = &ARM::tGPRRegClass;
4354   else
4355     RC = &ARM::GPRRegClass;
4356 
4357   // Transform the arguments stored in physical registers into virtual ones.
4358   Register Reg = MF.addLiveIn(VA.getLocReg(), RC);
4359   SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
4360 
4361   SDValue ArgValue2;
4362   if (NextVA.isMemLoc()) {
4363     MachineFrameInfo &MFI = MF.getFrameInfo();
4364     int FI = MFI.CreateFixedObject(4, NextVA.getLocMemOffset(), true);
4365 
4366     // Create load node to retrieve arguments from the stack.
4367     SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4368     ArgValue2 = DAG.getLoad(
4369         MVT::i32, dl, Root, FIN,
4370         MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
4371   } else {
4372     Reg = MF.addLiveIn(NextVA.getLocReg(), RC);
4373     ArgValue2 = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
4374   }
4375   if (!Subtarget->isLittle())
4376     std::swap (ArgValue, ArgValue2);
4377   return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, ArgValue, ArgValue2);
4378 }
4379 
4380 // The remaining GPRs hold either the beginning of variable-argument
4381 // data, or the beginning of an aggregate passed by value (usually
4382 // byval).  Either way, we allocate stack slots adjacent to the data
4383 // provided by our caller, and store the unallocated registers there.
4384 // If this is a variadic function, the va_list pointer will begin with
4385 // these values; otherwise, this reassembles a (byval) structure that
4386 // was split between registers and memory.
4387 // Return: The frame index registers were stored into.
StoreByValRegs(CCState & CCInfo,SelectionDAG & DAG,const SDLoc & dl,SDValue & Chain,const Value * OrigArg,unsigned InRegsParamRecordIdx,int ArgOffset,unsigned ArgSize) const4388 int ARMTargetLowering::StoreByValRegs(CCState &CCInfo, SelectionDAG &DAG,
4389                                       const SDLoc &dl, SDValue &Chain,
4390                                       const Value *OrigArg,
4391                                       unsigned InRegsParamRecordIdx,
4392                                       int ArgOffset, unsigned ArgSize) const {
4393   // Currently, two use-cases possible:
4394   // Case #1. Non-var-args function, and we meet first byval parameter.
4395   //          Setup first unallocated register as first byval register;
4396   //          eat all remained registers
4397   //          (these two actions are performed by HandleByVal method).
4398   //          Then, here, we initialize stack frame with
4399   //          "store-reg" instructions.
4400   // Case #2. Var-args function, that doesn't contain byval parameters.
4401   //          The same: eat all remained unallocated registers,
4402   //          initialize stack frame.
4403 
4404   MachineFunction &MF = DAG.getMachineFunction();
4405   MachineFrameInfo &MFI = MF.getFrameInfo();
4406   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
4407   unsigned RBegin, REnd;
4408   if (InRegsParamRecordIdx < CCInfo.getInRegsParamsCount()) {
4409     CCInfo.getInRegsParamInfo(InRegsParamRecordIdx, RBegin, REnd);
4410   } else {
4411     unsigned RBeginIdx = CCInfo.getFirstUnallocated(GPRArgRegs);
4412     RBegin = RBeginIdx == 4 ? (unsigned)ARM::R4 : GPRArgRegs[RBeginIdx];
4413     REnd = ARM::R4;
4414   }
4415 
4416   if (REnd != RBegin)
4417     ArgOffset = -4 * (ARM::R4 - RBegin);
4418 
4419   auto PtrVT = getPointerTy(DAG.getDataLayout());
4420   int FrameIndex = MFI.CreateFixedObject(ArgSize, ArgOffset, false);
4421   SDValue FIN = DAG.getFrameIndex(FrameIndex, PtrVT);
4422 
4423   SmallVector<SDValue, 4> MemOps;
4424   const TargetRegisterClass *RC =
4425       AFI->isThumb1OnlyFunction() ? &ARM::tGPRRegClass : &ARM::GPRRegClass;
4426 
4427   for (unsigned Reg = RBegin, i = 0; Reg < REnd; ++Reg, ++i) {
4428     Register VReg = MF.addLiveIn(Reg, RC);
4429     SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
4430     SDValue Store = DAG.getStore(Val.getValue(1), dl, Val, FIN,
4431                                  MachinePointerInfo(OrigArg, 4 * i));
4432     MemOps.push_back(Store);
4433     FIN = DAG.getNode(ISD::ADD, dl, PtrVT, FIN, DAG.getConstant(4, dl, PtrVT));
4434   }
4435 
4436   if (!MemOps.empty())
4437     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOps);
4438   return FrameIndex;
4439 }
4440 
4441 // Setup stack frame, the va_list pointer will start from.
VarArgStyleRegisters(CCState & CCInfo,SelectionDAG & DAG,const SDLoc & dl,SDValue & Chain,unsigned ArgOffset,unsigned TotalArgRegsSaveSize,bool ForceMutable) const4442 void ARMTargetLowering::VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
4443                                              const SDLoc &dl, SDValue &Chain,
4444                                              unsigned ArgOffset,
4445                                              unsigned TotalArgRegsSaveSize,
4446                                              bool ForceMutable) const {
4447   MachineFunction &MF = DAG.getMachineFunction();
4448   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
4449 
4450   // Try to store any remaining integer argument regs
4451   // to their spots on the stack so that they may be loaded by dereferencing
4452   // the result of va_next.
4453   // If there is no regs to be stored, just point address after last
4454   // argument passed via stack.
4455   int FrameIndex = StoreByValRegs(
4456       CCInfo, DAG, dl, Chain, nullptr, CCInfo.getInRegsParamsCount(),
4457       CCInfo.getStackSize(), std::max(4U, TotalArgRegsSaveSize));
4458   AFI->setVarArgsFrameIndex(FrameIndex);
4459 }
4460 
splitValueIntoRegisterParts(SelectionDAG & DAG,const SDLoc & DL,SDValue Val,SDValue * Parts,unsigned NumParts,MVT PartVT,std::optional<CallingConv::ID> CC) const4461 bool ARMTargetLowering::splitValueIntoRegisterParts(
4462     SelectionDAG &DAG, const SDLoc &DL, SDValue Val, SDValue *Parts,
4463     unsigned NumParts, MVT PartVT, std::optional<CallingConv::ID> CC) const {
4464   EVT ValueVT = Val.getValueType();
4465   if ((ValueVT == MVT::f16 || ValueVT == MVT::bf16) && PartVT == MVT::f32) {
4466     unsigned ValueBits = ValueVT.getSizeInBits();
4467     unsigned PartBits = PartVT.getSizeInBits();
4468     Val = DAG.getNode(ISD::BITCAST, DL, MVT::getIntegerVT(ValueBits), Val);
4469     Val = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::getIntegerVT(PartBits), Val);
4470     Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
4471     Parts[0] = Val;
4472     return true;
4473   }
4474   return false;
4475 }
4476 
joinRegisterPartsIntoValue(SelectionDAG & DAG,const SDLoc & DL,const SDValue * Parts,unsigned NumParts,MVT PartVT,EVT ValueVT,std::optional<CallingConv::ID> CC) const4477 SDValue ARMTargetLowering::joinRegisterPartsIntoValue(
4478     SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts, unsigned NumParts,
4479     MVT PartVT, EVT ValueVT, std::optional<CallingConv::ID> CC) const {
4480   if ((ValueVT == MVT::f16 || ValueVT == MVT::bf16) && PartVT == MVT::f32) {
4481     unsigned ValueBits = ValueVT.getSizeInBits();
4482     unsigned PartBits = PartVT.getSizeInBits();
4483     SDValue Val = Parts[0];
4484 
4485     Val = DAG.getNode(ISD::BITCAST, DL, MVT::getIntegerVT(PartBits), Val);
4486     Val = DAG.getNode(ISD::TRUNCATE, DL, MVT::getIntegerVT(ValueBits), Val);
4487     Val = DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
4488     return Val;
4489   }
4490   return SDValue();
4491 }
4492 
LowerFormalArguments(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,const SDLoc & dl,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const4493 SDValue ARMTargetLowering::LowerFormalArguments(
4494     SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
4495     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
4496     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
4497   MachineFunction &MF = DAG.getMachineFunction();
4498   MachineFrameInfo &MFI = MF.getFrameInfo();
4499 
4500   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
4501 
4502   // Assign locations to all of the incoming arguments.
4503   SmallVector<CCValAssign, 16> ArgLocs;
4504   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs,
4505                  *DAG.getContext());
4506   CCInfo.AnalyzeFormalArguments(Ins, CCAssignFnForCall(CallConv, isVarArg));
4507 
4508   Function::const_arg_iterator CurOrigArg = MF.getFunction().arg_begin();
4509   unsigned CurArgIdx = 0;
4510 
4511   // Initially ArgRegsSaveSize is zero.
4512   // Then we increase this value each time we meet byval parameter.
4513   // We also increase this value in case of varargs function.
4514   AFI->setArgRegsSaveSize(0);
4515 
4516   // Calculate the amount of stack space that we need to allocate to store
4517   // byval and variadic arguments that are passed in registers.
4518   // We need to know this before we allocate the first byval or variadic
4519   // argument, as they will be allocated a stack slot below the CFA (Canonical
4520   // Frame Address, the stack pointer at entry to the function).
4521   unsigned ArgRegBegin = ARM::R4;
4522   for (const CCValAssign &VA : ArgLocs) {
4523     if (CCInfo.getInRegsParamsProcessed() >= CCInfo.getInRegsParamsCount())
4524       break;
4525 
4526     unsigned Index = VA.getValNo();
4527     ISD::ArgFlagsTy Flags = Ins[Index].Flags;
4528     if (!Flags.isByVal())
4529       continue;
4530 
4531     assert(VA.isMemLoc() && "unexpected byval pointer in reg");
4532     unsigned RBegin, REnd;
4533     CCInfo.getInRegsParamInfo(CCInfo.getInRegsParamsProcessed(), RBegin, REnd);
4534     ArgRegBegin = std::min(ArgRegBegin, RBegin);
4535 
4536     CCInfo.nextInRegsParam();
4537   }
4538   CCInfo.rewindByValRegsInfo();
4539 
4540   int lastInsIndex = -1;
4541   if (isVarArg && MFI.hasVAStart()) {
4542     unsigned RegIdx = CCInfo.getFirstUnallocated(GPRArgRegs);
4543     if (RegIdx != std::size(GPRArgRegs))
4544       ArgRegBegin = std::min(ArgRegBegin, (unsigned)GPRArgRegs[RegIdx]);
4545   }
4546 
4547   unsigned TotalArgRegsSaveSize = 4 * (ARM::R4 - ArgRegBegin);
4548   AFI->setArgRegsSaveSize(TotalArgRegsSaveSize);
4549   auto PtrVT = getPointerTy(DAG.getDataLayout());
4550 
4551   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
4552     CCValAssign &VA = ArgLocs[i];
4553     if (Ins[VA.getValNo()].isOrigArg()) {
4554       std::advance(CurOrigArg,
4555                    Ins[VA.getValNo()].getOrigArgIndex() - CurArgIdx);
4556       CurArgIdx = Ins[VA.getValNo()].getOrigArgIndex();
4557     }
4558     // Arguments stored in registers.
4559     if (VA.isRegLoc()) {
4560       EVT RegVT = VA.getLocVT();
4561       SDValue ArgValue;
4562 
4563       if (VA.needsCustom() && VA.getLocVT() == MVT::v2f64) {
4564         // f64 and vector types are split up into multiple registers or
4565         // combinations of registers and stack slots.
4566         SDValue ArgValue1 =
4567             GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
4568         VA = ArgLocs[++i]; // skip ahead to next loc
4569         SDValue ArgValue2;
4570         if (VA.isMemLoc()) {
4571           int FI = MFI.CreateFixedObject(8, VA.getLocMemOffset(), true);
4572           SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
4573           ArgValue2 = DAG.getLoad(
4574               MVT::f64, dl, Chain, FIN,
4575               MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
4576         } else {
4577           ArgValue2 = GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
4578         }
4579         ArgValue = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
4580         ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, ArgValue,
4581                                ArgValue1, DAG.getIntPtrConstant(0, dl));
4582         ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, ArgValue,
4583                                ArgValue2, DAG.getIntPtrConstant(1, dl));
4584       } else if (VA.needsCustom() && VA.getLocVT() == MVT::f64) {
4585         ArgValue = GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
4586       } else {
4587         const TargetRegisterClass *RC;
4588 
4589         if (RegVT == MVT::f16 || RegVT == MVT::bf16)
4590           RC = &ARM::HPRRegClass;
4591         else if (RegVT == MVT::f32)
4592           RC = &ARM::SPRRegClass;
4593         else if (RegVT == MVT::f64 || RegVT == MVT::v4f16 ||
4594                  RegVT == MVT::v4bf16)
4595           RC = &ARM::DPRRegClass;
4596         else if (RegVT == MVT::v2f64 || RegVT == MVT::v8f16 ||
4597                  RegVT == MVT::v8bf16)
4598           RC = &ARM::QPRRegClass;
4599         else if (RegVT == MVT::i32)
4600           RC = AFI->isThumb1OnlyFunction() ? &ARM::tGPRRegClass
4601                                            : &ARM::GPRRegClass;
4602         else
4603           llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
4604 
4605         // Transform the arguments in physical registers into virtual ones.
4606         Register Reg = MF.addLiveIn(VA.getLocReg(), RC);
4607         ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
4608 
4609         // If this value is passed in r0 and has the returned attribute (e.g.
4610         // C++ 'structors), record this fact for later use.
4611         if (VA.getLocReg() == ARM::R0 && Ins[VA.getValNo()].Flags.isReturned()) {
4612           AFI->setPreservesR0();
4613         }
4614       }
4615 
4616       // If this is an 8 or 16-bit value, it is really passed promoted
4617       // to 32 bits.  Insert an assert[sz]ext to capture this, then
4618       // truncate to the right size.
4619       switch (VA.getLocInfo()) {
4620       default: llvm_unreachable("Unknown loc info!");
4621       case CCValAssign::Full: break;
4622       case CCValAssign::BCvt:
4623         ArgValue = DAG.getNode(ISD::BITCAST, dl, VA.getValVT(), ArgValue);
4624         break;
4625       }
4626 
4627       // f16 arguments have their size extended to 4 bytes and passed as if they
4628       // had been copied to the LSBs of a 32-bit register.
4629       // For that, it's passed extended to i32 (soft ABI) or to f32 (hard ABI)
4630       if (VA.needsCustom() &&
4631           (VA.getValVT() == MVT::f16 || VA.getValVT() == MVT::bf16))
4632         ArgValue = MoveToHPR(dl, DAG, VA.getLocVT(), VA.getValVT(), ArgValue);
4633 
4634       // On CMSE Entry Functions, formal integer arguments whose bitwidth is
4635       // less than 32 bits must be sign- or zero-extended in the callee for
4636       // security reasons. Although the ABI mandates an extension done by the
4637       // caller, the latter cannot be trusted to follow the rules of the ABI.
4638       const ISD::InputArg &Arg = Ins[VA.getValNo()];
4639       if (AFI->isCmseNSEntryFunction() && Arg.ArgVT.isScalarInteger() &&
4640           RegVT.isScalarInteger() && Arg.ArgVT.bitsLT(MVT::i32))
4641         ArgValue = handleCMSEValue(ArgValue, Arg, DAG, dl);
4642 
4643       InVals.push_back(ArgValue);
4644     } else { // VA.isRegLoc()
4645       // Only arguments passed on the stack should make it here.
4646       assert(VA.isMemLoc());
4647       assert(VA.getValVT() != MVT::i64 && "i64 should already be lowered");
4648 
4649       int index = VA.getValNo();
4650 
4651       // Some Ins[] entries become multiple ArgLoc[] entries.
4652       // Process them only once.
4653       if (index != lastInsIndex)
4654         {
4655           ISD::ArgFlagsTy Flags = Ins[index].Flags;
4656           // FIXME: For now, all byval parameter objects are marked mutable.
4657           // This can be changed with more analysis.
4658           // In case of tail call optimization mark all arguments mutable.
4659           // Since they could be overwritten by lowering of arguments in case of
4660           // a tail call.
4661           if (Flags.isByVal()) {
4662             assert(Ins[index].isOrigArg() &&
4663                    "Byval arguments cannot be implicit");
4664             unsigned CurByValIndex = CCInfo.getInRegsParamsProcessed();
4665 
4666             int FrameIndex = StoreByValRegs(
4667                 CCInfo, DAG, dl, Chain, &*CurOrigArg, CurByValIndex,
4668                 VA.getLocMemOffset(), Flags.getByValSize());
4669             InVals.push_back(DAG.getFrameIndex(FrameIndex, PtrVT));
4670             CCInfo.nextInRegsParam();
4671           } else {
4672             unsigned FIOffset = VA.getLocMemOffset();
4673             int FI = MFI.CreateFixedObject(VA.getLocVT().getSizeInBits()/8,
4674                                            FIOffset, true);
4675 
4676             // Create load nodes to retrieve arguments from the stack.
4677             SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
4678             InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
4679                                          MachinePointerInfo::getFixedStack(
4680                                              DAG.getMachineFunction(), FI)));
4681           }
4682           lastInsIndex = index;
4683         }
4684     }
4685   }
4686 
4687   // varargs
4688   if (isVarArg && MFI.hasVAStart()) {
4689     VarArgStyleRegisters(CCInfo, DAG, dl, Chain, CCInfo.getStackSize(),
4690                          TotalArgRegsSaveSize);
4691     if (AFI->isCmseNSEntryFunction()) {
4692       DiagnosticInfoUnsupported Diag(
4693           DAG.getMachineFunction().getFunction(),
4694           "secure entry function must not be variadic", dl.getDebugLoc());
4695       DAG.getContext()->diagnose(Diag);
4696     }
4697   }
4698 
4699   unsigned StackArgSize = CCInfo.getStackSize();
4700   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
4701   if (canGuaranteeTCO(CallConv, TailCallOpt)) {
4702     // The only way to guarantee a tail call is if the callee restores its
4703     // argument area, but it must also keep the stack aligned when doing so.
4704     const DataLayout &DL = DAG.getDataLayout();
4705     StackArgSize = alignTo(StackArgSize, DL.getStackAlignment());
4706 
4707     AFI->setArgumentStackToRestore(StackArgSize);
4708   }
4709   AFI->setArgumentStackSize(StackArgSize);
4710 
4711   if (CCInfo.getStackSize() > 0 && AFI->isCmseNSEntryFunction()) {
4712     DiagnosticInfoUnsupported Diag(
4713         DAG.getMachineFunction().getFunction(),
4714         "secure entry function requires arguments on stack", dl.getDebugLoc());
4715     DAG.getContext()->diagnose(Diag);
4716   }
4717 
4718   return Chain;
4719 }
4720 
4721 /// isFloatingPointZero - Return true if this is +0.0.
isFloatingPointZero(SDValue Op)4722 static bool isFloatingPointZero(SDValue Op) {
4723   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
4724     return CFP->getValueAPF().isPosZero();
4725   else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
4726     // Maybe this has already been legalized into the constant pool?
4727     if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
4728       SDValue WrapperOp = Op.getOperand(1).getOperand(0);
4729       if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
4730         if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
4731           return CFP->getValueAPF().isPosZero();
4732     }
4733   } else if (Op->getOpcode() == ISD::BITCAST &&
4734              Op->getValueType(0) == MVT::f64) {
4735     // Handle (ISD::BITCAST (ARMISD::VMOVIMM (ISD::TargetConstant 0)) MVT::f64)
4736     // created by LowerConstantFP().
4737     SDValue BitcastOp = Op->getOperand(0);
4738     if (BitcastOp->getOpcode() == ARMISD::VMOVIMM &&
4739         isNullConstant(BitcastOp->getOperand(0)))
4740       return true;
4741   }
4742   return false;
4743 }
4744 
4745 /// Returns appropriate ARM CMP (cmp) and corresponding condition code for
4746 /// the given operands.
getARMCmp(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDValue & ARMcc,SelectionDAG & DAG,const SDLoc & dl) const4747 SDValue ARMTargetLowering::getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
4748                                      SDValue &ARMcc, SelectionDAG &DAG,
4749                                      const SDLoc &dl) const {
4750   if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
4751     unsigned C = RHSC->getZExtValue();
4752     if (!isLegalICmpImmediate((int32_t)C)) {
4753       // Constant does not fit, try adjusting it by one.
4754       switch (CC) {
4755       default: break;
4756       case ISD::SETLT:
4757       case ISD::SETGE:
4758         if (C != 0x80000000 && isLegalICmpImmediate(C-1)) {
4759           CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
4760           RHS = DAG.getConstant(C - 1, dl, MVT::i32);
4761         }
4762         break;
4763       case ISD::SETULT:
4764       case ISD::SETUGE:
4765         if (C != 0 && isLegalICmpImmediate(C-1)) {
4766           CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
4767           RHS = DAG.getConstant(C - 1, dl, MVT::i32);
4768         }
4769         break;
4770       case ISD::SETLE:
4771       case ISD::SETGT:
4772         if (C != 0x7fffffff && isLegalICmpImmediate(C+1)) {
4773           CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
4774           RHS = DAG.getConstant(C + 1, dl, MVT::i32);
4775         }
4776         break;
4777       case ISD::SETULE:
4778       case ISD::SETUGT:
4779         if (C != 0xffffffff && isLegalICmpImmediate(C+1)) {
4780           CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
4781           RHS = DAG.getConstant(C + 1, dl, MVT::i32);
4782         }
4783         break;
4784       }
4785     }
4786   } else if ((ARM_AM::getShiftOpcForNode(LHS.getOpcode()) != ARM_AM::no_shift) &&
4787              (ARM_AM::getShiftOpcForNode(RHS.getOpcode()) == ARM_AM::no_shift)) {
4788     // In ARM and Thumb-2, the compare instructions can shift their second
4789     // operand.
4790     CC = ISD::getSetCCSwappedOperands(CC);
4791     std::swap(LHS, RHS);
4792   }
4793 
4794   // Thumb1 has very limited immediate modes, so turning an "and" into a
4795   // shift can save multiple instructions.
4796   //
4797   // If we have (x & C1), and C1 is an appropriate mask, we can transform it
4798   // into "((x << n) >> n)".  But that isn't necessarily profitable on its
4799   // own. If it's the operand to an unsigned comparison with an immediate,
4800   // we can eliminate one of the shifts: we transform
4801   // "((x << n) >> n) == C2" to "(x << n) == (C2 << n)".
4802   //
4803   // We avoid transforming cases which aren't profitable due to encoding
4804   // details:
4805   //
4806   // 1. C2 fits into the immediate field of a cmp, and the transformed version
4807   // would not; in that case, we're essentially trading one immediate load for
4808   // another.
4809   // 2. C1 is 255 or 65535, so we can use uxtb or uxth.
4810   // 3. C2 is zero; we have other code for this special case.
4811   //
4812   // FIXME: Figure out profitability for Thumb2; we usually can't save an
4813   // instruction, since the AND is always one instruction anyway, but we could
4814   // use narrow instructions in some cases.
4815   if (Subtarget->isThumb1Only() && LHS->getOpcode() == ISD::AND &&
4816       LHS->hasOneUse() && isa<ConstantSDNode>(LHS.getOperand(1)) &&
4817       LHS.getValueType() == MVT::i32 && isa<ConstantSDNode>(RHS) &&
4818       !isSignedIntSetCC(CC)) {
4819     unsigned Mask = LHS.getConstantOperandVal(1);
4820     auto *RHSC = cast<ConstantSDNode>(RHS.getNode());
4821     uint64_t RHSV = RHSC->getZExtValue();
4822     if (isMask_32(Mask) && (RHSV & ~Mask) == 0 && Mask != 255 && Mask != 65535) {
4823       unsigned ShiftBits = llvm::countl_zero(Mask);
4824       if (RHSV && (RHSV > 255 || (RHSV << ShiftBits) <= 255)) {
4825         SDValue ShiftAmt = DAG.getConstant(ShiftBits, dl, MVT::i32);
4826         LHS = DAG.getNode(ISD::SHL, dl, MVT::i32, LHS.getOperand(0), ShiftAmt);
4827         RHS = DAG.getConstant(RHSV << ShiftBits, dl, MVT::i32);
4828       }
4829     }
4830   }
4831 
4832   // The specific comparison "(x<<c) > 0x80000000U" can be optimized to a
4833   // single "lsls x, c+1".  The shift sets the "C" and "Z" flags the same
4834   // way a cmp would.
4835   // FIXME: Add support for ARM/Thumb2; this would need isel patterns, and
4836   // some tweaks to the heuristics for the previous and->shift transform.
4837   // FIXME: Optimize cases where the LHS isn't a shift.
4838   if (Subtarget->isThumb1Only() && LHS->getOpcode() == ISD::SHL &&
4839       isa<ConstantSDNode>(RHS) && RHS->getAsZExtVal() == 0x80000000U &&
4840       CC == ISD::SETUGT && isa<ConstantSDNode>(LHS.getOperand(1)) &&
4841       LHS.getConstantOperandVal(1) < 31) {
4842     unsigned ShiftAmt = LHS.getConstantOperandVal(1) + 1;
4843     SDValue Shift = DAG.getNode(ARMISD::LSLS, dl,
4844                                 DAG.getVTList(MVT::i32, MVT::i32),
4845                                 LHS.getOperand(0),
4846                                 DAG.getConstant(ShiftAmt, dl, MVT::i32));
4847     SDValue Chain = DAG.getCopyToReg(DAG.getEntryNode(), dl, ARM::CPSR,
4848                                      Shift.getValue(1), SDValue());
4849     ARMcc = DAG.getConstant(ARMCC::HI, dl, MVT::i32);
4850     return Chain.getValue(1);
4851   }
4852 
4853   ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
4854 
4855   // If the RHS is a constant zero then the V (overflow) flag will never be
4856   // set. This can allow us to simplify GE to PL or LT to MI, which can be
4857   // simpler for other passes (like the peephole optimiser) to deal with.
4858   if (isNullConstant(RHS)) {
4859     switch (CondCode) {
4860       default: break;
4861       case ARMCC::GE:
4862         CondCode = ARMCC::PL;
4863         break;
4864       case ARMCC::LT:
4865         CondCode = ARMCC::MI;
4866         break;
4867     }
4868   }
4869 
4870   ARMISD::NodeType CompareType;
4871   switch (CondCode) {
4872   default:
4873     CompareType = ARMISD::CMP;
4874     break;
4875   case ARMCC::EQ:
4876   case ARMCC::NE:
4877     // Uses only Z Flag
4878     CompareType = ARMISD::CMPZ;
4879     break;
4880   }
4881   ARMcc = DAG.getConstant(CondCode, dl, MVT::i32);
4882   return DAG.getNode(CompareType, dl, MVT::Glue, LHS, RHS);
4883 }
4884 
4885 /// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
getVFPCmp(SDValue LHS,SDValue RHS,SelectionDAG & DAG,const SDLoc & dl,bool Signaling) const4886 SDValue ARMTargetLowering::getVFPCmp(SDValue LHS, SDValue RHS,
4887                                      SelectionDAG &DAG, const SDLoc &dl,
4888                                      bool Signaling) const {
4889   assert(Subtarget->hasFP64() || RHS.getValueType() != MVT::f64);
4890   SDValue Cmp;
4891   if (!isFloatingPointZero(RHS))
4892     Cmp = DAG.getNode(Signaling ? ARMISD::CMPFPE : ARMISD::CMPFP,
4893                       dl, MVT::Glue, LHS, RHS);
4894   else
4895     Cmp = DAG.getNode(Signaling ? ARMISD::CMPFPEw0 : ARMISD::CMPFPw0,
4896                       dl, MVT::Glue, LHS);
4897   return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Glue, Cmp);
4898 }
4899 
4900 /// duplicateCmp - Glue values can have only one use, so this function
4901 /// duplicates a comparison node.
4902 SDValue
duplicateCmp(SDValue Cmp,SelectionDAG & DAG) const4903 ARMTargetLowering::duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const {
4904   unsigned Opc = Cmp.getOpcode();
4905   SDLoc DL(Cmp);
4906   if (Opc == ARMISD::CMP || Opc == ARMISD::CMPZ)
4907     return DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
4908 
4909   assert(Opc == ARMISD::FMSTAT && "unexpected comparison operation");
4910   Cmp = Cmp.getOperand(0);
4911   Opc = Cmp.getOpcode();
4912   if (Opc == ARMISD::CMPFP)
4913     Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
4914   else {
4915     assert(Opc == ARMISD::CMPFPw0 && "unexpected operand of FMSTAT");
4916     Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0));
4917   }
4918   return DAG.getNode(ARMISD::FMSTAT, DL, MVT::Glue, Cmp);
4919 }
4920 
4921 // This function returns three things: the arithmetic computation itself
4922 // (Value), a comparison (OverflowCmp), and a condition code (ARMcc).  The
4923 // comparison and the condition code define the case in which the arithmetic
4924 // computation *does not* overflow.
4925 std::pair<SDValue, SDValue>
getARMXALUOOp(SDValue Op,SelectionDAG & DAG,SDValue & ARMcc) const4926 ARMTargetLowering::getARMXALUOOp(SDValue Op, SelectionDAG &DAG,
4927                                  SDValue &ARMcc) const {
4928   assert(Op.getValueType() == MVT::i32 &&  "Unsupported value type");
4929 
4930   SDValue Value, OverflowCmp;
4931   SDValue LHS = Op.getOperand(0);
4932   SDValue RHS = Op.getOperand(1);
4933   SDLoc dl(Op);
4934 
4935   // FIXME: We are currently always generating CMPs because we don't support
4936   // generating CMN through the backend. This is not as good as the natural
4937   // CMP case because it causes a register dependency and cannot be folded
4938   // later.
4939 
4940   switch (Op.getOpcode()) {
4941   default:
4942     llvm_unreachable("Unknown overflow instruction!");
4943   case ISD::SADDO:
4944     ARMcc = DAG.getConstant(ARMCC::VC, dl, MVT::i32);
4945     Value = DAG.getNode(ISD::ADD, dl, Op.getValueType(), LHS, RHS);
4946     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, Value, LHS);
4947     break;
4948   case ISD::UADDO:
4949     ARMcc = DAG.getConstant(ARMCC::HS, dl, MVT::i32);
4950     // We use ADDC here to correspond to its use in LowerUnsignedALUO.
4951     // We do not use it in the USUBO case as Value may not be used.
4952     Value = DAG.getNode(ARMISD::ADDC, dl,
4953                         DAG.getVTList(Op.getValueType(), MVT::i32), LHS, RHS)
4954                 .getValue(0);
4955     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, Value, LHS);
4956     break;
4957   case ISD::SSUBO:
4958     ARMcc = DAG.getConstant(ARMCC::VC, dl, MVT::i32);
4959     Value = DAG.getNode(ISD::SUB, dl, Op.getValueType(), LHS, RHS);
4960     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, LHS, RHS);
4961     break;
4962   case ISD::USUBO:
4963     ARMcc = DAG.getConstant(ARMCC::HS, dl, MVT::i32);
4964     Value = DAG.getNode(ISD::SUB, dl, Op.getValueType(), LHS, RHS);
4965     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, LHS, RHS);
4966     break;
4967   case ISD::UMULO:
4968     // We generate a UMUL_LOHI and then check if the high word is 0.
4969     ARMcc = DAG.getConstant(ARMCC::EQ, dl, MVT::i32);
4970     Value = DAG.getNode(ISD::UMUL_LOHI, dl,
4971                         DAG.getVTList(Op.getValueType(), Op.getValueType()),
4972                         LHS, RHS);
4973     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, Value.getValue(1),
4974                               DAG.getConstant(0, dl, MVT::i32));
4975     Value = Value.getValue(0); // We only want the low 32 bits for the result.
4976     break;
4977   case ISD::SMULO:
4978     // We generate a SMUL_LOHI and then check if all the bits of the high word
4979     // are the same as the sign bit of the low word.
4980     ARMcc = DAG.getConstant(ARMCC::EQ, dl, MVT::i32);
4981     Value = DAG.getNode(ISD::SMUL_LOHI, dl,
4982                         DAG.getVTList(Op.getValueType(), Op.getValueType()),
4983                         LHS, RHS);
4984     OverflowCmp = DAG.getNode(ARMISD::CMP, dl, MVT::Glue, Value.getValue(1),
4985                               DAG.getNode(ISD::SRA, dl, Op.getValueType(),
4986                                           Value.getValue(0),
4987                                           DAG.getConstant(31, dl, MVT::i32)));
4988     Value = Value.getValue(0); // We only want the low 32 bits for the result.
4989     break;
4990   } // switch (...)
4991 
4992   return std::make_pair(Value, OverflowCmp);
4993 }
4994 
4995 SDValue
LowerSignedALUO(SDValue Op,SelectionDAG & DAG) const4996 ARMTargetLowering::LowerSignedALUO(SDValue Op, SelectionDAG &DAG) const {
4997   // Let legalize expand this if it isn't a legal type yet.
4998   if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
4999     return SDValue();
5000 
5001   SDValue Value, OverflowCmp;
5002   SDValue ARMcc;
5003   std::tie(Value, OverflowCmp) = getARMXALUOOp(Op, DAG, ARMcc);
5004   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5005   SDLoc dl(Op);
5006   // We use 0 and 1 as false and true values.
5007   SDValue TVal = DAG.getConstant(1, dl, MVT::i32);
5008   SDValue FVal = DAG.getConstant(0, dl, MVT::i32);
5009   EVT VT = Op.getValueType();
5010 
5011   SDValue Overflow = DAG.getNode(ARMISD::CMOV, dl, VT, TVal, FVal,
5012                                  ARMcc, CCR, OverflowCmp);
5013 
5014   SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
5015   return DAG.getNode(ISD::MERGE_VALUES, dl, VTs, Value, Overflow);
5016 }
5017 
ConvertBooleanCarryToCarryFlag(SDValue BoolCarry,SelectionDAG & DAG)5018 static SDValue ConvertBooleanCarryToCarryFlag(SDValue BoolCarry,
5019                                               SelectionDAG &DAG) {
5020   SDLoc DL(BoolCarry);
5021   EVT CarryVT = BoolCarry.getValueType();
5022 
5023   // This converts the boolean value carry into the carry flag by doing
5024   // ARMISD::SUBC Carry, 1
5025   SDValue Carry = DAG.getNode(ARMISD::SUBC, DL,
5026                               DAG.getVTList(CarryVT, MVT::i32),
5027                               BoolCarry, DAG.getConstant(1, DL, CarryVT));
5028   return Carry.getValue(1);
5029 }
5030 
ConvertCarryFlagToBooleanCarry(SDValue Flags,EVT VT,SelectionDAG & DAG)5031 static SDValue ConvertCarryFlagToBooleanCarry(SDValue Flags, EVT VT,
5032                                               SelectionDAG &DAG) {
5033   SDLoc DL(Flags);
5034 
5035   // Now convert the carry flag into a boolean carry. We do this
5036   // using ARMISD:ADDE 0, 0, Carry
5037   return DAG.getNode(ARMISD::ADDE, DL, DAG.getVTList(VT, MVT::i32),
5038                      DAG.getConstant(0, DL, MVT::i32),
5039                      DAG.getConstant(0, DL, MVT::i32), Flags);
5040 }
5041 
LowerUnsignedALUO(SDValue Op,SelectionDAG & DAG) const5042 SDValue ARMTargetLowering::LowerUnsignedALUO(SDValue Op,
5043                                              SelectionDAG &DAG) const {
5044   // Let legalize expand this if it isn't a legal type yet.
5045   if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
5046     return SDValue();
5047 
5048   SDValue LHS = Op.getOperand(0);
5049   SDValue RHS = Op.getOperand(1);
5050   SDLoc dl(Op);
5051 
5052   EVT VT = Op.getValueType();
5053   SDVTList VTs = DAG.getVTList(VT, MVT::i32);
5054   SDValue Value;
5055   SDValue Overflow;
5056   switch (Op.getOpcode()) {
5057   default:
5058     llvm_unreachable("Unknown overflow instruction!");
5059   case ISD::UADDO:
5060     Value = DAG.getNode(ARMISD::ADDC, dl, VTs, LHS, RHS);
5061     // Convert the carry flag into a boolean value.
5062     Overflow = ConvertCarryFlagToBooleanCarry(Value.getValue(1), VT, DAG);
5063     break;
5064   case ISD::USUBO: {
5065     Value = DAG.getNode(ARMISD::SUBC, dl, VTs, LHS, RHS);
5066     // Convert the carry flag into a boolean value.
5067     Overflow = ConvertCarryFlagToBooleanCarry(Value.getValue(1), VT, DAG);
5068     // ARMISD::SUBC returns 0 when we have to borrow, so make it an overflow
5069     // value. So compute 1 - C.
5070     Overflow = DAG.getNode(ISD::SUB, dl, MVT::i32,
5071                            DAG.getConstant(1, dl, MVT::i32), Overflow);
5072     break;
5073   }
5074   }
5075 
5076   return DAG.getNode(ISD::MERGE_VALUES, dl, VTs, Value, Overflow);
5077 }
5078 
LowerADDSUBSAT(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)5079 static SDValue LowerADDSUBSAT(SDValue Op, SelectionDAG &DAG,
5080                               const ARMSubtarget *Subtarget) {
5081   EVT VT = Op.getValueType();
5082   if (!Subtarget->hasV6Ops() || !Subtarget->hasDSP() || Subtarget->isThumb1Only())
5083     return SDValue();
5084   if (!VT.isSimple())
5085     return SDValue();
5086 
5087   unsigned NewOpcode;
5088   switch (VT.getSimpleVT().SimpleTy) {
5089   default:
5090     return SDValue();
5091   case MVT::i8:
5092     switch (Op->getOpcode()) {
5093     case ISD::UADDSAT:
5094       NewOpcode = ARMISD::UQADD8b;
5095       break;
5096     case ISD::SADDSAT:
5097       NewOpcode = ARMISD::QADD8b;
5098       break;
5099     case ISD::USUBSAT:
5100       NewOpcode = ARMISD::UQSUB8b;
5101       break;
5102     case ISD::SSUBSAT:
5103       NewOpcode = ARMISD::QSUB8b;
5104       break;
5105     }
5106     break;
5107   case MVT::i16:
5108     switch (Op->getOpcode()) {
5109     case ISD::UADDSAT:
5110       NewOpcode = ARMISD::UQADD16b;
5111       break;
5112     case ISD::SADDSAT:
5113       NewOpcode = ARMISD::QADD16b;
5114       break;
5115     case ISD::USUBSAT:
5116       NewOpcode = ARMISD::UQSUB16b;
5117       break;
5118     case ISD::SSUBSAT:
5119       NewOpcode = ARMISD::QSUB16b;
5120       break;
5121     }
5122     break;
5123   }
5124 
5125   SDLoc dl(Op);
5126   SDValue Add =
5127       DAG.getNode(NewOpcode, dl, MVT::i32,
5128                   DAG.getSExtOrTrunc(Op->getOperand(0), dl, MVT::i32),
5129                   DAG.getSExtOrTrunc(Op->getOperand(1), dl, MVT::i32));
5130   return DAG.getNode(ISD::TRUNCATE, dl, VT, Add);
5131 }
5132 
LowerSELECT(SDValue Op,SelectionDAG & DAG) const5133 SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
5134   SDValue Cond = Op.getOperand(0);
5135   SDValue SelectTrue = Op.getOperand(1);
5136   SDValue SelectFalse = Op.getOperand(2);
5137   SDLoc dl(Op);
5138   unsigned Opc = Cond.getOpcode();
5139 
5140   if (Cond.getResNo() == 1 &&
5141       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
5142        Opc == ISD::USUBO)) {
5143     if (!DAG.getTargetLoweringInfo().isTypeLegal(Cond->getValueType(0)))
5144       return SDValue();
5145 
5146     SDValue Value, OverflowCmp;
5147     SDValue ARMcc;
5148     std::tie(Value, OverflowCmp) = getARMXALUOOp(Cond, DAG, ARMcc);
5149     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5150     EVT VT = Op.getValueType();
5151 
5152     return getCMOV(dl, VT, SelectTrue, SelectFalse, ARMcc, CCR,
5153                    OverflowCmp, DAG);
5154   }
5155 
5156   // Convert:
5157   //
5158   //   (select (cmov 1, 0, cond), t, f) -> (cmov t, f, cond)
5159   //   (select (cmov 0, 1, cond), t, f) -> (cmov f, t, cond)
5160   //
5161   if (Cond.getOpcode() == ARMISD::CMOV && Cond.hasOneUse()) {
5162     const ConstantSDNode *CMOVTrue =
5163       dyn_cast<ConstantSDNode>(Cond.getOperand(0));
5164     const ConstantSDNode *CMOVFalse =
5165       dyn_cast<ConstantSDNode>(Cond.getOperand(1));
5166 
5167     if (CMOVTrue && CMOVFalse) {
5168       unsigned CMOVTrueVal = CMOVTrue->getZExtValue();
5169       unsigned CMOVFalseVal = CMOVFalse->getZExtValue();
5170 
5171       SDValue True;
5172       SDValue False;
5173       if (CMOVTrueVal == 1 && CMOVFalseVal == 0) {
5174         True = SelectTrue;
5175         False = SelectFalse;
5176       } else if (CMOVTrueVal == 0 && CMOVFalseVal == 1) {
5177         True = SelectFalse;
5178         False = SelectTrue;
5179       }
5180 
5181       if (True.getNode() && False.getNode()) {
5182         EVT VT = Op.getValueType();
5183         SDValue ARMcc = Cond.getOperand(2);
5184         SDValue CCR = Cond.getOperand(3);
5185         SDValue Cmp = duplicateCmp(Cond.getOperand(4), DAG);
5186         assert(True.getValueType() == VT);
5187         return getCMOV(dl, VT, True, False, ARMcc, CCR, Cmp, DAG);
5188       }
5189     }
5190   }
5191 
5192   // ARM's BooleanContents value is UndefinedBooleanContent. Mask out the
5193   // undefined bits before doing a full-word comparison with zero.
5194   Cond = DAG.getNode(ISD::AND, dl, Cond.getValueType(), Cond,
5195                      DAG.getConstant(1, dl, Cond.getValueType()));
5196 
5197   return DAG.getSelectCC(dl, Cond,
5198                          DAG.getConstant(0, dl, Cond.getValueType()),
5199                          SelectTrue, SelectFalse, ISD::SETNE);
5200 }
5201 
checkVSELConstraints(ISD::CondCode CC,ARMCC::CondCodes & CondCode,bool & swpCmpOps,bool & swpVselOps)5202 static void checkVSELConstraints(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
5203                                  bool &swpCmpOps, bool &swpVselOps) {
5204   // Start by selecting the GE condition code for opcodes that return true for
5205   // 'equality'
5206   if (CC == ISD::SETUGE || CC == ISD::SETOGE || CC == ISD::SETOLE ||
5207       CC == ISD::SETULE || CC == ISD::SETGE  || CC == ISD::SETLE)
5208     CondCode = ARMCC::GE;
5209 
5210   // and GT for opcodes that return false for 'equality'.
5211   else if (CC == ISD::SETUGT || CC == ISD::SETOGT || CC == ISD::SETOLT ||
5212            CC == ISD::SETULT || CC == ISD::SETGT  || CC == ISD::SETLT)
5213     CondCode = ARMCC::GT;
5214 
5215   // Since we are constrained to GE/GT, if the opcode contains 'less', we need
5216   // to swap the compare operands.
5217   if (CC == ISD::SETOLE || CC == ISD::SETULE || CC == ISD::SETOLT ||
5218       CC == ISD::SETULT || CC == ISD::SETLE  || CC == ISD::SETLT)
5219     swpCmpOps = true;
5220 
5221   // Both GT and GE are ordered comparisons, and return false for 'unordered'.
5222   // If we have an unordered opcode, we need to swap the operands to the VSEL
5223   // instruction (effectively negating the condition).
5224   //
5225   // This also has the effect of swapping which one of 'less' or 'greater'
5226   // returns true, so we also swap the compare operands. It also switches
5227   // whether we return true for 'equality', so we compensate by picking the
5228   // opposite condition code to our original choice.
5229   if (CC == ISD::SETULE || CC == ISD::SETULT || CC == ISD::SETUGE ||
5230       CC == ISD::SETUGT) {
5231     swpCmpOps = !swpCmpOps;
5232     swpVselOps = !swpVselOps;
5233     CondCode = CondCode == ARMCC::GT ? ARMCC::GE : ARMCC::GT;
5234   }
5235 
5236   // 'ordered' is 'anything but unordered', so use the VS condition code and
5237   // swap the VSEL operands.
5238   if (CC == ISD::SETO) {
5239     CondCode = ARMCC::VS;
5240     swpVselOps = true;
5241   }
5242 
5243   // 'unordered or not equal' is 'anything but equal', so use the EQ condition
5244   // code and swap the VSEL operands. Also do this if we don't care about the
5245   // unordered case.
5246   if (CC == ISD::SETUNE || CC == ISD::SETNE) {
5247     CondCode = ARMCC::EQ;
5248     swpVselOps = true;
5249   }
5250 }
5251 
getCMOV(const SDLoc & dl,EVT VT,SDValue FalseVal,SDValue TrueVal,SDValue ARMcc,SDValue CCR,SDValue Cmp,SelectionDAG & DAG) const5252 SDValue ARMTargetLowering::getCMOV(const SDLoc &dl, EVT VT, SDValue FalseVal,
5253                                    SDValue TrueVal, SDValue ARMcc, SDValue CCR,
5254                                    SDValue Cmp, SelectionDAG &DAG) const {
5255   if (!Subtarget->hasFP64() && VT == MVT::f64) {
5256     FalseVal = DAG.getNode(ARMISD::VMOVRRD, dl,
5257                            DAG.getVTList(MVT::i32, MVT::i32), FalseVal);
5258     TrueVal = DAG.getNode(ARMISD::VMOVRRD, dl,
5259                           DAG.getVTList(MVT::i32, MVT::i32), TrueVal);
5260 
5261     SDValue TrueLow = TrueVal.getValue(0);
5262     SDValue TrueHigh = TrueVal.getValue(1);
5263     SDValue FalseLow = FalseVal.getValue(0);
5264     SDValue FalseHigh = FalseVal.getValue(1);
5265 
5266     SDValue Low = DAG.getNode(ARMISD::CMOV, dl, MVT::i32, FalseLow, TrueLow,
5267                               ARMcc, CCR, Cmp);
5268     SDValue High = DAG.getNode(ARMISD::CMOV, dl, MVT::i32, FalseHigh, TrueHigh,
5269                                ARMcc, CCR, duplicateCmp(Cmp, DAG));
5270 
5271     return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Low, High);
5272   } else {
5273     return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMcc, CCR,
5274                        Cmp);
5275   }
5276 }
5277 
isGTorGE(ISD::CondCode CC)5278 static bool isGTorGE(ISD::CondCode CC) {
5279   return CC == ISD::SETGT || CC == ISD::SETGE;
5280 }
5281 
isLTorLE(ISD::CondCode CC)5282 static bool isLTorLE(ISD::CondCode CC) {
5283   return CC == ISD::SETLT || CC == ISD::SETLE;
5284 }
5285 
5286 // See if a conditional (LHS CC RHS ? TrueVal : FalseVal) is lower-saturating.
5287 // All of these conditions (and their <= and >= counterparts) will do:
5288 //          x < k ? k : x
5289 //          x > k ? x : k
5290 //          k < x ? x : k
5291 //          k > x ? k : x
isLowerSaturate(const SDValue LHS,const SDValue RHS,const SDValue TrueVal,const SDValue FalseVal,const ISD::CondCode CC,const SDValue K)5292 static bool isLowerSaturate(const SDValue LHS, const SDValue RHS,
5293                             const SDValue TrueVal, const SDValue FalseVal,
5294                             const ISD::CondCode CC, const SDValue K) {
5295   return (isGTorGE(CC) &&
5296           ((K == LHS && K == TrueVal) || (K == RHS && K == FalseVal))) ||
5297          (isLTorLE(CC) &&
5298           ((K == RHS && K == TrueVal) || (K == LHS && K == FalseVal)));
5299 }
5300 
5301 // Check if two chained conditionals could be converted into SSAT or USAT.
5302 //
5303 // SSAT can replace a set of two conditional selectors that bound a number to an
5304 // interval of type [k, ~k] when k + 1 is a power of 2. Here are some examples:
5305 //
5306 //     x < -k ? -k : (x > k ? k : x)
5307 //     x < -k ? -k : (x < k ? x : k)
5308 //     x > -k ? (x > k ? k : x) : -k
5309 //     x < k ? (x < -k ? -k : x) : k
5310 //     etc.
5311 //
5312 // LLVM canonicalizes these to either a min(max()) or a max(min())
5313 // pattern. This function tries to match one of these and will return a SSAT
5314 // node if successful.
5315 //
5316 // USAT works similarily to SSAT but bounds on the interval [0, k] where k + 1
5317 // is a power of 2.
LowerSaturatingConditional(SDValue Op,SelectionDAG & DAG)5318 static SDValue LowerSaturatingConditional(SDValue Op, SelectionDAG &DAG) {
5319   EVT VT = Op.getValueType();
5320   SDValue V1 = Op.getOperand(0);
5321   SDValue K1 = Op.getOperand(1);
5322   SDValue TrueVal1 = Op.getOperand(2);
5323   SDValue FalseVal1 = Op.getOperand(3);
5324   ISD::CondCode CC1 = cast<CondCodeSDNode>(Op.getOperand(4))->get();
5325 
5326   const SDValue Op2 = isa<ConstantSDNode>(TrueVal1) ? FalseVal1 : TrueVal1;
5327   if (Op2.getOpcode() != ISD::SELECT_CC)
5328     return SDValue();
5329 
5330   SDValue V2 = Op2.getOperand(0);
5331   SDValue K2 = Op2.getOperand(1);
5332   SDValue TrueVal2 = Op2.getOperand(2);
5333   SDValue FalseVal2 = Op2.getOperand(3);
5334   ISD::CondCode CC2 = cast<CondCodeSDNode>(Op2.getOperand(4))->get();
5335 
5336   SDValue V1Tmp = V1;
5337   SDValue V2Tmp = V2;
5338 
5339   // Check that the registers and the constants match a max(min()) or min(max())
5340   // pattern
5341   if (V1Tmp != TrueVal1 || V2Tmp != TrueVal2 || K1 != FalseVal1 ||
5342       K2 != FalseVal2 ||
5343       !((isGTorGE(CC1) && isLTorLE(CC2)) || (isLTorLE(CC1) && isGTorGE(CC2))))
5344     return SDValue();
5345 
5346   // Check that the constant in the lower-bound check is
5347   // the opposite of the constant in the upper-bound check
5348   // in 1's complement.
5349   if (!isa<ConstantSDNode>(K1) || !isa<ConstantSDNode>(K2))
5350     return SDValue();
5351 
5352   int64_t Val1 = cast<ConstantSDNode>(K1)->getSExtValue();
5353   int64_t Val2 = cast<ConstantSDNode>(K2)->getSExtValue();
5354   int64_t PosVal = std::max(Val1, Val2);
5355   int64_t NegVal = std::min(Val1, Val2);
5356 
5357   if (!((Val1 > Val2 && isLTorLE(CC1)) || (Val1 < Val2 && isLTorLE(CC2))) ||
5358       !isPowerOf2_64(PosVal + 1))
5359     return SDValue();
5360 
5361   // Handle the difference between USAT (unsigned) and SSAT (signed)
5362   // saturation
5363   // At this point, PosVal is guaranteed to be positive
5364   uint64_t K = PosVal;
5365   SDLoc dl(Op);
5366   if (Val1 == ~Val2)
5367     return DAG.getNode(ARMISD::SSAT, dl, VT, V2Tmp,
5368                        DAG.getConstant(llvm::countr_one(K), dl, VT));
5369   if (NegVal == 0)
5370     return DAG.getNode(ARMISD::USAT, dl, VT, V2Tmp,
5371                        DAG.getConstant(llvm::countr_one(K), dl, VT));
5372 
5373   return SDValue();
5374 }
5375 
5376 // Check if a condition of the type x < k ? k : x can be converted into a
5377 // bit operation instead of conditional moves.
5378 // Currently this is allowed given:
5379 // - The conditions and values match up
5380 // - k is 0 or -1 (all ones)
5381 // This function will not check the last condition, thats up to the caller
5382 // It returns true if the transformation can be made, and in such case
5383 // returns x in V, and k in SatK.
isLowerSaturatingConditional(const SDValue & Op,SDValue & V,SDValue & SatK)5384 static bool isLowerSaturatingConditional(const SDValue &Op, SDValue &V,
5385                                          SDValue &SatK)
5386 {
5387   SDValue LHS = Op.getOperand(0);
5388   SDValue RHS = Op.getOperand(1);
5389   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
5390   SDValue TrueVal = Op.getOperand(2);
5391   SDValue FalseVal = Op.getOperand(3);
5392 
5393   SDValue *K = isa<ConstantSDNode>(LHS) ? &LHS : isa<ConstantSDNode>(RHS)
5394                                                ? &RHS
5395                                                : nullptr;
5396 
5397   // No constant operation in comparison, early out
5398   if (!K)
5399     return false;
5400 
5401   SDValue KTmp = isa<ConstantSDNode>(TrueVal) ? TrueVal : FalseVal;
5402   V = (KTmp == TrueVal) ? FalseVal : TrueVal;
5403   SDValue VTmp = (K && *K == LHS) ? RHS : LHS;
5404 
5405   // If the constant on left and right side, or variable on left and right,
5406   // does not match, early out
5407   if (*K != KTmp || V != VTmp)
5408     return false;
5409 
5410   if (isLowerSaturate(LHS, RHS, TrueVal, FalseVal, CC, *K)) {
5411     SatK = *K;
5412     return true;
5413   }
5414 
5415   return false;
5416 }
5417 
isUnsupportedFloatingType(EVT VT) const5418 bool ARMTargetLowering::isUnsupportedFloatingType(EVT VT) const {
5419   if (VT == MVT::f32)
5420     return !Subtarget->hasVFP2Base();
5421   if (VT == MVT::f64)
5422     return !Subtarget->hasFP64();
5423   if (VT == MVT::f16)
5424     return !Subtarget->hasFullFP16();
5425   return false;
5426 }
5427 
LowerSELECT_CC(SDValue Op,SelectionDAG & DAG) const5428 SDValue ARMTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
5429   EVT VT = Op.getValueType();
5430   SDLoc dl(Op);
5431 
5432   // Try to convert two saturating conditional selects into a single SSAT
5433   if ((!Subtarget->isThumb() && Subtarget->hasV6Ops()) || Subtarget->isThumb2())
5434     if (SDValue SatValue = LowerSaturatingConditional(Op, DAG))
5435       return SatValue;
5436 
5437   // Try to convert expressions of the form x < k ? k : x (and similar forms)
5438   // into more efficient bit operations, which is possible when k is 0 or -1
5439   // On ARM and Thumb-2 which have flexible operand 2 this will result in
5440   // single instructions. On Thumb the shift and the bit operation will be two
5441   // instructions.
5442   // Only allow this transformation on full-width (32-bit) operations
5443   SDValue LowerSatConstant;
5444   SDValue SatValue;
5445   if (VT == MVT::i32 &&
5446       isLowerSaturatingConditional(Op, SatValue, LowerSatConstant)) {
5447     SDValue ShiftV = DAG.getNode(ISD::SRA, dl, VT, SatValue,
5448                                  DAG.getConstant(31, dl, VT));
5449     if (isNullConstant(LowerSatConstant)) {
5450       SDValue NotShiftV = DAG.getNode(ISD::XOR, dl, VT, ShiftV,
5451                                       DAG.getAllOnesConstant(dl, VT));
5452       return DAG.getNode(ISD::AND, dl, VT, SatValue, NotShiftV);
5453     } else if (isAllOnesConstant(LowerSatConstant))
5454       return DAG.getNode(ISD::OR, dl, VT, SatValue, ShiftV);
5455   }
5456 
5457   SDValue LHS = Op.getOperand(0);
5458   SDValue RHS = Op.getOperand(1);
5459   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
5460   SDValue TrueVal = Op.getOperand(2);
5461   SDValue FalseVal = Op.getOperand(3);
5462   ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FalseVal);
5463   ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TrueVal);
5464 
5465   if (Subtarget->hasV8_1MMainlineOps() && CFVal && CTVal &&
5466       LHS.getValueType() == MVT::i32 && RHS.getValueType() == MVT::i32) {
5467     unsigned TVal = CTVal->getZExtValue();
5468     unsigned FVal = CFVal->getZExtValue();
5469     unsigned Opcode = 0;
5470 
5471     if (TVal == ~FVal) {
5472       Opcode = ARMISD::CSINV;
5473     } else if (TVal == ~FVal + 1) {
5474       Opcode = ARMISD::CSNEG;
5475     } else if (TVal + 1 == FVal) {
5476       Opcode = ARMISD::CSINC;
5477     } else if (TVal == FVal + 1) {
5478       Opcode = ARMISD::CSINC;
5479       std::swap(TrueVal, FalseVal);
5480       std::swap(TVal, FVal);
5481       CC = ISD::getSetCCInverse(CC, LHS.getValueType());
5482     }
5483 
5484     if (Opcode) {
5485       // If one of the constants is cheaper than another, materialise the
5486       // cheaper one and let the csel generate the other.
5487       if (Opcode != ARMISD::CSINC &&
5488           HasLowerConstantMaterializationCost(FVal, TVal, Subtarget)) {
5489         std::swap(TrueVal, FalseVal);
5490         std::swap(TVal, FVal);
5491         CC = ISD::getSetCCInverse(CC, LHS.getValueType());
5492       }
5493 
5494       // Attempt to use ZR checking TVal is 0, possibly inverting the condition
5495       // to get there. CSINC not is invertable like the other two (~(~a) == a,
5496       // -(-a) == a, but (a+1)+1 != a).
5497       if (FVal == 0 && Opcode != ARMISD::CSINC) {
5498         std::swap(TrueVal, FalseVal);
5499         std::swap(TVal, FVal);
5500         CC = ISD::getSetCCInverse(CC, LHS.getValueType());
5501       }
5502 
5503       // Drops F's value because we can get it by inverting/negating TVal.
5504       FalseVal = TrueVal;
5505 
5506       SDValue ARMcc;
5507       SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
5508       EVT VT = TrueVal.getValueType();
5509       return DAG.getNode(Opcode, dl, VT, TrueVal, FalseVal, ARMcc, Cmp);
5510     }
5511   }
5512 
5513   if (isUnsupportedFloatingType(LHS.getValueType())) {
5514     DAG.getTargetLoweringInfo().softenSetCCOperands(
5515         DAG, LHS.getValueType(), LHS, RHS, CC, dl, LHS, RHS);
5516 
5517     // If softenSetCCOperands only returned one value, we should compare it to
5518     // zero.
5519     if (!RHS.getNode()) {
5520       RHS = DAG.getConstant(0, dl, LHS.getValueType());
5521       CC = ISD::SETNE;
5522     }
5523   }
5524 
5525   if (LHS.getValueType() == MVT::i32) {
5526     // Try to generate VSEL on ARMv8.
5527     // The VSEL instruction can't use all the usual ARM condition
5528     // codes: it only has two bits to select the condition code, so it's
5529     // constrained to use only GE, GT, VS and EQ.
5530     //
5531     // To implement all the various ISD::SETXXX opcodes, we sometimes need to
5532     // swap the operands of the previous compare instruction (effectively
5533     // inverting the compare condition, swapping 'less' and 'greater') and
5534     // sometimes need to swap the operands to the VSEL (which inverts the
5535     // condition in the sense of firing whenever the previous condition didn't)
5536     if (Subtarget->hasFPARMv8Base() && (TrueVal.getValueType() == MVT::f16 ||
5537                                         TrueVal.getValueType() == MVT::f32 ||
5538                                         TrueVal.getValueType() == MVT::f64)) {
5539       ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
5540       if (CondCode == ARMCC::LT || CondCode == ARMCC::LE ||
5541           CondCode == ARMCC::VC || CondCode == ARMCC::NE) {
5542         CC = ISD::getSetCCInverse(CC, LHS.getValueType());
5543         std::swap(TrueVal, FalseVal);
5544       }
5545     }
5546 
5547     SDValue ARMcc;
5548     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5549     SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
5550     // Choose GE over PL, which vsel does now support
5551     if (ARMcc->getAsZExtVal() == ARMCC::PL)
5552       ARMcc = DAG.getConstant(ARMCC::GE, dl, MVT::i32);
5553     return getCMOV(dl, VT, FalseVal, TrueVal, ARMcc, CCR, Cmp, DAG);
5554   }
5555 
5556   ARMCC::CondCodes CondCode, CondCode2;
5557   FPCCToARMCC(CC, CondCode, CondCode2);
5558 
5559   // Normalize the fp compare. If RHS is zero we prefer to keep it there so we
5560   // match CMPFPw0 instead of CMPFP, though we don't do this for f16 because we
5561   // must use VSEL (limited condition codes), due to not having conditional f16
5562   // moves.
5563   if (Subtarget->hasFPARMv8Base() &&
5564       !(isFloatingPointZero(RHS) && TrueVal.getValueType() != MVT::f16) &&
5565       (TrueVal.getValueType() == MVT::f16 ||
5566        TrueVal.getValueType() == MVT::f32 ||
5567        TrueVal.getValueType() == MVT::f64)) {
5568     bool swpCmpOps = false;
5569     bool swpVselOps = false;
5570     checkVSELConstraints(CC, CondCode, swpCmpOps, swpVselOps);
5571 
5572     if (CondCode == ARMCC::GT || CondCode == ARMCC::GE ||
5573         CondCode == ARMCC::VS || CondCode == ARMCC::EQ) {
5574       if (swpCmpOps)
5575         std::swap(LHS, RHS);
5576       if (swpVselOps)
5577         std::swap(TrueVal, FalseVal);
5578     }
5579   }
5580 
5581   SDValue ARMcc = DAG.getConstant(CondCode, dl, MVT::i32);
5582   SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
5583   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5584   SDValue Result = getCMOV(dl, VT, FalseVal, TrueVal, ARMcc, CCR, Cmp, DAG);
5585   if (CondCode2 != ARMCC::AL) {
5586     SDValue ARMcc2 = DAG.getConstant(CondCode2, dl, MVT::i32);
5587     // FIXME: Needs another CMP because flag can have but one use.
5588     SDValue Cmp2 = getVFPCmp(LHS, RHS, DAG, dl);
5589     Result = getCMOV(dl, VT, Result, TrueVal, ARMcc2, CCR, Cmp2, DAG);
5590   }
5591   return Result;
5592 }
5593 
5594 /// canChangeToInt - Given the fp compare operand, return true if it is suitable
5595 /// to morph to an integer compare sequence.
canChangeToInt(SDValue Op,bool & SeenZero,const ARMSubtarget * Subtarget)5596 static bool canChangeToInt(SDValue Op, bool &SeenZero,
5597                            const ARMSubtarget *Subtarget) {
5598   SDNode *N = Op.getNode();
5599   if (!N->hasOneUse())
5600     // Otherwise it requires moving the value from fp to integer registers.
5601     return false;
5602   if (!N->getNumValues())
5603     return false;
5604   EVT VT = Op.getValueType();
5605   if (VT != MVT::f32 && !Subtarget->isFPBrccSlow())
5606     // f32 case is generally profitable. f64 case only makes sense when vcmpe +
5607     // vmrs are very slow, e.g. cortex-a8.
5608     return false;
5609 
5610   if (isFloatingPointZero(Op)) {
5611     SeenZero = true;
5612     return true;
5613   }
5614   return ISD::isNormalLoad(N);
5615 }
5616 
bitcastf32Toi32(SDValue Op,SelectionDAG & DAG)5617 static SDValue bitcastf32Toi32(SDValue Op, SelectionDAG &DAG) {
5618   if (isFloatingPointZero(Op))
5619     return DAG.getConstant(0, SDLoc(Op), MVT::i32);
5620 
5621   if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Op))
5622     return DAG.getLoad(MVT::i32, SDLoc(Op), Ld->getChain(), Ld->getBasePtr(),
5623                        Ld->getPointerInfo(), Ld->getAlign(),
5624                        Ld->getMemOperand()->getFlags());
5625 
5626   llvm_unreachable("Unknown VFP cmp argument!");
5627 }
5628 
expandf64Toi32(SDValue Op,SelectionDAG & DAG,SDValue & RetVal1,SDValue & RetVal2)5629 static void expandf64Toi32(SDValue Op, SelectionDAG &DAG,
5630                            SDValue &RetVal1, SDValue &RetVal2) {
5631   SDLoc dl(Op);
5632 
5633   if (isFloatingPointZero(Op)) {
5634     RetVal1 = DAG.getConstant(0, dl, MVT::i32);
5635     RetVal2 = DAG.getConstant(0, dl, MVT::i32);
5636     return;
5637   }
5638 
5639   if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Op)) {
5640     SDValue Ptr = Ld->getBasePtr();
5641     RetVal1 =
5642         DAG.getLoad(MVT::i32, dl, Ld->getChain(), Ptr, Ld->getPointerInfo(),
5643                     Ld->getAlign(), Ld->getMemOperand()->getFlags());
5644 
5645     EVT PtrType = Ptr.getValueType();
5646     SDValue NewPtr = DAG.getNode(ISD::ADD, dl,
5647                                  PtrType, Ptr, DAG.getConstant(4, dl, PtrType));
5648     RetVal2 = DAG.getLoad(MVT::i32, dl, Ld->getChain(), NewPtr,
5649                           Ld->getPointerInfo().getWithOffset(4),
5650                           commonAlignment(Ld->getAlign(), 4),
5651                           Ld->getMemOperand()->getFlags());
5652     return;
5653   }
5654 
5655   llvm_unreachable("Unknown VFP cmp argument!");
5656 }
5657 
5658 /// OptimizeVFPBrcond - With -enable-unsafe-fp-math, it's legal to optimize some
5659 /// f32 and even f64 comparisons to integer ones.
5660 SDValue
OptimizeVFPBrcond(SDValue Op,SelectionDAG & DAG) const5661 ARMTargetLowering::OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const {
5662   SDValue Chain = Op.getOperand(0);
5663   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
5664   SDValue LHS = Op.getOperand(2);
5665   SDValue RHS = Op.getOperand(3);
5666   SDValue Dest = Op.getOperand(4);
5667   SDLoc dl(Op);
5668 
5669   bool LHSSeenZero = false;
5670   bool LHSOk = canChangeToInt(LHS, LHSSeenZero, Subtarget);
5671   bool RHSSeenZero = false;
5672   bool RHSOk = canChangeToInt(RHS, RHSSeenZero, Subtarget);
5673   if (LHSOk && RHSOk && (LHSSeenZero || RHSSeenZero)) {
5674     // If unsafe fp math optimization is enabled and there are no other uses of
5675     // the CMP operands, and the condition code is EQ or NE, we can optimize it
5676     // to an integer comparison.
5677     if (CC == ISD::SETOEQ)
5678       CC = ISD::SETEQ;
5679     else if (CC == ISD::SETUNE)
5680       CC = ISD::SETNE;
5681 
5682     SDValue Mask = DAG.getConstant(0x7fffffff, dl, MVT::i32);
5683     SDValue ARMcc;
5684     if (LHS.getValueType() == MVT::f32) {
5685       LHS = DAG.getNode(ISD::AND, dl, MVT::i32,
5686                         bitcastf32Toi32(LHS, DAG), Mask);
5687       RHS = DAG.getNode(ISD::AND, dl, MVT::i32,
5688                         bitcastf32Toi32(RHS, DAG), Mask);
5689       SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
5690       SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5691       return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
5692                          Chain, Dest, ARMcc, CCR, Cmp);
5693     }
5694 
5695     SDValue LHS1, LHS2;
5696     SDValue RHS1, RHS2;
5697     expandf64Toi32(LHS, DAG, LHS1, LHS2);
5698     expandf64Toi32(RHS, DAG, RHS1, RHS2);
5699     LHS2 = DAG.getNode(ISD::AND, dl, MVT::i32, LHS2, Mask);
5700     RHS2 = DAG.getNode(ISD::AND, dl, MVT::i32, RHS2, Mask);
5701     ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
5702     ARMcc = DAG.getConstant(CondCode, dl, MVT::i32);
5703     SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Glue);
5704     SDValue Ops[] = { Chain, ARMcc, LHS1, LHS2, RHS1, RHS2, Dest };
5705     return DAG.getNode(ARMISD::BCC_i64, dl, VTList, Ops);
5706   }
5707 
5708   return SDValue();
5709 }
5710 
LowerBRCOND(SDValue Op,SelectionDAG & DAG) const5711 SDValue ARMTargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
5712   SDValue Chain = Op.getOperand(0);
5713   SDValue Cond = Op.getOperand(1);
5714   SDValue Dest = Op.getOperand(2);
5715   SDLoc dl(Op);
5716 
5717   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a branch
5718   // instruction.
5719   unsigned Opc = Cond.getOpcode();
5720   bool OptimizeMul = (Opc == ISD::SMULO || Opc == ISD::UMULO) &&
5721                       !Subtarget->isThumb1Only();
5722   if (Cond.getResNo() == 1 &&
5723       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
5724        Opc == ISD::USUBO || OptimizeMul)) {
5725     // Only lower legal XALUO ops.
5726     if (!DAG.getTargetLoweringInfo().isTypeLegal(Cond->getValueType(0)))
5727       return SDValue();
5728 
5729     // The actual operation with overflow check.
5730     SDValue Value, OverflowCmp;
5731     SDValue ARMcc;
5732     std::tie(Value, OverflowCmp) = getARMXALUOOp(Cond, DAG, ARMcc);
5733 
5734     // Reverse the condition code.
5735     ARMCC::CondCodes CondCode =
5736         (ARMCC::CondCodes)cast<const ConstantSDNode>(ARMcc)->getZExtValue();
5737     CondCode = ARMCC::getOppositeCondition(CondCode);
5738     ARMcc = DAG.getConstant(CondCode, SDLoc(ARMcc), MVT::i32);
5739     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5740 
5741     return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other, Chain, Dest, ARMcc, CCR,
5742                        OverflowCmp);
5743   }
5744 
5745   return SDValue();
5746 }
5747 
LowerBR_CC(SDValue Op,SelectionDAG & DAG) const5748 SDValue ARMTargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
5749   SDValue Chain = Op.getOperand(0);
5750   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
5751   SDValue LHS = Op.getOperand(2);
5752   SDValue RHS = Op.getOperand(3);
5753   SDValue Dest = Op.getOperand(4);
5754   SDLoc dl(Op);
5755 
5756   if (isUnsupportedFloatingType(LHS.getValueType())) {
5757     DAG.getTargetLoweringInfo().softenSetCCOperands(
5758         DAG, LHS.getValueType(), LHS, RHS, CC, dl, LHS, RHS);
5759 
5760     // If softenSetCCOperands only returned one value, we should compare it to
5761     // zero.
5762     if (!RHS.getNode()) {
5763       RHS = DAG.getConstant(0, dl, LHS.getValueType());
5764       CC = ISD::SETNE;
5765     }
5766   }
5767 
5768   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a branch
5769   // instruction.
5770   unsigned Opc = LHS.getOpcode();
5771   bool OptimizeMul = (Opc == ISD::SMULO || Opc == ISD::UMULO) &&
5772                       !Subtarget->isThumb1Only();
5773   if (LHS.getResNo() == 1 && (isOneConstant(RHS) || isNullConstant(RHS)) &&
5774       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
5775        Opc == ISD::USUBO || OptimizeMul) &&
5776       (CC == ISD::SETEQ || CC == ISD::SETNE)) {
5777     // Only lower legal XALUO ops.
5778     if (!DAG.getTargetLoweringInfo().isTypeLegal(LHS->getValueType(0)))
5779       return SDValue();
5780 
5781     // The actual operation with overflow check.
5782     SDValue Value, OverflowCmp;
5783     SDValue ARMcc;
5784     std::tie(Value, OverflowCmp) = getARMXALUOOp(LHS.getValue(0), DAG, ARMcc);
5785 
5786     if ((CC == ISD::SETNE) != isOneConstant(RHS)) {
5787       // Reverse the condition code.
5788       ARMCC::CondCodes CondCode =
5789           (ARMCC::CondCodes)cast<const ConstantSDNode>(ARMcc)->getZExtValue();
5790       CondCode = ARMCC::getOppositeCondition(CondCode);
5791       ARMcc = DAG.getConstant(CondCode, SDLoc(ARMcc), MVT::i32);
5792     }
5793     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5794 
5795     return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other, Chain, Dest, ARMcc, CCR,
5796                        OverflowCmp);
5797   }
5798 
5799   if (LHS.getValueType() == MVT::i32) {
5800     SDValue ARMcc;
5801     SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
5802     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5803     return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
5804                        Chain, Dest, ARMcc, CCR, Cmp);
5805   }
5806 
5807   if (getTargetMachine().Options.UnsafeFPMath &&
5808       (CC == ISD::SETEQ || CC == ISD::SETOEQ ||
5809        CC == ISD::SETNE || CC == ISD::SETUNE)) {
5810     if (SDValue Result = OptimizeVFPBrcond(Op, DAG))
5811       return Result;
5812   }
5813 
5814   ARMCC::CondCodes CondCode, CondCode2;
5815   FPCCToARMCC(CC, CondCode, CondCode2);
5816 
5817   SDValue ARMcc = DAG.getConstant(CondCode, dl, MVT::i32);
5818   SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
5819   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
5820   SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Glue);
5821   SDValue Ops[] = { Chain, Dest, ARMcc, CCR, Cmp };
5822   SDValue Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops);
5823   if (CondCode2 != ARMCC::AL) {
5824     ARMcc = DAG.getConstant(CondCode2, dl, MVT::i32);
5825     SDValue Ops[] = { Res, Dest, ARMcc, CCR, Res.getValue(1) };
5826     Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops);
5827   }
5828   return Res;
5829 }
5830 
LowerBR_JT(SDValue Op,SelectionDAG & DAG) const5831 SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
5832   SDValue Chain = Op.getOperand(0);
5833   SDValue Table = Op.getOperand(1);
5834   SDValue Index = Op.getOperand(2);
5835   SDLoc dl(Op);
5836 
5837   EVT PTy = getPointerTy(DAG.getDataLayout());
5838   JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
5839   SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
5840   Table = DAG.getNode(ARMISD::WrapperJT, dl, MVT::i32, JTI);
5841   Index = DAG.getNode(ISD::MUL, dl, PTy, Index, DAG.getConstant(4, dl, PTy));
5842   SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Table, Index);
5843   if (Subtarget->isThumb2() || (Subtarget->hasV8MBaselineOps() && Subtarget->isThumb())) {
5844     // Thumb2 and ARMv8-M use a two-level jump. That is, it jumps into the jump table
5845     // which does another jump to the destination. This also makes it easier
5846     // to translate it to TBB / TBH later (Thumb2 only).
5847     // FIXME: This might not work if the function is extremely large.
5848     return DAG.getNode(ARMISD::BR2_JT, dl, MVT::Other, Chain,
5849                        Addr, Op.getOperand(2), JTI);
5850   }
5851   if (isPositionIndependent() || Subtarget->isROPI()) {
5852     Addr =
5853         DAG.getLoad((EVT)MVT::i32, dl, Chain, Addr,
5854                     MachinePointerInfo::getJumpTable(DAG.getMachineFunction()));
5855     Chain = Addr.getValue(1);
5856     Addr = DAG.getNode(ISD::ADD, dl, PTy, Table, Addr);
5857     return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI);
5858   } else {
5859     Addr =
5860         DAG.getLoad(PTy, dl, Chain, Addr,
5861                     MachinePointerInfo::getJumpTable(DAG.getMachineFunction()));
5862     Chain = Addr.getValue(1);
5863     return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI);
5864   }
5865 }
5866 
LowerVectorFP_TO_INT(SDValue Op,SelectionDAG & DAG)5867 static SDValue LowerVectorFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
5868   EVT VT = Op.getValueType();
5869   SDLoc dl(Op);
5870 
5871   if (Op.getValueType().getVectorElementType() == MVT::i32) {
5872     if (Op.getOperand(0).getValueType().getVectorElementType() == MVT::f32)
5873       return Op;
5874     return DAG.UnrollVectorOp(Op.getNode());
5875   }
5876 
5877   const bool HasFullFP16 = DAG.getSubtarget<ARMSubtarget>().hasFullFP16();
5878 
5879   EVT NewTy;
5880   const EVT OpTy = Op.getOperand(0).getValueType();
5881   if (OpTy == MVT::v4f32)
5882     NewTy = MVT::v4i32;
5883   else if (OpTy == MVT::v4f16 && HasFullFP16)
5884     NewTy = MVT::v4i16;
5885   else if (OpTy == MVT::v8f16 && HasFullFP16)
5886     NewTy = MVT::v8i16;
5887   else
5888     llvm_unreachable("Invalid type for custom lowering!");
5889 
5890   if (VT != MVT::v4i16 && VT != MVT::v8i16)
5891     return DAG.UnrollVectorOp(Op.getNode());
5892 
5893   Op = DAG.getNode(Op.getOpcode(), dl, NewTy, Op.getOperand(0));
5894   return DAG.getNode(ISD::TRUNCATE, dl, VT, Op);
5895 }
5896 
LowerFP_TO_INT(SDValue Op,SelectionDAG & DAG) const5897 SDValue ARMTargetLowering::LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) const {
5898   EVT VT = Op.getValueType();
5899   if (VT.isVector())
5900     return LowerVectorFP_TO_INT(Op, DAG);
5901 
5902   bool IsStrict = Op->isStrictFPOpcode();
5903   SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
5904 
5905   if (isUnsupportedFloatingType(SrcVal.getValueType())) {
5906     RTLIB::Libcall LC;
5907     if (Op.getOpcode() == ISD::FP_TO_SINT ||
5908         Op.getOpcode() == ISD::STRICT_FP_TO_SINT)
5909       LC = RTLIB::getFPTOSINT(SrcVal.getValueType(),
5910                               Op.getValueType());
5911     else
5912       LC = RTLIB::getFPTOUINT(SrcVal.getValueType(),
5913                               Op.getValueType());
5914     SDLoc Loc(Op);
5915     MakeLibCallOptions CallOptions;
5916     SDValue Chain = IsStrict ? Op.getOperand(0) : SDValue();
5917     SDValue Result;
5918     std::tie(Result, Chain) = makeLibCall(DAG, LC, Op.getValueType(), SrcVal,
5919                                           CallOptions, Loc, Chain);
5920     return IsStrict ? DAG.getMergeValues({Result, Chain}, Loc) : Result;
5921   }
5922 
5923   // FIXME: Remove this when we have strict fp instruction selection patterns
5924   if (IsStrict) {
5925     SDLoc Loc(Op);
5926     SDValue Result =
5927         DAG.getNode(Op.getOpcode() == ISD::STRICT_FP_TO_SINT ? ISD::FP_TO_SINT
5928                                                              : ISD::FP_TO_UINT,
5929                     Loc, Op.getValueType(), SrcVal);
5930     return DAG.getMergeValues({Result, Op.getOperand(0)}, Loc);
5931   }
5932 
5933   return Op;
5934 }
5935 
LowerFP_TO_INT_SAT(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)5936 static SDValue LowerFP_TO_INT_SAT(SDValue Op, SelectionDAG &DAG,
5937                                   const ARMSubtarget *Subtarget) {
5938   EVT VT = Op.getValueType();
5939   EVT ToVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
5940   EVT FromVT = Op.getOperand(0).getValueType();
5941 
5942   if (VT == MVT::i32 && ToVT == MVT::i32 && FromVT == MVT::f32)
5943     return Op;
5944   if (VT == MVT::i32 && ToVT == MVT::i32 && FromVT == MVT::f64 &&
5945       Subtarget->hasFP64())
5946     return Op;
5947   if (VT == MVT::i32 && ToVT == MVT::i32 && FromVT == MVT::f16 &&
5948       Subtarget->hasFullFP16())
5949     return Op;
5950   if (VT == MVT::v4i32 && ToVT == MVT::i32 && FromVT == MVT::v4f32 &&
5951       Subtarget->hasMVEFloatOps())
5952     return Op;
5953   if (VT == MVT::v8i16 && ToVT == MVT::i16 && FromVT == MVT::v8f16 &&
5954       Subtarget->hasMVEFloatOps())
5955     return Op;
5956 
5957   if (FromVT != MVT::v4f32 && FromVT != MVT::v8f16)
5958     return SDValue();
5959 
5960   SDLoc DL(Op);
5961   bool IsSigned = Op.getOpcode() == ISD::FP_TO_SINT_SAT;
5962   unsigned BW = ToVT.getScalarSizeInBits() - IsSigned;
5963   SDValue CVT = DAG.getNode(Op.getOpcode(), DL, VT, Op.getOperand(0),
5964                             DAG.getValueType(VT.getScalarType()));
5965   SDValue Max = DAG.getNode(IsSigned ? ISD::SMIN : ISD::UMIN, DL, VT, CVT,
5966                             DAG.getConstant((1 << BW) - 1, DL, VT));
5967   if (IsSigned)
5968     Max = DAG.getNode(ISD::SMAX, DL, VT, Max,
5969                       DAG.getConstant(-(1 << BW), DL, VT));
5970   return Max;
5971 }
5972 
LowerVectorINT_TO_FP(SDValue Op,SelectionDAG & DAG)5973 static SDValue LowerVectorINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
5974   EVT VT = Op.getValueType();
5975   SDLoc dl(Op);
5976 
5977   if (Op.getOperand(0).getValueType().getVectorElementType() == MVT::i32) {
5978     if (VT.getVectorElementType() == MVT::f32)
5979       return Op;
5980     return DAG.UnrollVectorOp(Op.getNode());
5981   }
5982 
5983   assert((Op.getOperand(0).getValueType() == MVT::v4i16 ||
5984           Op.getOperand(0).getValueType() == MVT::v8i16) &&
5985          "Invalid type for custom lowering!");
5986 
5987   const bool HasFullFP16 = DAG.getSubtarget<ARMSubtarget>().hasFullFP16();
5988 
5989   EVT DestVecType;
5990   if (VT == MVT::v4f32)
5991     DestVecType = MVT::v4i32;
5992   else if (VT == MVT::v4f16 && HasFullFP16)
5993     DestVecType = MVT::v4i16;
5994   else if (VT == MVT::v8f16 && HasFullFP16)
5995     DestVecType = MVT::v8i16;
5996   else
5997     return DAG.UnrollVectorOp(Op.getNode());
5998 
5999   unsigned CastOpc;
6000   unsigned Opc;
6001   switch (Op.getOpcode()) {
6002   default: llvm_unreachable("Invalid opcode!");
6003   case ISD::SINT_TO_FP:
6004     CastOpc = ISD::SIGN_EXTEND;
6005     Opc = ISD::SINT_TO_FP;
6006     break;
6007   case ISD::UINT_TO_FP:
6008     CastOpc = ISD::ZERO_EXTEND;
6009     Opc = ISD::UINT_TO_FP;
6010     break;
6011   }
6012 
6013   Op = DAG.getNode(CastOpc, dl, DestVecType, Op.getOperand(0));
6014   return DAG.getNode(Opc, dl, VT, Op);
6015 }
6016 
LowerINT_TO_FP(SDValue Op,SelectionDAG & DAG) const6017 SDValue ARMTargetLowering::LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) const {
6018   EVT VT = Op.getValueType();
6019   if (VT.isVector())
6020     return LowerVectorINT_TO_FP(Op, DAG);
6021   if (isUnsupportedFloatingType(VT)) {
6022     RTLIB::Libcall LC;
6023     if (Op.getOpcode() == ISD::SINT_TO_FP)
6024       LC = RTLIB::getSINTTOFP(Op.getOperand(0).getValueType(),
6025                               Op.getValueType());
6026     else
6027       LC = RTLIB::getUINTTOFP(Op.getOperand(0).getValueType(),
6028                               Op.getValueType());
6029     MakeLibCallOptions CallOptions;
6030     return makeLibCall(DAG, LC, Op.getValueType(), Op.getOperand(0),
6031                        CallOptions, SDLoc(Op)).first;
6032   }
6033 
6034   return Op;
6035 }
6036 
LowerFCOPYSIGN(SDValue Op,SelectionDAG & DAG) const6037 SDValue ARMTargetLowering::LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
6038   // Implement fcopysign with a fabs and a conditional fneg.
6039   SDValue Tmp0 = Op.getOperand(0);
6040   SDValue Tmp1 = Op.getOperand(1);
6041   SDLoc dl(Op);
6042   EVT VT = Op.getValueType();
6043   EVT SrcVT = Tmp1.getValueType();
6044   bool InGPR = Tmp0.getOpcode() == ISD::BITCAST ||
6045     Tmp0.getOpcode() == ARMISD::VMOVDRR;
6046   bool UseNEON = !InGPR && Subtarget->hasNEON();
6047 
6048   if (UseNEON) {
6049     // Use VBSL to copy the sign bit.
6050     unsigned EncodedVal = ARM_AM::createVMOVModImm(0x6, 0x80);
6051     SDValue Mask = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v2i32,
6052                                DAG.getTargetConstant(EncodedVal, dl, MVT::i32));
6053     EVT OpVT = (VT == MVT::f32) ? MVT::v2i32 : MVT::v1i64;
6054     if (VT == MVT::f64)
6055       Mask = DAG.getNode(ARMISD::VSHLIMM, dl, OpVT,
6056                          DAG.getNode(ISD::BITCAST, dl, OpVT, Mask),
6057                          DAG.getConstant(32, dl, MVT::i32));
6058     else /*if (VT == MVT::f32)*/
6059       Tmp0 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2f32, Tmp0);
6060     if (SrcVT == MVT::f32) {
6061       Tmp1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2f32, Tmp1);
6062       if (VT == MVT::f64)
6063         Tmp1 = DAG.getNode(ARMISD::VSHLIMM, dl, OpVT,
6064                            DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp1),
6065                            DAG.getConstant(32, dl, MVT::i32));
6066     } else if (VT == MVT::f32)
6067       Tmp1 = DAG.getNode(ARMISD::VSHRuIMM, dl, MVT::v1i64,
6068                          DAG.getNode(ISD::BITCAST, dl, MVT::v1i64, Tmp1),
6069                          DAG.getConstant(32, dl, MVT::i32));
6070     Tmp0 = DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp0);
6071     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp1);
6072 
6073     SDValue AllOnes = DAG.getTargetConstant(ARM_AM::createVMOVModImm(0xe, 0xff),
6074                                             dl, MVT::i32);
6075     AllOnes = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v8i8, AllOnes);
6076     SDValue MaskNot = DAG.getNode(ISD::XOR, dl, OpVT, Mask,
6077                                   DAG.getNode(ISD::BITCAST, dl, OpVT, AllOnes));
6078 
6079     SDValue Res = DAG.getNode(ISD::OR, dl, OpVT,
6080                               DAG.getNode(ISD::AND, dl, OpVT, Tmp1, Mask),
6081                               DAG.getNode(ISD::AND, dl, OpVT, Tmp0, MaskNot));
6082     if (VT == MVT::f32) {
6083       Res = DAG.getNode(ISD::BITCAST, dl, MVT::v2f32, Res);
6084       Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f32, Res,
6085                         DAG.getConstant(0, dl, MVT::i32));
6086     } else {
6087       Res = DAG.getNode(ISD::BITCAST, dl, MVT::f64, Res);
6088     }
6089 
6090     return Res;
6091   }
6092 
6093   // Bitcast operand 1 to i32.
6094   if (SrcVT == MVT::f64)
6095     Tmp1 = DAG.getNode(ARMISD::VMOVRRD, dl, DAG.getVTList(MVT::i32, MVT::i32),
6096                        Tmp1).getValue(1);
6097   Tmp1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Tmp1);
6098 
6099   // Or in the signbit with integer operations.
6100   SDValue Mask1 = DAG.getConstant(0x80000000, dl, MVT::i32);
6101   SDValue Mask2 = DAG.getConstant(0x7fffffff, dl, MVT::i32);
6102   Tmp1 = DAG.getNode(ISD::AND, dl, MVT::i32, Tmp1, Mask1);
6103   if (VT == MVT::f32) {
6104     Tmp0 = DAG.getNode(ISD::AND, dl, MVT::i32,
6105                        DAG.getNode(ISD::BITCAST, dl, MVT::i32, Tmp0), Mask2);
6106     return DAG.getNode(ISD::BITCAST, dl, MVT::f32,
6107                        DAG.getNode(ISD::OR, dl, MVT::i32, Tmp0, Tmp1));
6108   }
6109 
6110   // f64: Or the high part with signbit and then combine two parts.
6111   Tmp0 = DAG.getNode(ARMISD::VMOVRRD, dl, DAG.getVTList(MVT::i32, MVT::i32),
6112                      Tmp0);
6113   SDValue Lo = Tmp0.getValue(0);
6114   SDValue Hi = DAG.getNode(ISD::AND, dl, MVT::i32, Tmp0.getValue(1), Mask2);
6115   Hi = DAG.getNode(ISD::OR, dl, MVT::i32, Hi, Tmp1);
6116   return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
6117 }
6118 
LowerRETURNADDR(SDValue Op,SelectionDAG & DAG) const6119 SDValue ARMTargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const{
6120   MachineFunction &MF = DAG.getMachineFunction();
6121   MachineFrameInfo &MFI = MF.getFrameInfo();
6122   MFI.setReturnAddressIsTaken(true);
6123 
6124   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
6125     return SDValue();
6126 
6127   EVT VT = Op.getValueType();
6128   SDLoc dl(Op);
6129   unsigned Depth = Op.getConstantOperandVal(0);
6130   if (Depth) {
6131     SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
6132     SDValue Offset = DAG.getConstant(4, dl, MVT::i32);
6133     return DAG.getLoad(VT, dl, DAG.getEntryNode(),
6134                        DAG.getNode(ISD::ADD, dl, VT, FrameAddr, Offset),
6135                        MachinePointerInfo());
6136   }
6137 
6138   // Return LR, which contains the return address. Mark it an implicit live-in.
6139   Register Reg = MF.addLiveIn(ARM::LR, getRegClassFor(MVT::i32));
6140   return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
6141 }
6142 
LowerFRAMEADDR(SDValue Op,SelectionDAG & DAG) const6143 SDValue ARMTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
6144   const ARMBaseRegisterInfo &ARI =
6145     *static_cast<const ARMBaseRegisterInfo*>(RegInfo);
6146   MachineFunction &MF = DAG.getMachineFunction();
6147   MachineFrameInfo &MFI = MF.getFrameInfo();
6148   MFI.setFrameAddressIsTaken(true);
6149 
6150   EVT VT = Op.getValueType();
6151   SDLoc dl(Op);  // FIXME probably not meaningful
6152   unsigned Depth = Op.getConstantOperandVal(0);
6153   Register FrameReg = ARI.getFrameRegister(MF);
6154   SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
6155   while (Depth--)
6156     FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr,
6157                             MachinePointerInfo());
6158   return FrameAddr;
6159 }
6160 
6161 // FIXME? Maybe this could be a TableGen attribute on some registers and
6162 // this table could be generated automatically from RegInfo.
getRegisterByName(const char * RegName,LLT VT,const MachineFunction & MF) const6163 Register ARMTargetLowering::getRegisterByName(const char* RegName, LLT VT,
6164                                               const MachineFunction &MF) const {
6165   Register Reg = StringSwitch<unsigned>(RegName)
6166                        .Case("sp", ARM::SP)
6167                        .Default(0);
6168   if (Reg)
6169     return Reg;
6170   report_fatal_error(Twine("Invalid register name \""
6171                               + StringRef(RegName)  + "\"."));
6172 }
6173 
6174 // Result is 64 bit value so split into two 32 bit values and return as a
6175 // pair of values.
ExpandREAD_REGISTER(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG)6176 static void ExpandREAD_REGISTER(SDNode *N, SmallVectorImpl<SDValue> &Results,
6177                                 SelectionDAG &DAG) {
6178   SDLoc DL(N);
6179 
6180   // This function is only supposed to be called for i64 type destination.
6181   assert(N->getValueType(0) == MVT::i64
6182           && "ExpandREAD_REGISTER called for non-i64 type result.");
6183 
6184   SDValue Read = DAG.getNode(ISD::READ_REGISTER, DL,
6185                              DAG.getVTList(MVT::i32, MVT::i32, MVT::Other),
6186                              N->getOperand(0),
6187                              N->getOperand(1));
6188 
6189   Results.push_back(DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Read.getValue(0),
6190                     Read.getValue(1)));
6191   Results.push_back(Read.getOperand(0));
6192 }
6193 
6194 /// \p BC is a bitcast that is about to be turned into a VMOVDRR.
6195 /// When \p DstVT, the destination type of \p BC, is on the vector
6196 /// register bank and the source of bitcast, \p Op, operates on the same bank,
6197 /// it might be possible to combine them, such that everything stays on the
6198 /// vector register bank.
6199 /// \p return The node that would replace \p BT, if the combine
6200 /// is possible.
CombineVMOVDRRCandidateWithVecOp(const SDNode * BC,SelectionDAG & DAG)6201 static SDValue CombineVMOVDRRCandidateWithVecOp(const SDNode *BC,
6202                                                 SelectionDAG &DAG) {
6203   SDValue Op = BC->getOperand(0);
6204   EVT DstVT = BC->getValueType(0);
6205 
6206   // The only vector instruction that can produce a scalar (remember,
6207   // since the bitcast was about to be turned into VMOVDRR, the source
6208   // type is i64) from a vector is EXTRACT_VECTOR_ELT.
6209   // Moreover, we can do this combine only if there is one use.
6210   // Finally, if the destination type is not a vector, there is not
6211   // much point on forcing everything on the vector bank.
6212   if (!DstVT.isVector() || Op.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
6213       !Op.hasOneUse())
6214     return SDValue();
6215 
6216   // If the index is not constant, we will introduce an additional
6217   // multiply that will stick.
6218   // Give up in that case.
6219   ConstantSDNode *Index = dyn_cast<ConstantSDNode>(Op.getOperand(1));
6220   if (!Index)
6221     return SDValue();
6222   unsigned DstNumElt = DstVT.getVectorNumElements();
6223 
6224   // Compute the new index.
6225   const APInt &APIntIndex = Index->getAPIntValue();
6226   APInt NewIndex(APIntIndex.getBitWidth(), DstNumElt);
6227   NewIndex *= APIntIndex;
6228   // Check if the new constant index fits into i32.
6229   if (NewIndex.getBitWidth() > 32)
6230     return SDValue();
6231 
6232   // vMTy bitcast(i64 extractelt vNi64 src, i32 index) ->
6233   // vMTy extractsubvector vNxMTy (bitcast vNi64 src), i32 index*M)
6234   SDLoc dl(Op);
6235   SDValue ExtractSrc = Op.getOperand(0);
6236   EVT VecVT = EVT::getVectorVT(
6237       *DAG.getContext(), DstVT.getScalarType(),
6238       ExtractSrc.getValueType().getVectorNumElements() * DstNumElt);
6239   SDValue BitCast = DAG.getNode(ISD::BITCAST, dl, VecVT, ExtractSrc);
6240   return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, DstVT, BitCast,
6241                      DAG.getConstant(NewIndex.getZExtValue(), dl, MVT::i32));
6242 }
6243 
6244 /// ExpandBITCAST - If the target supports VFP, this function is called to
6245 /// expand a bit convert where either the source or destination type is i64 to
6246 /// use a VMOVDRR or VMOVRRD node.  This should not be done when the non-i64
6247 /// operand type is illegal (e.g., v2f32 for a target that doesn't support
6248 /// vectors), since the legalizer won't know what to do with that.
ExpandBITCAST(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget) const6249 SDValue ARMTargetLowering::ExpandBITCAST(SDNode *N, SelectionDAG &DAG,
6250                                          const ARMSubtarget *Subtarget) const {
6251   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6252   SDLoc dl(N);
6253   SDValue Op = N->getOperand(0);
6254 
6255   // This function is only supposed to be called for i16 and i64 types, either
6256   // as the source or destination of the bit convert.
6257   EVT SrcVT = Op.getValueType();
6258   EVT DstVT = N->getValueType(0);
6259 
6260   if ((SrcVT == MVT::i16 || SrcVT == MVT::i32) &&
6261       (DstVT == MVT::f16 || DstVT == MVT::bf16))
6262     return MoveToHPR(SDLoc(N), DAG, MVT::i32, DstVT.getSimpleVT(),
6263                      DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), MVT::i32, Op));
6264 
6265   if ((DstVT == MVT::i16 || DstVT == MVT::i32) &&
6266       (SrcVT == MVT::f16 || SrcVT == MVT::bf16))
6267     return DAG.getNode(
6268         ISD::TRUNCATE, SDLoc(N), DstVT,
6269         MoveFromHPR(SDLoc(N), DAG, MVT::i32, SrcVT.getSimpleVT(), Op));
6270 
6271   if (!(SrcVT == MVT::i64 || DstVT == MVT::i64))
6272     return SDValue();
6273 
6274   // Turn i64->f64 into VMOVDRR.
6275   if (SrcVT == MVT::i64 && TLI.isTypeLegal(DstVT)) {
6276     // Do not force values to GPRs (this is what VMOVDRR does for the inputs)
6277     // if we can combine the bitcast with its source.
6278     if (SDValue Val = CombineVMOVDRRCandidateWithVecOp(N, DAG))
6279       return Val;
6280     SDValue Lo, Hi;
6281     std::tie(Lo, Hi) = DAG.SplitScalar(Op, dl, MVT::i32, MVT::i32);
6282     return DAG.getNode(ISD::BITCAST, dl, DstVT,
6283                        DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi));
6284   }
6285 
6286   // Turn f64->i64 into VMOVRRD.
6287   if (DstVT == MVT::i64 && TLI.isTypeLegal(SrcVT)) {
6288     SDValue Cvt;
6289     if (DAG.getDataLayout().isBigEndian() && SrcVT.isVector() &&
6290         SrcVT.getVectorNumElements() > 1)
6291       Cvt = DAG.getNode(ARMISD::VMOVRRD, dl,
6292                         DAG.getVTList(MVT::i32, MVT::i32),
6293                         DAG.getNode(ARMISD::VREV64, dl, SrcVT, Op));
6294     else
6295       Cvt = DAG.getNode(ARMISD::VMOVRRD, dl,
6296                         DAG.getVTList(MVT::i32, MVT::i32), Op);
6297     // Merge the pieces into a single i64 value.
6298     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Cvt, Cvt.getValue(1));
6299   }
6300 
6301   return SDValue();
6302 }
6303 
6304 /// getZeroVector - Returns a vector of specified type with all zero elements.
6305 /// Zero vectors are used to represent vector negation and in those cases
6306 /// will be implemented with the NEON VNEG instruction.  However, VNEG does
6307 /// not support i64 elements, so sometimes the zero vectors will need to be
6308 /// explicitly constructed.  Regardless, use a canonical VMOV to create the
6309 /// zero vector.
getZeroVector(EVT VT,SelectionDAG & DAG,const SDLoc & dl)6310 static SDValue getZeroVector(EVT VT, SelectionDAG &DAG, const SDLoc &dl) {
6311   assert(VT.isVector() && "Expected a vector type");
6312   // The canonical modified immediate encoding of a zero vector is....0!
6313   SDValue EncodedVal = DAG.getTargetConstant(0, dl, MVT::i32);
6314   EVT VmovVT = VT.is128BitVector() ? MVT::v4i32 : MVT::v2i32;
6315   SDValue Vmov = DAG.getNode(ARMISD::VMOVIMM, dl, VmovVT, EncodedVal);
6316   return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
6317 }
6318 
6319 /// LowerShiftRightParts - Lower SRA_PARTS, which returns two
6320 /// i32 values and take a 2 x i32 value to shift plus a shift amount.
LowerShiftRightParts(SDValue Op,SelectionDAG & DAG) const6321 SDValue ARMTargetLowering::LowerShiftRightParts(SDValue Op,
6322                                                 SelectionDAG &DAG) const {
6323   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
6324   EVT VT = Op.getValueType();
6325   unsigned VTBits = VT.getSizeInBits();
6326   SDLoc dl(Op);
6327   SDValue ShOpLo = Op.getOperand(0);
6328   SDValue ShOpHi = Op.getOperand(1);
6329   SDValue ShAmt  = Op.getOperand(2);
6330   SDValue ARMcc;
6331   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
6332   unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
6333 
6334   assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
6335 
6336   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
6337                                  DAG.getConstant(VTBits, dl, MVT::i32), ShAmt);
6338   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
6339   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
6340                                    DAG.getConstant(VTBits, dl, MVT::i32));
6341   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
6342   SDValue LoSmallShift = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
6343   SDValue LoBigShift = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
6344   SDValue CmpLo = getARMCmp(ExtraShAmt, DAG.getConstant(0, dl, MVT::i32),
6345                             ISD::SETGE, ARMcc, DAG, dl);
6346   SDValue Lo = DAG.getNode(ARMISD::CMOV, dl, VT, LoSmallShift, LoBigShift,
6347                            ARMcc, CCR, CmpLo);
6348 
6349   SDValue HiSmallShift = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
6350   SDValue HiBigShift = Opc == ISD::SRA
6351                            ? DAG.getNode(Opc, dl, VT, ShOpHi,
6352                                          DAG.getConstant(VTBits - 1, dl, VT))
6353                            : DAG.getConstant(0, dl, VT);
6354   SDValue CmpHi = getARMCmp(ExtraShAmt, DAG.getConstant(0, dl, MVT::i32),
6355                             ISD::SETGE, ARMcc, DAG, dl);
6356   SDValue Hi = DAG.getNode(ARMISD::CMOV, dl, VT, HiSmallShift, HiBigShift,
6357                            ARMcc, CCR, CmpHi);
6358 
6359   SDValue Ops[2] = { Lo, Hi };
6360   return DAG.getMergeValues(Ops, dl);
6361 }
6362 
6363 /// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
6364 /// i32 values and take a 2 x i32 value to shift plus a shift amount.
LowerShiftLeftParts(SDValue Op,SelectionDAG & DAG) const6365 SDValue ARMTargetLowering::LowerShiftLeftParts(SDValue Op,
6366                                                SelectionDAG &DAG) const {
6367   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
6368   EVT VT = Op.getValueType();
6369   unsigned VTBits = VT.getSizeInBits();
6370   SDLoc dl(Op);
6371   SDValue ShOpLo = Op.getOperand(0);
6372   SDValue ShOpHi = Op.getOperand(1);
6373   SDValue ShAmt  = Op.getOperand(2);
6374   SDValue ARMcc;
6375   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
6376 
6377   assert(Op.getOpcode() == ISD::SHL_PARTS);
6378   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
6379                                  DAG.getConstant(VTBits, dl, MVT::i32), ShAmt);
6380   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
6381   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
6382   SDValue HiSmallShift = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
6383 
6384   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
6385                                    DAG.getConstant(VTBits, dl, MVT::i32));
6386   SDValue HiBigShift = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
6387   SDValue CmpHi = getARMCmp(ExtraShAmt, DAG.getConstant(0, dl, MVT::i32),
6388                             ISD::SETGE, ARMcc, DAG, dl);
6389   SDValue Hi = DAG.getNode(ARMISD::CMOV, dl, VT, HiSmallShift, HiBigShift,
6390                            ARMcc, CCR, CmpHi);
6391 
6392   SDValue CmpLo = getARMCmp(ExtraShAmt, DAG.getConstant(0, dl, MVT::i32),
6393                           ISD::SETGE, ARMcc, DAG, dl);
6394   SDValue LoSmallShift = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
6395   SDValue Lo = DAG.getNode(ARMISD::CMOV, dl, VT, LoSmallShift,
6396                            DAG.getConstant(0, dl, VT), ARMcc, CCR, CmpLo);
6397 
6398   SDValue Ops[2] = { Lo, Hi };
6399   return DAG.getMergeValues(Ops, dl);
6400 }
6401 
LowerGET_ROUNDING(SDValue Op,SelectionDAG & DAG) const6402 SDValue ARMTargetLowering::LowerGET_ROUNDING(SDValue Op,
6403                                              SelectionDAG &DAG) const {
6404   // The rounding mode is in bits 23:22 of the FPSCR.
6405   // The ARM rounding mode value to FLT_ROUNDS mapping is 0->1, 1->2, 2->3, 3->0
6406   // The formula we use to implement this is (((FPSCR + 1 << 22) >> 22) & 3)
6407   // so that the shift + and get folded into a bitfield extract.
6408   SDLoc dl(Op);
6409   SDValue Chain = Op.getOperand(0);
6410   SDValue Ops[] = {Chain,
6411                    DAG.getConstant(Intrinsic::arm_get_fpscr, dl, MVT::i32)};
6412 
6413   SDValue FPSCR =
6414       DAG.getNode(ISD::INTRINSIC_W_CHAIN, dl, {MVT::i32, MVT::Other}, Ops);
6415   Chain = FPSCR.getValue(1);
6416   SDValue FltRounds = DAG.getNode(ISD::ADD, dl, MVT::i32, FPSCR,
6417                                   DAG.getConstant(1U << 22, dl, MVT::i32));
6418   SDValue RMODE = DAG.getNode(ISD::SRL, dl, MVT::i32, FltRounds,
6419                               DAG.getConstant(22, dl, MVT::i32));
6420   SDValue And = DAG.getNode(ISD::AND, dl, MVT::i32, RMODE,
6421                             DAG.getConstant(3, dl, MVT::i32));
6422   return DAG.getMergeValues({And, Chain}, dl);
6423 }
6424 
LowerSET_ROUNDING(SDValue Op,SelectionDAG & DAG) const6425 SDValue ARMTargetLowering::LowerSET_ROUNDING(SDValue Op,
6426                                              SelectionDAG &DAG) const {
6427   SDLoc DL(Op);
6428   SDValue Chain = Op->getOperand(0);
6429   SDValue RMValue = Op->getOperand(1);
6430 
6431   // The rounding mode is in bits 23:22 of the FPSCR.
6432   // The llvm.set.rounding argument value to ARM rounding mode value mapping
6433   // is 0->3, 1->0, 2->1, 3->2. The formula we use to implement this is
6434   // ((arg - 1) & 3) << 22).
6435   //
6436   // It is expected that the argument of llvm.set.rounding is within the
6437   // segment [0, 3], so NearestTiesToAway (4) is not handled here. It is
6438   // responsibility of the code generated llvm.set.rounding to ensure this
6439   // condition.
6440 
6441   // Calculate new value of FPSCR[23:22].
6442   RMValue = DAG.getNode(ISD::SUB, DL, MVT::i32, RMValue,
6443                         DAG.getConstant(1, DL, MVT::i32));
6444   RMValue = DAG.getNode(ISD::AND, DL, MVT::i32, RMValue,
6445                         DAG.getConstant(0x3, DL, MVT::i32));
6446   RMValue = DAG.getNode(ISD::SHL, DL, MVT::i32, RMValue,
6447                         DAG.getConstant(ARM::RoundingBitsPos, DL, MVT::i32));
6448 
6449   // Get current value of FPSCR.
6450   SDValue Ops[] = {Chain,
6451                    DAG.getConstant(Intrinsic::arm_get_fpscr, DL, MVT::i32)};
6452   SDValue FPSCR =
6453       DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i32, MVT::Other}, Ops);
6454   Chain = FPSCR.getValue(1);
6455   FPSCR = FPSCR.getValue(0);
6456 
6457   // Put new rounding mode into FPSCR[23:22].
6458   const unsigned RMMask = ~(ARM::Rounding::rmMask << ARM::RoundingBitsPos);
6459   FPSCR = DAG.getNode(ISD::AND, DL, MVT::i32, FPSCR,
6460                       DAG.getConstant(RMMask, DL, MVT::i32));
6461   FPSCR = DAG.getNode(ISD::OR, DL, MVT::i32, FPSCR, RMValue);
6462   SDValue Ops2[] = {
6463       Chain, DAG.getConstant(Intrinsic::arm_set_fpscr, DL, MVT::i32), FPSCR};
6464   return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
6465 }
6466 
LowerSET_FPMODE(SDValue Op,SelectionDAG & DAG) const6467 SDValue ARMTargetLowering::LowerSET_FPMODE(SDValue Op,
6468                                            SelectionDAG &DAG) const {
6469   SDLoc DL(Op);
6470   SDValue Chain = Op->getOperand(0);
6471   SDValue Mode = Op->getOperand(1);
6472 
6473   // Generate nodes to build:
6474   // FPSCR = (FPSCR & FPStatusBits) | (Mode & ~FPStatusBits)
6475   SDValue Ops[] = {Chain,
6476                    DAG.getConstant(Intrinsic::arm_get_fpscr, DL, MVT::i32)};
6477   SDValue FPSCR =
6478       DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i32, MVT::Other}, Ops);
6479   Chain = FPSCR.getValue(1);
6480   FPSCR = FPSCR.getValue(0);
6481 
6482   SDValue FPSCRMasked =
6483       DAG.getNode(ISD::AND, DL, MVT::i32, FPSCR,
6484                   DAG.getConstant(ARM::FPStatusBits, DL, MVT::i32));
6485   SDValue InputMasked =
6486       DAG.getNode(ISD::AND, DL, MVT::i32, Mode,
6487                   DAG.getConstant(~ARM::FPStatusBits, DL, MVT::i32));
6488   FPSCR = DAG.getNode(ISD::OR, DL, MVT::i32, FPSCRMasked, InputMasked);
6489 
6490   SDValue Ops2[] = {
6491       Chain, DAG.getConstant(Intrinsic::arm_set_fpscr, DL, MVT::i32), FPSCR};
6492   return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
6493 }
6494 
LowerRESET_FPMODE(SDValue Op,SelectionDAG & DAG) const6495 SDValue ARMTargetLowering::LowerRESET_FPMODE(SDValue Op,
6496                                              SelectionDAG &DAG) const {
6497   SDLoc DL(Op);
6498   SDValue Chain = Op->getOperand(0);
6499 
6500   // To get the default FP mode all control bits are cleared:
6501   // FPSCR = FPSCR & (FPStatusBits | FPReservedBits)
6502   SDValue Ops[] = {Chain,
6503                    DAG.getConstant(Intrinsic::arm_get_fpscr, DL, MVT::i32)};
6504   SDValue FPSCR =
6505       DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i32, MVT::Other}, Ops);
6506   Chain = FPSCR.getValue(1);
6507   FPSCR = FPSCR.getValue(0);
6508 
6509   SDValue FPSCRMasked = DAG.getNode(
6510       ISD::AND, DL, MVT::i32, FPSCR,
6511       DAG.getConstant(ARM::FPStatusBits | ARM::FPReservedBits, DL, MVT::i32));
6512   SDValue Ops2[] = {Chain,
6513                     DAG.getConstant(Intrinsic::arm_set_fpscr, DL, MVT::i32),
6514                     FPSCRMasked};
6515   return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
6516 }
6517 
LowerCTTZ(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)6518 static SDValue LowerCTTZ(SDNode *N, SelectionDAG &DAG,
6519                          const ARMSubtarget *ST) {
6520   SDLoc dl(N);
6521   EVT VT = N->getValueType(0);
6522   if (VT.isVector() && ST->hasNEON()) {
6523 
6524     // Compute the least significant set bit: LSB = X & -X
6525     SDValue X = N->getOperand(0);
6526     SDValue NX = DAG.getNode(ISD::SUB, dl, VT, getZeroVector(VT, DAG, dl), X);
6527     SDValue LSB = DAG.getNode(ISD::AND, dl, VT, X, NX);
6528 
6529     EVT ElemTy = VT.getVectorElementType();
6530 
6531     if (ElemTy == MVT::i8) {
6532       // Compute with: cttz(x) = ctpop(lsb - 1)
6533       SDValue One = DAG.getNode(ARMISD::VMOVIMM, dl, VT,
6534                                 DAG.getTargetConstant(1, dl, ElemTy));
6535       SDValue Bits = DAG.getNode(ISD::SUB, dl, VT, LSB, One);
6536       return DAG.getNode(ISD::CTPOP, dl, VT, Bits);
6537     }
6538 
6539     if ((ElemTy == MVT::i16 || ElemTy == MVT::i32) &&
6540         (N->getOpcode() == ISD::CTTZ_ZERO_UNDEF)) {
6541       // Compute with: cttz(x) = (width - 1) - ctlz(lsb), if x != 0
6542       unsigned NumBits = ElemTy.getSizeInBits();
6543       SDValue WidthMinus1 =
6544           DAG.getNode(ARMISD::VMOVIMM, dl, VT,
6545                       DAG.getTargetConstant(NumBits - 1, dl, ElemTy));
6546       SDValue CTLZ = DAG.getNode(ISD::CTLZ, dl, VT, LSB);
6547       return DAG.getNode(ISD::SUB, dl, VT, WidthMinus1, CTLZ);
6548     }
6549 
6550     // Compute with: cttz(x) = ctpop(lsb - 1)
6551 
6552     // Compute LSB - 1.
6553     SDValue Bits;
6554     if (ElemTy == MVT::i64) {
6555       // Load constant 0xffff'ffff'ffff'ffff to register.
6556       SDValue FF = DAG.getNode(ARMISD::VMOVIMM, dl, VT,
6557                                DAG.getTargetConstant(0x1eff, dl, MVT::i32));
6558       Bits = DAG.getNode(ISD::ADD, dl, VT, LSB, FF);
6559     } else {
6560       SDValue One = DAG.getNode(ARMISD::VMOVIMM, dl, VT,
6561                                 DAG.getTargetConstant(1, dl, ElemTy));
6562       Bits = DAG.getNode(ISD::SUB, dl, VT, LSB, One);
6563     }
6564     return DAG.getNode(ISD::CTPOP, dl, VT, Bits);
6565   }
6566 
6567   if (!ST->hasV6T2Ops())
6568     return SDValue();
6569 
6570   SDValue rbit = DAG.getNode(ISD::BITREVERSE, dl, VT, N->getOperand(0));
6571   return DAG.getNode(ISD::CTLZ, dl, VT, rbit);
6572 }
6573 
LowerCTPOP(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)6574 static SDValue LowerCTPOP(SDNode *N, SelectionDAG &DAG,
6575                           const ARMSubtarget *ST) {
6576   EVT VT = N->getValueType(0);
6577   SDLoc DL(N);
6578 
6579   assert(ST->hasNEON() && "Custom ctpop lowering requires NEON.");
6580   assert((VT == MVT::v1i64 || VT == MVT::v2i64 || VT == MVT::v2i32 ||
6581           VT == MVT::v4i32 || VT == MVT::v4i16 || VT == MVT::v8i16) &&
6582          "Unexpected type for custom ctpop lowering");
6583 
6584   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
6585   EVT VT8Bit = VT.is64BitVector() ? MVT::v8i8 : MVT::v16i8;
6586   SDValue Res = DAG.getBitcast(VT8Bit, N->getOperand(0));
6587   Res = DAG.getNode(ISD::CTPOP, DL, VT8Bit, Res);
6588 
6589   // Widen v8i8/v16i8 CTPOP result to VT by repeatedly widening pairwise adds.
6590   unsigned EltSize = 8;
6591   unsigned NumElts = VT.is64BitVector() ? 8 : 16;
6592   while (EltSize != VT.getScalarSizeInBits()) {
6593     SmallVector<SDValue, 8> Ops;
6594     Ops.push_back(DAG.getConstant(Intrinsic::arm_neon_vpaddlu, DL,
6595                                   TLI.getPointerTy(DAG.getDataLayout())));
6596     Ops.push_back(Res);
6597 
6598     EltSize *= 2;
6599     NumElts /= 2;
6600     MVT WidenVT = MVT::getVectorVT(MVT::getIntegerVT(EltSize), NumElts);
6601     Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, WidenVT, Ops);
6602   }
6603 
6604   return Res;
6605 }
6606 
6607 /// Getvshiftimm - Check if this is a valid build_vector for the immediate
6608 /// operand of a vector shift operation, where all the elements of the
6609 /// build_vector must have the same constant integer value.
getVShiftImm(SDValue Op,unsigned ElementBits,int64_t & Cnt)6610 static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
6611   // Ignore bit_converts.
6612   while (Op.getOpcode() == ISD::BITCAST)
6613     Op = Op.getOperand(0);
6614   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
6615   APInt SplatBits, SplatUndef;
6616   unsigned SplatBitSize;
6617   bool HasAnyUndefs;
6618   if (!BVN ||
6619       !BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs,
6620                             ElementBits) ||
6621       SplatBitSize > ElementBits)
6622     return false;
6623   Cnt = SplatBits.getSExtValue();
6624   return true;
6625 }
6626 
6627 /// isVShiftLImm - Check if this is a valid build_vector for the immediate
6628 /// operand of a vector shift left operation.  That value must be in the range:
6629 ///   0 <= Value < ElementBits for a left shift; or
6630 ///   0 <= Value <= ElementBits for a long left shift.
isVShiftLImm(SDValue Op,EVT VT,bool isLong,int64_t & Cnt)6631 static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
6632   assert(VT.isVector() && "vector shift count is not a vector type");
6633   int64_t ElementBits = VT.getScalarSizeInBits();
6634   if (!getVShiftImm(Op, ElementBits, Cnt))
6635     return false;
6636   return (Cnt >= 0 && (isLong ? Cnt - 1 : Cnt) < ElementBits);
6637 }
6638 
6639 /// isVShiftRImm - Check if this is a valid build_vector for the immediate
6640 /// operand of a vector shift right operation.  For a shift opcode, the value
6641 /// is positive, but for an intrinsic the value count must be negative. The
6642 /// absolute value must be in the range:
6643 ///   1 <= |Value| <= ElementBits for a right shift; or
6644 ///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
isVShiftRImm(SDValue Op,EVT VT,bool isNarrow,bool isIntrinsic,int64_t & Cnt)6645 static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
6646                          int64_t &Cnt) {
6647   assert(VT.isVector() && "vector shift count is not a vector type");
6648   int64_t ElementBits = VT.getScalarSizeInBits();
6649   if (!getVShiftImm(Op, ElementBits, Cnt))
6650     return false;
6651   if (!isIntrinsic)
6652     return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits / 2 : ElementBits));
6653   if (Cnt >= -(isNarrow ? ElementBits / 2 : ElementBits) && Cnt <= -1) {
6654     Cnt = -Cnt;
6655     return true;
6656   }
6657   return false;
6658 }
6659 
LowerShift(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)6660 static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
6661                           const ARMSubtarget *ST) {
6662   EVT VT = N->getValueType(0);
6663   SDLoc dl(N);
6664   int64_t Cnt;
6665 
6666   if (!VT.isVector())
6667     return SDValue();
6668 
6669   // We essentially have two forms here. Shift by an immediate and shift by a
6670   // vector register (there are also shift by a gpr, but that is just handled
6671   // with a tablegen pattern). We cannot easily match shift by an immediate in
6672   // tablegen so we do that here and generate a VSHLIMM/VSHRsIMM/VSHRuIMM.
6673   // For shifting by a vector, we don't have VSHR, only VSHL (which can be
6674   // signed or unsigned, and a negative shift indicates a shift right).
6675   if (N->getOpcode() == ISD::SHL) {
6676     if (isVShiftLImm(N->getOperand(1), VT, false, Cnt))
6677       return DAG.getNode(ARMISD::VSHLIMM, dl, VT, N->getOperand(0),
6678                          DAG.getConstant(Cnt, dl, MVT::i32));
6679     return DAG.getNode(ARMISD::VSHLu, dl, VT, N->getOperand(0),
6680                        N->getOperand(1));
6681   }
6682 
6683   assert((N->getOpcode() == ISD::SRA || N->getOpcode() == ISD::SRL) &&
6684          "unexpected vector shift opcode");
6685 
6686   if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
6687     unsigned VShiftOpc =
6688         (N->getOpcode() == ISD::SRA ? ARMISD::VSHRsIMM : ARMISD::VSHRuIMM);
6689     return DAG.getNode(VShiftOpc, dl, VT, N->getOperand(0),
6690                        DAG.getConstant(Cnt, dl, MVT::i32));
6691   }
6692 
6693   // Other right shifts we don't have operations for (we use a shift left by a
6694   // negative number).
6695   EVT ShiftVT = N->getOperand(1).getValueType();
6696   SDValue NegatedCount = DAG.getNode(
6697       ISD::SUB, dl, ShiftVT, getZeroVector(ShiftVT, DAG, dl), N->getOperand(1));
6698   unsigned VShiftOpc =
6699       (N->getOpcode() == ISD::SRA ? ARMISD::VSHLs : ARMISD::VSHLu);
6700   return DAG.getNode(VShiftOpc, dl, VT, N->getOperand(0), NegatedCount);
6701 }
6702 
Expand64BitShift(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)6703 static SDValue Expand64BitShift(SDNode *N, SelectionDAG &DAG,
6704                                 const ARMSubtarget *ST) {
6705   EVT VT = N->getValueType(0);
6706   SDLoc dl(N);
6707 
6708   // We can get here for a node like i32 = ISD::SHL i32, i64
6709   if (VT != MVT::i64)
6710     return SDValue();
6711 
6712   assert((N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA ||
6713           N->getOpcode() == ISD::SHL) &&
6714          "Unknown shift to lower!");
6715 
6716   unsigned ShOpc = N->getOpcode();
6717   if (ST->hasMVEIntegerOps()) {
6718     SDValue ShAmt = N->getOperand(1);
6719     unsigned ShPartsOpc = ARMISD::LSLL;
6720     ConstantSDNode *Con = dyn_cast<ConstantSDNode>(ShAmt);
6721 
6722     // If the shift amount is greater than 32 or has a greater bitwidth than 64
6723     // then do the default optimisation
6724     if ((!Con && ShAmt->getValueType(0).getSizeInBits() > 64) ||
6725         (Con && (Con->getAPIntValue() == 0 || Con->getAPIntValue().uge(32))))
6726       return SDValue();
6727 
6728     // Extract the lower 32 bits of the shift amount if it's not an i32
6729     if (ShAmt->getValueType(0) != MVT::i32)
6730       ShAmt = DAG.getZExtOrTrunc(ShAmt, dl, MVT::i32);
6731 
6732     if (ShOpc == ISD::SRL) {
6733       if (!Con)
6734         // There is no t2LSRLr instruction so negate and perform an lsll if the
6735         // shift amount is in a register, emulating a right shift.
6736         ShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
6737                             DAG.getConstant(0, dl, MVT::i32), ShAmt);
6738       else
6739         // Else generate an lsrl on the immediate shift amount
6740         ShPartsOpc = ARMISD::LSRL;
6741     } else if (ShOpc == ISD::SRA)
6742       ShPartsOpc = ARMISD::ASRL;
6743 
6744     // Split Lower/Upper 32 bits of the destination/source
6745     SDValue Lo, Hi;
6746     std::tie(Lo, Hi) =
6747         DAG.SplitScalar(N->getOperand(0), dl, MVT::i32, MVT::i32);
6748     // Generate the shift operation as computed above
6749     Lo = DAG.getNode(ShPartsOpc, dl, DAG.getVTList(MVT::i32, MVT::i32), Lo, Hi,
6750                      ShAmt);
6751     // The upper 32 bits come from the second return value of lsll
6752     Hi = SDValue(Lo.getNode(), 1);
6753     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
6754   }
6755 
6756   // We only lower SRA, SRL of 1 here, all others use generic lowering.
6757   if (!isOneConstant(N->getOperand(1)) || N->getOpcode() == ISD::SHL)
6758     return SDValue();
6759 
6760   // If we are in thumb mode, we don't have RRX.
6761   if (ST->isThumb1Only())
6762     return SDValue();
6763 
6764   // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
6765   SDValue Lo, Hi;
6766   std::tie(Lo, Hi) = DAG.SplitScalar(N->getOperand(0), dl, MVT::i32, MVT::i32);
6767 
6768   // First, build a SRA_GLUE/SRL_GLUE op, which shifts the top part by one and
6769   // captures the result into a carry flag.
6770   unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_GLUE:ARMISD::SRA_GLUE;
6771   Hi = DAG.getNode(Opc, dl, DAG.getVTList(MVT::i32, MVT::Glue), Hi);
6772 
6773   // The low part is an ARMISD::RRX operand, which shifts the carry in.
6774   Lo = DAG.getNode(ARMISD::RRX, dl, MVT::i32, Lo, Hi.getValue(1));
6775 
6776   // Merge the pieces into a single i64 value.
6777  return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
6778 }
6779 
LowerVSETCC(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)6780 static SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG,
6781                            const ARMSubtarget *ST) {
6782   bool Invert = false;
6783   bool Swap = false;
6784   unsigned Opc = ARMCC::AL;
6785 
6786   SDValue Op0 = Op.getOperand(0);
6787   SDValue Op1 = Op.getOperand(1);
6788   SDValue CC = Op.getOperand(2);
6789   EVT VT = Op.getValueType();
6790   ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
6791   SDLoc dl(Op);
6792 
6793   EVT CmpVT;
6794   if (ST->hasNEON())
6795     CmpVT = Op0.getValueType().changeVectorElementTypeToInteger();
6796   else {
6797     assert(ST->hasMVEIntegerOps() &&
6798            "No hardware support for integer vector comparison!");
6799 
6800     if (Op.getValueType().getVectorElementType() != MVT::i1)
6801       return SDValue();
6802 
6803     // Make sure we expand floating point setcc to scalar if we do not have
6804     // mve.fp, so that we can handle them from there.
6805     if (Op0.getValueType().isFloatingPoint() && !ST->hasMVEFloatOps())
6806       return SDValue();
6807 
6808     CmpVT = VT;
6809   }
6810 
6811   if (Op0.getValueType().getVectorElementType() == MVT::i64 &&
6812       (SetCCOpcode == ISD::SETEQ || SetCCOpcode == ISD::SETNE)) {
6813     // Special-case integer 64-bit equality comparisons. They aren't legal,
6814     // but they can be lowered with a few vector instructions.
6815     unsigned CmpElements = CmpVT.getVectorNumElements() * 2;
6816     EVT SplitVT = EVT::getVectorVT(*DAG.getContext(), MVT::i32, CmpElements);
6817     SDValue CastOp0 = DAG.getNode(ISD::BITCAST, dl, SplitVT, Op0);
6818     SDValue CastOp1 = DAG.getNode(ISD::BITCAST, dl, SplitVT, Op1);
6819     SDValue Cmp = DAG.getNode(ISD::SETCC, dl, SplitVT, CastOp0, CastOp1,
6820                               DAG.getCondCode(ISD::SETEQ));
6821     SDValue Reversed = DAG.getNode(ARMISD::VREV64, dl, SplitVT, Cmp);
6822     SDValue Merged = DAG.getNode(ISD::AND, dl, SplitVT, Cmp, Reversed);
6823     Merged = DAG.getNode(ISD::BITCAST, dl, CmpVT, Merged);
6824     if (SetCCOpcode == ISD::SETNE)
6825       Merged = DAG.getNOT(dl, Merged, CmpVT);
6826     Merged = DAG.getSExtOrTrunc(Merged, dl, VT);
6827     return Merged;
6828   }
6829 
6830   if (CmpVT.getVectorElementType() == MVT::i64)
6831     // 64-bit comparisons are not legal in general.
6832     return SDValue();
6833 
6834   if (Op1.getValueType().isFloatingPoint()) {
6835     switch (SetCCOpcode) {
6836     default: llvm_unreachable("Illegal FP comparison");
6837     case ISD::SETUNE:
6838     case ISD::SETNE:
6839       if (ST->hasMVEFloatOps()) {
6840         Opc = ARMCC::NE; break;
6841       } else {
6842         Invert = true; [[fallthrough]];
6843       }
6844     case ISD::SETOEQ:
6845     case ISD::SETEQ:  Opc = ARMCC::EQ; break;
6846     case ISD::SETOLT:
6847     case ISD::SETLT: Swap = true; [[fallthrough]];
6848     case ISD::SETOGT:
6849     case ISD::SETGT:  Opc = ARMCC::GT; break;
6850     case ISD::SETOLE:
6851     case ISD::SETLE:  Swap = true; [[fallthrough]];
6852     case ISD::SETOGE:
6853     case ISD::SETGE: Opc = ARMCC::GE; break;
6854     case ISD::SETUGE: Swap = true; [[fallthrough]];
6855     case ISD::SETULE: Invert = true; Opc = ARMCC::GT; break;
6856     case ISD::SETUGT: Swap = true; [[fallthrough]];
6857     case ISD::SETULT: Invert = true; Opc = ARMCC::GE; break;
6858     case ISD::SETUEQ: Invert = true; [[fallthrough]];
6859     case ISD::SETONE: {
6860       // Expand this to (OLT | OGT).
6861       SDValue TmpOp0 = DAG.getNode(ARMISD::VCMP, dl, CmpVT, Op1, Op0,
6862                                    DAG.getConstant(ARMCC::GT, dl, MVT::i32));
6863       SDValue TmpOp1 = DAG.getNode(ARMISD::VCMP, dl, CmpVT, Op0, Op1,
6864                                    DAG.getConstant(ARMCC::GT, dl, MVT::i32));
6865       SDValue Result = DAG.getNode(ISD::OR, dl, CmpVT, TmpOp0, TmpOp1);
6866       if (Invert)
6867         Result = DAG.getNOT(dl, Result, VT);
6868       return Result;
6869     }
6870     case ISD::SETUO: Invert = true; [[fallthrough]];
6871     case ISD::SETO: {
6872       // Expand this to (OLT | OGE).
6873       SDValue TmpOp0 = DAG.getNode(ARMISD::VCMP, dl, CmpVT, Op1, Op0,
6874                                    DAG.getConstant(ARMCC::GT, dl, MVT::i32));
6875       SDValue TmpOp1 = DAG.getNode(ARMISD::VCMP, dl, CmpVT, Op0, Op1,
6876                                    DAG.getConstant(ARMCC::GE, dl, MVT::i32));
6877       SDValue Result = DAG.getNode(ISD::OR, dl, CmpVT, TmpOp0, TmpOp1);
6878       if (Invert)
6879         Result = DAG.getNOT(dl, Result, VT);
6880       return Result;
6881     }
6882     }
6883   } else {
6884     // Integer comparisons.
6885     switch (SetCCOpcode) {
6886     default: llvm_unreachable("Illegal integer comparison");
6887     case ISD::SETNE:
6888       if (ST->hasMVEIntegerOps()) {
6889         Opc = ARMCC::NE; break;
6890       } else {
6891         Invert = true; [[fallthrough]];
6892       }
6893     case ISD::SETEQ:  Opc = ARMCC::EQ; break;
6894     case ISD::SETLT:  Swap = true; [[fallthrough]];
6895     case ISD::SETGT:  Opc = ARMCC::GT; break;
6896     case ISD::SETLE:  Swap = true; [[fallthrough]];
6897     case ISD::SETGE:  Opc = ARMCC::GE; break;
6898     case ISD::SETULT: Swap = true; [[fallthrough]];
6899     case ISD::SETUGT: Opc = ARMCC::HI; break;
6900     case ISD::SETULE: Swap = true; [[fallthrough]];
6901     case ISD::SETUGE: Opc = ARMCC::HS; break;
6902     }
6903 
6904     // Detect VTST (Vector Test Bits) = icmp ne (and (op0, op1), zero).
6905     if (ST->hasNEON() && Opc == ARMCC::EQ) {
6906       SDValue AndOp;
6907       if (ISD::isBuildVectorAllZeros(Op1.getNode()))
6908         AndOp = Op0;
6909       else if (ISD::isBuildVectorAllZeros(Op0.getNode()))
6910         AndOp = Op1;
6911 
6912       // Ignore bitconvert.
6913       if (AndOp.getNode() && AndOp.getOpcode() == ISD::BITCAST)
6914         AndOp = AndOp.getOperand(0);
6915 
6916       if (AndOp.getNode() && AndOp.getOpcode() == ISD::AND) {
6917         Op0 = DAG.getNode(ISD::BITCAST, dl, CmpVT, AndOp.getOperand(0));
6918         Op1 = DAG.getNode(ISD::BITCAST, dl, CmpVT, AndOp.getOperand(1));
6919         SDValue Result = DAG.getNode(ARMISD::VTST, dl, CmpVT, Op0, Op1);
6920         if (!Invert)
6921           Result = DAG.getNOT(dl, Result, VT);
6922         return Result;
6923       }
6924     }
6925   }
6926 
6927   if (Swap)
6928     std::swap(Op0, Op1);
6929 
6930   // If one of the operands is a constant vector zero, attempt to fold the
6931   // comparison to a specialized compare-against-zero form.
6932   if (ISD::isBuildVectorAllZeros(Op0.getNode()) &&
6933       (Opc == ARMCC::GE || Opc == ARMCC::GT || Opc == ARMCC::EQ ||
6934        Opc == ARMCC::NE)) {
6935     if (Opc == ARMCC::GE)
6936       Opc = ARMCC::LE;
6937     else if (Opc == ARMCC::GT)
6938       Opc = ARMCC::LT;
6939     std::swap(Op0, Op1);
6940   }
6941 
6942   SDValue Result;
6943   if (ISD::isBuildVectorAllZeros(Op1.getNode()) &&
6944       (Opc == ARMCC::GE || Opc == ARMCC::GT || Opc == ARMCC::LE ||
6945        Opc == ARMCC::LT || Opc == ARMCC::NE || Opc == ARMCC::EQ))
6946     Result = DAG.getNode(ARMISD::VCMPZ, dl, CmpVT, Op0,
6947                          DAG.getConstant(Opc, dl, MVT::i32));
6948   else
6949     Result = DAG.getNode(ARMISD::VCMP, dl, CmpVT, Op0, Op1,
6950                          DAG.getConstant(Opc, dl, MVT::i32));
6951 
6952   Result = DAG.getSExtOrTrunc(Result, dl, VT);
6953 
6954   if (Invert)
6955     Result = DAG.getNOT(dl, Result, VT);
6956 
6957   return Result;
6958 }
6959 
LowerSETCCCARRY(SDValue Op,SelectionDAG & DAG)6960 static SDValue LowerSETCCCARRY(SDValue Op, SelectionDAG &DAG) {
6961   SDValue LHS = Op.getOperand(0);
6962   SDValue RHS = Op.getOperand(1);
6963   SDValue Carry = Op.getOperand(2);
6964   SDValue Cond = Op.getOperand(3);
6965   SDLoc DL(Op);
6966 
6967   assert(LHS.getSimpleValueType().isInteger() && "SETCCCARRY is integer only.");
6968 
6969   // ARMISD::SUBE expects a carry not a borrow like ISD::USUBO_CARRY so we
6970   // have to invert the carry first.
6971   Carry = DAG.getNode(ISD::SUB, DL, MVT::i32,
6972                       DAG.getConstant(1, DL, MVT::i32), Carry);
6973   // This converts the boolean value carry into the carry flag.
6974   Carry = ConvertBooleanCarryToCarryFlag(Carry, DAG);
6975 
6976   SDVTList VTs = DAG.getVTList(LHS.getValueType(), MVT::i32);
6977   SDValue Cmp = DAG.getNode(ARMISD::SUBE, DL, VTs, LHS, RHS, Carry);
6978 
6979   SDValue FVal = DAG.getConstant(0, DL, MVT::i32);
6980   SDValue TVal = DAG.getConstant(1, DL, MVT::i32);
6981   SDValue ARMcc = DAG.getConstant(
6982       IntCCToARMCC(cast<CondCodeSDNode>(Cond)->get()), DL, MVT::i32);
6983   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
6984   SDValue Chain = DAG.getCopyToReg(DAG.getEntryNode(), DL, ARM::CPSR,
6985                                    Cmp.getValue(1), SDValue());
6986   return DAG.getNode(ARMISD::CMOV, DL, Op.getValueType(), FVal, TVal, ARMcc,
6987                      CCR, Chain.getValue(1));
6988 }
6989 
6990 /// isVMOVModifiedImm - Check if the specified splat value corresponds to a
6991 /// valid vector constant for a NEON or MVE instruction with a "modified
6992 /// immediate" operand (e.g., VMOV).  If so, return the encoded value.
isVMOVModifiedImm(uint64_t SplatBits,uint64_t SplatUndef,unsigned SplatBitSize,SelectionDAG & DAG,const SDLoc & dl,EVT & VT,EVT VectorVT,VMOVModImmType type)6993 static SDValue isVMOVModifiedImm(uint64_t SplatBits, uint64_t SplatUndef,
6994                                  unsigned SplatBitSize, SelectionDAG &DAG,
6995                                  const SDLoc &dl, EVT &VT, EVT VectorVT,
6996                                  VMOVModImmType type) {
6997   unsigned OpCmode, Imm;
6998   bool is128Bits = VectorVT.is128BitVector();
6999 
7000   // SplatBitSize is set to the smallest size that splats the vector, so a
7001   // zero vector will always have SplatBitSize == 8.  However, NEON modified
7002   // immediate instructions others than VMOV do not support the 8-bit encoding
7003   // of a zero vector, and the default encoding of zero is supposed to be the
7004   // 32-bit version.
7005   if (SplatBits == 0)
7006     SplatBitSize = 32;
7007 
7008   switch (SplatBitSize) {
7009   case 8:
7010     if (type != VMOVModImm)
7011       return SDValue();
7012     // Any 1-byte value is OK.  Op=0, Cmode=1110.
7013     assert((SplatBits & ~0xff) == 0 && "one byte splat value is too big");
7014     OpCmode = 0xe;
7015     Imm = SplatBits;
7016     VT = is128Bits ? MVT::v16i8 : MVT::v8i8;
7017     break;
7018 
7019   case 16:
7020     // NEON's 16-bit VMOV supports splat values where only one byte is nonzero.
7021     VT = is128Bits ? MVT::v8i16 : MVT::v4i16;
7022     if ((SplatBits & ~0xff) == 0) {
7023       // Value = 0x00nn: Op=x, Cmode=100x.
7024       OpCmode = 0x8;
7025       Imm = SplatBits;
7026       break;
7027     }
7028     if ((SplatBits & ~0xff00) == 0) {
7029       // Value = 0xnn00: Op=x, Cmode=101x.
7030       OpCmode = 0xa;
7031       Imm = SplatBits >> 8;
7032       break;
7033     }
7034     return SDValue();
7035 
7036   case 32:
7037     // NEON's 32-bit VMOV supports splat values where:
7038     // * only one byte is nonzero, or
7039     // * the least significant byte is 0xff and the second byte is nonzero, or
7040     // * the least significant 2 bytes are 0xff and the third is nonzero.
7041     VT = is128Bits ? MVT::v4i32 : MVT::v2i32;
7042     if ((SplatBits & ~0xff) == 0) {
7043       // Value = 0x000000nn: Op=x, Cmode=000x.
7044       OpCmode = 0;
7045       Imm = SplatBits;
7046       break;
7047     }
7048     if ((SplatBits & ~0xff00) == 0) {
7049       // Value = 0x0000nn00: Op=x, Cmode=001x.
7050       OpCmode = 0x2;
7051       Imm = SplatBits >> 8;
7052       break;
7053     }
7054     if ((SplatBits & ~0xff0000) == 0) {
7055       // Value = 0x00nn0000: Op=x, Cmode=010x.
7056       OpCmode = 0x4;
7057       Imm = SplatBits >> 16;
7058       break;
7059     }
7060     if ((SplatBits & ~0xff000000) == 0) {
7061       // Value = 0xnn000000: Op=x, Cmode=011x.
7062       OpCmode = 0x6;
7063       Imm = SplatBits >> 24;
7064       break;
7065     }
7066 
7067     // cmode == 0b1100 and cmode == 0b1101 are not supported for VORR or VBIC
7068     if (type == OtherModImm) return SDValue();
7069 
7070     if ((SplatBits & ~0xffff) == 0 &&
7071         ((SplatBits | SplatUndef) & 0xff) == 0xff) {
7072       // Value = 0x0000nnff: Op=x, Cmode=1100.
7073       OpCmode = 0xc;
7074       Imm = SplatBits >> 8;
7075       break;
7076     }
7077 
7078     // cmode == 0b1101 is not supported for MVE VMVN
7079     if (type == MVEVMVNModImm)
7080       return SDValue();
7081 
7082     if ((SplatBits & ~0xffffff) == 0 &&
7083         ((SplatBits | SplatUndef) & 0xffff) == 0xffff) {
7084       // Value = 0x00nnffff: Op=x, Cmode=1101.
7085       OpCmode = 0xd;
7086       Imm = SplatBits >> 16;
7087       break;
7088     }
7089 
7090     // Note: there are a few 32-bit splat values (specifically: 00ffff00,
7091     // ff000000, ff0000ff, and ffff00ff) that are valid for VMOV.I64 but not
7092     // VMOV.I32.  A (very) minor optimization would be to replicate the value
7093     // and fall through here to test for a valid 64-bit splat.  But, then the
7094     // caller would also need to check and handle the change in size.
7095     return SDValue();
7096 
7097   case 64: {
7098     if (type != VMOVModImm)
7099       return SDValue();
7100     // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
7101     uint64_t BitMask = 0xff;
7102     unsigned ImmMask = 1;
7103     Imm = 0;
7104     for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
7105       if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
7106         Imm |= ImmMask;
7107       } else if ((SplatBits & BitMask) != 0) {
7108         return SDValue();
7109       }
7110       BitMask <<= 8;
7111       ImmMask <<= 1;
7112     }
7113 
7114     if (DAG.getDataLayout().isBigEndian()) {
7115       // Reverse the order of elements within the vector.
7116       unsigned BytesPerElem = VectorVT.getScalarSizeInBits() / 8;
7117       unsigned Mask = (1 << BytesPerElem) - 1;
7118       unsigned NumElems = 8 / BytesPerElem;
7119       unsigned NewImm = 0;
7120       for (unsigned ElemNum = 0; ElemNum < NumElems; ++ElemNum) {
7121         unsigned Elem = ((Imm >> ElemNum * BytesPerElem) & Mask);
7122         NewImm |= Elem << (NumElems - ElemNum - 1) * BytesPerElem;
7123       }
7124       Imm = NewImm;
7125     }
7126 
7127     // Op=1, Cmode=1110.
7128     OpCmode = 0x1e;
7129     VT = is128Bits ? MVT::v2i64 : MVT::v1i64;
7130     break;
7131   }
7132 
7133   default:
7134     llvm_unreachable("unexpected size for isVMOVModifiedImm");
7135   }
7136 
7137   unsigned EncodedVal = ARM_AM::createVMOVModImm(OpCmode, Imm);
7138   return DAG.getTargetConstant(EncodedVal, dl, MVT::i32);
7139 }
7140 
LowerConstantFP(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST) const7141 SDValue ARMTargetLowering::LowerConstantFP(SDValue Op, SelectionDAG &DAG,
7142                                            const ARMSubtarget *ST) const {
7143   EVT VT = Op.getValueType();
7144   bool IsDouble = (VT == MVT::f64);
7145   ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Op);
7146   const APFloat &FPVal = CFP->getValueAPF();
7147 
7148   // Prevent floating-point constants from using literal loads
7149   // when execute-only is enabled.
7150   if (ST->genExecuteOnly()) {
7151     // We shouldn't trigger this for v6m execute-only
7152     assert((!ST->isThumb1Only() || ST->hasV8MBaselineOps()) &&
7153            "Unexpected architecture");
7154 
7155     // If we can represent the constant as an immediate, don't lower it
7156     if (isFPImmLegal(FPVal, VT))
7157       return Op;
7158     // Otherwise, construct as integer, and move to float register
7159     APInt INTVal = FPVal.bitcastToAPInt();
7160     SDLoc DL(CFP);
7161     switch (VT.getSimpleVT().SimpleTy) {
7162       default:
7163         llvm_unreachable("Unknown floating point type!");
7164         break;
7165       case MVT::f64: {
7166         SDValue Lo = DAG.getConstant(INTVal.trunc(32), DL, MVT::i32);
7167         SDValue Hi = DAG.getConstant(INTVal.lshr(32).trunc(32), DL, MVT::i32);
7168         return DAG.getNode(ARMISD::VMOVDRR, DL, MVT::f64, Lo, Hi);
7169       }
7170       case MVT::f32:
7171           return DAG.getNode(ARMISD::VMOVSR, DL, VT,
7172               DAG.getConstant(INTVal, DL, MVT::i32));
7173     }
7174   }
7175 
7176   if (!ST->hasVFP3Base())
7177     return SDValue();
7178 
7179   // Use the default (constant pool) lowering for double constants when we have
7180   // an SP-only FPU
7181   if (IsDouble && !Subtarget->hasFP64())
7182     return SDValue();
7183 
7184   // Try splatting with a VMOV.f32...
7185   int ImmVal = IsDouble ? ARM_AM::getFP64Imm(FPVal) : ARM_AM::getFP32Imm(FPVal);
7186 
7187   if (ImmVal != -1) {
7188     if (IsDouble || !ST->useNEONForSinglePrecisionFP()) {
7189       // We have code in place to select a valid ConstantFP already, no need to
7190       // do any mangling.
7191       return Op;
7192     }
7193 
7194     // It's a float and we are trying to use NEON operations where
7195     // possible. Lower it to a splat followed by an extract.
7196     SDLoc DL(Op);
7197     SDValue NewVal = DAG.getTargetConstant(ImmVal, DL, MVT::i32);
7198     SDValue VecConstant = DAG.getNode(ARMISD::VMOVFPIMM, DL, MVT::v2f32,
7199                                       NewVal);
7200     return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::f32, VecConstant,
7201                        DAG.getConstant(0, DL, MVT::i32));
7202   }
7203 
7204   // The rest of our options are NEON only, make sure that's allowed before
7205   // proceeding..
7206   if (!ST->hasNEON() || (!IsDouble && !ST->useNEONForSinglePrecisionFP()))
7207     return SDValue();
7208 
7209   EVT VMovVT;
7210   uint64_t iVal = FPVal.bitcastToAPInt().getZExtValue();
7211 
7212   // It wouldn't really be worth bothering for doubles except for one very
7213   // important value, which does happen to match: 0.0. So make sure we don't do
7214   // anything stupid.
7215   if (IsDouble && (iVal & 0xffffffff) != (iVal >> 32))
7216     return SDValue();
7217 
7218   // Try a VMOV.i32 (FIXME: i8, i16, or i64 could work too).
7219   SDValue NewVal = isVMOVModifiedImm(iVal & 0xffffffffU, 0, 32, DAG, SDLoc(Op),
7220                                      VMovVT, VT, VMOVModImm);
7221   if (NewVal != SDValue()) {
7222     SDLoc DL(Op);
7223     SDValue VecConstant = DAG.getNode(ARMISD::VMOVIMM, DL, VMovVT,
7224                                       NewVal);
7225     if (IsDouble)
7226       return DAG.getNode(ISD::BITCAST, DL, MVT::f64, VecConstant);
7227 
7228     // It's a float: cast and extract a vector element.
7229     SDValue VecFConstant = DAG.getNode(ISD::BITCAST, DL, MVT::v2f32,
7230                                        VecConstant);
7231     return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::f32, VecFConstant,
7232                        DAG.getConstant(0, DL, MVT::i32));
7233   }
7234 
7235   // Finally, try a VMVN.i32
7236   NewVal = isVMOVModifiedImm(~iVal & 0xffffffffU, 0, 32, DAG, SDLoc(Op), VMovVT,
7237                              VT, VMVNModImm);
7238   if (NewVal != SDValue()) {
7239     SDLoc DL(Op);
7240     SDValue VecConstant = DAG.getNode(ARMISD::VMVNIMM, DL, VMovVT, NewVal);
7241 
7242     if (IsDouble)
7243       return DAG.getNode(ISD::BITCAST, DL, MVT::f64, VecConstant);
7244 
7245     // It's a float: cast and extract a vector element.
7246     SDValue VecFConstant = DAG.getNode(ISD::BITCAST, DL, MVT::v2f32,
7247                                        VecConstant);
7248     return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::f32, VecFConstant,
7249                        DAG.getConstant(0, DL, MVT::i32));
7250   }
7251 
7252   return SDValue();
7253 }
7254 
7255 // check if an VEXT instruction can handle the shuffle mask when the
7256 // vector sources of the shuffle are the same.
isSingletonVEXTMask(ArrayRef<int> M,EVT VT,unsigned & Imm)7257 static bool isSingletonVEXTMask(ArrayRef<int> M, EVT VT, unsigned &Imm) {
7258   unsigned NumElts = VT.getVectorNumElements();
7259 
7260   // Assume that the first shuffle index is not UNDEF.  Fail if it is.
7261   if (M[0] < 0)
7262     return false;
7263 
7264   Imm = M[0];
7265 
7266   // If this is a VEXT shuffle, the immediate value is the index of the first
7267   // element.  The other shuffle indices must be the successive elements after
7268   // the first one.
7269   unsigned ExpectedElt = Imm;
7270   for (unsigned i = 1; i < NumElts; ++i) {
7271     // Increment the expected index.  If it wraps around, just follow it
7272     // back to index zero and keep going.
7273     ++ExpectedElt;
7274     if (ExpectedElt == NumElts)
7275       ExpectedElt = 0;
7276 
7277     if (M[i] < 0) continue; // ignore UNDEF indices
7278     if (ExpectedElt != static_cast<unsigned>(M[i]))
7279       return false;
7280   }
7281 
7282   return true;
7283 }
7284 
isVEXTMask(ArrayRef<int> M,EVT VT,bool & ReverseVEXT,unsigned & Imm)7285 static bool isVEXTMask(ArrayRef<int> M, EVT VT,
7286                        bool &ReverseVEXT, unsigned &Imm) {
7287   unsigned NumElts = VT.getVectorNumElements();
7288   ReverseVEXT = false;
7289 
7290   // Assume that the first shuffle index is not UNDEF.  Fail if it is.
7291   if (M[0] < 0)
7292     return false;
7293 
7294   Imm = M[0];
7295 
7296   // If this is a VEXT shuffle, the immediate value is the index of the first
7297   // element.  The other shuffle indices must be the successive elements after
7298   // the first one.
7299   unsigned ExpectedElt = Imm;
7300   for (unsigned i = 1; i < NumElts; ++i) {
7301     // Increment the expected index.  If it wraps around, it may still be
7302     // a VEXT but the source vectors must be swapped.
7303     ExpectedElt += 1;
7304     if (ExpectedElt == NumElts * 2) {
7305       ExpectedElt = 0;
7306       ReverseVEXT = true;
7307     }
7308 
7309     if (M[i] < 0) continue; // ignore UNDEF indices
7310     if (ExpectedElt != static_cast<unsigned>(M[i]))
7311       return false;
7312   }
7313 
7314   // Adjust the index value if the source operands will be swapped.
7315   if (ReverseVEXT)
7316     Imm -= NumElts;
7317 
7318   return true;
7319 }
7320 
isVTBLMask(ArrayRef<int> M,EVT VT)7321 static bool isVTBLMask(ArrayRef<int> M, EVT VT) {
7322   // We can handle <8 x i8> vector shuffles. If the index in the mask is out of
7323   // range, then 0 is placed into the resulting vector. So pretty much any mask
7324   // of 8 elements can work here.
7325   return VT == MVT::v8i8 && M.size() == 8;
7326 }
7327 
SelectPairHalf(unsigned Elements,ArrayRef<int> Mask,unsigned Index)7328 static unsigned SelectPairHalf(unsigned Elements, ArrayRef<int> Mask,
7329                                unsigned Index) {
7330   if (Mask.size() == Elements * 2)
7331     return Index / Elements;
7332   return Mask[Index] == 0 ? 0 : 1;
7333 }
7334 
7335 // Checks whether the shuffle mask represents a vector transpose (VTRN) by
7336 // checking that pairs of elements in the shuffle mask represent the same index
7337 // in each vector, incrementing the expected index by 2 at each step.
7338 // e.g. For v1,v2 of type v4i32 a valid shuffle mask is: [0, 4, 2, 6]
7339 //  v1={a,b,c,d} => x=shufflevector v1, v2 shufflemask => x={a,e,c,g}
7340 //  v2={e,f,g,h}
7341 // WhichResult gives the offset for each element in the mask based on which
7342 // of the two results it belongs to.
7343 //
7344 // The transpose can be represented either as:
7345 // result1 = shufflevector v1, v2, result1_shuffle_mask
7346 // result2 = shufflevector v1, v2, result2_shuffle_mask
7347 // where v1/v2 and the shuffle masks have the same number of elements
7348 // (here WhichResult (see below) indicates which result is being checked)
7349 //
7350 // or as:
7351 // results = shufflevector v1, v2, shuffle_mask
7352 // where both results are returned in one vector and the shuffle mask has twice
7353 // as many elements as v1/v2 (here WhichResult will always be 0 if true) here we
7354 // want to check the low half and high half of the shuffle mask as if it were
7355 // the other case
isVTRNMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7356 static bool isVTRNMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
7357   unsigned EltSz = VT.getScalarSizeInBits();
7358   if (EltSz == 64)
7359     return false;
7360 
7361   unsigned NumElts = VT.getVectorNumElements();
7362   if (M.size() != NumElts && M.size() != NumElts*2)
7363     return false;
7364 
7365   // If the mask is twice as long as the input vector then we need to check the
7366   // upper and lower parts of the mask with a matching value for WhichResult
7367   // FIXME: A mask with only even values will be rejected in case the first
7368   // element is undefined, e.g. [-1, 4, 2, 6] will be rejected, because only
7369   // M[0] is used to determine WhichResult
7370   for (unsigned i = 0; i < M.size(); i += NumElts) {
7371     WhichResult = SelectPairHalf(NumElts, M, i);
7372     for (unsigned j = 0; j < NumElts; j += 2) {
7373       if ((M[i+j] >= 0 && (unsigned) M[i+j] != j + WhichResult) ||
7374           (M[i+j+1] >= 0 && (unsigned) M[i+j+1] != j + NumElts + WhichResult))
7375         return false;
7376     }
7377   }
7378 
7379   if (M.size() == NumElts*2)
7380     WhichResult = 0;
7381 
7382   return true;
7383 }
7384 
7385 /// isVTRN_v_undef_Mask - Special case of isVTRNMask for canonical form of
7386 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
7387 /// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
isVTRN_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7388 static bool isVTRN_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult){
7389   unsigned EltSz = VT.getScalarSizeInBits();
7390   if (EltSz == 64)
7391     return false;
7392 
7393   unsigned NumElts = VT.getVectorNumElements();
7394   if (M.size() != NumElts && M.size() != NumElts*2)
7395     return false;
7396 
7397   for (unsigned i = 0; i < M.size(); i += NumElts) {
7398     WhichResult = SelectPairHalf(NumElts, M, i);
7399     for (unsigned j = 0; j < NumElts; j += 2) {
7400       if ((M[i+j] >= 0 && (unsigned) M[i+j] != j + WhichResult) ||
7401           (M[i+j+1] >= 0 && (unsigned) M[i+j+1] != j + WhichResult))
7402         return false;
7403     }
7404   }
7405 
7406   if (M.size() == NumElts*2)
7407     WhichResult = 0;
7408 
7409   return true;
7410 }
7411 
7412 // Checks whether the shuffle mask represents a vector unzip (VUZP) by checking
7413 // that the mask elements are either all even and in steps of size 2 or all odd
7414 // and in steps of size 2.
7415 // e.g. For v1,v2 of type v4i32 a valid shuffle mask is: [0, 2, 4, 6]
7416 //  v1={a,b,c,d} => x=shufflevector v1, v2 shufflemask => x={a,c,e,g}
7417 //  v2={e,f,g,h}
7418 // Requires similar checks to that of isVTRNMask with
7419 // respect the how results are returned.
isVUZPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7420 static bool isVUZPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
7421   unsigned EltSz = VT.getScalarSizeInBits();
7422   if (EltSz == 64)
7423     return false;
7424 
7425   unsigned NumElts = VT.getVectorNumElements();
7426   if (M.size() != NumElts && M.size() != NumElts*2)
7427     return false;
7428 
7429   for (unsigned i = 0; i < M.size(); i += NumElts) {
7430     WhichResult = SelectPairHalf(NumElts, M, i);
7431     for (unsigned j = 0; j < NumElts; ++j) {
7432       if (M[i+j] >= 0 && (unsigned) M[i+j] != 2 * j + WhichResult)
7433         return false;
7434     }
7435   }
7436 
7437   if (M.size() == NumElts*2)
7438     WhichResult = 0;
7439 
7440   // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
7441   if (VT.is64BitVector() && EltSz == 32)
7442     return false;
7443 
7444   return true;
7445 }
7446 
7447 /// isVUZP_v_undef_Mask - Special case of isVUZPMask for canonical form of
7448 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
7449 /// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
isVUZP_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7450 static bool isVUZP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult){
7451   unsigned EltSz = VT.getScalarSizeInBits();
7452   if (EltSz == 64)
7453     return false;
7454 
7455   unsigned NumElts = VT.getVectorNumElements();
7456   if (M.size() != NumElts && M.size() != NumElts*2)
7457     return false;
7458 
7459   unsigned Half = NumElts / 2;
7460   for (unsigned i = 0; i < M.size(); i += NumElts) {
7461     WhichResult = SelectPairHalf(NumElts, M, i);
7462     for (unsigned j = 0; j < NumElts; j += Half) {
7463       unsigned Idx = WhichResult;
7464       for (unsigned k = 0; k < Half; ++k) {
7465         int MIdx = M[i + j + k];
7466         if (MIdx >= 0 && (unsigned) MIdx != Idx)
7467           return false;
7468         Idx += 2;
7469       }
7470     }
7471   }
7472 
7473   if (M.size() == NumElts*2)
7474     WhichResult = 0;
7475 
7476   // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
7477   if (VT.is64BitVector() && EltSz == 32)
7478     return false;
7479 
7480   return true;
7481 }
7482 
7483 // Checks whether the shuffle mask represents a vector zip (VZIP) by checking
7484 // that pairs of elements of the shufflemask represent the same index in each
7485 // vector incrementing sequentially through the vectors.
7486 // e.g. For v1,v2 of type v4i32 a valid shuffle mask is: [0, 4, 1, 5]
7487 //  v1={a,b,c,d} => x=shufflevector v1, v2 shufflemask => x={a,e,b,f}
7488 //  v2={e,f,g,h}
7489 // Requires similar checks to that of isVTRNMask with respect the how results
7490 // are returned.
isVZIPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7491 static bool isVZIPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
7492   unsigned EltSz = VT.getScalarSizeInBits();
7493   if (EltSz == 64)
7494     return false;
7495 
7496   unsigned NumElts = VT.getVectorNumElements();
7497   if (M.size() != NumElts && M.size() != NumElts*2)
7498     return false;
7499 
7500   for (unsigned i = 0; i < M.size(); i += NumElts) {
7501     WhichResult = SelectPairHalf(NumElts, M, i);
7502     unsigned Idx = WhichResult * NumElts / 2;
7503     for (unsigned j = 0; j < NumElts; j += 2) {
7504       if ((M[i+j] >= 0 && (unsigned) M[i+j] != Idx) ||
7505           (M[i+j+1] >= 0 && (unsigned) M[i+j+1] != Idx + NumElts))
7506         return false;
7507       Idx += 1;
7508     }
7509   }
7510 
7511   if (M.size() == NumElts*2)
7512     WhichResult = 0;
7513 
7514   // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
7515   if (VT.is64BitVector() && EltSz == 32)
7516     return false;
7517 
7518   return true;
7519 }
7520 
7521 /// isVZIP_v_undef_Mask - Special case of isVZIPMask for canonical form of
7522 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
7523 /// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
isVZIP_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)7524 static bool isVZIP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult){
7525   unsigned EltSz = VT.getScalarSizeInBits();
7526   if (EltSz == 64)
7527     return false;
7528 
7529   unsigned NumElts = VT.getVectorNumElements();
7530   if (M.size() != NumElts && M.size() != NumElts*2)
7531     return false;
7532 
7533   for (unsigned i = 0; i < M.size(); i += NumElts) {
7534     WhichResult = SelectPairHalf(NumElts, M, i);
7535     unsigned Idx = WhichResult * NumElts / 2;
7536     for (unsigned j = 0; j < NumElts; j += 2) {
7537       if ((M[i+j] >= 0 && (unsigned) M[i+j] != Idx) ||
7538           (M[i+j+1] >= 0 && (unsigned) M[i+j+1] != Idx))
7539         return false;
7540       Idx += 1;
7541     }
7542   }
7543 
7544   if (M.size() == NumElts*2)
7545     WhichResult = 0;
7546 
7547   // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
7548   if (VT.is64BitVector() && EltSz == 32)
7549     return false;
7550 
7551   return true;
7552 }
7553 
7554 /// Check if \p ShuffleMask is a NEON two-result shuffle (VZIP, VUZP, VTRN),
7555 /// and return the corresponding ARMISD opcode if it is, or 0 if it isn't.
isNEONTwoResultShuffleMask(ArrayRef<int> ShuffleMask,EVT VT,unsigned & WhichResult,bool & isV_UNDEF)7556 static unsigned isNEONTwoResultShuffleMask(ArrayRef<int> ShuffleMask, EVT VT,
7557                                            unsigned &WhichResult,
7558                                            bool &isV_UNDEF) {
7559   isV_UNDEF = false;
7560   if (isVTRNMask(ShuffleMask, VT, WhichResult))
7561     return ARMISD::VTRN;
7562   if (isVUZPMask(ShuffleMask, VT, WhichResult))
7563     return ARMISD::VUZP;
7564   if (isVZIPMask(ShuffleMask, VT, WhichResult))
7565     return ARMISD::VZIP;
7566 
7567   isV_UNDEF = true;
7568   if (isVTRN_v_undef_Mask(ShuffleMask, VT, WhichResult))
7569     return ARMISD::VTRN;
7570   if (isVUZP_v_undef_Mask(ShuffleMask, VT, WhichResult))
7571     return ARMISD::VUZP;
7572   if (isVZIP_v_undef_Mask(ShuffleMask, VT, WhichResult))
7573     return ARMISD::VZIP;
7574 
7575   return 0;
7576 }
7577 
7578 /// \return true if this is a reverse operation on an vector.
isReverseMask(ArrayRef<int> M,EVT VT)7579 static bool isReverseMask(ArrayRef<int> M, EVT VT) {
7580   unsigned NumElts = VT.getVectorNumElements();
7581   // Make sure the mask has the right size.
7582   if (NumElts != M.size())
7583       return false;
7584 
7585   // Look for <15, ..., 3, -1, 1, 0>.
7586   for (unsigned i = 0; i != NumElts; ++i)
7587     if (M[i] >= 0 && M[i] != (int) (NumElts - 1 - i))
7588       return false;
7589 
7590   return true;
7591 }
7592 
isTruncMask(ArrayRef<int> M,EVT VT,bool Top,bool SingleSource)7593 static bool isTruncMask(ArrayRef<int> M, EVT VT, bool Top, bool SingleSource) {
7594   unsigned NumElts = VT.getVectorNumElements();
7595   // Make sure the mask has the right size.
7596   if (NumElts != M.size() || (VT != MVT::v8i16 && VT != MVT::v16i8))
7597     return false;
7598 
7599   // Half-width truncation patterns (e.g. v4i32 -> v8i16):
7600   // !Top &&  SingleSource: <0, 2, 4, 6, 0, 2, 4, 6>
7601   // !Top && !SingleSource: <0, 2, 4, 6, 8, 10, 12, 14>
7602   //  Top &&  SingleSource: <1, 3, 5, 7, 1, 3, 5, 7>
7603   //  Top && !SingleSource: <1, 3, 5, 7, 9, 11, 13, 15>
7604   int Ofs = Top ? 1 : 0;
7605   int Upper = SingleSource ? 0 : NumElts;
7606   for (int i = 0, e = NumElts / 2; i != e; ++i) {
7607     if (M[i] >= 0 && M[i] != (i * 2) + Ofs)
7608       return false;
7609     if (M[i + e] >= 0 && M[i + e] != (i * 2) + Ofs + Upper)
7610       return false;
7611   }
7612   return true;
7613 }
7614 
isVMOVNMask(ArrayRef<int> M,EVT VT,bool Top,bool SingleSource)7615 static bool isVMOVNMask(ArrayRef<int> M, EVT VT, bool Top, bool SingleSource) {
7616   unsigned NumElts = VT.getVectorNumElements();
7617   // Make sure the mask has the right size.
7618   if (NumElts != M.size() || (VT != MVT::v8i16 && VT != MVT::v16i8))
7619     return false;
7620 
7621   // If Top
7622   //   Look for <0, N, 2, N+2, 4, N+4, ..>.
7623   //   This inserts Input2 into Input1
7624   // else if not Top
7625   //   Look for <0, N+1, 2, N+3, 4, N+5, ..>
7626   //   This inserts Input1 into Input2
7627   unsigned Offset = Top ? 0 : 1;
7628   unsigned N = SingleSource ? 0 : NumElts;
7629   for (unsigned i = 0; i < NumElts; i += 2) {
7630     if (M[i] >= 0 && M[i] != (int)i)
7631       return false;
7632     if (M[i + 1] >= 0 && M[i + 1] != (int)(N + i + Offset))
7633       return false;
7634   }
7635 
7636   return true;
7637 }
7638 
isVMOVNTruncMask(ArrayRef<int> M,EVT ToVT,bool rev)7639 static bool isVMOVNTruncMask(ArrayRef<int> M, EVT ToVT, bool rev) {
7640   unsigned NumElts = ToVT.getVectorNumElements();
7641   if (NumElts != M.size())
7642     return false;
7643 
7644   // Test if the Trunc can be convertable to a VMOVN with this shuffle. We are
7645   // looking for patterns of:
7646   // !rev: 0 N/2 1 N/2+1 2 N/2+2 ...
7647   //  rev: N/2 0 N/2+1 1 N/2+2 2 ...
7648 
7649   unsigned Off0 = rev ? NumElts / 2 : 0;
7650   unsigned Off1 = rev ? 0 : NumElts / 2;
7651   for (unsigned i = 0; i < NumElts; i += 2) {
7652     if (M[i] >= 0 && M[i] != (int)(Off0 + i / 2))
7653       return false;
7654     if (M[i + 1] >= 0 && M[i + 1] != (int)(Off1 + i / 2))
7655       return false;
7656   }
7657 
7658   return true;
7659 }
7660 
7661 // Reconstruct an MVE VCVT from a BuildVector of scalar fptrunc, all extracted
7662 // from a pair of inputs. For example:
7663 // BUILDVECTOR(FP_ROUND(EXTRACT_ELT(X, 0),
7664 //             FP_ROUND(EXTRACT_ELT(Y, 0),
7665 //             FP_ROUND(EXTRACT_ELT(X, 1),
7666 //             FP_ROUND(EXTRACT_ELT(Y, 1), ...)
LowerBuildVectorOfFPTrunc(SDValue BV,SelectionDAG & DAG,const ARMSubtarget * ST)7667 static SDValue LowerBuildVectorOfFPTrunc(SDValue BV, SelectionDAG &DAG,
7668                                          const ARMSubtarget *ST) {
7669   assert(BV.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
7670   if (!ST->hasMVEFloatOps())
7671     return SDValue();
7672 
7673   SDLoc dl(BV);
7674   EVT VT = BV.getValueType();
7675   if (VT != MVT::v8f16)
7676     return SDValue();
7677 
7678   // We are looking for a buildvector of fptrunc elements, where all the
7679   // elements are interleavingly extracted from two sources. Check the first two
7680   // items are valid enough and extract some info from them (they are checked
7681   // properly in the loop below).
7682   if (BV.getOperand(0).getOpcode() != ISD::FP_ROUND ||
7683       BV.getOperand(0).getOperand(0).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
7684       BV.getOperand(0).getOperand(0).getConstantOperandVal(1) != 0)
7685     return SDValue();
7686   if (BV.getOperand(1).getOpcode() != ISD::FP_ROUND ||
7687       BV.getOperand(1).getOperand(0).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
7688       BV.getOperand(1).getOperand(0).getConstantOperandVal(1) != 0)
7689     return SDValue();
7690   SDValue Op0 = BV.getOperand(0).getOperand(0).getOperand(0);
7691   SDValue Op1 = BV.getOperand(1).getOperand(0).getOperand(0);
7692   if (Op0.getValueType() != MVT::v4f32 || Op1.getValueType() != MVT::v4f32)
7693     return SDValue();
7694 
7695   // Check all the values in the BuildVector line up with our expectations.
7696   for (unsigned i = 1; i < 4; i++) {
7697     auto Check = [](SDValue Trunc, SDValue Op, unsigned Idx) {
7698       return Trunc.getOpcode() == ISD::FP_ROUND &&
7699              Trunc.getOperand(0).getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
7700              Trunc.getOperand(0).getOperand(0) == Op &&
7701              Trunc.getOperand(0).getConstantOperandVal(1) == Idx;
7702     };
7703     if (!Check(BV.getOperand(i * 2 + 0), Op0, i))
7704       return SDValue();
7705     if (!Check(BV.getOperand(i * 2 + 1), Op1, i))
7706       return SDValue();
7707   }
7708 
7709   SDValue N1 = DAG.getNode(ARMISD::VCVTN, dl, VT, DAG.getUNDEF(VT), Op0,
7710                            DAG.getConstant(0, dl, MVT::i32));
7711   return DAG.getNode(ARMISD::VCVTN, dl, VT, N1, Op1,
7712                      DAG.getConstant(1, dl, MVT::i32));
7713 }
7714 
7715 // Reconstruct an MVE VCVT from a BuildVector of scalar fpext, all extracted
7716 // from a single input on alternating lanes. For example:
7717 // BUILDVECTOR(FP_ROUND(EXTRACT_ELT(X, 0),
7718 //             FP_ROUND(EXTRACT_ELT(X, 2),
7719 //             FP_ROUND(EXTRACT_ELT(X, 4), ...)
LowerBuildVectorOfFPExt(SDValue BV,SelectionDAG & DAG,const ARMSubtarget * ST)7720 static SDValue LowerBuildVectorOfFPExt(SDValue BV, SelectionDAG &DAG,
7721                                        const ARMSubtarget *ST) {
7722   assert(BV.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
7723   if (!ST->hasMVEFloatOps())
7724     return SDValue();
7725 
7726   SDLoc dl(BV);
7727   EVT VT = BV.getValueType();
7728   if (VT != MVT::v4f32)
7729     return SDValue();
7730 
7731   // We are looking for a buildvector of fptext elements, where all the
7732   // elements are alternating lanes from a single source. For example <0,2,4,6>
7733   // or <1,3,5,7>. Check the first two items are valid enough and extract some
7734   // info from them (they are checked properly in the loop below).
7735   if (BV.getOperand(0).getOpcode() != ISD::FP_EXTEND ||
7736       BV.getOperand(0).getOperand(0).getOpcode() != ISD::EXTRACT_VECTOR_ELT)
7737     return SDValue();
7738   SDValue Op0 = BV.getOperand(0).getOperand(0).getOperand(0);
7739   int Offset = BV.getOperand(0).getOperand(0).getConstantOperandVal(1);
7740   if (Op0.getValueType() != MVT::v8f16 || (Offset != 0 && Offset != 1))
7741     return SDValue();
7742 
7743   // Check all the values in the BuildVector line up with our expectations.
7744   for (unsigned i = 1; i < 4; i++) {
7745     auto Check = [](SDValue Trunc, SDValue Op, unsigned Idx) {
7746       return Trunc.getOpcode() == ISD::FP_EXTEND &&
7747              Trunc.getOperand(0).getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
7748              Trunc.getOperand(0).getOperand(0) == Op &&
7749              Trunc.getOperand(0).getConstantOperandVal(1) == Idx;
7750     };
7751     if (!Check(BV.getOperand(i), Op0, 2 * i + Offset))
7752       return SDValue();
7753   }
7754 
7755   return DAG.getNode(ARMISD::VCVTL, dl, VT, Op0,
7756                      DAG.getConstant(Offset, dl, MVT::i32));
7757 }
7758 
7759 // If N is an integer constant that can be moved into a register in one
7760 // instruction, return an SDValue of such a constant (will become a MOV
7761 // instruction).  Otherwise return null.
IsSingleInstrConstant(SDValue N,SelectionDAG & DAG,const ARMSubtarget * ST,const SDLoc & dl)7762 static SDValue IsSingleInstrConstant(SDValue N, SelectionDAG &DAG,
7763                                      const ARMSubtarget *ST, const SDLoc &dl) {
7764   uint64_t Val;
7765   if (!isa<ConstantSDNode>(N))
7766     return SDValue();
7767   Val = N->getAsZExtVal();
7768 
7769   if (ST->isThumb1Only()) {
7770     if (Val <= 255 || ~Val <= 255)
7771       return DAG.getConstant(Val, dl, MVT::i32);
7772   } else {
7773     if (ARM_AM::getSOImmVal(Val) != -1 || ARM_AM::getSOImmVal(~Val) != -1)
7774       return DAG.getConstant(Val, dl, MVT::i32);
7775   }
7776   return SDValue();
7777 }
7778 
LowerBUILD_VECTOR_i1(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)7779 static SDValue LowerBUILD_VECTOR_i1(SDValue Op, SelectionDAG &DAG,
7780                                     const ARMSubtarget *ST) {
7781   SDLoc dl(Op);
7782   EVT VT = Op.getValueType();
7783 
7784   assert(ST->hasMVEIntegerOps() && "LowerBUILD_VECTOR_i1 called without MVE!");
7785 
7786   unsigned NumElts = VT.getVectorNumElements();
7787   unsigned BoolMask;
7788   unsigned BitsPerBool;
7789   if (NumElts == 2) {
7790     BitsPerBool = 8;
7791     BoolMask = 0xff;
7792   } else if (NumElts == 4) {
7793     BitsPerBool = 4;
7794     BoolMask = 0xf;
7795   } else if (NumElts == 8) {
7796     BitsPerBool = 2;
7797     BoolMask = 0x3;
7798   } else if (NumElts == 16) {
7799     BitsPerBool = 1;
7800     BoolMask = 0x1;
7801   } else
7802     return SDValue();
7803 
7804   // If this is a single value copied into all lanes (a splat), we can just sign
7805   // extend that single value
7806   SDValue FirstOp = Op.getOperand(0);
7807   if (!isa<ConstantSDNode>(FirstOp) &&
7808       llvm::all_of(llvm::drop_begin(Op->ops()), [&FirstOp](const SDUse &U) {
7809         return U.get().isUndef() || U.get() == FirstOp;
7810       })) {
7811     SDValue Ext = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, MVT::i32, FirstOp,
7812                               DAG.getValueType(MVT::i1));
7813     return DAG.getNode(ARMISD::PREDICATE_CAST, dl, Op.getValueType(), Ext);
7814   }
7815 
7816   // First create base with bits set where known
7817   unsigned Bits32 = 0;
7818   for (unsigned i = 0; i < NumElts; ++i) {
7819     SDValue V = Op.getOperand(i);
7820     if (!isa<ConstantSDNode>(V) && !V.isUndef())
7821       continue;
7822     bool BitSet = V.isUndef() ? false : V->getAsZExtVal();
7823     if (BitSet)
7824       Bits32 |= BoolMask << (i * BitsPerBool);
7825   }
7826 
7827   // Add in unknown nodes
7828   SDValue Base = DAG.getNode(ARMISD::PREDICATE_CAST, dl, VT,
7829                              DAG.getConstant(Bits32, dl, MVT::i32));
7830   for (unsigned i = 0; i < NumElts; ++i) {
7831     SDValue V = Op.getOperand(i);
7832     if (isa<ConstantSDNode>(V) || V.isUndef())
7833       continue;
7834     Base = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Base, V,
7835                        DAG.getConstant(i, dl, MVT::i32));
7836   }
7837 
7838   return Base;
7839 }
7840 
LowerBUILD_VECTORToVIDUP(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)7841 static SDValue LowerBUILD_VECTORToVIDUP(SDValue Op, SelectionDAG &DAG,
7842                                         const ARMSubtarget *ST) {
7843   if (!ST->hasMVEIntegerOps())
7844     return SDValue();
7845 
7846   // We are looking for a buildvector where each element is Op[0] + i*N
7847   EVT VT = Op.getValueType();
7848   SDValue Op0 = Op.getOperand(0);
7849   unsigned NumElts = VT.getVectorNumElements();
7850 
7851   // Get the increment value from operand 1
7852   SDValue Op1 = Op.getOperand(1);
7853   if (Op1.getOpcode() != ISD::ADD || Op1.getOperand(0) != Op0 ||
7854       !isa<ConstantSDNode>(Op1.getOperand(1)))
7855     return SDValue();
7856   unsigned N = Op1.getConstantOperandVal(1);
7857   if (N != 1 && N != 2 && N != 4 && N != 8)
7858     return SDValue();
7859 
7860   // Check that each other operand matches
7861   for (unsigned I = 2; I < NumElts; I++) {
7862     SDValue OpI = Op.getOperand(I);
7863     if (OpI.getOpcode() != ISD::ADD || OpI.getOperand(0) != Op0 ||
7864         !isa<ConstantSDNode>(OpI.getOperand(1)) ||
7865         OpI.getConstantOperandVal(1) != I * N)
7866       return SDValue();
7867   }
7868 
7869   SDLoc DL(Op);
7870   return DAG.getNode(ARMISD::VIDUP, DL, DAG.getVTList(VT, MVT::i32), Op0,
7871                      DAG.getConstant(N, DL, MVT::i32));
7872 }
7873 
7874 // Returns true if the operation N can be treated as qr instruction variant at
7875 // operand Op.
IsQRMVEInstruction(const SDNode * N,const SDNode * Op)7876 static bool IsQRMVEInstruction(const SDNode *N, const SDNode *Op) {
7877   switch (N->getOpcode()) {
7878   case ISD::ADD:
7879   case ISD::MUL:
7880   case ISD::SADDSAT:
7881   case ISD::UADDSAT:
7882     return true;
7883   case ISD::SUB:
7884   case ISD::SSUBSAT:
7885   case ISD::USUBSAT:
7886     return N->getOperand(1).getNode() == Op;
7887   case ISD::INTRINSIC_WO_CHAIN:
7888     switch (N->getConstantOperandVal(0)) {
7889     case Intrinsic::arm_mve_add_predicated:
7890     case Intrinsic::arm_mve_mul_predicated:
7891     case Intrinsic::arm_mve_qadd_predicated:
7892     case Intrinsic::arm_mve_vhadd:
7893     case Intrinsic::arm_mve_hadd_predicated:
7894     case Intrinsic::arm_mve_vqdmulh:
7895     case Intrinsic::arm_mve_qdmulh_predicated:
7896     case Intrinsic::arm_mve_vqrdmulh:
7897     case Intrinsic::arm_mve_qrdmulh_predicated:
7898     case Intrinsic::arm_mve_vqdmull:
7899     case Intrinsic::arm_mve_vqdmull_predicated:
7900       return true;
7901     case Intrinsic::arm_mve_sub_predicated:
7902     case Intrinsic::arm_mve_qsub_predicated:
7903     case Intrinsic::arm_mve_vhsub:
7904     case Intrinsic::arm_mve_hsub_predicated:
7905       return N->getOperand(2).getNode() == Op;
7906     default:
7907       return false;
7908     }
7909   default:
7910     return false;
7911   }
7912 }
7913 
7914 // If this is a case we can't handle, return null and let the default
7915 // expansion code take care of it.
LowerBUILD_VECTOR(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST) const7916 SDValue ARMTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
7917                                              const ARMSubtarget *ST) const {
7918   BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
7919   SDLoc dl(Op);
7920   EVT VT = Op.getValueType();
7921 
7922   if (ST->hasMVEIntegerOps() && VT.getScalarSizeInBits() == 1)
7923     return LowerBUILD_VECTOR_i1(Op, DAG, ST);
7924 
7925   if (SDValue R = LowerBUILD_VECTORToVIDUP(Op, DAG, ST))
7926     return R;
7927 
7928   APInt SplatBits, SplatUndef;
7929   unsigned SplatBitSize;
7930   bool HasAnyUndefs;
7931   if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
7932     if (SplatUndef.isAllOnes())
7933       return DAG.getUNDEF(VT);
7934 
7935     // If all the users of this constant splat are qr instruction variants,
7936     // generate a vdup of the constant.
7937     if (ST->hasMVEIntegerOps() && VT.getScalarSizeInBits() == SplatBitSize &&
7938         (SplatBitSize == 8 || SplatBitSize == 16 || SplatBitSize == 32) &&
7939         all_of(BVN->uses(),
7940                [BVN](const SDNode *U) { return IsQRMVEInstruction(U, BVN); })) {
7941       EVT DupVT = SplatBitSize == 32   ? MVT::v4i32
7942                   : SplatBitSize == 16 ? MVT::v8i16
7943                                        : MVT::v16i8;
7944       SDValue Const = DAG.getConstant(SplatBits.getZExtValue(), dl, MVT::i32);
7945       SDValue VDup = DAG.getNode(ARMISD::VDUP, dl, DupVT, Const);
7946       return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, VDup);
7947     }
7948 
7949     if ((ST->hasNEON() && SplatBitSize <= 64) ||
7950         (ST->hasMVEIntegerOps() && SplatBitSize <= 64)) {
7951       // Check if an immediate VMOV works.
7952       EVT VmovVT;
7953       SDValue Val =
7954           isVMOVModifiedImm(SplatBits.getZExtValue(), SplatUndef.getZExtValue(),
7955                             SplatBitSize, DAG, dl, VmovVT, VT, VMOVModImm);
7956 
7957       if (Val.getNode()) {
7958         SDValue Vmov = DAG.getNode(ARMISD::VMOVIMM, dl, VmovVT, Val);
7959         return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
7960       }
7961 
7962       // Try an immediate VMVN.
7963       uint64_t NegatedImm = (~SplatBits).getZExtValue();
7964       Val = isVMOVModifiedImm(
7965           NegatedImm, SplatUndef.getZExtValue(), SplatBitSize, DAG, dl, VmovVT,
7966           VT, ST->hasMVEIntegerOps() ? MVEVMVNModImm : VMVNModImm);
7967       if (Val.getNode()) {
7968         SDValue Vmov = DAG.getNode(ARMISD::VMVNIMM, dl, VmovVT, Val);
7969         return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
7970       }
7971 
7972       // Use vmov.f32 to materialize other v2f32 and v4f32 splats.
7973       if ((VT == MVT::v2f32 || VT == MVT::v4f32) && SplatBitSize == 32) {
7974         int ImmVal = ARM_AM::getFP32Imm(SplatBits);
7975         if (ImmVal != -1) {
7976           SDValue Val = DAG.getTargetConstant(ImmVal, dl, MVT::i32);
7977           return DAG.getNode(ARMISD::VMOVFPIMM, dl, VT, Val);
7978         }
7979       }
7980 
7981       // If we are under MVE, generate a VDUP(constant), bitcast to the original
7982       // type.
7983       if (ST->hasMVEIntegerOps() &&
7984           (SplatBitSize == 8 || SplatBitSize == 16 || SplatBitSize == 32)) {
7985         EVT DupVT = SplatBitSize == 32   ? MVT::v4i32
7986                     : SplatBitSize == 16 ? MVT::v8i16
7987                                          : MVT::v16i8;
7988         SDValue Const = DAG.getConstant(SplatBits.getZExtValue(), dl, MVT::i32);
7989         SDValue VDup = DAG.getNode(ARMISD::VDUP, dl, DupVT, Const);
7990         return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, VDup);
7991       }
7992     }
7993   }
7994 
7995   // Scan through the operands to see if only one value is used.
7996   //
7997   // As an optimisation, even if more than one value is used it may be more
7998   // profitable to splat with one value then change some lanes.
7999   //
8000   // Heuristically we decide to do this if the vector has a "dominant" value,
8001   // defined as splatted to more than half of the lanes.
8002   unsigned NumElts = VT.getVectorNumElements();
8003   bool isOnlyLowElement = true;
8004   bool usesOnlyOneValue = true;
8005   bool hasDominantValue = false;
8006   bool isConstant = true;
8007 
8008   // Map of the number of times a particular SDValue appears in the
8009   // element list.
8010   DenseMap<SDValue, unsigned> ValueCounts;
8011   SDValue Value;
8012   for (unsigned i = 0; i < NumElts; ++i) {
8013     SDValue V = Op.getOperand(i);
8014     if (V.isUndef())
8015       continue;
8016     if (i > 0)
8017       isOnlyLowElement = false;
8018     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
8019       isConstant = false;
8020 
8021     ValueCounts.insert(std::make_pair(V, 0));
8022     unsigned &Count = ValueCounts[V];
8023 
8024     // Is this value dominant? (takes up more than half of the lanes)
8025     if (++Count > (NumElts / 2)) {
8026       hasDominantValue = true;
8027       Value = V;
8028     }
8029   }
8030   if (ValueCounts.size() != 1)
8031     usesOnlyOneValue = false;
8032   if (!Value.getNode() && !ValueCounts.empty())
8033     Value = ValueCounts.begin()->first;
8034 
8035   if (ValueCounts.empty())
8036     return DAG.getUNDEF(VT);
8037 
8038   // Loads are better lowered with insert_vector_elt/ARMISD::BUILD_VECTOR.
8039   // Keep going if we are hitting this case.
8040   if (isOnlyLowElement && !ISD::isNormalLoad(Value.getNode()))
8041     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
8042 
8043   unsigned EltSize = VT.getScalarSizeInBits();
8044 
8045   // Use VDUP for non-constant splats.  For f32 constant splats, reduce to
8046   // i32 and try again.
8047   if (hasDominantValue && EltSize <= 32) {
8048     if (!isConstant) {
8049       SDValue N;
8050 
8051       // If we are VDUPing a value that comes directly from a vector, that will
8052       // cause an unnecessary move to and from a GPR, where instead we could
8053       // just use VDUPLANE. We can only do this if the lane being extracted
8054       // is at a constant index, as the VDUP from lane instructions only have
8055       // constant-index forms.
8056       ConstantSDNode *constIndex;
8057       if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
8058           (constIndex = dyn_cast<ConstantSDNode>(Value->getOperand(1)))) {
8059         // We need to create a new undef vector to use for the VDUPLANE if the
8060         // size of the vector from which we get the value is different than the
8061         // size of the vector that we need to create. We will insert the element
8062         // such that the register coalescer will remove unnecessary copies.
8063         if (VT != Value->getOperand(0).getValueType()) {
8064           unsigned index = constIndex->getAPIntValue().getLimitedValue() %
8065                              VT.getVectorNumElements();
8066           N =  DAG.getNode(ARMISD::VDUPLANE, dl, VT,
8067                  DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, DAG.getUNDEF(VT),
8068                         Value, DAG.getConstant(index, dl, MVT::i32)),
8069                            DAG.getConstant(index, dl, MVT::i32));
8070         } else
8071           N = DAG.getNode(ARMISD::VDUPLANE, dl, VT,
8072                         Value->getOperand(0), Value->getOperand(1));
8073       } else
8074         N = DAG.getNode(ARMISD::VDUP, dl, VT, Value);
8075 
8076       if (!usesOnlyOneValue) {
8077         // The dominant value was splatted as 'N', but we now have to insert
8078         // all differing elements.
8079         for (unsigned I = 0; I < NumElts; ++I) {
8080           if (Op.getOperand(I) == Value)
8081             continue;
8082           SmallVector<SDValue, 3> Ops;
8083           Ops.push_back(N);
8084           Ops.push_back(Op.getOperand(I));
8085           Ops.push_back(DAG.getConstant(I, dl, MVT::i32));
8086           N = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Ops);
8087         }
8088       }
8089       return N;
8090     }
8091     if (VT.getVectorElementType().isFloatingPoint()) {
8092       SmallVector<SDValue, 8> Ops;
8093       MVT FVT = VT.getVectorElementType().getSimpleVT();
8094       assert(FVT == MVT::f32 || FVT == MVT::f16);
8095       MVT IVT = (FVT == MVT::f32) ? MVT::i32 : MVT::i16;
8096       for (unsigned i = 0; i < NumElts; ++i)
8097         Ops.push_back(DAG.getNode(ISD::BITCAST, dl, IVT,
8098                                   Op.getOperand(i)));
8099       EVT VecVT = EVT::getVectorVT(*DAG.getContext(), IVT, NumElts);
8100       SDValue Val = DAG.getBuildVector(VecVT, dl, Ops);
8101       Val = LowerBUILD_VECTOR(Val, DAG, ST);
8102       if (Val.getNode())
8103         return DAG.getNode(ISD::BITCAST, dl, VT, Val);
8104     }
8105     if (usesOnlyOneValue) {
8106       SDValue Val = IsSingleInstrConstant(Value, DAG, ST, dl);
8107       if (isConstant && Val.getNode())
8108         return DAG.getNode(ARMISD::VDUP, dl, VT, Val);
8109     }
8110   }
8111 
8112   // If all elements are constants and the case above didn't get hit, fall back
8113   // to the default expansion, which will generate a load from the constant
8114   // pool.
8115   if (isConstant)
8116     return SDValue();
8117 
8118   // Reconstruct the BUILDVECTOR to one of the legal shuffles (such as vext and
8119   // vmovn). Empirical tests suggest this is rarely worth it for vectors of
8120   // length <= 2.
8121   if (NumElts >= 4)
8122     if (SDValue shuffle = ReconstructShuffle(Op, DAG))
8123       return shuffle;
8124 
8125   // Attempt to turn a buildvector of scalar fptrunc's or fpext's back into
8126   // VCVT's
8127   if (SDValue VCVT = LowerBuildVectorOfFPTrunc(Op, DAG, Subtarget))
8128     return VCVT;
8129   if (SDValue VCVT = LowerBuildVectorOfFPExt(Op, DAG, Subtarget))
8130     return VCVT;
8131 
8132   if (ST->hasNEON() && VT.is128BitVector() && VT != MVT::v2f64 && VT != MVT::v4f32) {
8133     // If we haven't found an efficient lowering, try splitting a 128-bit vector
8134     // into two 64-bit vectors; we might discover a better way to lower it.
8135     SmallVector<SDValue, 64> Ops(Op->op_begin(), Op->op_begin() + NumElts);
8136     EVT ExtVT = VT.getVectorElementType();
8137     EVT HVT = EVT::getVectorVT(*DAG.getContext(), ExtVT, NumElts / 2);
8138     SDValue Lower = DAG.getBuildVector(HVT, dl, ArrayRef(&Ops[0], NumElts / 2));
8139     if (Lower.getOpcode() == ISD::BUILD_VECTOR)
8140       Lower = LowerBUILD_VECTOR(Lower, DAG, ST);
8141     SDValue Upper =
8142         DAG.getBuildVector(HVT, dl, ArrayRef(&Ops[NumElts / 2], NumElts / 2));
8143     if (Upper.getOpcode() == ISD::BUILD_VECTOR)
8144       Upper = LowerBUILD_VECTOR(Upper, DAG, ST);
8145     if (Lower && Upper)
8146       return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, Lower, Upper);
8147   }
8148 
8149   // Vectors with 32- or 64-bit elements can be built by directly assigning
8150   // the subregisters.  Lower it to an ARMISD::BUILD_VECTOR so the operands
8151   // will be legalized.
8152   if (EltSize >= 32) {
8153     // Do the expansion with floating-point types, since that is what the VFP
8154     // registers are defined to use, and since i64 is not legal.
8155     EVT EltVT = EVT::getFloatingPointVT(EltSize);
8156     EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
8157     SmallVector<SDValue, 8> Ops;
8158     for (unsigned i = 0; i < NumElts; ++i)
8159       Ops.push_back(DAG.getNode(ISD::BITCAST, dl, EltVT, Op.getOperand(i)));
8160     SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, Ops);
8161     return DAG.getNode(ISD::BITCAST, dl, VT, Val);
8162   }
8163 
8164   // If all else fails, just use a sequence of INSERT_VECTOR_ELT when we
8165   // know the default expansion would otherwise fall back on something even
8166   // worse. For a vector with one or two non-undef values, that's
8167   // scalar_to_vector for the elements followed by a shuffle (provided the
8168   // shuffle is valid for the target) and materialization element by element
8169   // on the stack followed by a load for everything else.
8170   if (!isConstant && !usesOnlyOneValue) {
8171     SDValue Vec = DAG.getUNDEF(VT);
8172     for (unsigned i = 0 ; i < NumElts; ++i) {
8173       SDValue V = Op.getOperand(i);
8174       if (V.isUndef())
8175         continue;
8176       SDValue LaneIdx = DAG.getConstant(i, dl, MVT::i32);
8177       Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Vec, V, LaneIdx);
8178     }
8179     return Vec;
8180   }
8181 
8182   return SDValue();
8183 }
8184 
8185 // Gather data to see if the operation can be modelled as a
8186 // shuffle in combination with VEXTs.
ReconstructShuffle(SDValue Op,SelectionDAG & DAG) const8187 SDValue ARMTargetLowering::ReconstructShuffle(SDValue Op,
8188                                               SelectionDAG &DAG) const {
8189   assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
8190   SDLoc dl(Op);
8191   EVT VT = Op.getValueType();
8192   unsigned NumElts = VT.getVectorNumElements();
8193 
8194   struct ShuffleSourceInfo {
8195     SDValue Vec;
8196     unsigned MinElt = std::numeric_limits<unsigned>::max();
8197     unsigned MaxElt = 0;
8198 
8199     // We may insert some combination of BITCASTs and VEXT nodes to force Vec to
8200     // be compatible with the shuffle we intend to construct. As a result
8201     // ShuffleVec will be some sliding window into the original Vec.
8202     SDValue ShuffleVec;
8203 
8204     // Code should guarantee that element i in Vec starts at element "WindowBase
8205     // + i * WindowScale in ShuffleVec".
8206     int WindowBase = 0;
8207     int WindowScale = 1;
8208 
8209     ShuffleSourceInfo(SDValue Vec) : Vec(Vec), ShuffleVec(Vec) {}
8210 
8211     bool operator ==(SDValue OtherVec) { return Vec == OtherVec; }
8212   };
8213 
8214   // First gather all vectors used as an immediate source for this BUILD_VECTOR
8215   // node.
8216   SmallVector<ShuffleSourceInfo, 2> Sources;
8217   for (unsigned i = 0; i < NumElts; ++i) {
8218     SDValue V = Op.getOperand(i);
8219     if (V.isUndef())
8220       continue;
8221     else if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT) {
8222       // A shuffle can only come from building a vector from various
8223       // elements of other vectors.
8224       return SDValue();
8225     } else if (!isa<ConstantSDNode>(V.getOperand(1))) {
8226       // Furthermore, shuffles require a constant mask, whereas extractelts
8227       // accept variable indices.
8228       return SDValue();
8229     }
8230 
8231     // Add this element source to the list if it's not already there.
8232     SDValue SourceVec = V.getOperand(0);
8233     auto Source = llvm::find(Sources, SourceVec);
8234     if (Source == Sources.end())
8235       Source = Sources.insert(Sources.end(), ShuffleSourceInfo(SourceVec));
8236 
8237     // Update the minimum and maximum lane number seen.
8238     unsigned EltNo = V.getConstantOperandVal(1);
8239     Source->MinElt = std::min(Source->MinElt, EltNo);
8240     Source->MaxElt = std::max(Source->MaxElt, EltNo);
8241   }
8242 
8243   // Currently only do something sane when at most two source vectors
8244   // are involved.
8245   if (Sources.size() > 2)
8246     return SDValue();
8247 
8248   // Find out the smallest element size among result and two sources, and use
8249   // it as element size to build the shuffle_vector.
8250   EVT SmallestEltTy = VT.getVectorElementType();
8251   for (auto &Source : Sources) {
8252     EVT SrcEltTy = Source.Vec.getValueType().getVectorElementType();
8253     if (SrcEltTy.bitsLT(SmallestEltTy))
8254       SmallestEltTy = SrcEltTy;
8255   }
8256   unsigned ResMultiplier =
8257       VT.getScalarSizeInBits() / SmallestEltTy.getSizeInBits();
8258   NumElts = VT.getSizeInBits() / SmallestEltTy.getSizeInBits();
8259   EVT ShuffleVT = EVT::getVectorVT(*DAG.getContext(), SmallestEltTy, NumElts);
8260 
8261   // If the source vector is too wide or too narrow, we may nevertheless be able
8262   // to construct a compatible shuffle either by concatenating it with UNDEF or
8263   // extracting a suitable range of elements.
8264   for (auto &Src : Sources) {
8265     EVT SrcVT = Src.ShuffleVec.getValueType();
8266 
8267     uint64_t SrcVTSize = SrcVT.getFixedSizeInBits();
8268     uint64_t VTSize = VT.getFixedSizeInBits();
8269     if (SrcVTSize == VTSize)
8270       continue;
8271 
8272     // This stage of the search produces a source with the same element type as
8273     // the original, but with a total width matching the BUILD_VECTOR output.
8274     EVT EltVT = SrcVT.getVectorElementType();
8275     unsigned NumSrcElts = VTSize / EltVT.getFixedSizeInBits();
8276     EVT DestVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumSrcElts);
8277 
8278     if (SrcVTSize < VTSize) {
8279       if (2 * SrcVTSize != VTSize)
8280         return SDValue();
8281       // We can pad out the smaller vector for free, so if it's part of a
8282       // shuffle...
8283       Src.ShuffleVec =
8284           DAG.getNode(ISD::CONCAT_VECTORS, dl, DestVT, Src.ShuffleVec,
8285                       DAG.getUNDEF(Src.ShuffleVec.getValueType()));
8286       continue;
8287     }
8288 
8289     if (SrcVTSize != 2 * VTSize)
8290       return SDValue();
8291 
8292     if (Src.MaxElt - Src.MinElt >= NumSrcElts) {
8293       // Span too large for a VEXT to cope
8294       return SDValue();
8295     }
8296 
8297     if (Src.MinElt >= NumSrcElts) {
8298       // The extraction can just take the second half
8299       Src.ShuffleVec =
8300           DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, DestVT, Src.ShuffleVec,
8301                       DAG.getConstant(NumSrcElts, dl, MVT::i32));
8302       Src.WindowBase = -NumSrcElts;
8303     } else if (Src.MaxElt < NumSrcElts) {
8304       // The extraction can just take the first half
8305       Src.ShuffleVec =
8306           DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, DestVT, Src.ShuffleVec,
8307                       DAG.getConstant(0, dl, MVT::i32));
8308     } else {
8309       // An actual VEXT is needed
8310       SDValue VEXTSrc1 =
8311           DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, DestVT, Src.ShuffleVec,
8312                       DAG.getConstant(0, dl, MVT::i32));
8313       SDValue VEXTSrc2 =
8314           DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, DestVT, Src.ShuffleVec,
8315                       DAG.getConstant(NumSrcElts, dl, MVT::i32));
8316 
8317       Src.ShuffleVec = DAG.getNode(ARMISD::VEXT, dl, DestVT, VEXTSrc1,
8318                                    VEXTSrc2,
8319                                    DAG.getConstant(Src.MinElt, dl, MVT::i32));
8320       Src.WindowBase = -Src.MinElt;
8321     }
8322   }
8323 
8324   // Another possible incompatibility occurs from the vector element types. We
8325   // can fix this by bitcasting the source vectors to the same type we intend
8326   // for the shuffle.
8327   for (auto &Src : Sources) {
8328     EVT SrcEltTy = Src.ShuffleVec.getValueType().getVectorElementType();
8329     if (SrcEltTy == SmallestEltTy)
8330       continue;
8331     assert(ShuffleVT.getVectorElementType() == SmallestEltTy);
8332     Src.ShuffleVec = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, ShuffleVT, Src.ShuffleVec);
8333     Src.WindowScale = SrcEltTy.getSizeInBits() / SmallestEltTy.getSizeInBits();
8334     Src.WindowBase *= Src.WindowScale;
8335   }
8336 
8337   // Final check before we try to actually produce a shuffle.
8338   LLVM_DEBUG(for (auto Src
8339                   : Sources)
8340                  assert(Src.ShuffleVec.getValueType() == ShuffleVT););
8341 
8342   // The stars all align, our next step is to produce the mask for the shuffle.
8343   SmallVector<int, 8> Mask(ShuffleVT.getVectorNumElements(), -1);
8344   int BitsPerShuffleLane = ShuffleVT.getScalarSizeInBits();
8345   for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
8346     SDValue Entry = Op.getOperand(i);
8347     if (Entry.isUndef())
8348       continue;
8349 
8350     auto Src = llvm::find(Sources, Entry.getOperand(0));
8351     int EltNo = cast<ConstantSDNode>(Entry.getOperand(1))->getSExtValue();
8352 
8353     // EXTRACT_VECTOR_ELT performs an implicit any_ext; BUILD_VECTOR an implicit
8354     // trunc. So only std::min(SrcBits, DestBits) actually get defined in this
8355     // segment.
8356     EVT OrigEltTy = Entry.getOperand(0).getValueType().getVectorElementType();
8357     int BitsDefined = std::min(OrigEltTy.getScalarSizeInBits(),
8358                                VT.getScalarSizeInBits());
8359     int LanesDefined = BitsDefined / BitsPerShuffleLane;
8360 
8361     // This source is expected to fill ResMultiplier lanes of the final shuffle,
8362     // starting at the appropriate offset.
8363     int *LaneMask = &Mask[i * ResMultiplier];
8364 
8365     int ExtractBase = EltNo * Src->WindowScale + Src->WindowBase;
8366     ExtractBase += NumElts * (Src - Sources.begin());
8367     for (int j = 0; j < LanesDefined; ++j)
8368       LaneMask[j] = ExtractBase + j;
8369   }
8370 
8371 
8372   // We can't handle more than two sources. This should have already
8373   // been checked before this point.
8374   assert(Sources.size() <= 2 && "Too many sources!");
8375 
8376   SDValue ShuffleOps[] = { DAG.getUNDEF(ShuffleVT), DAG.getUNDEF(ShuffleVT) };
8377   for (unsigned i = 0; i < Sources.size(); ++i)
8378     ShuffleOps[i] = Sources[i].ShuffleVec;
8379 
8380   SDValue Shuffle = buildLegalVectorShuffle(ShuffleVT, dl, ShuffleOps[0],
8381                                             ShuffleOps[1], Mask, DAG);
8382   if (!Shuffle)
8383     return SDValue();
8384   return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, Shuffle);
8385 }
8386 
8387 enum ShuffleOpCodes {
8388   OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
8389   OP_VREV,
8390   OP_VDUP0,
8391   OP_VDUP1,
8392   OP_VDUP2,
8393   OP_VDUP3,
8394   OP_VEXT1,
8395   OP_VEXT2,
8396   OP_VEXT3,
8397   OP_VUZPL, // VUZP, left result
8398   OP_VUZPR, // VUZP, right result
8399   OP_VZIPL, // VZIP, left result
8400   OP_VZIPR, // VZIP, right result
8401   OP_VTRNL, // VTRN, left result
8402   OP_VTRNR  // VTRN, right result
8403 };
8404 
isLegalMVEShuffleOp(unsigned PFEntry)8405 static bool isLegalMVEShuffleOp(unsigned PFEntry) {
8406   unsigned OpNum = (PFEntry >> 26) & 0x0F;
8407   switch (OpNum) {
8408   case OP_COPY:
8409   case OP_VREV:
8410   case OP_VDUP0:
8411   case OP_VDUP1:
8412   case OP_VDUP2:
8413   case OP_VDUP3:
8414     return true;
8415   }
8416   return false;
8417 }
8418 
8419 /// isShuffleMaskLegal - Targets can use this to indicate that they only
8420 /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
8421 /// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
8422 /// are assumed to be legal.
isShuffleMaskLegal(ArrayRef<int> M,EVT VT) const8423 bool ARMTargetLowering::isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const {
8424   if (VT.getVectorNumElements() == 4 &&
8425       (VT.is128BitVector() || VT.is64BitVector())) {
8426     unsigned PFIndexes[4];
8427     for (unsigned i = 0; i != 4; ++i) {
8428       if (M[i] < 0)
8429         PFIndexes[i] = 8;
8430       else
8431         PFIndexes[i] = M[i];
8432     }
8433 
8434     // Compute the index in the perfect shuffle table.
8435     unsigned PFTableIndex =
8436       PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
8437     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
8438     unsigned Cost = (PFEntry >> 30);
8439 
8440     if (Cost <= 4 && (Subtarget->hasNEON() || isLegalMVEShuffleOp(PFEntry)))
8441       return true;
8442   }
8443 
8444   bool ReverseVEXT, isV_UNDEF;
8445   unsigned Imm, WhichResult;
8446 
8447   unsigned EltSize = VT.getScalarSizeInBits();
8448   if (EltSize >= 32 ||
8449       ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
8450       ShuffleVectorInst::isIdentityMask(M, M.size()) ||
8451       isVREVMask(M, VT, 64) ||
8452       isVREVMask(M, VT, 32) ||
8453       isVREVMask(M, VT, 16))
8454     return true;
8455   else if (Subtarget->hasNEON() &&
8456            (isVEXTMask(M, VT, ReverseVEXT, Imm) ||
8457             isVTBLMask(M, VT) ||
8458             isNEONTwoResultShuffleMask(M, VT, WhichResult, isV_UNDEF)))
8459     return true;
8460   else if ((VT == MVT::v8i16 || VT == MVT::v8f16 || VT == MVT::v16i8) &&
8461            isReverseMask(M, VT))
8462     return true;
8463   else if (Subtarget->hasMVEIntegerOps() &&
8464            (isVMOVNMask(M, VT, true, false) ||
8465             isVMOVNMask(M, VT, false, false) || isVMOVNMask(M, VT, true, true)))
8466     return true;
8467   else if (Subtarget->hasMVEIntegerOps() &&
8468            (isTruncMask(M, VT, false, false) ||
8469             isTruncMask(M, VT, false, true) ||
8470             isTruncMask(M, VT, true, false) || isTruncMask(M, VT, true, true)))
8471     return true;
8472   else
8473     return false;
8474 }
8475 
8476 /// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
8477 /// the specified operations to build the shuffle.
GeneratePerfectShuffle(unsigned PFEntry,SDValue LHS,SDValue RHS,SelectionDAG & DAG,const SDLoc & dl)8478 static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
8479                                       SDValue RHS, SelectionDAG &DAG,
8480                                       const SDLoc &dl) {
8481   unsigned OpNum = (PFEntry >> 26) & 0x0F;
8482   unsigned LHSID = (PFEntry >> 13) & ((1 << 13)-1);
8483   unsigned RHSID = (PFEntry >>  0) & ((1 << 13)-1);
8484 
8485   if (OpNum == OP_COPY) {
8486     if (LHSID == (1*9+2)*9+3) return LHS;
8487     assert(LHSID == ((4*9+5)*9+6)*9+7 && "Illegal OP_COPY!");
8488     return RHS;
8489   }
8490 
8491   SDValue OpLHS, OpRHS;
8492   OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
8493   OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
8494   EVT VT = OpLHS.getValueType();
8495 
8496   switch (OpNum) {
8497   default: llvm_unreachable("Unknown shuffle opcode!");
8498   case OP_VREV:
8499     // VREV divides the vector in half and swaps within the half.
8500     if (VT.getScalarSizeInBits() == 32)
8501       return DAG.getNode(ARMISD::VREV64, dl, VT, OpLHS);
8502     // vrev <4 x i16> -> VREV32
8503     if (VT.getScalarSizeInBits() == 16)
8504       return DAG.getNode(ARMISD::VREV32, dl, VT, OpLHS);
8505     // vrev <4 x i8> -> VREV16
8506     assert(VT.getScalarSizeInBits() == 8);
8507     return DAG.getNode(ARMISD::VREV16, dl, VT, OpLHS);
8508   case OP_VDUP0:
8509   case OP_VDUP1:
8510   case OP_VDUP2:
8511   case OP_VDUP3:
8512     return DAG.getNode(ARMISD::VDUPLANE, dl, VT,
8513                        OpLHS, DAG.getConstant(OpNum-OP_VDUP0, dl, MVT::i32));
8514   case OP_VEXT1:
8515   case OP_VEXT2:
8516   case OP_VEXT3:
8517     return DAG.getNode(ARMISD::VEXT, dl, VT,
8518                        OpLHS, OpRHS,
8519                        DAG.getConstant(OpNum - OP_VEXT1 + 1, dl, MVT::i32));
8520   case OP_VUZPL:
8521   case OP_VUZPR:
8522     return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
8523                        OpLHS, OpRHS).getValue(OpNum-OP_VUZPL);
8524   case OP_VZIPL:
8525   case OP_VZIPR:
8526     return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
8527                        OpLHS, OpRHS).getValue(OpNum-OP_VZIPL);
8528   case OP_VTRNL:
8529   case OP_VTRNR:
8530     return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
8531                        OpLHS, OpRHS).getValue(OpNum-OP_VTRNL);
8532   }
8533 }
8534 
LowerVECTOR_SHUFFLEv8i8(SDValue Op,ArrayRef<int> ShuffleMask,SelectionDAG & DAG)8535 static SDValue LowerVECTOR_SHUFFLEv8i8(SDValue Op,
8536                                        ArrayRef<int> ShuffleMask,
8537                                        SelectionDAG &DAG) {
8538   // Check to see if we can use the VTBL instruction.
8539   SDValue V1 = Op.getOperand(0);
8540   SDValue V2 = Op.getOperand(1);
8541   SDLoc DL(Op);
8542 
8543   SmallVector<SDValue, 8> VTBLMask;
8544   for (int I : ShuffleMask)
8545     VTBLMask.push_back(DAG.getConstant(I, DL, MVT::i32));
8546 
8547   if (V2.getNode()->isUndef())
8548     return DAG.getNode(ARMISD::VTBL1, DL, MVT::v8i8, V1,
8549                        DAG.getBuildVector(MVT::v8i8, DL, VTBLMask));
8550 
8551   return DAG.getNode(ARMISD::VTBL2, DL, MVT::v8i8, V1, V2,
8552                      DAG.getBuildVector(MVT::v8i8, DL, VTBLMask));
8553 }
8554 
LowerReverse_VECTOR_SHUFFLE(SDValue Op,SelectionDAG & DAG)8555 static SDValue LowerReverse_VECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
8556   SDLoc DL(Op);
8557   EVT VT = Op.getValueType();
8558 
8559   assert((VT == MVT::v8i16 || VT == MVT::v8f16 || VT == MVT::v16i8) &&
8560          "Expect an v8i16/v16i8 type");
8561   SDValue OpLHS = DAG.getNode(ARMISD::VREV64, DL, VT, Op.getOperand(0));
8562   // For a v16i8 type: After the VREV, we have got <7, ..., 0, 15, ..., 8>. Now,
8563   // extract the first 8 bytes into the top double word and the last 8 bytes
8564   // into the bottom double word, through a new vector shuffle that will be
8565   // turned into a VEXT on Neon, or a couple of VMOVDs on MVE.
8566   std::vector<int> NewMask;
8567   for (unsigned i = 0; i < VT.getVectorNumElements() / 2; i++)
8568     NewMask.push_back(VT.getVectorNumElements() / 2 + i);
8569   for (unsigned i = 0; i < VT.getVectorNumElements() / 2; i++)
8570     NewMask.push_back(i);
8571   return DAG.getVectorShuffle(VT, DL, OpLHS, OpLHS, NewMask);
8572 }
8573 
getVectorTyFromPredicateVector(EVT VT)8574 static EVT getVectorTyFromPredicateVector(EVT VT) {
8575   switch (VT.getSimpleVT().SimpleTy) {
8576   case MVT::v2i1:
8577     return MVT::v2f64;
8578   case MVT::v4i1:
8579     return MVT::v4i32;
8580   case MVT::v8i1:
8581     return MVT::v8i16;
8582   case MVT::v16i1:
8583     return MVT::v16i8;
8584   default:
8585     llvm_unreachable("Unexpected vector predicate type");
8586   }
8587 }
8588 
PromoteMVEPredVector(SDLoc dl,SDValue Pred,EVT VT,SelectionDAG & DAG)8589 static SDValue PromoteMVEPredVector(SDLoc dl, SDValue Pred, EVT VT,
8590                                     SelectionDAG &DAG) {
8591   // Converting from boolean predicates to integers involves creating a vector
8592   // of all ones or all zeroes and selecting the lanes based upon the real
8593   // predicate.
8594   SDValue AllOnes =
8595       DAG.getTargetConstant(ARM_AM::createVMOVModImm(0xe, 0xff), dl, MVT::i32);
8596   AllOnes = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v16i8, AllOnes);
8597 
8598   SDValue AllZeroes =
8599       DAG.getTargetConstant(ARM_AM::createVMOVModImm(0xe, 0x0), dl, MVT::i32);
8600   AllZeroes = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v16i8, AllZeroes);
8601 
8602   // Get full vector type from predicate type
8603   EVT NewVT = getVectorTyFromPredicateVector(VT);
8604 
8605   SDValue RecastV1;
8606   // If the real predicate is an v8i1 or v4i1 (not v16i1) then we need to recast
8607   // this to a v16i1. This cannot be done with an ordinary bitcast because the
8608   // sizes are not the same. We have to use a MVE specific PREDICATE_CAST node,
8609   // since we know in hardware the sizes are really the same.
8610   if (VT != MVT::v16i1)
8611     RecastV1 = DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::v16i1, Pred);
8612   else
8613     RecastV1 = Pred;
8614 
8615   // Select either all ones or zeroes depending upon the real predicate bits.
8616   SDValue PredAsVector =
8617       DAG.getNode(ISD::VSELECT, dl, MVT::v16i8, RecastV1, AllOnes, AllZeroes);
8618 
8619   // Recast our new predicate-as-integer v16i8 vector into something
8620   // appropriate for the shuffle, i.e. v4i32 for a real v4i1 predicate.
8621   return DAG.getNode(ISD::BITCAST, dl, NewVT, PredAsVector);
8622 }
8623 
LowerVECTOR_SHUFFLE_i1(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)8624 static SDValue LowerVECTOR_SHUFFLE_i1(SDValue Op, SelectionDAG &DAG,
8625                                       const ARMSubtarget *ST) {
8626   EVT VT = Op.getValueType();
8627   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
8628   ArrayRef<int> ShuffleMask = SVN->getMask();
8629 
8630   assert(ST->hasMVEIntegerOps() &&
8631          "No support for vector shuffle of boolean predicates");
8632 
8633   SDValue V1 = Op.getOperand(0);
8634   SDValue V2 = Op.getOperand(1);
8635   SDLoc dl(Op);
8636   if (isReverseMask(ShuffleMask, VT)) {
8637     SDValue cast = DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::i32, V1);
8638     SDValue rbit = DAG.getNode(ISD::BITREVERSE, dl, MVT::i32, cast);
8639     SDValue srl = DAG.getNode(ISD::SRL, dl, MVT::i32, rbit,
8640                               DAG.getConstant(16, dl, MVT::i32));
8641     return DAG.getNode(ARMISD::PREDICATE_CAST, dl, VT, srl);
8642   }
8643 
8644   // Until we can come up with optimised cases for every single vector
8645   // shuffle in existence we have chosen the least painful strategy. This is
8646   // to essentially promote the boolean predicate to a 8-bit integer, where
8647   // each predicate represents a byte. Then we fall back on a normal integer
8648   // vector shuffle and convert the result back into a predicate vector. In
8649   // many cases the generated code might be even better than scalar code
8650   // operating on bits. Just imagine trying to shuffle 8 arbitrary 2-bit
8651   // fields in a register into 8 other arbitrary 2-bit fields!
8652   SDValue PredAsVector1 = PromoteMVEPredVector(dl, V1, VT, DAG);
8653   EVT NewVT = PredAsVector1.getValueType();
8654   SDValue PredAsVector2 = V2.isUndef() ? DAG.getUNDEF(NewVT)
8655                                        : PromoteMVEPredVector(dl, V2, VT, DAG);
8656   assert(PredAsVector2.getValueType() == NewVT &&
8657          "Expected identical vector type in expanded i1 shuffle!");
8658 
8659   // Do the shuffle!
8660   SDValue Shuffled = DAG.getVectorShuffle(NewVT, dl, PredAsVector1,
8661                                           PredAsVector2, ShuffleMask);
8662 
8663   // Now return the result of comparing the shuffled vector with zero,
8664   // which will generate a real predicate, i.e. v4i1, v8i1 or v16i1. For a v2i1
8665   // we convert to a v4i1 compare to fill in the two halves of the i64 as i32s.
8666   if (VT == MVT::v2i1) {
8667     SDValue BC = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, Shuffled);
8668     SDValue Cmp = DAG.getNode(ARMISD::VCMPZ, dl, MVT::v4i1, BC,
8669                               DAG.getConstant(ARMCC::NE, dl, MVT::i32));
8670     return DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::v2i1, Cmp);
8671   }
8672   return DAG.getNode(ARMISD::VCMPZ, dl, VT, Shuffled,
8673                      DAG.getConstant(ARMCC::NE, dl, MVT::i32));
8674 }
8675 
LowerVECTOR_SHUFFLEUsingMovs(SDValue Op,ArrayRef<int> ShuffleMask,SelectionDAG & DAG)8676 static SDValue LowerVECTOR_SHUFFLEUsingMovs(SDValue Op,
8677                                             ArrayRef<int> ShuffleMask,
8678                                             SelectionDAG &DAG) {
8679   // Attempt to lower the vector shuffle using as many whole register movs as
8680   // possible. This is useful for types smaller than 32bits, which would
8681   // often otherwise become a series for grp movs.
8682   SDLoc dl(Op);
8683   EVT VT = Op.getValueType();
8684   if (VT.getScalarSizeInBits() >= 32)
8685     return SDValue();
8686 
8687   assert((VT == MVT::v8i16 || VT == MVT::v8f16 || VT == MVT::v16i8) &&
8688          "Unexpected vector type");
8689   int NumElts = VT.getVectorNumElements();
8690   int QuarterSize = NumElts / 4;
8691   // The four final parts of the vector, as i32's
8692   SDValue Parts[4];
8693 
8694   // Look for full lane vmovs like <0,1,2,3> or <u,5,6,7> etc, (but not
8695   // <u,u,u,u>), returning the vmov lane index
8696   auto getMovIdx = [](ArrayRef<int> ShuffleMask, int Start, int Length) {
8697     // Detect which mov lane this would be from the first non-undef element.
8698     int MovIdx = -1;
8699     for (int i = 0; i < Length; i++) {
8700       if (ShuffleMask[Start + i] >= 0) {
8701         if (ShuffleMask[Start + i] % Length != i)
8702           return -1;
8703         MovIdx = ShuffleMask[Start + i] / Length;
8704         break;
8705       }
8706     }
8707     // If all items are undef, leave this for other combines
8708     if (MovIdx == -1)
8709       return -1;
8710     // Check the remaining values are the correct part of the same mov
8711     for (int i = 1; i < Length; i++) {
8712       if (ShuffleMask[Start + i] >= 0 &&
8713           (ShuffleMask[Start + i] / Length != MovIdx ||
8714            ShuffleMask[Start + i] % Length != i))
8715         return -1;
8716     }
8717     return MovIdx;
8718   };
8719 
8720   for (int Part = 0; Part < 4; ++Part) {
8721     // Does this part look like a mov
8722     int Elt = getMovIdx(ShuffleMask, Part * QuarterSize, QuarterSize);
8723     if (Elt != -1) {
8724       SDValue Input = Op->getOperand(0);
8725       if (Elt >= 4) {
8726         Input = Op->getOperand(1);
8727         Elt -= 4;
8728       }
8729       SDValue BitCast = DAG.getBitcast(MVT::v4f32, Input);
8730       Parts[Part] = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f32, BitCast,
8731                                 DAG.getConstant(Elt, dl, MVT::i32));
8732     }
8733   }
8734 
8735   // Nothing interesting found, just return
8736   if (!Parts[0] && !Parts[1] && !Parts[2] && !Parts[3])
8737     return SDValue();
8738 
8739   // The other parts need to be built with the old shuffle vector, cast to a
8740   // v4i32 and extract_vector_elts
8741   if (!Parts[0] || !Parts[1] || !Parts[2] || !Parts[3]) {
8742     SmallVector<int, 16> NewShuffleMask;
8743     for (int Part = 0; Part < 4; ++Part)
8744       for (int i = 0; i < QuarterSize; i++)
8745         NewShuffleMask.push_back(
8746             Parts[Part] ? -1 : ShuffleMask[Part * QuarterSize + i]);
8747     SDValue NewShuffle = DAG.getVectorShuffle(
8748         VT, dl, Op->getOperand(0), Op->getOperand(1), NewShuffleMask);
8749     SDValue BitCast = DAG.getBitcast(MVT::v4f32, NewShuffle);
8750 
8751     for (int Part = 0; Part < 4; ++Part)
8752       if (!Parts[Part])
8753         Parts[Part] = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f32,
8754                                   BitCast, DAG.getConstant(Part, dl, MVT::i32));
8755   }
8756   // Build a vector out of the various parts and bitcast it back to the original
8757   // type.
8758   SDValue NewVec = DAG.getNode(ARMISD::BUILD_VECTOR, dl, MVT::v4f32, Parts);
8759   return DAG.getBitcast(VT, NewVec);
8760 }
8761 
LowerVECTOR_SHUFFLEUsingOneOff(SDValue Op,ArrayRef<int> ShuffleMask,SelectionDAG & DAG)8762 static SDValue LowerVECTOR_SHUFFLEUsingOneOff(SDValue Op,
8763                                               ArrayRef<int> ShuffleMask,
8764                                               SelectionDAG &DAG) {
8765   SDValue V1 = Op.getOperand(0);
8766   SDValue V2 = Op.getOperand(1);
8767   EVT VT = Op.getValueType();
8768   unsigned NumElts = VT.getVectorNumElements();
8769 
8770   // An One-Off Identity mask is one that is mostly an identity mask from as
8771   // single source but contains a single element out-of-place, either from a
8772   // different vector or from another position in the same vector. As opposed to
8773   // lowering this via a ARMISD::BUILD_VECTOR we can generate an extract/insert
8774   // pair directly.
8775   auto isOneOffIdentityMask = [](ArrayRef<int> Mask, EVT VT, int BaseOffset,
8776                                  int &OffElement) {
8777     OffElement = -1;
8778     int NonUndef = 0;
8779     for (int i = 0, NumMaskElts = Mask.size(); i < NumMaskElts; ++i) {
8780       if (Mask[i] == -1)
8781         continue;
8782       NonUndef++;
8783       if (Mask[i] != i + BaseOffset) {
8784         if (OffElement == -1)
8785           OffElement = i;
8786         else
8787           return false;
8788       }
8789     }
8790     return NonUndef > 2 && OffElement != -1;
8791   };
8792   int OffElement;
8793   SDValue VInput;
8794   if (isOneOffIdentityMask(ShuffleMask, VT, 0, OffElement))
8795     VInput = V1;
8796   else if (isOneOffIdentityMask(ShuffleMask, VT, NumElts, OffElement))
8797     VInput = V2;
8798   else
8799     return SDValue();
8800 
8801   SDLoc dl(Op);
8802   EVT SVT = VT.getScalarType() == MVT::i8 || VT.getScalarType() == MVT::i16
8803                 ? MVT::i32
8804                 : VT.getScalarType();
8805   SDValue Elt = DAG.getNode(
8806       ISD::EXTRACT_VECTOR_ELT, dl, SVT,
8807       ShuffleMask[OffElement] < (int)NumElts ? V1 : V2,
8808       DAG.getVectorIdxConstant(ShuffleMask[OffElement] % NumElts, dl));
8809   return DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, VInput, Elt,
8810                      DAG.getVectorIdxConstant(OffElement % NumElts, dl));
8811 }
8812 
LowerVECTOR_SHUFFLE(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)8813 static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG,
8814                                    const ARMSubtarget *ST) {
8815   SDValue V1 = Op.getOperand(0);
8816   SDValue V2 = Op.getOperand(1);
8817   SDLoc dl(Op);
8818   EVT VT = Op.getValueType();
8819   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
8820   unsigned EltSize = VT.getScalarSizeInBits();
8821 
8822   if (ST->hasMVEIntegerOps() && EltSize == 1)
8823     return LowerVECTOR_SHUFFLE_i1(Op, DAG, ST);
8824 
8825   // Convert shuffles that are directly supported on NEON to target-specific
8826   // DAG nodes, instead of keeping them as shuffles and matching them again
8827   // during code selection.  This is more efficient and avoids the possibility
8828   // of inconsistencies between legalization and selection.
8829   // FIXME: floating-point vectors should be canonicalized to integer vectors
8830   // of the same time so that they get CSEd properly.
8831   ArrayRef<int> ShuffleMask = SVN->getMask();
8832 
8833   if (EltSize <= 32) {
8834     if (SVN->isSplat()) {
8835       int Lane = SVN->getSplatIndex();
8836       // If this is undef splat, generate it via "just" vdup, if possible.
8837       if (Lane == -1) Lane = 0;
8838 
8839       // Test if V1 is a SCALAR_TO_VECTOR.
8840       if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR) {
8841         return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
8842       }
8843       // Test if V1 is a BUILD_VECTOR which is equivalent to a SCALAR_TO_VECTOR
8844       // (and probably will turn into a SCALAR_TO_VECTOR once legalization
8845       // reaches it).
8846       if (Lane == 0 && V1.getOpcode() == ISD::BUILD_VECTOR &&
8847           !isa<ConstantSDNode>(V1.getOperand(0))) {
8848         bool IsScalarToVector = true;
8849         for (unsigned i = 1, e = V1.getNumOperands(); i != e; ++i)
8850           if (!V1.getOperand(i).isUndef()) {
8851             IsScalarToVector = false;
8852             break;
8853           }
8854         if (IsScalarToVector)
8855           return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
8856       }
8857       return DAG.getNode(ARMISD::VDUPLANE, dl, VT, V1,
8858                          DAG.getConstant(Lane, dl, MVT::i32));
8859     }
8860 
8861     bool ReverseVEXT = false;
8862     unsigned Imm = 0;
8863     if (ST->hasNEON() && isVEXTMask(ShuffleMask, VT, ReverseVEXT, Imm)) {
8864       if (ReverseVEXT)
8865         std::swap(V1, V2);
8866       return DAG.getNode(ARMISD::VEXT, dl, VT, V1, V2,
8867                          DAG.getConstant(Imm, dl, MVT::i32));
8868     }
8869 
8870     if (isVREVMask(ShuffleMask, VT, 64))
8871       return DAG.getNode(ARMISD::VREV64, dl, VT, V1);
8872     if (isVREVMask(ShuffleMask, VT, 32))
8873       return DAG.getNode(ARMISD::VREV32, dl, VT, V1);
8874     if (isVREVMask(ShuffleMask, VT, 16))
8875       return DAG.getNode(ARMISD::VREV16, dl, VT, V1);
8876 
8877     if (ST->hasNEON() && V2->isUndef() && isSingletonVEXTMask(ShuffleMask, VT, Imm)) {
8878       return DAG.getNode(ARMISD::VEXT, dl, VT, V1, V1,
8879                          DAG.getConstant(Imm, dl, MVT::i32));
8880     }
8881 
8882     // Check for Neon shuffles that modify both input vectors in place.
8883     // If both results are used, i.e., if there are two shuffles with the same
8884     // source operands and with masks corresponding to both results of one of
8885     // these operations, DAG memoization will ensure that a single node is
8886     // used for both shuffles.
8887     unsigned WhichResult = 0;
8888     bool isV_UNDEF = false;
8889     if (ST->hasNEON()) {
8890       if (unsigned ShuffleOpc = isNEONTwoResultShuffleMask(
8891               ShuffleMask, VT, WhichResult, isV_UNDEF)) {
8892         if (isV_UNDEF)
8893           V2 = V1;
8894         return DAG.getNode(ShuffleOpc, dl, DAG.getVTList(VT, VT), V1, V2)
8895             .getValue(WhichResult);
8896       }
8897     }
8898     if (ST->hasMVEIntegerOps()) {
8899       if (isVMOVNMask(ShuffleMask, VT, false, false))
8900         return DAG.getNode(ARMISD::VMOVN, dl, VT, V2, V1,
8901                            DAG.getConstant(0, dl, MVT::i32));
8902       if (isVMOVNMask(ShuffleMask, VT, true, false))
8903         return DAG.getNode(ARMISD::VMOVN, dl, VT, V1, V2,
8904                            DAG.getConstant(1, dl, MVT::i32));
8905       if (isVMOVNMask(ShuffleMask, VT, true, true))
8906         return DAG.getNode(ARMISD::VMOVN, dl, VT, V1, V1,
8907                            DAG.getConstant(1, dl, MVT::i32));
8908     }
8909 
8910     // Also check for these shuffles through CONCAT_VECTORS: we canonicalize
8911     // shuffles that produce a result larger than their operands with:
8912     //   shuffle(concat(v1, undef), concat(v2, undef))
8913     // ->
8914     //   shuffle(concat(v1, v2), undef)
8915     // because we can access quad vectors (see PerformVECTOR_SHUFFLECombine).
8916     //
8917     // This is useful in the general case, but there are special cases where
8918     // native shuffles produce larger results: the two-result ops.
8919     //
8920     // Look through the concat when lowering them:
8921     //   shuffle(concat(v1, v2), undef)
8922     // ->
8923     //   concat(VZIP(v1, v2):0, :1)
8924     //
8925     if (ST->hasNEON() && V1->getOpcode() == ISD::CONCAT_VECTORS && V2->isUndef()) {
8926       SDValue SubV1 = V1->getOperand(0);
8927       SDValue SubV2 = V1->getOperand(1);
8928       EVT SubVT = SubV1.getValueType();
8929 
8930       // We expect these to have been canonicalized to -1.
8931       assert(llvm::all_of(ShuffleMask, [&](int i) {
8932         return i < (int)VT.getVectorNumElements();
8933       }) && "Unexpected shuffle index into UNDEF operand!");
8934 
8935       if (unsigned ShuffleOpc = isNEONTwoResultShuffleMask(
8936               ShuffleMask, SubVT, WhichResult, isV_UNDEF)) {
8937         if (isV_UNDEF)
8938           SubV2 = SubV1;
8939         assert((WhichResult == 0) &&
8940                "In-place shuffle of concat can only have one result!");
8941         SDValue Res = DAG.getNode(ShuffleOpc, dl, DAG.getVTList(SubVT, SubVT),
8942                                   SubV1, SubV2);
8943         return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, Res.getValue(0),
8944                            Res.getValue(1));
8945       }
8946     }
8947   }
8948 
8949   if (ST->hasMVEIntegerOps() && EltSize <= 32) {
8950     if (SDValue V = LowerVECTOR_SHUFFLEUsingOneOff(Op, ShuffleMask, DAG))
8951       return V;
8952 
8953     for (bool Top : {false, true}) {
8954       for (bool SingleSource : {false, true}) {
8955         if (isTruncMask(ShuffleMask, VT, Top, SingleSource)) {
8956           MVT FromSVT = MVT::getIntegerVT(EltSize * 2);
8957           MVT FromVT = MVT::getVectorVT(FromSVT, ShuffleMask.size() / 2);
8958           SDValue Lo = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, FromVT, V1);
8959           SDValue Hi = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, FromVT,
8960                                    SingleSource ? V1 : V2);
8961           if (Top) {
8962             SDValue Amt = DAG.getConstant(EltSize, dl, FromVT);
8963             Lo = DAG.getNode(ISD::SRL, dl, FromVT, Lo, Amt);
8964             Hi = DAG.getNode(ISD::SRL, dl, FromVT, Hi, Amt);
8965           }
8966           return DAG.getNode(ARMISD::MVETRUNC, dl, VT, Lo, Hi);
8967         }
8968       }
8969     }
8970   }
8971 
8972   // If the shuffle is not directly supported and it has 4 elements, use
8973   // the PerfectShuffle-generated table to synthesize it from other shuffles.
8974   unsigned NumElts = VT.getVectorNumElements();
8975   if (NumElts == 4) {
8976     unsigned PFIndexes[4];
8977     for (unsigned i = 0; i != 4; ++i) {
8978       if (ShuffleMask[i] < 0)
8979         PFIndexes[i] = 8;
8980       else
8981         PFIndexes[i] = ShuffleMask[i];
8982     }
8983 
8984     // Compute the index in the perfect shuffle table.
8985     unsigned PFTableIndex =
8986       PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
8987     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
8988     unsigned Cost = (PFEntry >> 30);
8989 
8990     if (Cost <= 4) {
8991       if (ST->hasNEON())
8992         return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
8993       else if (isLegalMVEShuffleOp(PFEntry)) {
8994         unsigned LHSID = (PFEntry >> 13) & ((1 << 13)-1);
8995         unsigned RHSID = (PFEntry >>  0) & ((1 << 13)-1);
8996         unsigned PFEntryLHS = PerfectShuffleTable[LHSID];
8997         unsigned PFEntryRHS = PerfectShuffleTable[RHSID];
8998         if (isLegalMVEShuffleOp(PFEntryLHS) && isLegalMVEShuffleOp(PFEntryRHS))
8999           return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
9000       }
9001     }
9002   }
9003 
9004   // Implement shuffles with 32- or 64-bit elements as ARMISD::BUILD_VECTORs.
9005   if (EltSize >= 32) {
9006     // Do the expansion with floating-point types, since that is what the VFP
9007     // registers are defined to use, and since i64 is not legal.
9008     EVT EltVT = EVT::getFloatingPointVT(EltSize);
9009     EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
9010     V1 = DAG.getNode(ISD::BITCAST, dl, VecVT, V1);
9011     V2 = DAG.getNode(ISD::BITCAST, dl, VecVT, V2);
9012     SmallVector<SDValue, 8> Ops;
9013     for (unsigned i = 0; i < NumElts; ++i) {
9014       if (ShuffleMask[i] < 0)
9015         Ops.push_back(DAG.getUNDEF(EltVT));
9016       else
9017         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
9018                                   ShuffleMask[i] < (int)NumElts ? V1 : V2,
9019                                   DAG.getConstant(ShuffleMask[i] & (NumElts-1),
9020                                                   dl, MVT::i32)));
9021     }
9022     SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, Ops);
9023     return DAG.getNode(ISD::BITCAST, dl, VT, Val);
9024   }
9025 
9026   if ((VT == MVT::v8i16 || VT == MVT::v8f16 || VT == MVT::v16i8) &&
9027       isReverseMask(ShuffleMask, VT))
9028     return LowerReverse_VECTOR_SHUFFLE(Op, DAG);
9029 
9030   if (ST->hasNEON() && VT == MVT::v8i8)
9031     if (SDValue NewOp = LowerVECTOR_SHUFFLEv8i8(Op, ShuffleMask, DAG))
9032       return NewOp;
9033 
9034   if (ST->hasMVEIntegerOps())
9035     if (SDValue NewOp = LowerVECTOR_SHUFFLEUsingMovs(Op, ShuffleMask, DAG))
9036       return NewOp;
9037 
9038   return SDValue();
9039 }
9040 
LowerINSERT_VECTOR_ELT_i1(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9041 static SDValue LowerINSERT_VECTOR_ELT_i1(SDValue Op, SelectionDAG &DAG,
9042                                          const ARMSubtarget *ST) {
9043   EVT VecVT = Op.getOperand(0).getValueType();
9044   SDLoc dl(Op);
9045 
9046   assert(ST->hasMVEIntegerOps() &&
9047          "LowerINSERT_VECTOR_ELT_i1 called without MVE!");
9048 
9049   SDValue Conv =
9050       DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::i32, Op->getOperand(0));
9051   unsigned Lane = Op.getConstantOperandVal(2);
9052   unsigned LaneWidth =
9053       getVectorTyFromPredicateVector(VecVT).getScalarSizeInBits() / 8;
9054   unsigned Mask = ((1 << LaneWidth) - 1) << Lane * LaneWidth;
9055   SDValue Ext = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, MVT::i32,
9056                             Op.getOperand(1), DAG.getValueType(MVT::i1));
9057   SDValue BFI = DAG.getNode(ARMISD::BFI, dl, MVT::i32, Conv, Ext,
9058                             DAG.getConstant(~Mask, dl, MVT::i32));
9059   return DAG.getNode(ARMISD::PREDICATE_CAST, dl, Op.getValueType(), BFI);
9060 }
9061 
LowerINSERT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG) const9062 SDValue ARMTargetLowering::LowerINSERT_VECTOR_ELT(SDValue Op,
9063                                                   SelectionDAG &DAG) const {
9064   // INSERT_VECTOR_ELT is legal only for immediate indexes.
9065   SDValue Lane = Op.getOperand(2);
9066   if (!isa<ConstantSDNode>(Lane))
9067     return SDValue();
9068 
9069   SDValue Elt = Op.getOperand(1);
9070   EVT EltVT = Elt.getValueType();
9071 
9072   if (Subtarget->hasMVEIntegerOps() &&
9073       Op.getValueType().getScalarSizeInBits() == 1)
9074     return LowerINSERT_VECTOR_ELT_i1(Op, DAG, Subtarget);
9075 
9076   if (getTypeAction(*DAG.getContext(), EltVT) ==
9077       TargetLowering::TypeSoftPromoteHalf) {
9078     // INSERT_VECTOR_ELT doesn't want f16 operands promoting to f32,
9079     // but the type system will try to do that if we don't intervene.
9080     // Reinterpret any such vector-element insertion as one with the
9081     // corresponding integer types.
9082 
9083     SDLoc dl(Op);
9084 
9085     EVT IEltVT = MVT::getIntegerVT(EltVT.getScalarSizeInBits());
9086     assert(getTypeAction(*DAG.getContext(), IEltVT) !=
9087            TargetLowering::TypeSoftPromoteHalf);
9088 
9089     SDValue VecIn = Op.getOperand(0);
9090     EVT VecVT = VecIn.getValueType();
9091     EVT IVecVT = EVT::getVectorVT(*DAG.getContext(), IEltVT,
9092                                   VecVT.getVectorNumElements());
9093 
9094     SDValue IElt = DAG.getNode(ISD::BITCAST, dl, IEltVT, Elt);
9095     SDValue IVecIn = DAG.getNode(ISD::BITCAST, dl, IVecVT, VecIn);
9096     SDValue IVecOut = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, IVecVT,
9097                                   IVecIn, IElt, Lane);
9098     return DAG.getNode(ISD::BITCAST, dl, VecVT, IVecOut);
9099   }
9100 
9101   return Op;
9102 }
9103 
LowerEXTRACT_VECTOR_ELT_i1(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9104 static SDValue LowerEXTRACT_VECTOR_ELT_i1(SDValue Op, SelectionDAG &DAG,
9105                                           const ARMSubtarget *ST) {
9106   EVT VecVT = Op.getOperand(0).getValueType();
9107   SDLoc dl(Op);
9108 
9109   assert(ST->hasMVEIntegerOps() &&
9110          "LowerINSERT_VECTOR_ELT_i1 called without MVE!");
9111 
9112   SDValue Conv =
9113       DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::i32, Op->getOperand(0));
9114   unsigned Lane = Op.getConstantOperandVal(1);
9115   unsigned LaneWidth =
9116       getVectorTyFromPredicateVector(VecVT).getScalarSizeInBits() / 8;
9117   SDValue Shift = DAG.getNode(ISD::SRL, dl, MVT::i32, Conv,
9118                               DAG.getConstant(Lane * LaneWidth, dl, MVT::i32));
9119   return Shift;
9120 }
9121 
LowerEXTRACT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9122 static SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG,
9123                                        const ARMSubtarget *ST) {
9124   // EXTRACT_VECTOR_ELT is legal only for immediate indexes.
9125   SDValue Lane = Op.getOperand(1);
9126   if (!isa<ConstantSDNode>(Lane))
9127     return SDValue();
9128 
9129   SDValue Vec = Op.getOperand(0);
9130   EVT VT = Vec.getValueType();
9131 
9132   if (ST->hasMVEIntegerOps() && VT.getScalarSizeInBits() == 1)
9133     return LowerEXTRACT_VECTOR_ELT_i1(Op, DAG, ST);
9134 
9135   if (Op.getValueType() == MVT::i32 && Vec.getScalarValueSizeInBits() < 32) {
9136     SDLoc dl(Op);
9137     return DAG.getNode(ARMISD::VGETLANEu, dl, MVT::i32, Vec, Lane);
9138   }
9139 
9140   return Op;
9141 }
9142 
LowerCONCAT_VECTORS_i1(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9143 static SDValue LowerCONCAT_VECTORS_i1(SDValue Op, SelectionDAG &DAG,
9144                                       const ARMSubtarget *ST) {
9145   SDLoc dl(Op);
9146   assert(Op.getValueType().getScalarSizeInBits() == 1 &&
9147          "Unexpected custom CONCAT_VECTORS lowering");
9148   assert(isPowerOf2_32(Op.getNumOperands()) &&
9149          "Unexpected custom CONCAT_VECTORS lowering");
9150   assert(ST->hasMVEIntegerOps() &&
9151          "CONCAT_VECTORS lowering only supported for MVE");
9152 
9153   auto ConcatPair = [&](SDValue V1, SDValue V2) {
9154     EVT Op1VT = V1.getValueType();
9155     EVT Op2VT = V2.getValueType();
9156     assert(Op1VT == Op2VT && "Operand types don't match!");
9157     assert((Op1VT == MVT::v2i1 || Op1VT == MVT::v4i1 || Op1VT == MVT::v8i1) &&
9158            "Unexpected i1 concat operations!");
9159     EVT VT = Op1VT.getDoubleNumVectorElementsVT(*DAG.getContext());
9160 
9161     SDValue NewV1 = PromoteMVEPredVector(dl, V1, Op1VT, DAG);
9162     SDValue NewV2 = PromoteMVEPredVector(dl, V2, Op2VT, DAG);
9163 
9164     // We now have Op1 + Op2 promoted to vectors of integers, where v8i1 gets
9165     // promoted to v8i16, etc.
9166     MVT ElType =
9167         getVectorTyFromPredicateVector(VT).getScalarType().getSimpleVT();
9168     unsigned NumElts = 2 * Op1VT.getVectorNumElements();
9169 
9170     EVT ConcatVT = MVT::getVectorVT(ElType, NumElts);
9171     if (Op1VT == MVT::v4i1 || Op1VT == MVT::v8i1) {
9172       // Use MVETRUNC to truncate the combined NewV1::NewV2 into the smaller
9173       // ConcatVT.
9174       SDValue ConVec =
9175           DAG.getNode(ARMISD::MVETRUNC, dl, ConcatVT, NewV1, NewV2);
9176       return DAG.getNode(ARMISD::VCMPZ, dl, VT, ConVec,
9177                          DAG.getConstant(ARMCC::NE, dl, MVT::i32));
9178     }
9179 
9180     // Extract the vector elements from Op1 and Op2 one by one and truncate them
9181     // to be the right size for the destination. For example, if Op1 is v4i1
9182     // then the promoted vector is v4i32. The result of concatenation gives a
9183     // v8i1, which when promoted is v8i16. That means each i32 element from Op1
9184     // needs truncating to i16 and inserting in the result.
9185     auto ExtractInto = [&DAG, &dl](SDValue NewV, SDValue ConVec, unsigned &j) {
9186       EVT NewVT = NewV.getValueType();
9187       EVT ConcatVT = ConVec.getValueType();
9188       unsigned ExtScale = 1;
9189       if (NewVT == MVT::v2f64) {
9190         NewV = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, NewV);
9191         ExtScale = 2;
9192       }
9193       for (unsigned i = 0, e = NewVT.getVectorNumElements(); i < e; i++, j++) {
9194         SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32, NewV,
9195                                   DAG.getIntPtrConstant(i * ExtScale, dl));
9196         ConVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, ConcatVT, ConVec, Elt,
9197                              DAG.getConstant(j, dl, MVT::i32));
9198       }
9199       return ConVec;
9200     };
9201     unsigned j = 0;
9202     SDValue ConVec = DAG.getNode(ISD::UNDEF, dl, ConcatVT);
9203     ConVec = ExtractInto(NewV1, ConVec, j);
9204     ConVec = ExtractInto(NewV2, ConVec, j);
9205 
9206     // Now return the result of comparing the subvector with zero, which will
9207     // generate a real predicate, i.e. v4i1, v8i1 or v16i1.
9208     return DAG.getNode(ARMISD::VCMPZ, dl, VT, ConVec,
9209                        DAG.getConstant(ARMCC::NE, dl, MVT::i32));
9210   };
9211 
9212   // Concat each pair of subvectors and pack into the lower half of the array.
9213   SmallVector<SDValue> ConcatOps(Op->op_begin(), Op->op_end());
9214   while (ConcatOps.size() > 1) {
9215     for (unsigned I = 0, E = ConcatOps.size(); I != E; I += 2) {
9216       SDValue V1 = ConcatOps[I];
9217       SDValue V2 = ConcatOps[I + 1];
9218       ConcatOps[I / 2] = ConcatPair(V1, V2);
9219     }
9220     ConcatOps.resize(ConcatOps.size() / 2);
9221   }
9222   return ConcatOps[0];
9223 }
9224 
LowerCONCAT_VECTORS(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9225 static SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG,
9226                                    const ARMSubtarget *ST) {
9227   EVT VT = Op->getValueType(0);
9228   if (ST->hasMVEIntegerOps() && VT.getScalarSizeInBits() == 1)
9229     return LowerCONCAT_VECTORS_i1(Op, DAG, ST);
9230 
9231   // The only time a CONCAT_VECTORS operation can have legal types is when
9232   // two 64-bit vectors are concatenated to a 128-bit vector.
9233   assert(Op.getValueType().is128BitVector() && Op.getNumOperands() == 2 &&
9234          "unexpected CONCAT_VECTORS");
9235   SDLoc dl(Op);
9236   SDValue Val = DAG.getUNDEF(MVT::v2f64);
9237   SDValue Op0 = Op.getOperand(0);
9238   SDValue Op1 = Op.getOperand(1);
9239   if (!Op0.isUndef())
9240     Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
9241                       DAG.getNode(ISD::BITCAST, dl, MVT::f64, Op0),
9242                       DAG.getIntPtrConstant(0, dl));
9243   if (!Op1.isUndef())
9244     Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
9245                       DAG.getNode(ISD::BITCAST, dl, MVT::f64, Op1),
9246                       DAG.getIntPtrConstant(1, dl));
9247   return DAG.getNode(ISD::BITCAST, dl, Op.getValueType(), Val);
9248 }
9249 
LowerEXTRACT_SUBVECTOR(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9250 static SDValue LowerEXTRACT_SUBVECTOR(SDValue Op, SelectionDAG &DAG,
9251                                       const ARMSubtarget *ST) {
9252   SDValue V1 = Op.getOperand(0);
9253   SDValue V2 = Op.getOperand(1);
9254   SDLoc dl(Op);
9255   EVT VT = Op.getValueType();
9256   EVT Op1VT = V1.getValueType();
9257   unsigned NumElts = VT.getVectorNumElements();
9258   unsigned Index = V2->getAsZExtVal();
9259 
9260   assert(VT.getScalarSizeInBits() == 1 &&
9261          "Unexpected custom EXTRACT_SUBVECTOR lowering");
9262   assert(ST->hasMVEIntegerOps() &&
9263          "EXTRACT_SUBVECTOR lowering only supported for MVE");
9264 
9265   SDValue NewV1 = PromoteMVEPredVector(dl, V1, Op1VT, DAG);
9266 
9267   // We now have Op1 promoted to a vector of integers, where v8i1 gets
9268   // promoted to v8i16, etc.
9269 
9270   MVT ElType = getVectorTyFromPredicateVector(VT).getScalarType().getSimpleVT();
9271 
9272   if (NumElts == 2) {
9273     EVT SubVT = MVT::v4i32;
9274     SDValue SubVec = DAG.getNode(ISD::UNDEF, dl, SubVT);
9275     for (unsigned i = Index, j = 0; i < (Index + NumElts); i++, j += 2) {
9276       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32, NewV1,
9277                                 DAG.getIntPtrConstant(i, dl));
9278       SubVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, SubVT, SubVec, Elt,
9279                            DAG.getConstant(j, dl, MVT::i32));
9280       SubVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, SubVT, SubVec, Elt,
9281                            DAG.getConstant(j + 1, dl, MVT::i32));
9282     }
9283     SDValue Cmp = DAG.getNode(ARMISD::VCMPZ, dl, MVT::v4i1, SubVec,
9284                               DAG.getConstant(ARMCC::NE, dl, MVT::i32));
9285     return DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::v2i1, Cmp);
9286   }
9287 
9288   EVT SubVT = MVT::getVectorVT(ElType, NumElts);
9289   SDValue SubVec = DAG.getNode(ISD::UNDEF, dl, SubVT);
9290   for (unsigned i = Index, j = 0; i < (Index + NumElts); i++, j++) {
9291     SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32, NewV1,
9292                               DAG.getIntPtrConstant(i, dl));
9293     SubVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, SubVT, SubVec, Elt,
9294                          DAG.getConstant(j, dl, MVT::i32));
9295   }
9296 
9297   // Now return the result of comparing the subvector with zero,
9298   // which will generate a real predicate, i.e. v4i1, v8i1 or v16i1.
9299   return DAG.getNode(ARMISD::VCMPZ, dl, VT, SubVec,
9300                      DAG.getConstant(ARMCC::NE, dl, MVT::i32));
9301 }
9302 
9303 // Turn a truncate into a predicate (an i1 vector) into icmp(and(x, 1), 0).
LowerTruncatei1(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)9304 static SDValue LowerTruncatei1(SDNode *N, SelectionDAG &DAG,
9305                                const ARMSubtarget *ST) {
9306   assert(ST->hasMVEIntegerOps() && "Expected MVE!");
9307   EVT VT = N->getValueType(0);
9308   assert((VT == MVT::v16i1 || VT == MVT::v8i1 || VT == MVT::v4i1) &&
9309          "Expected a vector i1 type!");
9310   SDValue Op = N->getOperand(0);
9311   EVT FromVT = Op.getValueType();
9312   SDLoc DL(N);
9313 
9314   SDValue And =
9315       DAG.getNode(ISD::AND, DL, FromVT, Op, DAG.getConstant(1, DL, FromVT));
9316   return DAG.getNode(ISD::SETCC, DL, VT, And, DAG.getConstant(0, DL, FromVT),
9317                      DAG.getCondCode(ISD::SETNE));
9318 }
9319 
LowerTruncate(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)9320 static SDValue LowerTruncate(SDNode *N, SelectionDAG &DAG,
9321                              const ARMSubtarget *Subtarget) {
9322   if (!Subtarget->hasMVEIntegerOps())
9323     return SDValue();
9324 
9325   EVT ToVT = N->getValueType(0);
9326   if (ToVT.getScalarType() == MVT::i1)
9327     return LowerTruncatei1(N, DAG, Subtarget);
9328 
9329   // MVE does not have a single instruction to perform the truncation of a v4i32
9330   // into the lower half of a v8i16, in the same way that a NEON vmovn would.
9331   // Most of the instructions in MVE follow the 'Beats' system, where moving
9332   // values from different lanes is usually something that the instructions
9333   // avoid.
9334   //
9335   // Instead it has top/bottom instructions such as VMOVLT/B and VMOVNT/B,
9336   // which take a the top/bottom half of a larger lane and extend it (or do the
9337   // opposite, truncating into the top/bottom lane from a larger lane). Note
9338   // that because of the way we widen lanes, a v4i16 is really a v4i32 using the
9339   // bottom 16bits from each vector lane. This works really well with T/B
9340   // instructions, but that doesn't extend to v8i32->v8i16 where the lanes need
9341   // to move order.
9342   //
9343   // But truncates and sext/zext are always going to be fairly common from llvm.
9344   // We have several options for how to deal with them:
9345   // - Wherever possible combine them into an instruction that makes them
9346   //   "free". This includes loads/stores, which can perform the trunc as part
9347   //   of the memory operation. Or certain shuffles that can be turned into
9348   //   VMOVN/VMOVL.
9349   // - Lane Interleaving to transform blocks surrounded by ext/trunc. So
9350   //   trunc(mul(sext(a), sext(b))) may become
9351   //   VMOVNT(VMUL(VMOVLB(a), VMOVLB(b)), VMUL(VMOVLT(a), VMOVLT(b))). (Which in
9352   //   this case can use VMULL). This is performed in the
9353   //   MVELaneInterleavingPass.
9354   // - Otherwise we have an option. By default we would expand the
9355   //   zext/sext/trunc into a series of lane extract/inserts going via GPR
9356   //   registers. One for each vector lane in the vector. This can obviously be
9357   //   very expensive.
9358   // - The other option is to use the fact that loads/store can extend/truncate
9359   //   to turn a trunc into two truncating stack stores and a stack reload. This
9360   //   becomes 3 back-to-back memory operations, but at least that is less than
9361   //   all the insert/extracts.
9362   //
9363   // In order to do the last, we convert certain trunc's into MVETRUNC, which
9364   // are either optimized where they can be, or eventually lowered into stack
9365   // stores/loads. This prevents us from splitting a v8i16 trunc into two stores
9366   // two early, where other instructions would be better, and stops us from
9367   // having to reconstruct multiple buildvector shuffles into loads/stores.
9368   if (ToVT != MVT::v8i16 && ToVT != MVT::v16i8)
9369     return SDValue();
9370   EVT FromVT = N->getOperand(0).getValueType();
9371   if (FromVT != MVT::v8i32 && FromVT != MVT::v16i16)
9372     return SDValue();
9373 
9374   SDValue Lo, Hi;
9375   std::tie(Lo, Hi) = DAG.SplitVectorOperand(N, 0);
9376   SDLoc DL(N);
9377   return DAG.getNode(ARMISD::MVETRUNC, DL, ToVT, Lo, Hi);
9378 }
9379 
LowerVectorExtend(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)9380 static SDValue LowerVectorExtend(SDNode *N, SelectionDAG &DAG,
9381                                  const ARMSubtarget *Subtarget) {
9382   if (!Subtarget->hasMVEIntegerOps())
9383     return SDValue();
9384 
9385   // See LowerTruncate above for an explanation of MVEEXT/MVETRUNC.
9386 
9387   EVT ToVT = N->getValueType(0);
9388   if (ToVT != MVT::v16i32 && ToVT != MVT::v8i32 && ToVT != MVT::v16i16)
9389     return SDValue();
9390   SDValue Op = N->getOperand(0);
9391   EVT FromVT = Op.getValueType();
9392   if (FromVT != MVT::v8i16 && FromVT != MVT::v16i8)
9393     return SDValue();
9394 
9395   SDLoc DL(N);
9396   EVT ExtVT = ToVT.getHalfNumVectorElementsVT(*DAG.getContext());
9397   if (ToVT.getScalarType() == MVT::i32 && FromVT.getScalarType() == MVT::i8)
9398     ExtVT = MVT::v8i16;
9399 
9400   unsigned Opcode =
9401       N->getOpcode() == ISD::SIGN_EXTEND ? ARMISD::MVESEXT : ARMISD::MVEZEXT;
9402   SDValue Ext = DAG.getNode(Opcode, DL, DAG.getVTList(ExtVT, ExtVT), Op);
9403   SDValue Ext1 = Ext.getValue(1);
9404 
9405   if (ToVT.getScalarType() == MVT::i32 && FromVT.getScalarType() == MVT::i8) {
9406     Ext = DAG.getNode(N->getOpcode(), DL, MVT::v8i32, Ext);
9407     Ext1 = DAG.getNode(N->getOpcode(), DL, MVT::v8i32, Ext1);
9408   }
9409 
9410   return DAG.getNode(ISD::CONCAT_VECTORS, DL, ToVT, Ext, Ext1);
9411 }
9412 
9413 /// isExtendedBUILD_VECTOR - Check if N is a constant BUILD_VECTOR where each
9414 /// element has been zero/sign-extended, depending on the isSigned parameter,
9415 /// from an integer type half its size.
isExtendedBUILD_VECTOR(SDNode * N,SelectionDAG & DAG,bool isSigned)9416 static bool isExtendedBUILD_VECTOR(SDNode *N, SelectionDAG &DAG,
9417                                    bool isSigned) {
9418   // A v2i64 BUILD_VECTOR will have been legalized to a BITCAST from v4i32.
9419   EVT VT = N->getValueType(0);
9420   if (VT == MVT::v2i64 && N->getOpcode() == ISD::BITCAST) {
9421     SDNode *BVN = N->getOperand(0).getNode();
9422     if (BVN->getValueType(0) != MVT::v4i32 ||
9423         BVN->getOpcode() != ISD::BUILD_VECTOR)
9424       return false;
9425     unsigned LoElt = DAG.getDataLayout().isBigEndian() ? 1 : 0;
9426     unsigned HiElt = 1 - LoElt;
9427     ConstantSDNode *Lo0 = dyn_cast<ConstantSDNode>(BVN->getOperand(LoElt));
9428     ConstantSDNode *Hi0 = dyn_cast<ConstantSDNode>(BVN->getOperand(HiElt));
9429     ConstantSDNode *Lo1 = dyn_cast<ConstantSDNode>(BVN->getOperand(LoElt+2));
9430     ConstantSDNode *Hi1 = dyn_cast<ConstantSDNode>(BVN->getOperand(HiElt+2));
9431     if (!Lo0 || !Hi0 || !Lo1 || !Hi1)
9432       return false;
9433     if (isSigned) {
9434       if (Hi0->getSExtValue() == Lo0->getSExtValue() >> 32 &&
9435           Hi1->getSExtValue() == Lo1->getSExtValue() >> 32)
9436         return true;
9437     } else {
9438       if (Hi0->isZero() && Hi1->isZero())
9439         return true;
9440     }
9441     return false;
9442   }
9443 
9444   if (N->getOpcode() != ISD::BUILD_VECTOR)
9445     return false;
9446 
9447   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
9448     SDNode *Elt = N->getOperand(i).getNode();
9449     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Elt)) {
9450       unsigned EltSize = VT.getScalarSizeInBits();
9451       unsigned HalfSize = EltSize / 2;
9452       if (isSigned) {
9453         if (!isIntN(HalfSize, C->getSExtValue()))
9454           return false;
9455       } else {
9456         if (!isUIntN(HalfSize, C->getZExtValue()))
9457           return false;
9458       }
9459       continue;
9460     }
9461     return false;
9462   }
9463 
9464   return true;
9465 }
9466 
9467 /// isSignExtended - Check if a node is a vector value that is sign-extended
9468 /// or a constant BUILD_VECTOR with sign-extended elements.
isSignExtended(SDNode * N,SelectionDAG & DAG)9469 static bool isSignExtended(SDNode *N, SelectionDAG &DAG) {
9470   if (N->getOpcode() == ISD::SIGN_EXTEND || ISD::isSEXTLoad(N))
9471     return true;
9472   if (isExtendedBUILD_VECTOR(N, DAG, true))
9473     return true;
9474   return false;
9475 }
9476 
9477 /// isZeroExtended - Check if a node is a vector value that is zero-extended (or
9478 /// any-extended) or a constant BUILD_VECTOR with zero-extended elements.
isZeroExtended(SDNode * N,SelectionDAG & DAG)9479 static bool isZeroExtended(SDNode *N, SelectionDAG &DAG) {
9480   if (N->getOpcode() == ISD::ZERO_EXTEND || N->getOpcode() == ISD::ANY_EXTEND ||
9481       ISD::isZEXTLoad(N))
9482     return true;
9483   if (isExtendedBUILD_VECTOR(N, DAG, false))
9484     return true;
9485   return false;
9486 }
9487 
getExtensionTo64Bits(const EVT & OrigVT)9488 static EVT getExtensionTo64Bits(const EVT &OrigVT) {
9489   if (OrigVT.getSizeInBits() >= 64)
9490     return OrigVT;
9491 
9492   assert(OrigVT.isSimple() && "Expecting a simple value type");
9493 
9494   MVT::SimpleValueType OrigSimpleTy = OrigVT.getSimpleVT().SimpleTy;
9495   switch (OrigSimpleTy) {
9496   default: llvm_unreachable("Unexpected Vector Type");
9497   case MVT::v2i8:
9498   case MVT::v2i16:
9499      return MVT::v2i32;
9500   case MVT::v4i8:
9501     return  MVT::v4i16;
9502   }
9503 }
9504 
9505 /// AddRequiredExtensionForVMULL - Add a sign/zero extension to extend the total
9506 /// value size to 64 bits. We need a 64-bit D register as an operand to VMULL.
9507 /// We insert the required extension here to get the vector to fill a D register.
AddRequiredExtensionForVMULL(SDValue N,SelectionDAG & DAG,const EVT & OrigTy,const EVT & ExtTy,unsigned ExtOpcode)9508 static SDValue AddRequiredExtensionForVMULL(SDValue N, SelectionDAG &DAG,
9509                                             const EVT &OrigTy,
9510                                             const EVT &ExtTy,
9511                                             unsigned ExtOpcode) {
9512   // The vector originally had a size of OrigTy. It was then extended to ExtTy.
9513   // We expect the ExtTy to be 128-bits total. If the OrigTy is less than
9514   // 64-bits we need to insert a new extension so that it will be 64-bits.
9515   assert(ExtTy.is128BitVector() && "Unexpected extension size");
9516   if (OrigTy.getSizeInBits() >= 64)
9517     return N;
9518 
9519   // Must extend size to at least 64 bits to be used as an operand for VMULL.
9520   EVT NewVT = getExtensionTo64Bits(OrigTy);
9521 
9522   return DAG.getNode(ExtOpcode, SDLoc(N), NewVT, N);
9523 }
9524 
9525 /// SkipLoadExtensionForVMULL - return a load of the original vector size that
9526 /// does not do any sign/zero extension. If the original vector is less
9527 /// than 64 bits, an appropriate extension will be added after the load to
9528 /// reach a total size of 64 bits. We have to add the extension separately
9529 /// because ARM does not have a sign/zero extending load for vectors.
SkipLoadExtensionForVMULL(LoadSDNode * LD,SelectionDAG & DAG)9530 static SDValue SkipLoadExtensionForVMULL(LoadSDNode *LD, SelectionDAG& DAG) {
9531   EVT ExtendedTy = getExtensionTo64Bits(LD->getMemoryVT());
9532 
9533   // The load already has the right type.
9534   if (ExtendedTy == LD->getMemoryVT())
9535     return DAG.getLoad(LD->getMemoryVT(), SDLoc(LD), LD->getChain(),
9536                        LD->getBasePtr(), LD->getPointerInfo(), LD->getAlign(),
9537                        LD->getMemOperand()->getFlags());
9538 
9539   // We need to create a zextload/sextload. We cannot just create a load
9540   // followed by a zext/zext node because LowerMUL is also run during normal
9541   // operation legalization where we can't create illegal types.
9542   return DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD), ExtendedTy,
9543                         LD->getChain(), LD->getBasePtr(), LD->getPointerInfo(),
9544                         LD->getMemoryVT(), LD->getAlign(),
9545                         LD->getMemOperand()->getFlags());
9546 }
9547 
9548 /// SkipExtensionForVMULL - For a node that is a SIGN_EXTEND, ZERO_EXTEND,
9549 /// ANY_EXTEND, extending load, or BUILD_VECTOR with extended elements, return
9550 /// the unextended value. The unextended vector should be 64 bits so that it can
9551 /// be used as an operand to a VMULL instruction. If the original vector size
9552 /// before extension is less than 64 bits we add a an extension to resize
9553 /// the vector to 64 bits.
SkipExtensionForVMULL(SDNode * N,SelectionDAG & DAG)9554 static SDValue SkipExtensionForVMULL(SDNode *N, SelectionDAG &DAG) {
9555   if (N->getOpcode() == ISD::SIGN_EXTEND ||
9556       N->getOpcode() == ISD::ZERO_EXTEND || N->getOpcode() == ISD::ANY_EXTEND)
9557     return AddRequiredExtensionForVMULL(N->getOperand(0), DAG,
9558                                         N->getOperand(0)->getValueType(0),
9559                                         N->getValueType(0),
9560                                         N->getOpcode());
9561 
9562   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
9563     assert((ISD::isSEXTLoad(LD) || ISD::isZEXTLoad(LD)) &&
9564            "Expected extending load");
9565 
9566     SDValue newLoad = SkipLoadExtensionForVMULL(LD, DAG);
9567     DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), newLoad.getValue(1));
9568     unsigned Opcode = ISD::isSEXTLoad(LD) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
9569     SDValue extLoad =
9570         DAG.getNode(Opcode, SDLoc(newLoad), LD->getValueType(0), newLoad);
9571     DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 0), extLoad);
9572 
9573     return newLoad;
9574   }
9575 
9576   // Otherwise, the value must be a BUILD_VECTOR.  For v2i64, it will
9577   // have been legalized as a BITCAST from v4i32.
9578   if (N->getOpcode() == ISD::BITCAST) {
9579     SDNode *BVN = N->getOperand(0).getNode();
9580     assert(BVN->getOpcode() == ISD::BUILD_VECTOR &&
9581            BVN->getValueType(0) == MVT::v4i32 && "expected v4i32 BUILD_VECTOR");
9582     unsigned LowElt = DAG.getDataLayout().isBigEndian() ? 1 : 0;
9583     return DAG.getBuildVector(
9584         MVT::v2i32, SDLoc(N),
9585         {BVN->getOperand(LowElt), BVN->getOperand(LowElt + 2)});
9586   }
9587   // Construct a new BUILD_VECTOR with elements truncated to half the size.
9588   assert(N->getOpcode() == ISD::BUILD_VECTOR && "expected BUILD_VECTOR");
9589   EVT VT = N->getValueType(0);
9590   unsigned EltSize = VT.getScalarSizeInBits() / 2;
9591   unsigned NumElts = VT.getVectorNumElements();
9592   MVT TruncVT = MVT::getIntegerVT(EltSize);
9593   SmallVector<SDValue, 8> Ops;
9594   SDLoc dl(N);
9595   for (unsigned i = 0; i != NumElts; ++i) {
9596     const APInt &CInt = N->getConstantOperandAPInt(i);
9597     // Element types smaller than 32 bits are not legal, so use i32 elements.
9598     // The values are implicitly truncated so sext vs. zext doesn't matter.
9599     Ops.push_back(DAG.getConstant(CInt.zextOrTrunc(32), dl, MVT::i32));
9600   }
9601   return DAG.getBuildVector(MVT::getVectorVT(TruncVT, NumElts), dl, Ops);
9602 }
9603 
isAddSubSExt(SDNode * N,SelectionDAG & DAG)9604 static bool isAddSubSExt(SDNode *N, SelectionDAG &DAG) {
9605   unsigned Opcode = N->getOpcode();
9606   if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
9607     SDNode *N0 = N->getOperand(0).getNode();
9608     SDNode *N1 = N->getOperand(1).getNode();
9609     return N0->hasOneUse() && N1->hasOneUse() &&
9610       isSignExtended(N0, DAG) && isSignExtended(N1, DAG);
9611   }
9612   return false;
9613 }
9614 
isAddSubZExt(SDNode * N,SelectionDAG & DAG)9615 static bool isAddSubZExt(SDNode *N, SelectionDAG &DAG) {
9616   unsigned Opcode = N->getOpcode();
9617   if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
9618     SDNode *N0 = N->getOperand(0).getNode();
9619     SDNode *N1 = N->getOperand(1).getNode();
9620     return N0->hasOneUse() && N1->hasOneUse() &&
9621       isZeroExtended(N0, DAG) && isZeroExtended(N1, DAG);
9622   }
9623   return false;
9624 }
9625 
LowerMUL(SDValue Op,SelectionDAG & DAG)9626 static SDValue LowerMUL(SDValue Op, SelectionDAG &DAG) {
9627   // Multiplications are only custom-lowered for 128-bit vectors so that
9628   // VMULL can be detected.  Otherwise v2i64 multiplications are not legal.
9629   EVT VT = Op.getValueType();
9630   assert(VT.is128BitVector() && VT.isInteger() &&
9631          "unexpected type for custom-lowering ISD::MUL");
9632   SDNode *N0 = Op.getOperand(0).getNode();
9633   SDNode *N1 = Op.getOperand(1).getNode();
9634   unsigned NewOpc = 0;
9635   bool isMLA = false;
9636   bool isN0SExt = isSignExtended(N0, DAG);
9637   bool isN1SExt = isSignExtended(N1, DAG);
9638   if (isN0SExt && isN1SExt)
9639     NewOpc = ARMISD::VMULLs;
9640   else {
9641     bool isN0ZExt = isZeroExtended(N0, DAG);
9642     bool isN1ZExt = isZeroExtended(N1, DAG);
9643     if (isN0ZExt && isN1ZExt)
9644       NewOpc = ARMISD::VMULLu;
9645     else if (isN1SExt || isN1ZExt) {
9646       // Look for (s/zext A + s/zext B) * (s/zext C). We want to turn these
9647       // into (s/zext A * s/zext C) + (s/zext B * s/zext C)
9648       if (isN1SExt && isAddSubSExt(N0, DAG)) {
9649         NewOpc = ARMISD::VMULLs;
9650         isMLA = true;
9651       } else if (isN1ZExt && isAddSubZExt(N0, DAG)) {
9652         NewOpc = ARMISD::VMULLu;
9653         isMLA = true;
9654       } else if (isN0ZExt && isAddSubZExt(N1, DAG)) {
9655         std::swap(N0, N1);
9656         NewOpc = ARMISD::VMULLu;
9657         isMLA = true;
9658       }
9659     }
9660 
9661     if (!NewOpc) {
9662       if (VT == MVT::v2i64)
9663         // Fall through to expand this.  It is not legal.
9664         return SDValue();
9665       else
9666         // Other vector multiplications are legal.
9667         return Op;
9668     }
9669   }
9670 
9671   // Legalize to a VMULL instruction.
9672   SDLoc DL(Op);
9673   SDValue Op0;
9674   SDValue Op1 = SkipExtensionForVMULL(N1, DAG);
9675   if (!isMLA) {
9676     Op0 = SkipExtensionForVMULL(N0, DAG);
9677     assert(Op0.getValueType().is64BitVector() &&
9678            Op1.getValueType().is64BitVector() &&
9679            "unexpected types for extended operands to VMULL");
9680     return DAG.getNode(NewOpc, DL, VT, Op0, Op1);
9681   }
9682 
9683   // Optimizing (zext A + zext B) * C, to (VMULL A, C) + (VMULL B, C) during
9684   // isel lowering to take advantage of no-stall back to back vmul + vmla.
9685   //   vmull q0, d4, d6
9686   //   vmlal q0, d5, d6
9687   // is faster than
9688   //   vaddl q0, d4, d5
9689   //   vmovl q1, d6
9690   //   vmul  q0, q0, q1
9691   SDValue N00 = SkipExtensionForVMULL(N0->getOperand(0).getNode(), DAG);
9692   SDValue N01 = SkipExtensionForVMULL(N0->getOperand(1).getNode(), DAG);
9693   EVT Op1VT = Op1.getValueType();
9694   return DAG.getNode(N0->getOpcode(), DL, VT,
9695                      DAG.getNode(NewOpc, DL, VT,
9696                                DAG.getNode(ISD::BITCAST, DL, Op1VT, N00), Op1),
9697                      DAG.getNode(NewOpc, DL, VT,
9698                                DAG.getNode(ISD::BITCAST, DL, Op1VT, N01), Op1));
9699 }
9700 
LowerSDIV_v4i8(SDValue X,SDValue Y,const SDLoc & dl,SelectionDAG & DAG)9701 static SDValue LowerSDIV_v4i8(SDValue X, SDValue Y, const SDLoc &dl,
9702                               SelectionDAG &DAG) {
9703   // TODO: Should this propagate fast-math-flags?
9704 
9705   // Convert to float
9706   // float4 xf = vcvt_f32_s32(vmovl_s16(a.lo));
9707   // float4 yf = vcvt_f32_s32(vmovl_s16(b.lo));
9708   X = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, X);
9709   Y = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, Y);
9710   X = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, X);
9711   Y = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, Y);
9712   // Get reciprocal estimate.
9713   // float4 recip = vrecpeq_f32(yf);
9714   Y = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9715                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, dl, MVT::i32),
9716                    Y);
9717   // Because char has a smaller range than uchar, we can actually get away
9718   // without any newton steps.  This requires that we use a weird bias
9719   // of 0xb000, however (again, this has been exhaustively tested).
9720   // float4 result = as_float4(as_int4(xf*recip) + 0xb000);
9721   X = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, X, Y);
9722   X = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, X);
9723   Y = DAG.getConstant(0xb000, dl, MVT::v4i32);
9724   X = DAG.getNode(ISD::ADD, dl, MVT::v4i32, X, Y);
9725   X = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, X);
9726   // Convert back to short.
9727   X = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, X);
9728   X = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, X);
9729   return X;
9730 }
9731 
LowerSDIV_v4i16(SDValue N0,SDValue N1,const SDLoc & dl,SelectionDAG & DAG)9732 static SDValue LowerSDIV_v4i16(SDValue N0, SDValue N1, const SDLoc &dl,
9733                                SelectionDAG &DAG) {
9734   // TODO: Should this propagate fast-math-flags?
9735 
9736   SDValue N2;
9737   // Convert to float.
9738   // float4 yf = vcvt_f32_s32(vmovl_s16(y));
9739   // float4 xf = vcvt_f32_s32(vmovl_s16(x));
9740   N0 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, N0);
9741   N1 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, N1);
9742   N0 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N0);
9743   N1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N1);
9744 
9745   // Use reciprocal estimate and one refinement step.
9746   // float4 recip = vrecpeq_f32(yf);
9747   // recip *= vrecpsq_f32(yf, recip);
9748   N2 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9749                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, dl, MVT::i32),
9750                    N1);
9751   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9752                    DAG.getConstant(Intrinsic::arm_neon_vrecps, dl, MVT::i32),
9753                    N1, N2);
9754   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
9755   // Because short has a smaller range than ushort, we can actually get away
9756   // with only a single newton step.  This requires that we use a weird bias
9757   // of 89, however (again, this has been exhaustively tested).
9758   // float4 result = as_float4(as_int4(xf*recip) + 0x89);
9759   N0 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N0, N2);
9760   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, N0);
9761   N1 = DAG.getConstant(0x89, dl, MVT::v4i32);
9762   N0 = DAG.getNode(ISD::ADD, dl, MVT::v4i32, N0, N1);
9763   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, N0);
9764   // Convert back to integer and return.
9765   // return vmovn_s32(vcvt_s32_f32(result));
9766   N0 = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, N0);
9767   N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, N0);
9768   return N0;
9769 }
9770 
LowerSDIV(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9771 static SDValue LowerSDIV(SDValue Op, SelectionDAG &DAG,
9772                          const ARMSubtarget *ST) {
9773   EVT VT = Op.getValueType();
9774   assert((VT == MVT::v4i16 || VT == MVT::v8i8) &&
9775          "unexpected type for custom-lowering ISD::SDIV");
9776 
9777   SDLoc dl(Op);
9778   SDValue N0 = Op.getOperand(0);
9779   SDValue N1 = Op.getOperand(1);
9780   SDValue N2, N3;
9781 
9782   if (VT == MVT::v8i8) {
9783     N0 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v8i16, N0);
9784     N1 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v8i16, N1);
9785 
9786     N2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
9787                      DAG.getIntPtrConstant(4, dl));
9788     N3 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
9789                      DAG.getIntPtrConstant(4, dl));
9790     N0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
9791                      DAG.getIntPtrConstant(0, dl));
9792     N1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
9793                      DAG.getIntPtrConstant(0, dl));
9794 
9795     N0 = LowerSDIV_v4i8(N0, N1, dl, DAG); // v4i16
9796     N2 = LowerSDIV_v4i8(N2, N3, dl, DAG); // v4i16
9797 
9798     N0 = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v8i16, N0, N2);
9799     N0 = LowerCONCAT_VECTORS(N0, DAG, ST);
9800 
9801     N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v8i8, N0);
9802     return N0;
9803   }
9804   return LowerSDIV_v4i16(N0, N1, dl, DAG);
9805 }
9806 
LowerUDIV(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)9807 static SDValue LowerUDIV(SDValue Op, SelectionDAG &DAG,
9808                          const ARMSubtarget *ST) {
9809   // TODO: Should this propagate fast-math-flags?
9810   EVT VT = Op.getValueType();
9811   assert((VT == MVT::v4i16 || VT == MVT::v8i8) &&
9812          "unexpected type for custom-lowering ISD::UDIV");
9813 
9814   SDLoc dl(Op);
9815   SDValue N0 = Op.getOperand(0);
9816   SDValue N1 = Op.getOperand(1);
9817   SDValue N2, N3;
9818 
9819   if (VT == MVT::v8i8) {
9820     N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v8i16, N0);
9821     N1 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v8i16, N1);
9822 
9823     N2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
9824                      DAG.getIntPtrConstant(4, dl));
9825     N3 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
9826                      DAG.getIntPtrConstant(4, dl));
9827     N0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
9828                      DAG.getIntPtrConstant(0, dl));
9829     N1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
9830                      DAG.getIntPtrConstant(0, dl));
9831 
9832     N0 = LowerSDIV_v4i16(N0, N1, dl, DAG); // v4i16
9833     N2 = LowerSDIV_v4i16(N2, N3, dl, DAG); // v4i16
9834 
9835     N0 = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v8i16, N0, N2);
9836     N0 = LowerCONCAT_VECTORS(N0, DAG, ST);
9837 
9838     N0 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v8i8,
9839                      DAG.getConstant(Intrinsic::arm_neon_vqmovnsu, dl,
9840                                      MVT::i32),
9841                      N0);
9842     return N0;
9843   }
9844 
9845   // v4i16 sdiv ... Convert to float.
9846   // float4 yf = vcvt_f32_s32(vmovl_u16(y));
9847   // float4 xf = vcvt_f32_s32(vmovl_u16(x));
9848   N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v4i32, N0);
9849   N1 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v4i32, N1);
9850   N0 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N0);
9851   SDValue BN1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N1);
9852 
9853   // Use reciprocal estimate and two refinement steps.
9854   // float4 recip = vrecpeq_f32(yf);
9855   // recip *= vrecpsq_f32(yf, recip);
9856   // recip *= vrecpsq_f32(yf, recip);
9857   N2 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9858                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, dl, MVT::i32),
9859                    BN1);
9860   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9861                    DAG.getConstant(Intrinsic::arm_neon_vrecps, dl, MVT::i32),
9862                    BN1, N2);
9863   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
9864   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
9865                    DAG.getConstant(Intrinsic::arm_neon_vrecps, dl, MVT::i32),
9866                    BN1, N2);
9867   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
9868   // Simply multiplying by the reciprocal estimate can leave us a few ulps
9869   // too low, so we add 2 ulps (exhaustive testing shows that this is enough,
9870   // and that it will never cause us to return an answer too large).
9871   // float4 result = as_float4(as_int4(xf*recip) + 2);
9872   N0 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N0, N2);
9873   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, N0);
9874   N1 = DAG.getConstant(2, dl, MVT::v4i32);
9875   N0 = DAG.getNode(ISD::ADD, dl, MVT::v4i32, N0, N1);
9876   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, N0);
9877   // Convert back to integer and return.
9878   // return vmovn_u32(vcvt_s32_f32(result));
9879   N0 = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, N0);
9880   N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, N0);
9881   return N0;
9882 }
9883 
LowerUADDSUBO_CARRY(SDValue Op,SelectionDAG & DAG)9884 static SDValue LowerUADDSUBO_CARRY(SDValue Op, SelectionDAG &DAG) {
9885   SDNode *N = Op.getNode();
9886   EVT VT = N->getValueType(0);
9887   SDVTList VTs = DAG.getVTList(VT, MVT::i32);
9888 
9889   SDValue Carry = Op.getOperand(2);
9890 
9891   SDLoc DL(Op);
9892 
9893   SDValue Result;
9894   if (Op.getOpcode() == ISD::UADDO_CARRY) {
9895     // This converts the boolean value carry into the carry flag.
9896     Carry = ConvertBooleanCarryToCarryFlag(Carry, DAG);
9897 
9898     // Do the addition proper using the carry flag we wanted.
9899     Result = DAG.getNode(ARMISD::ADDE, DL, VTs, Op.getOperand(0),
9900                          Op.getOperand(1), Carry);
9901 
9902     // Now convert the carry flag into a boolean value.
9903     Carry = ConvertCarryFlagToBooleanCarry(Result.getValue(1), VT, DAG);
9904   } else {
9905     // ARMISD::SUBE expects a carry not a borrow like ISD::USUBO_CARRY so we
9906     // have to invert the carry first.
9907     Carry = DAG.getNode(ISD::SUB, DL, MVT::i32,
9908                         DAG.getConstant(1, DL, MVT::i32), Carry);
9909     // This converts the boolean value carry into the carry flag.
9910     Carry = ConvertBooleanCarryToCarryFlag(Carry, DAG);
9911 
9912     // Do the subtraction proper using the carry flag we wanted.
9913     Result = DAG.getNode(ARMISD::SUBE, DL, VTs, Op.getOperand(0),
9914                          Op.getOperand(1), Carry);
9915 
9916     // Now convert the carry flag into a boolean value.
9917     Carry = ConvertCarryFlagToBooleanCarry(Result.getValue(1), VT, DAG);
9918     // But the carry returned by ARMISD::SUBE is not a borrow as expected
9919     // by ISD::USUBO_CARRY, so compute 1 - C.
9920     Carry = DAG.getNode(ISD::SUB, DL, MVT::i32,
9921                         DAG.getConstant(1, DL, MVT::i32), Carry);
9922   }
9923 
9924   // Return both values.
9925   return DAG.getNode(ISD::MERGE_VALUES, DL, N->getVTList(), Result, Carry);
9926 }
9927 
LowerFSINCOS(SDValue Op,SelectionDAG & DAG) const9928 SDValue ARMTargetLowering::LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const {
9929   assert(Subtarget->isTargetDarwin());
9930 
9931   // For iOS, we want to call an alternative entry point: __sincos_stret,
9932   // return values are passed via sret.
9933   SDLoc dl(Op);
9934   SDValue Arg = Op.getOperand(0);
9935   EVT ArgVT = Arg.getValueType();
9936   Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
9937   auto PtrVT = getPointerTy(DAG.getDataLayout());
9938 
9939   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
9940   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
9941 
9942   // Pair of floats / doubles used to pass the result.
9943   Type *RetTy = StructType::get(ArgTy, ArgTy);
9944   auto &DL = DAG.getDataLayout();
9945 
9946   ArgListTy Args;
9947   bool ShouldUseSRet = Subtarget->isAPCS_ABI();
9948   SDValue SRet;
9949   if (ShouldUseSRet) {
9950     // Create stack object for sret.
9951     const uint64_t ByteSize = DL.getTypeAllocSize(RetTy);
9952     const Align StackAlign = DL.getPrefTypeAlign(RetTy);
9953     int FrameIdx = MFI.CreateStackObject(ByteSize, StackAlign, false);
9954     SRet = DAG.getFrameIndex(FrameIdx, TLI.getPointerTy(DL));
9955 
9956     ArgListEntry Entry;
9957     Entry.Node = SRet;
9958     Entry.Ty = PointerType::getUnqual(RetTy->getContext());
9959     Entry.IsSExt = false;
9960     Entry.IsZExt = false;
9961     Entry.IsSRet = true;
9962     Args.push_back(Entry);
9963     RetTy = Type::getVoidTy(*DAG.getContext());
9964   }
9965 
9966   ArgListEntry Entry;
9967   Entry.Node = Arg;
9968   Entry.Ty = ArgTy;
9969   Entry.IsSExt = false;
9970   Entry.IsZExt = false;
9971   Args.push_back(Entry);
9972 
9973   RTLIB::Libcall LC =
9974       (ArgVT == MVT::f64) ? RTLIB::SINCOS_STRET_F64 : RTLIB::SINCOS_STRET_F32;
9975   const char *LibcallName = getLibcallName(LC);
9976   CallingConv::ID CC = getLibcallCallingConv(LC);
9977   SDValue Callee = DAG.getExternalSymbol(LibcallName, getPointerTy(DL));
9978 
9979   TargetLowering::CallLoweringInfo CLI(DAG);
9980   CLI.setDebugLoc(dl)
9981       .setChain(DAG.getEntryNode())
9982       .setCallee(CC, RetTy, Callee, std::move(Args))
9983       .setDiscardResult(ShouldUseSRet);
9984   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
9985 
9986   if (!ShouldUseSRet)
9987     return CallResult.first;
9988 
9989   SDValue LoadSin =
9990       DAG.getLoad(ArgVT, dl, CallResult.second, SRet, MachinePointerInfo());
9991 
9992   // Address of cos field.
9993   SDValue Add = DAG.getNode(ISD::ADD, dl, PtrVT, SRet,
9994                             DAG.getIntPtrConstant(ArgVT.getStoreSize(), dl));
9995   SDValue LoadCos =
9996       DAG.getLoad(ArgVT, dl, LoadSin.getValue(1), Add, MachinePointerInfo());
9997 
9998   SDVTList Tys = DAG.getVTList(ArgVT, ArgVT);
9999   return DAG.getNode(ISD::MERGE_VALUES, dl, Tys,
10000                      LoadSin.getValue(0), LoadCos.getValue(0));
10001 }
10002 
LowerWindowsDIVLibCall(SDValue Op,SelectionDAG & DAG,bool Signed,SDValue & Chain) const10003 SDValue ARMTargetLowering::LowerWindowsDIVLibCall(SDValue Op, SelectionDAG &DAG,
10004                                                   bool Signed,
10005                                                   SDValue &Chain) const {
10006   EVT VT = Op.getValueType();
10007   assert((VT == MVT::i32 || VT == MVT::i64) &&
10008          "unexpected type for custom lowering DIV");
10009   SDLoc dl(Op);
10010 
10011   const auto &DL = DAG.getDataLayout();
10012   const auto &TLI = DAG.getTargetLoweringInfo();
10013 
10014   const char *Name = nullptr;
10015   if (Signed)
10016     Name = (VT == MVT::i32) ? "__rt_sdiv" : "__rt_sdiv64";
10017   else
10018     Name = (VT == MVT::i32) ? "__rt_udiv" : "__rt_udiv64";
10019 
10020   SDValue ES = DAG.getExternalSymbol(Name, TLI.getPointerTy(DL));
10021 
10022   ARMTargetLowering::ArgListTy Args;
10023 
10024   for (auto AI : {1, 0}) {
10025     ArgListEntry Arg;
10026     Arg.Node = Op.getOperand(AI);
10027     Arg.Ty = Arg.Node.getValueType().getTypeForEVT(*DAG.getContext());
10028     Args.push_back(Arg);
10029   }
10030 
10031   CallLoweringInfo CLI(DAG);
10032   CLI.setDebugLoc(dl)
10033     .setChain(Chain)
10034     .setCallee(CallingConv::ARM_AAPCS_VFP, VT.getTypeForEVT(*DAG.getContext()),
10035                ES, std::move(Args));
10036 
10037   return LowerCallTo(CLI).first;
10038 }
10039 
10040 // This is a code size optimisation: return the original SDIV node to
10041 // DAGCombiner when we don't want to expand SDIV into a sequence of
10042 // instructions, and an empty node otherwise which will cause the
10043 // SDIV to be expanded in DAGCombine.
10044 SDValue
BuildSDIVPow2(SDNode * N,const APInt & Divisor,SelectionDAG & DAG,SmallVectorImpl<SDNode * > & Created) const10045 ARMTargetLowering::BuildSDIVPow2(SDNode *N, const APInt &Divisor,
10046                                  SelectionDAG &DAG,
10047                                  SmallVectorImpl<SDNode *> &Created) const {
10048   // TODO: Support SREM
10049   if (N->getOpcode() != ISD::SDIV)
10050     return SDValue();
10051 
10052   const auto &ST = DAG.getSubtarget<ARMSubtarget>();
10053   const bool MinSize = ST.hasMinSize();
10054   const bool HasDivide = ST.isThumb() ? ST.hasDivideInThumbMode()
10055                                       : ST.hasDivideInARMMode();
10056 
10057   // Don't touch vector types; rewriting this may lead to scalarizing
10058   // the int divs.
10059   if (N->getOperand(0).getValueType().isVector())
10060     return SDValue();
10061 
10062   // Bail if MinSize is not set, and also for both ARM and Thumb mode we need
10063   // hwdiv support for this to be really profitable.
10064   if (!(MinSize && HasDivide))
10065     return SDValue();
10066 
10067   // ARM mode is a bit simpler than Thumb: we can handle large power
10068   // of 2 immediates with 1 mov instruction; no further checks required,
10069   // just return the sdiv node.
10070   if (!ST.isThumb())
10071     return SDValue(N, 0);
10072 
10073   // In Thumb mode, immediates larger than 128 need a wide 4-byte MOV,
10074   // and thus lose the code size benefits of a MOVS that requires only 2.
10075   // TargetTransformInfo and 'getIntImmCodeSizeCost' could be helpful here,
10076   // but as it's doing exactly this, it's not worth the trouble to get TTI.
10077   if (Divisor.sgt(128))
10078     return SDValue();
10079 
10080   return SDValue(N, 0);
10081 }
10082 
LowerDIV_Windows(SDValue Op,SelectionDAG & DAG,bool Signed) const10083 SDValue ARMTargetLowering::LowerDIV_Windows(SDValue Op, SelectionDAG &DAG,
10084                                             bool Signed) const {
10085   assert(Op.getValueType() == MVT::i32 &&
10086          "unexpected type for custom lowering DIV");
10087   SDLoc dl(Op);
10088 
10089   SDValue DBZCHK = DAG.getNode(ARMISD::WIN__DBZCHK, dl, MVT::Other,
10090                                DAG.getEntryNode(), Op.getOperand(1));
10091 
10092   return LowerWindowsDIVLibCall(Op, DAG, Signed, DBZCHK);
10093 }
10094 
WinDBZCheckDenominator(SelectionDAG & DAG,SDNode * N,SDValue InChain)10095 static SDValue WinDBZCheckDenominator(SelectionDAG &DAG, SDNode *N, SDValue InChain) {
10096   SDLoc DL(N);
10097   SDValue Op = N->getOperand(1);
10098   if (N->getValueType(0) == MVT::i32)
10099     return DAG.getNode(ARMISD::WIN__DBZCHK, DL, MVT::Other, InChain, Op);
10100   SDValue Lo, Hi;
10101   std::tie(Lo, Hi) = DAG.SplitScalar(Op, DL, MVT::i32, MVT::i32);
10102   return DAG.getNode(ARMISD::WIN__DBZCHK, DL, MVT::Other, InChain,
10103                      DAG.getNode(ISD::OR, DL, MVT::i32, Lo, Hi));
10104 }
10105 
ExpandDIV_Windows(SDValue Op,SelectionDAG & DAG,bool Signed,SmallVectorImpl<SDValue> & Results) const10106 void ARMTargetLowering::ExpandDIV_Windows(
10107     SDValue Op, SelectionDAG &DAG, bool Signed,
10108     SmallVectorImpl<SDValue> &Results) const {
10109   const auto &DL = DAG.getDataLayout();
10110   const auto &TLI = DAG.getTargetLoweringInfo();
10111 
10112   assert(Op.getValueType() == MVT::i64 &&
10113          "unexpected type for custom lowering DIV");
10114   SDLoc dl(Op);
10115 
10116   SDValue DBZCHK = WinDBZCheckDenominator(DAG, Op.getNode(), DAG.getEntryNode());
10117 
10118   SDValue Result = LowerWindowsDIVLibCall(Op, DAG, Signed, DBZCHK);
10119 
10120   SDValue Lower = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Result);
10121   SDValue Upper = DAG.getNode(ISD::SRL, dl, MVT::i64, Result,
10122                               DAG.getConstant(32, dl, TLI.getPointerTy(DL)));
10123   Upper = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Upper);
10124 
10125   Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lower, Upper));
10126 }
10127 
LowerPredicateLoad(SDValue Op,SelectionDAG & DAG)10128 static SDValue LowerPredicateLoad(SDValue Op, SelectionDAG &DAG) {
10129   LoadSDNode *LD = cast<LoadSDNode>(Op.getNode());
10130   EVT MemVT = LD->getMemoryVT();
10131   assert((MemVT == MVT::v2i1 || MemVT == MVT::v4i1 || MemVT == MVT::v8i1 ||
10132           MemVT == MVT::v16i1) &&
10133          "Expected a predicate type!");
10134   assert(MemVT == Op.getValueType());
10135   assert(LD->getExtensionType() == ISD::NON_EXTLOAD &&
10136          "Expected a non-extending load");
10137   assert(LD->isUnindexed() && "Expected a unindexed load");
10138 
10139   // The basic MVE VLDR on a v2i1/v4i1/v8i1 actually loads the entire 16bit
10140   // predicate, with the "v4i1" bits spread out over the 16 bits loaded. We
10141   // need to make sure that 8/4/2 bits are actually loaded into the correct
10142   // place, which means loading the value and then shuffling the values into
10143   // the bottom bits of the predicate.
10144   // Equally, VLDR for an v16i1 will actually load 32bits (so will be incorrect
10145   // for BE).
10146   // Speaking of BE, apparently the rest of llvm will assume a reverse order to
10147   // a natural VMSR(load), so needs to be reversed.
10148 
10149   SDLoc dl(Op);
10150   SDValue Load = DAG.getExtLoad(
10151       ISD::EXTLOAD, dl, MVT::i32, LD->getChain(), LD->getBasePtr(),
10152       EVT::getIntegerVT(*DAG.getContext(), MemVT.getSizeInBits()),
10153       LD->getMemOperand());
10154   SDValue Val = Load;
10155   if (DAG.getDataLayout().isBigEndian())
10156     Val = DAG.getNode(ISD::SRL, dl, MVT::i32,
10157                       DAG.getNode(ISD::BITREVERSE, dl, MVT::i32, Load),
10158                       DAG.getConstant(32 - MemVT.getSizeInBits(), dl, MVT::i32));
10159   SDValue Pred = DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::v16i1, Val);
10160   if (MemVT != MVT::v16i1)
10161     Pred = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MemVT, Pred,
10162                        DAG.getConstant(0, dl, MVT::i32));
10163   return DAG.getMergeValues({Pred, Load.getValue(1)}, dl);
10164 }
10165 
LowerLOAD(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const10166 void ARMTargetLowering::LowerLOAD(SDNode *N, SmallVectorImpl<SDValue> &Results,
10167                                   SelectionDAG &DAG) const {
10168   LoadSDNode *LD = cast<LoadSDNode>(N);
10169   EVT MemVT = LD->getMemoryVT();
10170   assert(LD->isUnindexed() && "Loads should be unindexed at this point.");
10171 
10172   if (MemVT == MVT::i64 && Subtarget->hasV5TEOps() &&
10173       !Subtarget->isThumb1Only() && LD->isVolatile() &&
10174       LD->getAlign() >= Subtarget->getDualLoadStoreAlignment()) {
10175     SDLoc dl(N);
10176     SDValue Result = DAG.getMemIntrinsicNode(
10177         ARMISD::LDRD, dl, DAG.getVTList({MVT::i32, MVT::i32, MVT::Other}),
10178         {LD->getChain(), LD->getBasePtr()}, MemVT, LD->getMemOperand());
10179     SDValue Lo = Result.getValue(DAG.getDataLayout().isLittleEndian() ? 0 : 1);
10180     SDValue Hi = Result.getValue(DAG.getDataLayout().isLittleEndian() ? 1 : 0);
10181     SDValue Pair = DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
10182     Results.append({Pair, Result.getValue(2)});
10183   }
10184 }
10185 
LowerPredicateStore(SDValue Op,SelectionDAG & DAG)10186 static SDValue LowerPredicateStore(SDValue Op, SelectionDAG &DAG) {
10187   StoreSDNode *ST = cast<StoreSDNode>(Op.getNode());
10188   EVT MemVT = ST->getMemoryVT();
10189   assert((MemVT == MVT::v2i1 || MemVT == MVT::v4i1 || MemVT == MVT::v8i1 ||
10190           MemVT == MVT::v16i1) &&
10191          "Expected a predicate type!");
10192   assert(MemVT == ST->getValue().getValueType());
10193   assert(!ST->isTruncatingStore() && "Expected a non-extending store");
10194   assert(ST->isUnindexed() && "Expected a unindexed store");
10195 
10196   // Only store the v2i1 or v4i1 or v8i1 worth of bits, via a buildvector with
10197   // top bits unset and a scalar store.
10198   SDLoc dl(Op);
10199   SDValue Build = ST->getValue();
10200   if (MemVT != MVT::v16i1) {
10201     SmallVector<SDValue, 16> Ops;
10202     for (unsigned I = 0; I < MemVT.getVectorNumElements(); I++) {
10203       unsigned Elt = DAG.getDataLayout().isBigEndian()
10204                          ? MemVT.getVectorNumElements() - I - 1
10205                          : I;
10206       Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i32, Build,
10207                                 DAG.getConstant(Elt, dl, MVT::i32)));
10208     }
10209     for (unsigned I = MemVT.getVectorNumElements(); I < 16; I++)
10210       Ops.push_back(DAG.getUNDEF(MVT::i32));
10211     Build = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v16i1, Ops);
10212   }
10213   SDValue GRP = DAG.getNode(ARMISD::PREDICATE_CAST, dl, MVT::i32, Build);
10214   if (MemVT == MVT::v16i1 && DAG.getDataLayout().isBigEndian())
10215     GRP = DAG.getNode(ISD::SRL, dl, MVT::i32,
10216                       DAG.getNode(ISD::BITREVERSE, dl, MVT::i32, GRP),
10217                       DAG.getConstant(16, dl, MVT::i32));
10218   return DAG.getTruncStore(
10219       ST->getChain(), dl, GRP, ST->getBasePtr(),
10220       EVT::getIntegerVT(*DAG.getContext(), MemVT.getSizeInBits()),
10221       ST->getMemOperand());
10222 }
10223 
LowerSTORE(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)10224 static SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG,
10225                           const ARMSubtarget *Subtarget) {
10226   StoreSDNode *ST = cast<StoreSDNode>(Op.getNode());
10227   EVT MemVT = ST->getMemoryVT();
10228   assert(ST->isUnindexed() && "Stores should be unindexed at this point.");
10229 
10230   if (MemVT == MVT::i64 && Subtarget->hasV5TEOps() &&
10231       !Subtarget->isThumb1Only() && ST->isVolatile() &&
10232       ST->getAlign() >= Subtarget->getDualLoadStoreAlignment()) {
10233     SDNode *N = Op.getNode();
10234     SDLoc dl(N);
10235 
10236     SDValue Lo = DAG.getNode(
10237         ISD::EXTRACT_ELEMENT, dl, MVT::i32, ST->getValue(),
10238         DAG.getTargetConstant(DAG.getDataLayout().isLittleEndian() ? 0 : 1, dl,
10239                               MVT::i32));
10240     SDValue Hi = DAG.getNode(
10241         ISD::EXTRACT_ELEMENT, dl, MVT::i32, ST->getValue(),
10242         DAG.getTargetConstant(DAG.getDataLayout().isLittleEndian() ? 1 : 0, dl,
10243                               MVT::i32));
10244 
10245     return DAG.getMemIntrinsicNode(ARMISD::STRD, dl, DAG.getVTList(MVT::Other),
10246                                    {ST->getChain(), Lo, Hi, ST->getBasePtr()},
10247                                    MemVT, ST->getMemOperand());
10248   } else if (Subtarget->hasMVEIntegerOps() &&
10249              ((MemVT == MVT::v2i1 || MemVT == MVT::v4i1 || MemVT == MVT::v8i1 ||
10250                MemVT == MVT::v16i1))) {
10251     return LowerPredicateStore(Op, DAG);
10252   }
10253 
10254   return SDValue();
10255 }
10256 
isZeroVector(SDValue N)10257 static bool isZeroVector(SDValue N) {
10258   return (ISD::isBuildVectorAllZeros(N.getNode()) ||
10259           (N->getOpcode() == ARMISD::VMOVIMM &&
10260            isNullConstant(N->getOperand(0))));
10261 }
10262 
LowerMLOAD(SDValue Op,SelectionDAG & DAG)10263 static SDValue LowerMLOAD(SDValue Op, SelectionDAG &DAG) {
10264   MaskedLoadSDNode *N = cast<MaskedLoadSDNode>(Op.getNode());
10265   MVT VT = Op.getSimpleValueType();
10266   SDValue Mask = N->getMask();
10267   SDValue PassThru = N->getPassThru();
10268   SDLoc dl(Op);
10269 
10270   if (isZeroVector(PassThru))
10271     return Op;
10272 
10273   // MVE Masked loads use zero as the passthru value. Here we convert undef to
10274   // zero too, and other values are lowered to a select.
10275   SDValue ZeroVec = DAG.getNode(ARMISD::VMOVIMM, dl, VT,
10276                                 DAG.getTargetConstant(0, dl, MVT::i32));
10277   SDValue NewLoad = DAG.getMaskedLoad(
10278       VT, dl, N->getChain(), N->getBasePtr(), N->getOffset(), Mask, ZeroVec,
10279       N->getMemoryVT(), N->getMemOperand(), N->getAddressingMode(),
10280       N->getExtensionType(), N->isExpandingLoad());
10281   SDValue Combo = NewLoad;
10282   bool PassThruIsCastZero = (PassThru.getOpcode() == ISD::BITCAST ||
10283                              PassThru.getOpcode() == ARMISD::VECTOR_REG_CAST) &&
10284                             isZeroVector(PassThru->getOperand(0));
10285   if (!PassThru.isUndef() && !PassThruIsCastZero)
10286     Combo = DAG.getNode(ISD::VSELECT, dl, VT, Mask, NewLoad, PassThru);
10287   return DAG.getMergeValues({Combo, NewLoad.getValue(1)}, dl);
10288 }
10289 
LowerVecReduce(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)10290 static SDValue LowerVecReduce(SDValue Op, SelectionDAG &DAG,
10291                               const ARMSubtarget *ST) {
10292   if (!ST->hasMVEIntegerOps())
10293     return SDValue();
10294 
10295   SDLoc dl(Op);
10296   unsigned BaseOpcode = 0;
10297   switch (Op->getOpcode()) {
10298   default: llvm_unreachable("Expected VECREDUCE opcode");
10299   case ISD::VECREDUCE_FADD: BaseOpcode = ISD::FADD; break;
10300   case ISD::VECREDUCE_FMUL: BaseOpcode = ISD::FMUL; break;
10301   case ISD::VECREDUCE_MUL:  BaseOpcode = ISD::MUL; break;
10302   case ISD::VECREDUCE_AND:  BaseOpcode = ISD::AND; break;
10303   case ISD::VECREDUCE_OR:   BaseOpcode = ISD::OR; break;
10304   case ISD::VECREDUCE_XOR:  BaseOpcode = ISD::XOR; break;
10305   case ISD::VECREDUCE_FMAX: BaseOpcode = ISD::FMAXNUM; break;
10306   case ISD::VECREDUCE_FMIN: BaseOpcode = ISD::FMINNUM; break;
10307   }
10308 
10309   SDValue Op0 = Op->getOperand(0);
10310   EVT VT = Op0.getValueType();
10311   EVT EltVT = VT.getVectorElementType();
10312   unsigned NumElts = VT.getVectorNumElements();
10313   unsigned NumActiveLanes = NumElts;
10314 
10315   assert((NumActiveLanes == 16 || NumActiveLanes == 8 || NumActiveLanes == 4 ||
10316           NumActiveLanes == 2) &&
10317          "Only expected a power 2 vector size");
10318 
10319   // Use Mul(X, Rev(X)) until 4 items remain. Going down to 4 vector elements
10320   // allows us to easily extract vector elements from the lanes.
10321   while (NumActiveLanes > 4) {
10322     unsigned RevOpcode = NumActiveLanes == 16 ? ARMISD::VREV16 : ARMISD::VREV32;
10323     SDValue Rev = DAG.getNode(RevOpcode, dl, VT, Op0);
10324     Op0 = DAG.getNode(BaseOpcode, dl, VT, Op0, Rev);
10325     NumActiveLanes /= 2;
10326   }
10327 
10328   SDValue Res;
10329   if (NumActiveLanes == 4) {
10330     // The remaining 4 elements are summed sequentially
10331     SDValue Ext0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10332                               DAG.getConstant(0 * NumElts / 4, dl, MVT::i32));
10333     SDValue Ext1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10334                               DAG.getConstant(1 * NumElts / 4, dl, MVT::i32));
10335     SDValue Ext2 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10336                               DAG.getConstant(2 * NumElts / 4, dl, MVT::i32));
10337     SDValue Ext3 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10338                               DAG.getConstant(3 * NumElts / 4, dl, MVT::i32));
10339     SDValue Res0 = DAG.getNode(BaseOpcode, dl, EltVT, Ext0, Ext1, Op->getFlags());
10340     SDValue Res1 = DAG.getNode(BaseOpcode, dl, EltVT, Ext2, Ext3, Op->getFlags());
10341     Res = DAG.getNode(BaseOpcode, dl, EltVT, Res0, Res1, Op->getFlags());
10342   } else {
10343     SDValue Ext0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10344                               DAG.getConstant(0, dl, MVT::i32));
10345     SDValue Ext1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10346                               DAG.getConstant(1, dl, MVT::i32));
10347     Res = DAG.getNode(BaseOpcode, dl, EltVT, Ext0, Ext1, Op->getFlags());
10348   }
10349 
10350   // Result type may be wider than element type.
10351   if (EltVT != Op->getValueType(0))
10352     Res = DAG.getNode(ISD::ANY_EXTEND, dl, Op->getValueType(0), Res);
10353   return Res;
10354 }
10355 
LowerVecReduceF(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)10356 static SDValue LowerVecReduceF(SDValue Op, SelectionDAG &DAG,
10357                                const ARMSubtarget *ST) {
10358   if (!ST->hasMVEFloatOps())
10359     return SDValue();
10360   return LowerVecReduce(Op, DAG, ST);
10361 }
10362 
LowerVecReduceMinMax(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * ST)10363 static SDValue LowerVecReduceMinMax(SDValue Op, SelectionDAG &DAG,
10364                                     const ARMSubtarget *ST) {
10365   if (!ST->hasNEON())
10366     return SDValue();
10367 
10368   SDLoc dl(Op);
10369   SDValue Op0 = Op->getOperand(0);
10370   EVT VT = Op0.getValueType();
10371   EVT EltVT = VT.getVectorElementType();
10372 
10373   unsigned PairwiseIntrinsic = 0;
10374   switch (Op->getOpcode()) {
10375   default:
10376     llvm_unreachable("Expected VECREDUCE opcode");
10377   case ISD::VECREDUCE_UMIN:
10378     PairwiseIntrinsic = Intrinsic::arm_neon_vpminu;
10379     break;
10380   case ISD::VECREDUCE_UMAX:
10381     PairwiseIntrinsic = Intrinsic::arm_neon_vpmaxu;
10382     break;
10383   case ISD::VECREDUCE_SMIN:
10384     PairwiseIntrinsic = Intrinsic::arm_neon_vpmins;
10385     break;
10386   case ISD::VECREDUCE_SMAX:
10387     PairwiseIntrinsic = Intrinsic::arm_neon_vpmaxs;
10388     break;
10389   }
10390   SDValue PairwiseOp = DAG.getConstant(PairwiseIntrinsic, dl, MVT::i32);
10391 
10392   unsigned NumElts = VT.getVectorNumElements();
10393   unsigned NumActiveLanes = NumElts;
10394 
10395   assert((NumActiveLanes == 16 || NumActiveLanes == 8 || NumActiveLanes == 4 ||
10396           NumActiveLanes == 2) &&
10397          "Only expected a power 2 vector size");
10398 
10399   // Split 128-bit vectors, since vpmin/max takes 2 64-bit vectors.
10400   if (VT.is128BitVector()) {
10401     SDValue Lo, Hi;
10402     std::tie(Lo, Hi) = DAG.SplitVector(Op0, dl);
10403     VT = Lo.getValueType();
10404     Op0 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT, {PairwiseOp, Lo, Hi});
10405     NumActiveLanes /= 2;
10406   }
10407 
10408   // Use pairwise reductions until one lane remains
10409   while (NumActiveLanes > 1) {
10410     Op0 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT, {PairwiseOp, Op0, Op0});
10411     NumActiveLanes /= 2;
10412   }
10413 
10414   SDValue Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
10415                             DAG.getConstant(0, dl, MVT::i32));
10416 
10417   // Result type may be wider than element type.
10418   if (EltVT != Op.getValueType()) {
10419     unsigned Extend = 0;
10420     switch (Op->getOpcode()) {
10421     default:
10422       llvm_unreachable("Expected VECREDUCE opcode");
10423     case ISD::VECREDUCE_UMIN:
10424     case ISD::VECREDUCE_UMAX:
10425       Extend = ISD::ZERO_EXTEND;
10426       break;
10427     case ISD::VECREDUCE_SMIN:
10428     case ISD::VECREDUCE_SMAX:
10429       Extend = ISD::SIGN_EXTEND;
10430       break;
10431     }
10432     Res = DAG.getNode(Extend, dl, Op.getValueType(), Res);
10433   }
10434   return Res;
10435 }
10436 
LowerAtomicLoadStore(SDValue Op,SelectionDAG & DAG)10437 static SDValue LowerAtomicLoadStore(SDValue Op, SelectionDAG &DAG) {
10438   if (isStrongerThanMonotonic(cast<AtomicSDNode>(Op)->getSuccessOrdering()))
10439     // Acquire/Release load/store is not legal for targets without a dmb or
10440     // equivalent available.
10441     return SDValue();
10442 
10443   // Monotonic load/store is legal for all targets.
10444   return Op;
10445 }
10446 
ReplaceREADCYCLECOUNTER(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG,const ARMSubtarget * Subtarget)10447 static void ReplaceREADCYCLECOUNTER(SDNode *N,
10448                                     SmallVectorImpl<SDValue> &Results,
10449                                     SelectionDAG &DAG,
10450                                     const ARMSubtarget *Subtarget) {
10451   SDLoc DL(N);
10452   // Under Power Management extensions, the cycle-count is:
10453   //    mrc p15, #0, <Rt>, c9, c13, #0
10454   SDValue Ops[] = { N->getOperand(0), // Chain
10455                     DAG.getTargetConstant(Intrinsic::arm_mrc, DL, MVT::i32),
10456                     DAG.getTargetConstant(15, DL, MVT::i32),
10457                     DAG.getTargetConstant(0, DL, MVT::i32),
10458                     DAG.getTargetConstant(9, DL, MVT::i32),
10459                     DAG.getTargetConstant(13, DL, MVT::i32),
10460                     DAG.getTargetConstant(0, DL, MVT::i32)
10461   };
10462 
10463   SDValue Cycles32 = DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL,
10464                                  DAG.getVTList(MVT::i32, MVT::Other), Ops);
10465   Results.push_back(DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Cycles32,
10466                                 DAG.getConstant(0, DL, MVT::i32)));
10467   Results.push_back(Cycles32.getValue(1));
10468 }
10469 
createGPRPairNode(SelectionDAG & DAG,SDValue V)10470 static SDValue createGPRPairNode(SelectionDAG &DAG, SDValue V) {
10471   SDLoc dl(V.getNode());
10472   auto [VLo, VHi] = DAG.SplitScalar(V, dl, MVT::i32, MVT::i32);
10473   bool isBigEndian = DAG.getDataLayout().isBigEndian();
10474   if (isBigEndian)
10475     std::swap (VLo, VHi);
10476   SDValue RegClass =
10477       DAG.getTargetConstant(ARM::GPRPairRegClassID, dl, MVT::i32);
10478   SDValue SubReg0 = DAG.getTargetConstant(ARM::gsub_0, dl, MVT::i32);
10479   SDValue SubReg1 = DAG.getTargetConstant(ARM::gsub_1, dl, MVT::i32);
10480   const SDValue Ops[] = { RegClass, VLo, SubReg0, VHi, SubReg1 };
10481   return SDValue(
10482       DAG.getMachineNode(TargetOpcode::REG_SEQUENCE, dl, MVT::Untyped, Ops), 0);
10483 }
10484 
ReplaceCMP_SWAP_64Results(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG)10485 static void ReplaceCMP_SWAP_64Results(SDNode *N,
10486                                        SmallVectorImpl<SDValue> & Results,
10487                                        SelectionDAG &DAG) {
10488   assert(N->getValueType(0) == MVT::i64 &&
10489          "AtomicCmpSwap on types less than 64 should be legal");
10490   SDValue Ops[] = {N->getOperand(1),
10491                    createGPRPairNode(DAG, N->getOperand(2)),
10492                    createGPRPairNode(DAG, N->getOperand(3)),
10493                    N->getOperand(0)};
10494   SDNode *CmpSwap = DAG.getMachineNode(
10495       ARM::CMP_SWAP_64, SDLoc(N),
10496       DAG.getVTList(MVT::Untyped, MVT::i32, MVT::Other), Ops);
10497 
10498   MachineMemOperand *MemOp = cast<MemSDNode>(N)->getMemOperand();
10499   DAG.setNodeMemRefs(cast<MachineSDNode>(CmpSwap), {MemOp});
10500 
10501   bool isBigEndian = DAG.getDataLayout().isBigEndian();
10502 
10503   SDValue Lo =
10504       DAG.getTargetExtractSubreg(isBigEndian ? ARM::gsub_1 : ARM::gsub_0,
10505                                  SDLoc(N), MVT::i32, SDValue(CmpSwap, 0));
10506   SDValue Hi =
10507       DAG.getTargetExtractSubreg(isBigEndian ? ARM::gsub_0 : ARM::gsub_1,
10508                                  SDLoc(N), MVT::i32, SDValue(CmpSwap, 0));
10509   Results.push_back(DAG.getNode(ISD::BUILD_PAIR, SDLoc(N), MVT::i64, Lo, Hi));
10510   Results.push_back(SDValue(CmpSwap, 2));
10511 }
10512 
LowerFSETCC(SDValue Op,SelectionDAG & DAG) const10513 SDValue ARMTargetLowering::LowerFSETCC(SDValue Op, SelectionDAG &DAG) const {
10514   SDLoc dl(Op);
10515   EVT VT = Op.getValueType();
10516   SDValue Chain = Op.getOperand(0);
10517   SDValue LHS = Op.getOperand(1);
10518   SDValue RHS = Op.getOperand(2);
10519   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(3))->get();
10520   bool IsSignaling = Op.getOpcode() == ISD::STRICT_FSETCCS;
10521 
10522   // If we don't have instructions of this float type then soften to a libcall
10523   // and use SETCC instead.
10524   if (isUnsupportedFloatingType(LHS.getValueType())) {
10525     DAG.getTargetLoweringInfo().softenSetCCOperands(
10526       DAG, LHS.getValueType(), LHS, RHS, CC, dl, LHS, RHS, Chain, IsSignaling);
10527     if (!RHS.getNode()) {
10528       RHS = DAG.getConstant(0, dl, LHS.getValueType());
10529       CC = ISD::SETNE;
10530     }
10531     SDValue Result = DAG.getNode(ISD::SETCC, dl, VT, LHS, RHS,
10532                                  DAG.getCondCode(CC));
10533     return DAG.getMergeValues({Result, Chain}, dl);
10534   }
10535 
10536   ARMCC::CondCodes CondCode, CondCode2;
10537   FPCCToARMCC(CC, CondCode, CondCode2);
10538 
10539   // FIXME: Chain is not handled correctly here. Currently the FPSCR is implicit
10540   // in CMPFP and CMPFPE, but instead it should be made explicit by these
10541   // instructions using a chain instead of glue. This would also fix the problem
10542   // here (and also in LowerSELECT_CC) where we generate two comparisons when
10543   // CondCode2 != AL.
10544   SDValue True = DAG.getConstant(1, dl, VT);
10545   SDValue False =  DAG.getConstant(0, dl, VT);
10546   SDValue ARMcc = DAG.getConstant(CondCode, dl, MVT::i32);
10547   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
10548   SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl, IsSignaling);
10549   SDValue Result = getCMOV(dl, VT, False, True, ARMcc, CCR, Cmp, DAG);
10550   if (CondCode2 != ARMCC::AL) {
10551     ARMcc = DAG.getConstant(CondCode2, dl, MVT::i32);
10552     Cmp = getVFPCmp(LHS, RHS, DAG, dl, IsSignaling);
10553     Result = getCMOV(dl, VT, Result, True, ARMcc, CCR, Cmp, DAG);
10554   }
10555   return DAG.getMergeValues({Result, Chain}, dl);
10556 }
10557 
LowerSPONENTRY(SDValue Op,SelectionDAG & DAG) const10558 SDValue ARMTargetLowering::LowerSPONENTRY(SDValue Op, SelectionDAG &DAG) const {
10559   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
10560 
10561   EVT VT = getPointerTy(DAG.getDataLayout());
10562   SDLoc DL(Op);
10563   int FI = MFI.CreateFixedObject(4, 0, false);
10564   return DAG.getFrameIndex(FI, VT);
10565 }
10566 
LowerOperation(SDValue Op,SelectionDAG & DAG) const10567 SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
10568   LLVM_DEBUG(dbgs() << "Lowering node: "; Op.dump());
10569   switch (Op.getOpcode()) {
10570   default: llvm_unreachable("Don't know how to custom lower this!");
10571   case ISD::WRITE_REGISTER: return LowerWRITE_REGISTER(Op, DAG);
10572   case ISD::ConstantPool: return LowerConstantPool(Op, DAG);
10573   case ISD::BlockAddress:  return LowerBlockAddress(Op, DAG);
10574   case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
10575   case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG);
10576   case ISD::SELECT:        return LowerSELECT(Op, DAG);
10577   case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG);
10578   case ISD::BRCOND:        return LowerBRCOND(Op, DAG);
10579   case ISD::BR_CC:         return LowerBR_CC(Op, DAG);
10580   case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
10581   case ISD::VASTART:       return LowerVASTART(Op, DAG);
10582   case ISD::ATOMIC_FENCE:  return LowerATOMIC_FENCE(Op, DAG, Subtarget);
10583   case ISD::PREFETCH:      return LowerPREFETCH(Op, DAG, Subtarget);
10584   case ISD::SINT_TO_FP:
10585   case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
10586   case ISD::STRICT_FP_TO_SINT:
10587   case ISD::STRICT_FP_TO_UINT:
10588   case ISD::FP_TO_SINT:
10589   case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
10590   case ISD::FP_TO_SINT_SAT:
10591   case ISD::FP_TO_UINT_SAT: return LowerFP_TO_INT_SAT(Op, DAG, Subtarget);
10592   case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
10593   case ISD::RETURNADDR:    return LowerRETURNADDR(Op, DAG);
10594   case ISD::FRAMEADDR:     return LowerFRAMEADDR(Op, DAG);
10595   case ISD::EH_SJLJ_SETJMP: return LowerEH_SJLJ_SETJMP(Op, DAG);
10596   case ISD::EH_SJLJ_LONGJMP: return LowerEH_SJLJ_LONGJMP(Op, DAG);
10597   case ISD::EH_SJLJ_SETUP_DISPATCH: return LowerEH_SJLJ_SETUP_DISPATCH(Op, DAG);
10598   case ISD::INTRINSIC_VOID: return LowerINTRINSIC_VOID(Op, DAG, Subtarget);
10599   case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG,
10600                                                                Subtarget);
10601   case ISD::BITCAST:       return ExpandBITCAST(Op.getNode(), DAG, Subtarget);
10602   case ISD::SHL:
10603   case ISD::SRL:
10604   case ISD::SRA:           return LowerShift(Op.getNode(), DAG, Subtarget);
10605   case ISD::SREM:          return LowerREM(Op.getNode(), DAG);
10606   case ISD::UREM:          return LowerREM(Op.getNode(), DAG);
10607   case ISD::SHL_PARTS:     return LowerShiftLeftParts(Op, DAG);
10608   case ISD::SRL_PARTS:
10609   case ISD::SRA_PARTS:     return LowerShiftRightParts(Op, DAG);
10610   case ISD::CTTZ:
10611   case ISD::CTTZ_ZERO_UNDEF: return LowerCTTZ(Op.getNode(), DAG, Subtarget);
10612   case ISD::CTPOP:         return LowerCTPOP(Op.getNode(), DAG, Subtarget);
10613   case ISD::SETCC:         return LowerVSETCC(Op, DAG, Subtarget);
10614   case ISD::SETCCCARRY:    return LowerSETCCCARRY(Op, DAG);
10615   case ISD::ConstantFP:    return LowerConstantFP(Op, DAG, Subtarget);
10616   case ISD::BUILD_VECTOR:  return LowerBUILD_VECTOR(Op, DAG, Subtarget);
10617   case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG, Subtarget);
10618   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG, Subtarget);
10619   case ISD::INSERT_VECTOR_ELT: return LowerINSERT_VECTOR_ELT(Op, DAG);
10620   case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG, Subtarget);
10621   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG, Subtarget);
10622   case ISD::TRUNCATE:      return LowerTruncate(Op.getNode(), DAG, Subtarget);
10623   case ISD::SIGN_EXTEND:
10624   case ISD::ZERO_EXTEND:   return LowerVectorExtend(Op.getNode(), DAG, Subtarget);
10625   case ISD::GET_ROUNDING:  return LowerGET_ROUNDING(Op, DAG);
10626   case ISD::SET_ROUNDING:  return LowerSET_ROUNDING(Op, DAG);
10627   case ISD::SET_FPMODE:
10628     return LowerSET_FPMODE(Op, DAG);
10629   case ISD::RESET_FPMODE:
10630     return LowerRESET_FPMODE(Op, DAG);
10631   case ISD::MUL:           return LowerMUL(Op, DAG);
10632   case ISD::SDIV:
10633     if (Subtarget->isTargetWindows() && !Op.getValueType().isVector())
10634       return LowerDIV_Windows(Op, DAG, /* Signed */ true);
10635     return LowerSDIV(Op, DAG, Subtarget);
10636   case ISD::UDIV:
10637     if (Subtarget->isTargetWindows() && !Op.getValueType().isVector())
10638       return LowerDIV_Windows(Op, DAG, /* Signed */ false);
10639     return LowerUDIV(Op, DAG, Subtarget);
10640   case ISD::UADDO_CARRY:
10641   case ISD::USUBO_CARRY:
10642     return LowerUADDSUBO_CARRY(Op, DAG);
10643   case ISD::SADDO:
10644   case ISD::SSUBO:
10645     return LowerSignedALUO(Op, DAG);
10646   case ISD::UADDO:
10647   case ISD::USUBO:
10648     return LowerUnsignedALUO(Op, DAG);
10649   case ISD::SADDSAT:
10650   case ISD::SSUBSAT:
10651   case ISD::UADDSAT:
10652   case ISD::USUBSAT:
10653     return LowerADDSUBSAT(Op, DAG, Subtarget);
10654   case ISD::LOAD:
10655     return LowerPredicateLoad(Op, DAG);
10656   case ISD::STORE:
10657     return LowerSTORE(Op, DAG, Subtarget);
10658   case ISD::MLOAD:
10659     return LowerMLOAD(Op, DAG);
10660   case ISD::VECREDUCE_MUL:
10661   case ISD::VECREDUCE_AND:
10662   case ISD::VECREDUCE_OR:
10663   case ISD::VECREDUCE_XOR:
10664     return LowerVecReduce(Op, DAG, Subtarget);
10665   case ISD::VECREDUCE_FADD:
10666   case ISD::VECREDUCE_FMUL:
10667   case ISD::VECREDUCE_FMIN:
10668   case ISD::VECREDUCE_FMAX:
10669     return LowerVecReduceF(Op, DAG, Subtarget);
10670   case ISD::VECREDUCE_UMIN:
10671   case ISD::VECREDUCE_UMAX:
10672   case ISD::VECREDUCE_SMIN:
10673   case ISD::VECREDUCE_SMAX:
10674     return LowerVecReduceMinMax(Op, DAG, Subtarget);
10675   case ISD::ATOMIC_LOAD:
10676   case ISD::ATOMIC_STORE:  return LowerAtomicLoadStore(Op, DAG);
10677   case ISD::FSINCOS:       return LowerFSINCOS(Op, DAG);
10678   case ISD::SDIVREM:
10679   case ISD::UDIVREM:       return LowerDivRem(Op, DAG);
10680   case ISD::DYNAMIC_STACKALLOC:
10681     if (Subtarget->isTargetWindows())
10682       return LowerDYNAMIC_STACKALLOC(Op, DAG);
10683     llvm_unreachable("Don't know how to custom lower this!");
10684   case ISD::STRICT_FP_ROUND:
10685   case ISD::FP_ROUND: return LowerFP_ROUND(Op, DAG);
10686   case ISD::STRICT_FP_EXTEND:
10687   case ISD::FP_EXTEND: return LowerFP_EXTEND(Op, DAG);
10688   case ISD::STRICT_FSETCC:
10689   case ISD::STRICT_FSETCCS: return LowerFSETCC(Op, DAG);
10690   case ISD::SPONENTRY:
10691     return LowerSPONENTRY(Op, DAG);
10692   case ARMISD::WIN__DBZCHK: return SDValue();
10693   }
10694 }
10695 
ReplaceLongIntrinsic(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG)10696 static void ReplaceLongIntrinsic(SDNode *N, SmallVectorImpl<SDValue> &Results,
10697                                  SelectionDAG &DAG) {
10698   unsigned IntNo = N->getConstantOperandVal(0);
10699   unsigned Opc = 0;
10700   if (IntNo == Intrinsic::arm_smlald)
10701     Opc = ARMISD::SMLALD;
10702   else if (IntNo == Intrinsic::arm_smlaldx)
10703     Opc = ARMISD::SMLALDX;
10704   else if (IntNo == Intrinsic::arm_smlsld)
10705     Opc = ARMISD::SMLSLD;
10706   else if (IntNo == Intrinsic::arm_smlsldx)
10707     Opc = ARMISD::SMLSLDX;
10708   else
10709     return;
10710 
10711   SDLoc dl(N);
10712   SDValue Lo, Hi;
10713   std::tie(Lo, Hi) = DAG.SplitScalar(N->getOperand(3), dl, MVT::i32, MVT::i32);
10714 
10715   SDValue LongMul = DAG.getNode(Opc, dl,
10716                                 DAG.getVTList(MVT::i32, MVT::i32),
10717                                 N->getOperand(1), N->getOperand(2),
10718                                 Lo, Hi);
10719   Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64,
10720                                 LongMul.getValue(0), LongMul.getValue(1)));
10721 }
10722 
10723 /// ReplaceNodeResults - Replace the results of node with an illegal result
10724 /// type with new values built out of custom code.
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const10725 void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
10726                                            SmallVectorImpl<SDValue> &Results,
10727                                            SelectionDAG &DAG) const {
10728   SDValue Res;
10729   switch (N->getOpcode()) {
10730   default:
10731     llvm_unreachable("Don't know how to custom expand this!");
10732   case ISD::READ_REGISTER:
10733     ExpandREAD_REGISTER(N, Results, DAG);
10734     break;
10735   case ISD::BITCAST:
10736     Res = ExpandBITCAST(N, DAG, Subtarget);
10737     break;
10738   case ISD::SRL:
10739   case ISD::SRA:
10740   case ISD::SHL:
10741     Res = Expand64BitShift(N, DAG, Subtarget);
10742     break;
10743   case ISD::SREM:
10744   case ISD::UREM:
10745     Res = LowerREM(N, DAG);
10746     break;
10747   case ISD::SDIVREM:
10748   case ISD::UDIVREM:
10749     Res = LowerDivRem(SDValue(N, 0), DAG);
10750     assert(Res.getNumOperands() == 2 && "DivRem needs two values");
10751     Results.push_back(Res.getValue(0));
10752     Results.push_back(Res.getValue(1));
10753     return;
10754   case ISD::SADDSAT:
10755   case ISD::SSUBSAT:
10756   case ISD::UADDSAT:
10757   case ISD::USUBSAT:
10758     Res = LowerADDSUBSAT(SDValue(N, 0), DAG, Subtarget);
10759     break;
10760   case ISD::READCYCLECOUNTER:
10761     ReplaceREADCYCLECOUNTER(N, Results, DAG, Subtarget);
10762     return;
10763   case ISD::UDIV:
10764   case ISD::SDIV:
10765     assert(Subtarget->isTargetWindows() && "can only expand DIV on Windows");
10766     return ExpandDIV_Windows(SDValue(N, 0), DAG, N->getOpcode() == ISD::SDIV,
10767                              Results);
10768   case ISD::ATOMIC_CMP_SWAP:
10769     ReplaceCMP_SWAP_64Results(N, Results, DAG);
10770     return;
10771   case ISD::INTRINSIC_WO_CHAIN:
10772     return ReplaceLongIntrinsic(N, Results, DAG);
10773   case ISD::LOAD:
10774     LowerLOAD(N, Results, DAG);
10775     break;
10776   case ISD::TRUNCATE:
10777     Res = LowerTruncate(N, DAG, Subtarget);
10778     break;
10779   case ISD::SIGN_EXTEND:
10780   case ISD::ZERO_EXTEND:
10781     Res = LowerVectorExtend(N, DAG, Subtarget);
10782     break;
10783   case ISD::FP_TO_SINT_SAT:
10784   case ISD::FP_TO_UINT_SAT:
10785     Res = LowerFP_TO_INT_SAT(SDValue(N, 0), DAG, Subtarget);
10786     break;
10787   }
10788   if (Res.getNode())
10789     Results.push_back(Res);
10790 }
10791 
10792 //===----------------------------------------------------------------------===//
10793 //                           ARM Scheduler Hooks
10794 //===----------------------------------------------------------------------===//
10795 
10796 /// SetupEntryBlockForSjLj - Insert code into the entry block that creates and
10797 /// registers the function context.
SetupEntryBlockForSjLj(MachineInstr & MI,MachineBasicBlock * MBB,MachineBasicBlock * DispatchBB,int FI) const10798 void ARMTargetLowering::SetupEntryBlockForSjLj(MachineInstr &MI,
10799                                                MachineBasicBlock *MBB,
10800                                                MachineBasicBlock *DispatchBB,
10801                                                int FI) const {
10802   assert(!Subtarget->isROPI() && !Subtarget->isRWPI() &&
10803          "ROPI/RWPI not currently supported with SjLj");
10804   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
10805   DebugLoc dl = MI.getDebugLoc();
10806   MachineFunction *MF = MBB->getParent();
10807   MachineRegisterInfo *MRI = &MF->getRegInfo();
10808   MachineConstantPool *MCP = MF->getConstantPool();
10809   ARMFunctionInfo *AFI = MF->getInfo<ARMFunctionInfo>();
10810   const Function &F = MF->getFunction();
10811 
10812   bool isThumb = Subtarget->isThumb();
10813   bool isThumb2 = Subtarget->isThumb2();
10814 
10815   unsigned PCLabelId = AFI->createPICLabelUId();
10816   unsigned PCAdj = (isThumb || isThumb2) ? 4 : 8;
10817   ARMConstantPoolValue *CPV =
10818     ARMConstantPoolMBB::Create(F.getContext(), DispatchBB, PCLabelId, PCAdj);
10819   unsigned CPI = MCP->getConstantPoolIndex(CPV, Align(4));
10820 
10821   const TargetRegisterClass *TRC = isThumb ? &ARM::tGPRRegClass
10822                                            : &ARM::GPRRegClass;
10823 
10824   // Grab constant pool and fixed stack memory operands.
10825   MachineMemOperand *CPMMO =
10826       MF->getMachineMemOperand(MachinePointerInfo::getConstantPool(*MF),
10827                                MachineMemOperand::MOLoad, 4, Align(4));
10828 
10829   MachineMemOperand *FIMMOSt =
10830       MF->getMachineMemOperand(MachinePointerInfo::getFixedStack(*MF, FI),
10831                                MachineMemOperand::MOStore, 4, Align(4));
10832 
10833   // Load the address of the dispatch MBB into the jump buffer.
10834   if (isThumb2) {
10835     // Incoming value: jbuf
10836     //   ldr.n  r5, LCPI1_1
10837     //   orr    r5, r5, #1
10838     //   add    r5, pc
10839     //   str    r5, [$jbuf, #+4] ; &jbuf[1]
10840     Register NewVReg1 = MRI->createVirtualRegister(TRC);
10841     BuildMI(*MBB, MI, dl, TII->get(ARM::t2LDRpci), NewVReg1)
10842         .addConstantPoolIndex(CPI)
10843         .addMemOperand(CPMMO)
10844         .add(predOps(ARMCC::AL));
10845     // Set the low bit because of thumb mode.
10846     Register NewVReg2 = MRI->createVirtualRegister(TRC);
10847     BuildMI(*MBB, MI, dl, TII->get(ARM::t2ORRri), NewVReg2)
10848         .addReg(NewVReg1, RegState::Kill)
10849         .addImm(0x01)
10850         .add(predOps(ARMCC::AL))
10851         .add(condCodeOp());
10852     Register NewVReg3 = MRI->createVirtualRegister(TRC);
10853     BuildMI(*MBB, MI, dl, TII->get(ARM::tPICADD), NewVReg3)
10854       .addReg(NewVReg2, RegState::Kill)
10855       .addImm(PCLabelId);
10856     BuildMI(*MBB, MI, dl, TII->get(ARM::t2STRi12))
10857         .addReg(NewVReg3, RegState::Kill)
10858         .addFrameIndex(FI)
10859         .addImm(36) // &jbuf[1] :: pc
10860         .addMemOperand(FIMMOSt)
10861         .add(predOps(ARMCC::AL));
10862   } else if (isThumb) {
10863     // Incoming value: jbuf
10864     //   ldr.n  r1, LCPI1_4
10865     //   add    r1, pc
10866     //   mov    r2, #1
10867     //   orrs   r1, r2
10868     //   add    r2, $jbuf, #+4 ; &jbuf[1]
10869     //   str    r1, [r2]
10870     Register NewVReg1 = MRI->createVirtualRegister(TRC);
10871     BuildMI(*MBB, MI, dl, TII->get(ARM::tLDRpci), NewVReg1)
10872         .addConstantPoolIndex(CPI)
10873         .addMemOperand(CPMMO)
10874         .add(predOps(ARMCC::AL));
10875     Register NewVReg2 = MRI->createVirtualRegister(TRC);
10876     BuildMI(*MBB, MI, dl, TII->get(ARM::tPICADD), NewVReg2)
10877       .addReg(NewVReg1, RegState::Kill)
10878       .addImm(PCLabelId);
10879     // Set the low bit because of thumb mode.
10880     Register NewVReg3 = MRI->createVirtualRegister(TRC);
10881     BuildMI(*MBB, MI, dl, TII->get(ARM::tMOVi8), NewVReg3)
10882         .addReg(ARM::CPSR, RegState::Define)
10883         .addImm(1)
10884         .add(predOps(ARMCC::AL));
10885     Register NewVReg4 = MRI->createVirtualRegister(TRC);
10886     BuildMI(*MBB, MI, dl, TII->get(ARM::tORR), NewVReg4)
10887         .addReg(ARM::CPSR, RegState::Define)
10888         .addReg(NewVReg2, RegState::Kill)
10889         .addReg(NewVReg3, RegState::Kill)
10890         .add(predOps(ARMCC::AL));
10891     Register NewVReg5 = MRI->createVirtualRegister(TRC);
10892     BuildMI(*MBB, MI, dl, TII->get(ARM::tADDframe), NewVReg5)
10893             .addFrameIndex(FI)
10894             .addImm(36); // &jbuf[1] :: pc
10895     BuildMI(*MBB, MI, dl, TII->get(ARM::tSTRi))
10896         .addReg(NewVReg4, RegState::Kill)
10897         .addReg(NewVReg5, RegState::Kill)
10898         .addImm(0)
10899         .addMemOperand(FIMMOSt)
10900         .add(predOps(ARMCC::AL));
10901   } else {
10902     // Incoming value: jbuf
10903     //   ldr  r1, LCPI1_1
10904     //   add  r1, pc, r1
10905     //   str  r1, [$jbuf, #+4] ; &jbuf[1]
10906     Register NewVReg1 = MRI->createVirtualRegister(TRC);
10907     BuildMI(*MBB, MI, dl, TII->get(ARM::LDRi12), NewVReg1)
10908         .addConstantPoolIndex(CPI)
10909         .addImm(0)
10910         .addMemOperand(CPMMO)
10911         .add(predOps(ARMCC::AL));
10912     Register NewVReg2 = MRI->createVirtualRegister(TRC);
10913     BuildMI(*MBB, MI, dl, TII->get(ARM::PICADD), NewVReg2)
10914         .addReg(NewVReg1, RegState::Kill)
10915         .addImm(PCLabelId)
10916         .add(predOps(ARMCC::AL));
10917     BuildMI(*MBB, MI, dl, TII->get(ARM::STRi12))
10918         .addReg(NewVReg2, RegState::Kill)
10919         .addFrameIndex(FI)
10920         .addImm(36) // &jbuf[1] :: pc
10921         .addMemOperand(FIMMOSt)
10922         .add(predOps(ARMCC::AL));
10923   }
10924 }
10925 
EmitSjLjDispatchBlock(MachineInstr & MI,MachineBasicBlock * MBB) const10926 void ARMTargetLowering::EmitSjLjDispatchBlock(MachineInstr &MI,
10927                                               MachineBasicBlock *MBB) const {
10928   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
10929   DebugLoc dl = MI.getDebugLoc();
10930   MachineFunction *MF = MBB->getParent();
10931   MachineRegisterInfo *MRI = &MF->getRegInfo();
10932   MachineFrameInfo &MFI = MF->getFrameInfo();
10933   int FI = MFI.getFunctionContextIndex();
10934 
10935   const TargetRegisterClass *TRC = Subtarget->isThumb() ? &ARM::tGPRRegClass
10936                                                         : &ARM::GPRnopcRegClass;
10937 
10938   // Get a mapping of the call site numbers to all of the landing pads they're
10939   // associated with.
10940   DenseMap<unsigned, SmallVector<MachineBasicBlock*, 2>> CallSiteNumToLPad;
10941   unsigned MaxCSNum = 0;
10942   for (MachineBasicBlock &BB : *MF) {
10943     if (!BB.isEHPad())
10944       continue;
10945 
10946     // FIXME: We should assert that the EH_LABEL is the first MI in the landing
10947     // pad.
10948     for (MachineInstr &II : BB) {
10949       if (!II.isEHLabel())
10950         continue;
10951 
10952       MCSymbol *Sym = II.getOperand(0).getMCSymbol();
10953       if (!MF->hasCallSiteLandingPad(Sym)) continue;
10954 
10955       SmallVectorImpl<unsigned> &CallSiteIdxs = MF->getCallSiteLandingPad(Sym);
10956       for (unsigned Idx : CallSiteIdxs) {
10957         CallSiteNumToLPad[Idx].push_back(&BB);
10958         MaxCSNum = std::max(MaxCSNum, Idx);
10959       }
10960       break;
10961     }
10962   }
10963 
10964   // Get an ordered list of the machine basic blocks for the jump table.
10965   std::vector<MachineBasicBlock*> LPadList;
10966   SmallPtrSet<MachineBasicBlock*, 32> InvokeBBs;
10967   LPadList.reserve(CallSiteNumToLPad.size());
10968   for (unsigned I = 1; I <= MaxCSNum; ++I) {
10969     SmallVectorImpl<MachineBasicBlock*> &MBBList = CallSiteNumToLPad[I];
10970     for (MachineBasicBlock *MBB : MBBList) {
10971       LPadList.push_back(MBB);
10972       InvokeBBs.insert(MBB->pred_begin(), MBB->pred_end());
10973     }
10974   }
10975 
10976   assert(!LPadList.empty() &&
10977          "No landing pad destinations for the dispatch jump table!");
10978 
10979   // Create the jump table and associated information.
10980   MachineJumpTableInfo *JTI =
10981     MF->getOrCreateJumpTableInfo(MachineJumpTableInfo::EK_Inline);
10982   unsigned MJTI = JTI->createJumpTableIndex(LPadList);
10983 
10984   // Create the MBBs for the dispatch code.
10985 
10986   // Shove the dispatch's address into the return slot in the function context.
10987   MachineBasicBlock *DispatchBB = MF->CreateMachineBasicBlock();
10988   DispatchBB->setIsEHPad();
10989 
10990   MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock();
10991   unsigned trap_opcode;
10992   if (Subtarget->isThumb())
10993     trap_opcode = ARM::tTRAP;
10994   else
10995     trap_opcode = Subtarget->useNaClTrap() ? ARM::TRAPNaCl : ARM::TRAP;
10996 
10997   BuildMI(TrapBB, dl, TII->get(trap_opcode));
10998   DispatchBB->addSuccessor(TrapBB);
10999 
11000   MachineBasicBlock *DispContBB = MF->CreateMachineBasicBlock();
11001   DispatchBB->addSuccessor(DispContBB);
11002 
11003   // Insert and MBBs.
11004   MF->insert(MF->end(), DispatchBB);
11005   MF->insert(MF->end(), DispContBB);
11006   MF->insert(MF->end(), TrapBB);
11007 
11008   // Insert code into the entry block that creates and registers the function
11009   // context.
11010   SetupEntryBlockForSjLj(MI, MBB, DispatchBB, FI);
11011 
11012   MachineMemOperand *FIMMOLd = MF->getMachineMemOperand(
11013       MachinePointerInfo::getFixedStack(*MF, FI),
11014       MachineMemOperand::MOLoad | MachineMemOperand::MOVolatile, 4, Align(4));
11015 
11016   MachineInstrBuilder MIB;
11017   MIB = BuildMI(DispatchBB, dl, TII->get(ARM::Int_eh_sjlj_dispatchsetup));
11018 
11019   const ARMBaseInstrInfo *AII = static_cast<const ARMBaseInstrInfo*>(TII);
11020   const ARMBaseRegisterInfo &RI = AII->getRegisterInfo();
11021 
11022   // Add a register mask with no preserved registers.  This results in all
11023   // registers being marked as clobbered. This can't work if the dispatch block
11024   // is in a Thumb1 function and is linked with ARM code which uses the FP
11025   // registers, as there is no way to preserve the FP registers in Thumb1 mode.
11026   MIB.addRegMask(RI.getSjLjDispatchPreservedMask(*MF));
11027 
11028   bool IsPositionIndependent = isPositionIndependent();
11029   unsigned NumLPads = LPadList.size();
11030   if (Subtarget->isThumb2()) {
11031     Register NewVReg1 = MRI->createVirtualRegister(TRC);
11032     BuildMI(DispatchBB, dl, TII->get(ARM::t2LDRi12), NewVReg1)
11033         .addFrameIndex(FI)
11034         .addImm(4)
11035         .addMemOperand(FIMMOLd)
11036         .add(predOps(ARMCC::AL));
11037 
11038     if (NumLPads < 256) {
11039       BuildMI(DispatchBB, dl, TII->get(ARM::t2CMPri))
11040           .addReg(NewVReg1)
11041           .addImm(LPadList.size())
11042           .add(predOps(ARMCC::AL));
11043     } else {
11044       Register VReg1 = MRI->createVirtualRegister(TRC);
11045       BuildMI(DispatchBB, dl, TII->get(ARM::t2MOVi16), VReg1)
11046           .addImm(NumLPads & 0xFFFF)
11047           .add(predOps(ARMCC::AL));
11048 
11049       unsigned VReg2 = VReg1;
11050       if ((NumLPads & 0xFFFF0000) != 0) {
11051         VReg2 = MRI->createVirtualRegister(TRC);
11052         BuildMI(DispatchBB, dl, TII->get(ARM::t2MOVTi16), VReg2)
11053             .addReg(VReg1)
11054             .addImm(NumLPads >> 16)
11055             .add(predOps(ARMCC::AL));
11056       }
11057 
11058       BuildMI(DispatchBB, dl, TII->get(ARM::t2CMPrr))
11059           .addReg(NewVReg1)
11060           .addReg(VReg2)
11061           .add(predOps(ARMCC::AL));
11062     }
11063 
11064     BuildMI(DispatchBB, dl, TII->get(ARM::t2Bcc))
11065       .addMBB(TrapBB)
11066       .addImm(ARMCC::HI)
11067       .addReg(ARM::CPSR);
11068 
11069     Register NewVReg3 = MRI->createVirtualRegister(TRC);
11070     BuildMI(DispContBB, dl, TII->get(ARM::t2LEApcrelJT), NewVReg3)
11071         .addJumpTableIndex(MJTI)
11072         .add(predOps(ARMCC::AL));
11073 
11074     Register NewVReg4 = MRI->createVirtualRegister(TRC);
11075     BuildMI(DispContBB, dl, TII->get(ARM::t2ADDrs), NewVReg4)
11076         .addReg(NewVReg3, RegState::Kill)
11077         .addReg(NewVReg1)
11078         .addImm(ARM_AM::getSORegOpc(ARM_AM::lsl, 2))
11079         .add(predOps(ARMCC::AL))
11080         .add(condCodeOp());
11081 
11082     BuildMI(DispContBB, dl, TII->get(ARM::t2BR_JT))
11083       .addReg(NewVReg4, RegState::Kill)
11084       .addReg(NewVReg1)
11085       .addJumpTableIndex(MJTI);
11086   } else if (Subtarget->isThumb()) {
11087     Register NewVReg1 = MRI->createVirtualRegister(TRC);
11088     BuildMI(DispatchBB, dl, TII->get(ARM::tLDRspi), NewVReg1)
11089         .addFrameIndex(FI)
11090         .addImm(1)
11091         .addMemOperand(FIMMOLd)
11092         .add(predOps(ARMCC::AL));
11093 
11094     if (NumLPads < 256) {
11095       BuildMI(DispatchBB, dl, TII->get(ARM::tCMPi8))
11096           .addReg(NewVReg1)
11097           .addImm(NumLPads)
11098           .add(predOps(ARMCC::AL));
11099     } else {
11100       MachineConstantPool *ConstantPool = MF->getConstantPool();
11101       Type *Int32Ty = Type::getInt32Ty(MF->getFunction().getContext());
11102       const Constant *C = ConstantInt::get(Int32Ty, NumLPads);
11103 
11104       // MachineConstantPool wants an explicit alignment.
11105       Align Alignment = MF->getDataLayout().getPrefTypeAlign(Int32Ty);
11106       unsigned Idx = ConstantPool->getConstantPoolIndex(C, Alignment);
11107 
11108       Register VReg1 = MRI->createVirtualRegister(TRC);
11109       BuildMI(DispatchBB, dl, TII->get(ARM::tLDRpci))
11110           .addReg(VReg1, RegState::Define)
11111           .addConstantPoolIndex(Idx)
11112           .add(predOps(ARMCC::AL));
11113       BuildMI(DispatchBB, dl, TII->get(ARM::tCMPr))
11114           .addReg(NewVReg1)
11115           .addReg(VReg1)
11116           .add(predOps(ARMCC::AL));
11117     }
11118 
11119     BuildMI(DispatchBB, dl, TII->get(ARM::tBcc))
11120       .addMBB(TrapBB)
11121       .addImm(ARMCC::HI)
11122       .addReg(ARM::CPSR);
11123 
11124     Register NewVReg2 = MRI->createVirtualRegister(TRC);
11125     BuildMI(DispContBB, dl, TII->get(ARM::tLSLri), NewVReg2)
11126         .addReg(ARM::CPSR, RegState::Define)
11127         .addReg(NewVReg1)
11128         .addImm(2)
11129         .add(predOps(ARMCC::AL));
11130 
11131     Register NewVReg3 = MRI->createVirtualRegister(TRC);
11132     BuildMI(DispContBB, dl, TII->get(ARM::tLEApcrelJT), NewVReg3)
11133         .addJumpTableIndex(MJTI)
11134         .add(predOps(ARMCC::AL));
11135 
11136     Register NewVReg4 = MRI->createVirtualRegister(TRC);
11137     BuildMI(DispContBB, dl, TII->get(ARM::tADDrr), NewVReg4)
11138         .addReg(ARM::CPSR, RegState::Define)
11139         .addReg(NewVReg2, RegState::Kill)
11140         .addReg(NewVReg3)
11141         .add(predOps(ARMCC::AL));
11142 
11143     MachineMemOperand *JTMMOLd =
11144         MF->getMachineMemOperand(MachinePointerInfo::getJumpTable(*MF),
11145                                  MachineMemOperand::MOLoad, 4, Align(4));
11146 
11147     Register NewVReg5 = MRI->createVirtualRegister(TRC);
11148     BuildMI(DispContBB, dl, TII->get(ARM::tLDRi), NewVReg5)
11149         .addReg(NewVReg4, RegState::Kill)
11150         .addImm(0)
11151         .addMemOperand(JTMMOLd)
11152         .add(predOps(ARMCC::AL));
11153 
11154     unsigned NewVReg6 = NewVReg5;
11155     if (IsPositionIndependent) {
11156       NewVReg6 = MRI->createVirtualRegister(TRC);
11157       BuildMI(DispContBB, dl, TII->get(ARM::tADDrr), NewVReg6)
11158           .addReg(ARM::CPSR, RegState::Define)
11159           .addReg(NewVReg5, RegState::Kill)
11160           .addReg(NewVReg3)
11161           .add(predOps(ARMCC::AL));
11162     }
11163 
11164     BuildMI(DispContBB, dl, TII->get(ARM::tBR_JTr))
11165       .addReg(NewVReg6, RegState::Kill)
11166       .addJumpTableIndex(MJTI);
11167   } else {
11168     Register NewVReg1 = MRI->createVirtualRegister(TRC);
11169     BuildMI(DispatchBB, dl, TII->get(ARM::LDRi12), NewVReg1)
11170         .addFrameIndex(FI)
11171         .addImm(4)
11172         .addMemOperand(FIMMOLd)
11173         .add(predOps(ARMCC::AL));
11174 
11175     if (NumLPads < 256) {
11176       BuildMI(DispatchBB, dl, TII->get(ARM::CMPri))
11177           .addReg(NewVReg1)
11178           .addImm(NumLPads)
11179           .add(predOps(ARMCC::AL));
11180     } else if (Subtarget->hasV6T2Ops() && isUInt<16>(NumLPads)) {
11181       Register VReg1 = MRI->createVirtualRegister(TRC);
11182       BuildMI(DispatchBB, dl, TII->get(ARM::MOVi16), VReg1)
11183           .addImm(NumLPads & 0xFFFF)
11184           .add(predOps(ARMCC::AL));
11185 
11186       unsigned VReg2 = VReg1;
11187       if ((NumLPads & 0xFFFF0000) != 0) {
11188         VReg2 = MRI->createVirtualRegister(TRC);
11189         BuildMI(DispatchBB, dl, TII->get(ARM::MOVTi16), VReg2)
11190             .addReg(VReg1)
11191             .addImm(NumLPads >> 16)
11192             .add(predOps(ARMCC::AL));
11193       }
11194 
11195       BuildMI(DispatchBB, dl, TII->get(ARM::CMPrr))
11196           .addReg(NewVReg1)
11197           .addReg(VReg2)
11198           .add(predOps(ARMCC::AL));
11199     } else {
11200       MachineConstantPool *ConstantPool = MF->getConstantPool();
11201       Type *Int32Ty = Type::getInt32Ty(MF->getFunction().getContext());
11202       const Constant *C = ConstantInt::get(Int32Ty, NumLPads);
11203 
11204       // MachineConstantPool wants an explicit alignment.
11205       Align Alignment = MF->getDataLayout().getPrefTypeAlign(Int32Ty);
11206       unsigned Idx = ConstantPool->getConstantPoolIndex(C, Alignment);
11207 
11208       Register VReg1 = MRI->createVirtualRegister(TRC);
11209       BuildMI(DispatchBB, dl, TII->get(ARM::LDRcp))
11210           .addReg(VReg1, RegState::Define)
11211           .addConstantPoolIndex(Idx)
11212           .addImm(0)
11213           .add(predOps(ARMCC::AL));
11214       BuildMI(DispatchBB, dl, TII->get(ARM::CMPrr))
11215           .addReg(NewVReg1)
11216           .addReg(VReg1, RegState::Kill)
11217           .add(predOps(ARMCC::AL));
11218     }
11219 
11220     BuildMI(DispatchBB, dl, TII->get(ARM::Bcc))
11221       .addMBB(TrapBB)
11222       .addImm(ARMCC::HI)
11223       .addReg(ARM::CPSR);
11224 
11225     Register NewVReg3 = MRI->createVirtualRegister(TRC);
11226     BuildMI(DispContBB, dl, TII->get(ARM::MOVsi), NewVReg3)
11227         .addReg(NewVReg1)
11228         .addImm(ARM_AM::getSORegOpc(ARM_AM::lsl, 2))
11229         .add(predOps(ARMCC::AL))
11230         .add(condCodeOp());
11231     Register NewVReg4 = MRI->createVirtualRegister(TRC);
11232     BuildMI(DispContBB, dl, TII->get(ARM::LEApcrelJT), NewVReg4)
11233         .addJumpTableIndex(MJTI)
11234         .add(predOps(ARMCC::AL));
11235 
11236     MachineMemOperand *JTMMOLd =
11237         MF->getMachineMemOperand(MachinePointerInfo::getJumpTable(*MF),
11238                                  MachineMemOperand::MOLoad, 4, Align(4));
11239     Register NewVReg5 = MRI->createVirtualRegister(TRC);
11240     BuildMI(DispContBB, dl, TII->get(ARM::LDRrs), NewVReg5)
11241         .addReg(NewVReg3, RegState::Kill)
11242         .addReg(NewVReg4)
11243         .addImm(0)
11244         .addMemOperand(JTMMOLd)
11245         .add(predOps(ARMCC::AL));
11246 
11247     if (IsPositionIndependent) {
11248       BuildMI(DispContBB, dl, TII->get(ARM::BR_JTadd))
11249         .addReg(NewVReg5, RegState::Kill)
11250         .addReg(NewVReg4)
11251         .addJumpTableIndex(MJTI);
11252     } else {
11253       BuildMI(DispContBB, dl, TII->get(ARM::BR_JTr))
11254         .addReg(NewVReg5, RegState::Kill)
11255         .addJumpTableIndex(MJTI);
11256     }
11257   }
11258 
11259   // Add the jump table entries as successors to the MBB.
11260   SmallPtrSet<MachineBasicBlock*, 8> SeenMBBs;
11261   for (MachineBasicBlock *CurMBB : LPadList) {
11262     if (SeenMBBs.insert(CurMBB).second)
11263       DispContBB->addSuccessor(CurMBB);
11264   }
11265 
11266   // N.B. the order the invoke BBs are processed in doesn't matter here.
11267   const MCPhysReg *SavedRegs = RI.getCalleeSavedRegs(MF);
11268   SmallVector<MachineBasicBlock*, 64> MBBLPads;
11269   for (MachineBasicBlock *BB : InvokeBBs) {
11270 
11271     // Remove the landing pad successor from the invoke block and replace it
11272     // with the new dispatch block.
11273     SmallVector<MachineBasicBlock*, 4> Successors(BB->successors());
11274     while (!Successors.empty()) {
11275       MachineBasicBlock *SMBB = Successors.pop_back_val();
11276       if (SMBB->isEHPad()) {
11277         BB->removeSuccessor(SMBB);
11278         MBBLPads.push_back(SMBB);
11279       }
11280     }
11281 
11282     BB->addSuccessor(DispatchBB, BranchProbability::getZero());
11283     BB->normalizeSuccProbs();
11284 
11285     // Find the invoke call and mark all of the callee-saved registers as
11286     // 'implicit defined' so that they're spilled. This prevents code from
11287     // moving instructions to before the EH block, where they will never be
11288     // executed.
11289     for (MachineBasicBlock::reverse_iterator
11290            II = BB->rbegin(), IE = BB->rend(); II != IE; ++II) {
11291       if (!II->isCall()) continue;
11292 
11293       DenseMap<unsigned, bool> DefRegs;
11294       for (MachineInstr::mop_iterator
11295              OI = II->operands_begin(), OE = II->operands_end();
11296            OI != OE; ++OI) {
11297         if (!OI->isReg()) continue;
11298         DefRegs[OI->getReg()] = true;
11299       }
11300 
11301       MachineInstrBuilder MIB(*MF, &*II);
11302 
11303       for (unsigned i = 0; SavedRegs[i] != 0; ++i) {
11304         unsigned Reg = SavedRegs[i];
11305         if (Subtarget->isThumb2() &&
11306             !ARM::tGPRRegClass.contains(Reg) &&
11307             !ARM::hGPRRegClass.contains(Reg))
11308           continue;
11309         if (Subtarget->isThumb1Only() && !ARM::tGPRRegClass.contains(Reg))
11310           continue;
11311         if (!Subtarget->isThumb() && !ARM::GPRRegClass.contains(Reg))
11312           continue;
11313         if (!DefRegs[Reg])
11314           MIB.addReg(Reg, RegState::ImplicitDefine | RegState::Dead);
11315       }
11316 
11317       break;
11318     }
11319   }
11320 
11321   // Mark all former landing pads as non-landing pads. The dispatch is the only
11322   // landing pad now.
11323   for (MachineBasicBlock *MBBLPad : MBBLPads)
11324     MBBLPad->setIsEHPad(false);
11325 
11326   // The instruction is gone now.
11327   MI.eraseFromParent();
11328 }
11329 
11330 static
OtherSucc(MachineBasicBlock * MBB,MachineBasicBlock * Succ)11331 MachineBasicBlock *OtherSucc(MachineBasicBlock *MBB, MachineBasicBlock *Succ) {
11332   for (MachineBasicBlock *S : MBB->successors())
11333     if (S != Succ)
11334       return S;
11335   llvm_unreachable("Expecting a BB with two successors!");
11336 }
11337 
11338 /// Return the load opcode for a given load size. If load size >= 8,
11339 /// neon opcode will be returned.
getLdOpcode(unsigned LdSize,bool IsThumb1,bool IsThumb2)11340 static unsigned getLdOpcode(unsigned LdSize, bool IsThumb1, bool IsThumb2) {
11341   if (LdSize >= 8)
11342     return LdSize == 16 ? ARM::VLD1q32wb_fixed
11343                         : LdSize == 8 ? ARM::VLD1d32wb_fixed : 0;
11344   if (IsThumb1)
11345     return LdSize == 4 ? ARM::tLDRi
11346                        : LdSize == 2 ? ARM::tLDRHi
11347                                      : LdSize == 1 ? ARM::tLDRBi : 0;
11348   if (IsThumb2)
11349     return LdSize == 4 ? ARM::t2LDR_POST
11350                        : LdSize == 2 ? ARM::t2LDRH_POST
11351                                      : LdSize == 1 ? ARM::t2LDRB_POST : 0;
11352   return LdSize == 4 ? ARM::LDR_POST_IMM
11353                      : LdSize == 2 ? ARM::LDRH_POST
11354                                    : LdSize == 1 ? ARM::LDRB_POST_IMM : 0;
11355 }
11356 
11357 /// Return the store opcode for a given store size. If store size >= 8,
11358 /// neon opcode will be returned.
getStOpcode(unsigned StSize,bool IsThumb1,bool IsThumb2)11359 static unsigned getStOpcode(unsigned StSize, bool IsThumb1, bool IsThumb2) {
11360   if (StSize >= 8)
11361     return StSize == 16 ? ARM::VST1q32wb_fixed
11362                         : StSize == 8 ? ARM::VST1d32wb_fixed : 0;
11363   if (IsThumb1)
11364     return StSize == 4 ? ARM::tSTRi
11365                        : StSize == 2 ? ARM::tSTRHi
11366                                      : StSize == 1 ? ARM::tSTRBi : 0;
11367   if (IsThumb2)
11368     return StSize == 4 ? ARM::t2STR_POST
11369                        : StSize == 2 ? ARM::t2STRH_POST
11370                                      : StSize == 1 ? ARM::t2STRB_POST : 0;
11371   return StSize == 4 ? ARM::STR_POST_IMM
11372                      : StSize == 2 ? ARM::STRH_POST
11373                                    : StSize == 1 ? ARM::STRB_POST_IMM : 0;
11374 }
11375 
11376 /// Emit a post-increment load operation with given size. The instructions
11377 /// will be added to BB at Pos.
emitPostLd(MachineBasicBlock * BB,MachineBasicBlock::iterator Pos,const TargetInstrInfo * TII,const DebugLoc & dl,unsigned LdSize,unsigned Data,unsigned AddrIn,unsigned AddrOut,bool IsThumb1,bool IsThumb2)11378 static void emitPostLd(MachineBasicBlock *BB, MachineBasicBlock::iterator Pos,
11379                        const TargetInstrInfo *TII, const DebugLoc &dl,
11380                        unsigned LdSize, unsigned Data, unsigned AddrIn,
11381                        unsigned AddrOut, bool IsThumb1, bool IsThumb2) {
11382   unsigned LdOpc = getLdOpcode(LdSize, IsThumb1, IsThumb2);
11383   assert(LdOpc != 0 && "Should have a load opcode");
11384   if (LdSize >= 8) {
11385     BuildMI(*BB, Pos, dl, TII->get(LdOpc), Data)
11386         .addReg(AddrOut, RegState::Define)
11387         .addReg(AddrIn)
11388         .addImm(0)
11389         .add(predOps(ARMCC::AL));
11390   } else if (IsThumb1) {
11391     // load + update AddrIn
11392     BuildMI(*BB, Pos, dl, TII->get(LdOpc), Data)
11393         .addReg(AddrIn)
11394         .addImm(0)
11395         .add(predOps(ARMCC::AL));
11396     BuildMI(*BB, Pos, dl, TII->get(ARM::tADDi8), AddrOut)
11397         .add(t1CondCodeOp())
11398         .addReg(AddrIn)
11399         .addImm(LdSize)
11400         .add(predOps(ARMCC::AL));
11401   } else if (IsThumb2) {
11402     BuildMI(*BB, Pos, dl, TII->get(LdOpc), Data)
11403         .addReg(AddrOut, RegState::Define)
11404         .addReg(AddrIn)
11405         .addImm(LdSize)
11406         .add(predOps(ARMCC::AL));
11407   } else { // arm
11408     BuildMI(*BB, Pos, dl, TII->get(LdOpc), Data)
11409         .addReg(AddrOut, RegState::Define)
11410         .addReg(AddrIn)
11411         .addReg(0)
11412         .addImm(LdSize)
11413         .add(predOps(ARMCC::AL));
11414   }
11415 }
11416 
11417 /// Emit a post-increment store operation with given size. The instructions
11418 /// will be added to BB at Pos.
emitPostSt(MachineBasicBlock * BB,MachineBasicBlock::iterator Pos,const TargetInstrInfo * TII,const DebugLoc & dl,unsigned StSize,unsigned Data,unsigned AddrIn,unsigned AddrOut,bool IsThumb1,bool IsThumb2)11419 static void emitPostSt(MachineBasicBlock *BB, MachineBasicBlock::iterator Pos,
11420                        const TargetInstrInfo *TII, const DebugLoc &dl,
11421                        unsigned StSize, unsigned Data, unsigned AddrIn,
11422                        unsigned AddrOut, bool IsThumb1, bool IsThumb2) {
11423   unsigned StOpc = getStOpcode(StSize, IsThumb1, IsThumb2);
11424   assert(StOpc != 0 && "Should have a store opcode");
11425   if (StSize >= 8) {
11426     BuildMI(*BB, Pos, dl, TII->get(StOpc), AddrOut)
11427         .addReg(AddrIn)
11428         .addImm(0)
11429         .addReg(Data)
11430         .add(predOps(ARMCC::AL));
11431   } else if (IsThumb1) {
11432     // store + update AddrIn
11433     BuildMI(*BB, Pos, dl, TII->get(StOpc))
11434         .addReg(Data)
11435         .addReg(AddrIn)
11436         .addImm(0)
11437         .add(predOps(ARMCC::AL));
11438     BuildMI(*BB, Pos, dl, TII->get(ARM::tADDi8), AddrOut)
11439         .add(t1CondCodeOp())
11440         .addReg(AddrIn)
11441         .addImm(StSize)
11442         .add(predOps(ARMCC::AL));
11443   } else if (IsThumb2) {
11444     BuildMI(*BB, Pos, dl, TII->get(StOpc), AddrOut)
11445         .addReg(Data)
11446         .addReg(AddrIn)
11447         .addImm(StSize)
11448         .add(predOps(ARMCC::AL));
11449   } else { // arm
11450     BuildMI(*BB, Pos, dl, TII->get(StOpc), AddrOut)
11451         .addReg(Data)
11452         .addReg(AddrIn)
11453         .addReg(0)
11454         .addImm(StSize)
11455         .add(predOps(ARMCC::AL));
11456   }
11457 }
11458 
11459 MachineBasicBlock *
EmitStructByval(MachineInstr & MI,MachineBasicBlock * BB) const11460 ARMTargetLowering::EmitStructByval(MachineInstr &MI,
11461                                    MachineBasicBlock *BB) const {
11462   // This pseudo instruction has 3 operands: dst, src, size
11463   // We expand it to a loop if size > Subtarget->getMaxInlineSizeThreshold().
11464   // Otherwise, we will generate unrolled scalar copies.
11465   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
11466   const BasicBlock *LLVM_BB = BB->getBasicBlock();
11467   MachineFunction::iterator It = ++BB->getIterator();
11468 
11469   Register dest = MI.getOperand(0).getReg();
11470   Register src = MI.getOperand(1).getReg();
11471   unsigned SizeVal = MI.getOperand(2).getImm();
11472   unsigned Alignment = MI.getOperand(3).getImm();
11473   DebugLoc dl = MI.getDebugLoc();
11474 
11475   MachineFunction *MF = BB->getParent();
11476   MachineRegisterInfo &MRI = MF->getRegInfo();
11477   unsigned UnitSize = 0;
11478   const TargetRegisterClass *TRC = nullptr;
11479   const TargetRegisterClass *VecTRC = nullptr;
11480 
11481   bool IsThumb1 = Subtarget->isThumb1Only();
11482   bool IsThumb2 = Subtarget->isThumb2();
11483   bool IsThumb = Subtarget->isThumb();
11484 
11485   if (Alignment & 1) {
11486     UnitSize = 1;
11487   } else if (Alignment & 2) {
11488     UnitSize = 2;
11489   } else {
11490     // Check whether we can use NEON instructions.
11491     if (!MF->getFunction().hasFnAttribute(Attribute::NoImplicitFloat) &&
11492         Subtarget->hasNEON()) {
11493       if ((Alignment % 16 == 0) && SizeVal >= 16)
11494         UnitSize = 16;
11495       else if ((Alignment % 8 == 0) && SizeVal >= 8)
11496         UnitSize = 8;
11497     }
11498     // Can't use NEON instructions.
11499     if (UnitSize == 0)
11500       UnitSize = 4;
11501   }
11502 
11503   // Select the correct opcode and register class for unit size load/store
11504   bool IsNeon = UnitSize >= 8;
11505   TRC = IsThumb ? &ARM::tGPRRegClass : &ARM::GPRRegClass;
11506   if (IsNeon)
11507     VecTRC = UnitSize == 16 ? &ARM::DPairRegClass
11508                             : UnitSize == 8 ? &ARM::DPRRegClass
11509                                             : nullptr;
11510 
11511   unsigned BytesLeft = SizeVal % UnitSize;
11512   unsigned LoopSize = SizeVal - BytesLeft;
11513 
11514   if (SizeVal <= Subtarget->getMaxInlineSizeThreshold()) {
11515     // Use LDR and STR to copy.
11516     // [scratch, srcOut] = LDR_POST(srcIn, UnitSize)
11517     // [destOut] = STR_POST(scratch, destIn, UnitSize)
11518     unsigned srcIn = src;
11519     unsigned destIn = dest;
11520     for (unsigned i = 0; i < LoopSize; i+=UnitSize) {
11521       Register srcOut = MRI.createVirtualRegister(TRC);
11522       Register destOut = MRI.createVirtualRegister(TRC);
11523       Register scratch = MRI.createVirtualRegister(IsNeon ? VecTRC : TRC);
11524       emitPostLd(BB, MI, TII, dl, UnitSize, scratch, srcIn, srcOut,
11525                  IsThumb1, IsThumb2);
11526       emitPostSt(BB, MI, TII, dl, UnitSize, scratch, destIn, destOut,
11527                  IsThumb1, IsThumb2);
11528       srcIn = srcOut;
11529       destIn = destOut;
11530     }
11531 
11532     // Handle the leftover bytes with LDRB and STRB.
11533     // [scratch, srcOut] = LDRB_POST(srcIn, 1)
11534     // [destOut] = STRB_POST(scratch, destIn, 1)
11535     for (unsigned i = 0; i < BytesLeft; i++) {
11536       Register srcOut = MRI.createVirtualRegister(TRC);
11537       Register destOut = MRI.createVirtualRegister(TRC);
11538       Register scratch = MRI.createVirtualRegister(TRC);
11539       emitPostLd(BB, MI, TII, dl, 1, scratch, srcIn, srcOut,
11540                  IsThumb1, IsThumb2);
11541       emitPostSt(BB, MI, TII, dl, 1, scratch, destIn, destOut,
11542                  IsThumb1, IsThumb2);
11543       srcIn = srcOut;
11544       destIn = destOut;
11545     }
11546     MI.eraseFromParent(); // The instruction is gone now.
11547     return BB;
11548   }
11549 
11550   // Expand the pseudo op to a loop.
11551   // thisMBB:
11552   //   ...
11553   //   movw varEnd, # --> with thumb2
11554   //   movt varEnd, #
11555   //   ldrcp varEnd, idx --> without thumb2
11556   //   fallthrough --> loopMBB
11557   // loopMBB:
11558   //   PHI varPhi, varEnd, varLoop
11559   //   PHI srcPhi, src, srcLoop
11560   //   PHI destPhi, dst, destLoop
11561   //   [scratch, srcLoop] = LDR_POST(srcPhi, UnitSize)
11562   //   [destLoop] = STR_POST(scratch, destPhi, UnitSize)
11563   //   subs varLoop, varPhi, #UnitSize
11564   //   bne loopMBB
11565   //   fallthrough --> exitMBB
11566   // exitMBB:
11567   //   epilogue to handle left-over bytes
11568   //   [scratch, srcOut] = LDRB_POST(srcLoop, 1)
11569   //   [destOut] = STRB_POST(scratch, destLoop, 1)
11570   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
11571   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
11572   MF->insert(It, loopMBB);
11573   MF->insert(It, exitMBB);
11574 
11575   // Set the call frame size on entry to the new basic blocks.
11576   unsigned CallFrameSize = TII->getCallFrameSizeAt(MI);
11577   loopMBB->setCallFrameSize(CallFrameSize);
11578   exitMBB->setCallFrameSize(CallFrameSize);
11579 
11580   // Transfer the remainder of BB and its successor edges to exitMBB.
11581   exitMBB->splice(exitMBB->begin(), BB,
11582                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
11583   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
11584 
11585   // Load an immediate to varEnd.
11586   Register varEnd = MRI.createVirtualRegister(TRC);
11587   if (Subtarget->useMovt()) {
11588     BuildMI(BB, dl, TII->get(IsThumb ? ARM::t2MOVi32imm : ARM::MOVi32imm),
11589             varEnd)
11590         .addImm(LoopSize);
11591   } else if (Subtarget->genExecuteOnly()) {
11592     assert(IsThumb && "Non-thumb expected to have used movt");
11593     BuildMI(BB, dl, TII->get(ARM::tMOVi32imm), varEnd).addImm(LoopSize);
11594   } else {
11595     MachineConstantPool *ConstantPool = MF->getConstantPool();
11596     Type *Int32Ty = Type::getInt32Ty(MF->getFunction().getContext());
11597     const Constant *C = ConstantInt::get(Int32Ty, LoopSize);
11598 
11599     // MachineConstantPool wants an explicit alignment.
11600     Align Alignment = MF->getDataLayout().getPrefTypeAlign(Int32Ty);
11601     unsigned Idx = ConstantPool->getConstantPoolIndex(C, Alignment);
11602     MachineMemOperand *CPMMO =
11603         MF->getMachineMemOperand(MachinePointerInfo::getConstantPool(*MF),
11604                                  MachineMemOperand::MOLoad, 4, Align(4));
11605 
11606     if (IsThumb)
11607       BuildMI(*BB, MI, dl, TII->get(ARM::tLDRpci))
11608           .addReg(varEnd, RegState::Define)
11609           .addConstantPoolIndex(Idx)
11610           .add(predOps(ARMCC::AL))
11611           .addMemOperand(CPMMO);
11612     else
11613       BuildMI(*BB, MI, dl, TII->get(ARM::LDRcp))
11614           .addReg(varEnd, RegState::Define)
11615           .addConstantPoolIndex(Idx)
11616           .addImm(0)
11617           .add(predOps(ARMCC::AL))
11618           .addMemOperand(CPMMO);
11619   }
11620   BB->addSuccessor(loopMBB);
11621 
11622   // Generate the loop body:
11623   //   varPhi = PHI(varLoop, varEnd)
11624   //   srcPhi = PHI(srcLoop, src)
11625   //   destPhi = PHI(destLoop, dst)
11626   MachineBasicBlock *entryBB = BB;
11627   BB = loopMBB;
11628   Register varLoop = MRI.createVirtualRegister(TRC);
11629   Register varPhi = MRI.createVirtualRegister(TRC);
11630   Register srcLoop = MRI.createVirtualRegister(TRC);
11631   Register srcPhi = MRI.createVirtualRegister(TRC);
11632   Register destLoop = MRI.createVirtualRegister(TRC);
11633   Register destPhi = MRI.createVirtualRegister(TRC);
11634 
11635   BuildMI(*BB, BB->begin(), dl, TII->get(ARM::PHI), varPhi)
11636     .addReg(varLoop).addMBB(loopMBB)
11637     .addReg(varEnd).addMBB(entryBB);
11638   BuildMI(BB, dl, TII->get(ARM::PHI), srcPhi)
11639     .addReg(srcLoop).addMBB(loopMBB)
11640     .addReg(src).addMBB(entryBB);
11641   BuildMI(BB, dl, TII->get(ARM::PHI), destPhi)
11642     .addReg(destLoop).addMBB(loopMBB)
11643     .addReg(dest).addMBB(entryBB);
11644 
11645   //   [scratch, srcLoop] = LDR_POST(srcPhi, UnitSize)
11646   //   [destLoop] = STR_POST(scratch, destPhi, UnitSiz)
11647   Register scratch = MRI.createVirtualRegister(IsNeon ? VecTRC : TRC);
11648   emitPostLd(BB, BB->end(), TII, dl, UnitSize, scratch, srcPhi, srcLoop,
11649              IsThumb1, IsThumb2);
11650   emitPostSt(BB, BB->end(), TII, dl, UnitSize, scratch, destPhi, destLoop,
11651              IsThumb1, IsThumb2);
11652 
11653   // Decrement loop variable by UnitSize.
11654   if (IsThumb1) {
11655     BuildMI(*BB, BB->end(), dl, TII->get(ARM::tSUBi8), varLoop)
11656         .add(t1CondCodeOp())
11657         .addReg(varPhi)
11658         .addImm(UnitSize)
11659         .add(predOps(ARMCC::AL));
11660   } else {
11661     MachineInstrBuilder MIB =
11662         BuildMI(*BB, BB->end(), dl,
11663                 TII->get(IsThumb2 ? ARM::t2SUBri : ARM::SUBri), varLoop);
11664     MIB.addReg(varPhi)
11665         .addImm(UnitSize)
11666         .add(predOps(ARMCC::AL))
11667         .add(condCodeOp());
11668     MIB->getOperand(5).setReg(ARM::CPSR);
11669     MIB->getOperand(5).setIsDef(true);
11670   }
11671   BuildMI(*BB, BB->end(), dl,
11672           TII->get(IsThumb1 ? ARM::tBcc : IsThumb2 ? ARM::t2Bcc : ARM::Bcc))
11673       .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
11674 
11675   // loopMBB can loop back to loopMBB or fall through to exitMBB.
11676   BB->addSuccessor(loopMBB);
11677   BB->addSuccessor(exitMBB);
11678 
11679   // Add epilogue to handle BytesLeft.
11680   BB = exitMBB;
11681   auto StartOfExit = exitMBB->begin();
11682 
11683   //   [scratch, srcOut] = LDRB_POST(srcLoop, 1)
11684   //   [destOut] = STRB_POST(scratch, destLoop, 1)
11685   unsigned srcIn = srcLoop;
11686   unsigned destIn = destLoop;
11687   for (unsigned i = 0; i < BytesLeft; i++) {
11688     Register srcOut = MRI.createVirtualRegister(TRC);
11689     Register destOut = MRI.createVirtualRegister(TRC);
11690     Register scratch = MRI.createVirtualRegister(TRC);
11691     emitPostLd(BB, StartOfExit, TII, dl, 1, scratch, srcIn, srcOut,
11692                IsThumb1, IsThumb2);
11693     emitPostSt(BB, StartOfExit, TII, dl, 1, scratch, destIn, destOut,
11694                IsThumb1, IsThumb2);
11695     srcIn = srcOut;
11696     destIn = destOut;
11697   }
11698 
11699   MI.eraseFromParent(); // The instruction is gone now.
11700   return BB;
11701 }
11702 
11703 MachineBasicBlock *
EmitLowered__chkstk(MachineInstr & MI,MachineBasicBlock * MBB) const11704 ARMTargetLowering::EmitLowered__chkstk(MachineInstr &MI,
11705                                        MachineBasicBlock *MBB) const {
11706   const TargetMachine &TM = getTargetMachine();
11707   const TargetInstrInfo &TII = *Subtarget->getInstrInfo();
11708   DebugLoc DL = MI.getDebugLoc();
11709 
11710   assert(Subtarget->isTargetWindows() &&
11711          "__chkstk is only supported on Windows");
11712   assert(Subtarget->isThumb2() && "Windows on ARM requires Thumb-2 mode");
11713 
11714   // __chkstk takes the number of words to allocate on the stack in R4, and
11715   // returns the stack adjustment in number of bytes in R4.  This will not
11716   // clober any other registers (other than the obvious lr).
11717   //
11718   // Although, technically, IP should be considered a register which may be
11719   // clobbered, the call itself will not touch it.  Windows on ARM is a pure
11720   // thumb-2 environment, so there is no interworking required.  As a result, we
11721   // do not expect a veneer to be emitted by the linker, clobbering IP.
11722   //
11723   // Each module receives its own copy of __chkstk, so no import thunk is
11724   // required, again, ensuring that IP is not clobbered.
11725   //
11726   // Finally, although some linkers may theoretically provide a trampoline for
11727   // out of range calls (which is quite common due to a 32M range limitation of
11728   // branches for Thumb), we can generate the long-call version via
11729   // -mcmodel=large, alleviating the need for the trampoline which may clobber
11730   // IP.
11731 
11732   switch (TM.getCodeModel()) {
11733   case CodeModel::Tiny:
11734     llvm_unreachable("Tiny code model not available on ARM.");
11735   case CodeModel::Small:
11736   case CodeModel::Medium:
11737   case CodeModel::Kernel:
11738     BuildMI(*MBB, MI, DL, TII.get(ARM::tBL))
11739         .add(predOps(ARMCC::AL))
11740         .addExternalSymbol("__chkstk")
11741         .addReg(ARM::R4, RegState::Implicit | RegState::Kill)
11742         .addReg(ARM::R4, RegState::Implicit | RegState::Define)
11743         .addReg(ARM::R12,
11744                 RegState::Implicit | RegState::Define | RegState::Dead)
11745         .addReg(ARM::CPSR,
11746                 RegState::Implicit | RegState::Define | RegState::Dead);
11747     break;
11748   case CodeModel::Large: {
11749     MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
11750     Register Reg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11751 
11752     BuildMI(*MBB, MI, DL, TII.get(ARM::t2MOVi32imm), Reg)
11753       .addExternalSymbol("__chkstk");
11754     BuildMI(*MBB, MI, DL, TII.get(gettBLXrOpcode(*MBB->getParent())))
11755         .add(predOps(ARMCC::AL))
11756         .addReg(Reg, RegState::Kill)
11757         .addReg(ARM::R4, RegState::Implicit | RegState::Kill)
11758         .addReg(ARM::R4, RegState::Implicit | RegState::Define)
11759         .addReg(ARM::R12,
11760                 RegState::Implicit | RegState::Define | RegState::Dead)
11761         .addReg(ARM::CPSR,
11762                 RegState::Implicit | RegState::Define | RegState::Dead);
11763     break;
11764   }
11765   }
11766 
11767   BuildMI(*MBB, MI, DL, TII.get(ARM::t2SUBrr), ARM::SP)
11768       .addReg(ARM::SP, RegState::Kill)
11769       .addReg(ARM::R4, RegState::Kill)
11770       .setMIFlags(MachineInstr::FrameSetup)
11771       .add(predOps(ARMCC::AL))
11772       .add(condCodeOp());
11773 
11774   MI.eraseFromParent();
11775   return MBB;
11776 }
11777 
11778 MachineBasicBlock *
EmitLowered__dbzchk(MachineInstr & MI,MachineBasicBlock * MBB) const11779 ARMTargetLowering::EmitLowered__dbzchk(MachineInstr &MI,
11780                                        MachineBasicBlock *MBB) const {
11781   DebugLoc DL = MI.getDebugLoc();
11782   MachineFunction *MF = MBB->getParent();
11783   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
11784 
11785   MachineBasicBlock *ContBB = MF->CreateMachineBasicBlock();
11786   MF->insert(++MBB->getIterator(), ContBB);
11787   ContBB->splice(ContBB->begin(), MBB,
11788                  std::next(MachineBasicBlock::iterator(MI)), MBB->end());
11789   ContBB->transferSuccessorsAndUpdatePHIs(MBB);
11790   MBB->addSuccessor(ContBB);
11791 
11792   MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock();
11793   BuildMI(TrapBB, DL, TII->get(ARM::t__brkdiv0));
11794   MF->push_back(TrapBB);
11795   MBB->addSuccessor(TrapBB);
11796 
11797   BuildMI(*MBB, MI, DL, TII->get(ARM::tCMPi8))
11798       .addReg(MI.getOperand(0).getReg())
11799       .addImm(0)
11800       .add(predOps(ARMCC::AL));
11801   BuildMI(*MBB, MI, DL, TII->get(ARM::t2Bcc))
11802       .addMBB(TrapBB)
11803       .addImm(ARMCC::EQ)
11804       .addReg(ARM::CPSR);
11805 
11806   MI.eraseFromParent();
11807   return ContBB;
11808 }
11809 
11810 // The CPSR operand of SelectItr might be missing a kill marker
11811 // because there were multiple uses of CPSR, and ISel didn't know
11812 // which to mark. Figure out whether SelectItr should have had a
11813 // kill marker, and set it if it should. Returns the correct kill
11814 // marker value.
checkAndUpdateCPSRKill(MachineBasicBlock::iterator SelectItr,MachineBasicBlock * BB,const TargetRegisterInfo * TRI)11815 static bool checkAndUpdateCPSRKill(MachineBasicBlock::iterator SelectItr,
11816                                    MachineBasicBlock* BB,
11817                                    const TargetRegisterInfo* TRI) {
11818   // Scan forward through BB for a use/def of CPSR.
11819   MachineBasicBlock::iterator miI(std::next(SelectItr));
11820   for (MachineBasicBlock::iterator miE = BB->end(); miI != miE; ++miI) {
11821     const MachineInstr& mi = *miI;
11822     if (mi.readsRegister(ARM::CPSR, /*TRI=*/nullptr))
11823       return false;
11824     if (mi.definesRegister(ARM::CPSR, /*TRI=*/nullptr))
11825       break; // Should have kill-flag - update below.
11826   }
11827 
11828   // If we hit the end of the block, check whether CPSR is live into a
11829   // successor.
11830   if (miI == BB->end()) {
11831     for (MachineBasicBlock *Succ : BB->successors())
11832       if (Succ->isLiveIn(ARM::CPSR))
11833         return false;
11834   }
11835 
11836   // We found a def, or hit the end of the basic block and CPSR wasn't live
11837   // out. SelectMI should have a kill flag on CPSR.
11838   SelectItr->addRegisterKilled(ARM::CPSR, TRI);
11839   return true;
11840 }
11841 
11842 /// Adds logic in loop entry MBB to calculate loop iteration count and adds
11843 /// t2WhileLoopSetup and t2WhileLoopStart to generate WLS loop
genTPEntry(MachineBasicBlock * TpEntry,MachineBasicBlock * TpLoopBody,MachineBasicBlock * TpExit,Register OpSizeReg,const TargetInstrInfo * TII,DebugLoc Dl,MachineRegisterInfo & MRI)11844 static Register genTPEntry(MachineBasicBlock *TpEntry,
11845                            MachineBasicBlock *TpLoopBody,
11846                            MachineBasicBlock *TpExit, Register OpSizeReg,
11847                            const TargetInstrInfo *TII, DebugLoc Dl,
11848                            MachineRegisterInfo &MRI) {
11849   // Calculates loop iteration count = ceil(n/16) = (n + 15) >> 4.
11850   Register AddDestReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11851   BuildMI(TpEntry, Dl, TII->get(ARM::t2ADDri), AddDestReg)
11852       .addUse(OpSizeReg)
11853       .addImm(15)
11854       .add(predOps(ARMCC::AL))
11855       .addReg(0);
11856 
11857   Register LsrDestReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11858   BuildMI(TpEntry, Dl, TII->get(ARM::t2LSRri), LsrDestReg)
11859       .addUse(AddDestReg, RegState::Kill)
11860       .addImm(4)
11861       .add(predOps(ARMCC::AL))
11862       .addReg(0);
11863 
11864   Register TotalIterationsReg = MRI.createVirtualRegister(&ARM::GPRlrRegClass);
11865   BuildMI(TpEntry, Dl, TII->get(ARM::t2WhileLoopSetup), TotalIterationsReg)
11866       .addUse(LsrDestReg, RegState::Kill);
11867 
11868   BuildMI(TpEntry, Dl, TII->get(ARM::t2WhileLoopStart))
11869       .addUse(TotalIterationsReg)
11870       .addMBB(TpExit);
11871 
11872   BuildMI(TpEntry, Dl, TII->get(ARM::t2B))
11873       .addMBB(TpLoopBody)
11874       .add(predOps(ARMCC::AL));
11875 
11876   return TotalIterationsReg;
11877 }
11878 
11879 /// Adds logic in the loopBody MBB to generate MVE_VCTP, t2DoLoopDec and
11880 /// t2DoLoopEnd. These are used by later passes to generate tail predicated
11881 /// loops.
genTPLoopBody(MachineBasicBlock * TpLoopBody,MachineBasicBlock * TpEntry,MachineBasicBlock * TpExit,const TargetInstrInfo * TII,DebugLoc Dl,MachineRegisterInfo & MRI,Register OpSrcReg,Register OpDestReg,Register ElementCountReg,Register TotalIterationsReg,bool IsMemcpy)11882 static void genTPLoopBody(MachineBasicBlock *TpLoopBody,
11883                           MachineBasicBlock *TpEntry, MachineBasicBlock *TpExit,
11884                           const TargetInstrInfo *TII, DebugLoc Dl,
11885                           MachineRegisterInfo &MRI, Register OpSrcReg,
11886                           Register OpDestReg, Register ElementCountReg,
11887                           Register TotalIterationsReg, bool IsMemcpy) {
11888   // First insert 4 PHI nodes for: Current pointer to Src (if memcpy), Dest
11889   // array, loop iteration counter, predication counter.
11890 
11891   Register SrcPhiReg, CurrSrcReg;
11892   if (IsMemcpy) {
11893     //  Current position in the src array
11894     SrcPhiReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11895     CurrSrcReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11896     BuildMI(TpLoopBody, Dl, TII->get(ARM::PHI), SrcPhiReg)
11897         .addUse(OpSrcReg)
11898         .addMBB(TpEntry)
11899         .addUse(CurrSrcReg)
11900         .addMBB(TpLoopBody);
11901   }
11902 
11903   // Current position in the dest array
11904   Register DestPhiReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11905   Register CurrDestReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11906   BuildMI(TpLoopBody, Dl, TII->get(ARM::PHI), DestPhiReg)
11907       .addUse(OpDestReg)
11908       .addMBB(TpEntry)
11909       .addUse(CurrDestReg)
11910       .addMBB(TpLoopBody);
11911 
11912   // Current loop counter
11913   Register LoopCounterPhiReg = MRI.createVirtualRegister(&ARM::GPRlrRegClass);
11914   Register RemainingLoopIterationsReg =
11915       MRI.createVirtualRegister(&ARM::GPRlrRegClass);
11916   BuildMI(TpLoopBody, Dl, TII->get(ARM::PHI), LoopCounterPhiReg)
11917       .addUse(TotalIterationsReg)
11918       .addMBB(TpEntry)
11919       .addUse(RemainingLoopIterationsReg)
11920       .addMBB(TpLoopBody);
11921 
11922   // Predication counter
11923   Register PredCounterPhiReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11924   Register RemainingElementsReg = MRI.createVirtualRegister(&ARM::rGPRRegClass);
11925   BuildMI(TpLoopBody, Dl, TII->get(ARM::PHI), PredCounterPhiReg)
11926       .addUse(ElementCountReg)
11927       .addMBB(TpEntry)
11928       .addUse(RemainingElementsReg)
11929       .addMBB(TpLoopBody);
11930 
11931   // Pass predication counter to VCTP
11932   Register VccrReg = MRI.createVirtualRegister(&ARM::VCCRRegClass);
11933   BuildMI(TpLoopBody, Dl, TII->get(ARM::MVE_VCTP8), VccrReg)
11934       .addUse(PredCounterPhiReg)
11935       .addImm(ARMVCC::None)
11936       .addReg(0)
11937       .addReg(0);
11938 
11939   BuildMI(TpLoopBody, Dl, TII->get(ARM::t2SUBri), RemainingElementsReg)
11940       .addUse(PredCounterPhiReg)
11941       .addImm(16)
11942       .add(predOps(ARMCC::AL))
11943       .addReg(0);
11944 
11945   // VLDRB (only if memcpy) and VSTRB instructions, predicated using VPR
11946   Register SrcValueReg;
11947   if (IsMemcpy) {
11948     SrcValueReg = MRI.createVirtualRegister(&ARM::MQPRRegClass);
11949     BuildMI(TpLoopBody, Dl, TII->get(ARM::MVE_VLDRBU8_post))
11950         .addDef(CurrSrcReg)
11951         .addDef(SrcValueReg)
11952         .addReg(SrcPhiReg)
11953         .addImm(16)
11954         .addImm(ARMVCC::Then)
11955         .addUse(VccrReg)
11956         .addReg(0);
11957   } else
11958     SrcValueReg = OpSrcReg;
11959 
11960   BuildMI(TpLoopBody, Dl, TII->get(ARM::MVE_VSTRBU8_post))
11961       .addDef(CurrDestReg)
11962       .addUse(SrcValueReg)
11963       .addReg(DestPhiReg)
11964       .addImm(16)
11965       .addImm(ARMVCC::Then)
11966       .addUse(VccrReg)
11967       .addReg(0);
11968 
11969   // Add the pseudoInstrs for decrementing the loop counter and marking the
11970   // end:t2DoLoopDec and t2DoLoopEnd
11971   BuildMI(TpLoopBody, Dl, TII->get(ARM::t2LoopDec), RemainingLoopIterationsReg)
11972       .addUse(LoopCounterPhiReg)
11973       .addImm(1);
11974 
11975   BuildMI(TpLoopBody, Dl, TII->get(ARM::t2LoopEnd))
11976       .addUse(RemainingLoopIterationsReg)
11977       .addMBB(TpLoopBody);
11978 
11979   BuildMI(TpLoopBody, Dl, TII->get(ARM::t2B))
11980       .addMBB(TpExit)
11981       .add(predOps(ARMCC::AL));
11982 }
11983 
11984 MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr & MI,MachineBasicBlock * BB) const11985 ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
11986                                                MachineBasicBlock *BB) const {
11987   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
11988   DebugLoc dl = MI.getDebugLoc();
11989   bool isThumb2 = Subtarget->isThumb2();
11990   switch (MI.getOpcode()) {
11991   default: {
11992     MI.print(errs());
11993     llvm_unreachable("Unexpected instr type to insert");
11994   }
11995 
11996   // Thumb1 post-indexed loads are really just single-register LDMs.
11997   case ARM::tLDR_postidx: {
11998     MachineOperand Def(MI.getOperand(1));
11999     BuildMI(*BB, MI, dl, TII->get(ARM::tLDMIA_UPD))
12000         .add(Def)  // Rn_wb
12001         .add(MI.getOperand(2))  // Rn
12002         .add(MI.getOperand(3))  // PredImm
12003         .add(MI.getOperand(4))  // PredReg
12004         .add(MI.getOperand(0))  // Rt
12005         .cloneMemRefs(MI);
12006     MI.eraseFromParent();
12007     return BB;
12008   }
12009 
12010   case ARM::MVE_MEMCPYLOOPINST:
12011   case ARM::MVE_MEMSETLOOPINST: {
12012 
12013     // Transformation below expands MVE_MEMCPYLOOPINST/MVE_MEMSETLOOPINST Pseudo
12014     // into a Tail Predicated (TP) Loop. It adds the instructions to calculate
12015     // the iteration count =ceil(size_in_bytes/16)) in the TP entry block and
12016     // adds the relevant instructions in the TP loop Body for generation of a
12017     // WLSTP loop.
12018 
12019     // Below is relevant portion of the CFG after the transformation.
12020     // The Machine Basic Blocks are shown along with branch conditions (in
12021     // brackets). Note that TP entry/exit MBBs depict the entry/exit of this
12022     // portion of the CFG and may not necessarily be the entry/exit of the
12023     // function.
12024 
12025     //             (Relevant) CFG after transformation:
12026     //               TP entry MBB
12027     //                   |
12028     //          |-----------------|
12029     //       (n <= 0)          (n > 0)
12030     //          |                 |
12031     //          |         TP loop Body MBB<--|
12032     //          |                |           |
12033     //           \               |___________|
12034     //            \             /
12035     //              TP exit MBB
12036 
12037     MachineFunction *MF = BB->getParent();
12038     MachineFunctionProperties &Properties = MF->getProperties();
12039     MachineRegisterInfo &MRI = MF->getRegInfo();
12040 
12041     Register OpDestReg = MI.getOperand(0).getReg();
12042     Register OpSrcReg = MI.getOperand(1).getReg();
12043     Register OpSizeReg = MI.getOperand(2).getReg();
12044 
12045     // Allocate the required MBBs and add to parent function.
12046     MachineBasicBlock *TpEntry = BB;
12047     MachineBasicBlock *TpLoopBody = MF->CreateMachineBasicBlock();
12048     MachineBasicBlock *TpExit;
12049 
12050     MF->push_back(TpLoopBody);
12051 
12052     // If any instructions are present in the current block after
12053     // MVE_MEMCPYLOOPINST or MVE_MEMSETLOOPINST, split the current block and
12054     // move the instructions into the newly created exit block. If there are no
12055     // instructions add an explicit branch to the FallThrough block and then
12056     // split.
12057     //
12058     // The split is required for two reasons:
12059     // 1) A terminator(t2WhileLoopStart) will be placed at that site.
12060     // 2) Since a TPLoopBody will be added later, any phis in successive blocks
12061     //    need to be updated. splitAt() already handles this.
12062     TpExit = BB->splitAt(MI, false);
12063     if (TpExit == BB) {
12064       assert(BB->canFallThrough() && "Exit Block must be Fallthrough of the "
12065                                      "block containing memcpy/memset Pseudo");
12066       TpExit = BB->getFallThrough();
12067       BuildMI(BB, dl, TII->get(ARM::t2B))
12068           .addMBB(TpExit)
12069           .add(predOps(ARMCC::AL));
12070       TpExit = BB->splitAt(MI, false);
12071     }
12072 
12073     // Add logic for iteration count
12074     Register TotalIterationsReg =
12075         genTPEntry(TpEntry, TpLoopBody, TpExit, OpSizeReg, TII, dl, MRI);
12076 
12077     // Add the vectorized (and predicated) loads/store instructions
12078     bool IsMemcpy = MI.getOpcode() == ARM::MVE_MEMCPYLOOPINST;
12079     genTPLoopBody(TpLoopBody, TpEntry, TpExit, TII, dl, MRI, OpSrcReg,
12080                   OpDestReg, OpSizeReg, TotalIterationsReg, IsMemcpy);
12081 
12082     // Required to avoid conflict with the MachineVerifier during testing.
12083     Properties.reset(MachineFunctionProperties::Property::NoPHIs);
12084 
12085     // Connect the blocks
12086     TpEntry->addSuccessor(TpLoopBody);
12087     TpLoopBody->addSuccessor(TpLoopBody);
12088     TpLoopBody->addSuccessor(TpExit);
12089 
12090     // Reorder for a more natural layout
12091     TpLoopBody->moveAfter(TpEntry);
12092     TpExit->moveAfter(TpLoopBody);
12093 
12094     // Finally, remove the memcpy Pseudo Instruction
12095     MI.eraseFromParent();
12096 
12097     // Return the exit block as it may contain other instructions requiring a
12098     // custom inserter
12099     return TpExit;
12100   }
12101 
12102   // The Thumb2 pre-indexed stores have the same MI operands, they just
12103   // define them differently in the .td files from the isel patterns, so
12104   // they need pseudos.
12105   case ARM::t2STR_preidx:
12106     MI.setDesc(TII->get(ARM::t2STR_PRE));
12107     return BB;
12108   case ARM::t2STRB_preidx:
12109     MI.setDesc(TII->get(ARM::t2STRB_PRE));
12110     return BB;
12111   case ARM::t2STRH_preidx:
12112     MI.setDesc(TII->get(ARM::t2STRH_PRE));
12113     return BB;
12114 
12115   case ARM::STRi_preidx:
12116   case ARM::STRBi_preidx: {
12117     unsigned NewOpc = MI.getOpcode() == ARM::STRi_preidx ? ARM::STR_PRE_IMM
12118                                                          : ARM::STRB_PRE_IMM;
12119     // Decode the offset.
12120     unsigned Offset = MI.getOperand(4).getImm();
12121     bool isSub = ARM_AM::getAM2Op(Offset) == ARM_AM::sub;
12122     Offset = ARM_AM::getAM2Offset(Offset);
12123     if (isSub)
12124       Offset = -Offset;
12125 
12126     MachineMemOperand *MMO = *MI.memoperands_begin();
12127     BuildMI(*BB, MI, dl, TII->get(NewOpc))
12128         .add(MI.getOperand(0)) // Rn_wb
12129         .add(MI.getOperand(1)) // Rt
12130         .add(MI.getOperand(2)) // Rn
12131         .addImm(Offset)        // offset (skip GPR==zero_reg)
12132         .add(MI.getOperand(5)) // pred
12133         .add(MI.getOperand(6))
12134         .addMemOperand(MMO);
12135     MI.eraseFromParent();
12136     return BB;
12137   }
12138   case ARM::STRr_preidx:
12139   case ARM::STRBr_preidx:
12140   case ARM::STRH_preidx: {
12141     unsigned NewOpc;
12142     switch (MI.getOpcode()) {
12143     default: llvm_unreachable("unexpected opcode!");
12144     case ARM::STRr_preidx: NewOpc = ARM::STR_PRE_REG; break;
12145     case ARM::STRBr_preidx: NewOpc = ARM::STRB_PRE_REG; break;
12146     case ARM::STRH_preidx: NewOpc = ARM::STRH_PRE; break;
12147     }
12148     MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(NewOpc));
12149     for (const MachineOperand &MO : MI.operands())
12150       MIB.add(MO);
12151     MI.eraseFromParent();
12152     return BB;
12153   }
12154 
12155   case ARM::tMOVCCr_pseudo: {
12156     // To "insert" a SELECT_CC instruction, we actually have to insert the
12157     // diamond control-flow pattern.  The incoming instruction knows the
12158     // destination vreg to set, the condition code register to branch on, the
12159     // true/false values to select between, and a branch opcode to use.
12160     const BasicBlock *LLVM_BB = BB->getBasicBlock();
12161     MachineFunction::iterator It = ++BB->getIterator();
12162 
12163     //  thisMBB:
12164     //  ...
12165     //   TrueVal = ...
12166     //   cmpTY ccX, r1, r2
12167     //   bCC copy1MBB
12168     //   fallthrough --> copy0MBB
12169     MachineBasicBlock *thisMBB  = BB;
12170     MachineFunction *F = BB->getParent();
12171     MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
12172     MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
12173     F->insert(It, copy0MBB);
12174     F->insert(It, sinkMBB);
12175 
12176     // Set the call frame size on entry to the new basic blocks.
12177     unsigned CallFrameSize = TII->getCallFrameSizeAt(MI);
12178     copy0MBB->setCallFrameSize(CallFrameSize);
12179     sinkMBB->setCallFrameSize(CallFrameSize);
12180 
12181     // Check whether CPSR is live past the tMOVCCr_pseudo.
12182     const TargetRegisterInfo *TRI = Subtarget->getRegisterInfo();
12183     if (!MI.killsRegister(ARM::CPSR, /*TRI=*/nullptr) &&
12184         !checkAndUpdateCPSRKill(MI, thisMBB, TRI)) {
12185       copy0MBB->addLiveIn(ARM::CPSR);
12186       sinkMBB->addLiveIn(ARM::CPSR);
12187     }
12188 
12189     // Transfer the remainder of BB and its successor edges to sinkMBB.
12190     sinkMBB->splice(sinkMBB->begin(), BB,
12191                     std::next(MachineBasicBlock::iterator(MI)), BB->end());
12192     sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
12193 
12194     BB->addSuccessor(copy0MBB);
12195     BB->addSuccessor(sinkMBB);
12196 
12197     BuildMI(BB, dl, TII->get(ARM::tBcc))
12198         .addMBB(sinkMBB)
12199         .addImm(MI.getOperand(3).getImm())
12200         .addReg(MI.getOperand(4).getReg());
12201 
12202     //  copy0MBB:
12203     //   %FalseValue = ...
12204     //   # fallthrough to sinkMBB
12205     BB = copy0MBB;
12206 
12207     // Update machine-CFG edges
12208     BB->addSuccessor(sinkMBB);
12209 
12210     //  sinkMBB:
12211     //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
12212     //  ...
12213     BB = sinkMBB;
12214     BuildMI(*BB, BB->begin(), dl, TII->get(ARM::PHI), MI.getOperand(0).getReg())
12215         .addReg(MI.getOperand(1).getReg())
12216         .addMBB(copy0MBB)
12217         .addReg(MI.getOperand(2).getReg())
12218         .addMBB(thisMBB);
12219 
12220     MI.eraseFromParent(); // The pseudo instruction is gone now.
12221     return BB;
12222   }
12223 
12224   case ARM::BCCi64:
12225   case ARM::BCCZi64: {
12226     // If there is an unconditional branch to the other successor, remove it.
12227     BB->erase(std::next(MachineBasicBlock::iterator(MI)), BB->end());
12228 
12229     // Compare both parts that make up the double comparison separately for
12230     // equality.
12231     bool RHSisZero = MI.getOpcode() == ARM::BCCZi64;
12232 
12233     Register LHS1 = MI.getOperand(1).getReg();
12234     Register LHS2 = MI.getOperand(2).getReg();
12235     if (RHSisZero) {
12236       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
12237           .addReg(LHS1)
12238           .addImm(0)
12239           .add(predOps(ARMCC::AL));
12240       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
12241         .addReg(LHS2).addImm(0)
12242         .addImm(ARMCC::EQ).addReg(ARM::CPSR);
12243     } else {
12244       Register RHS1 = MI.getOperand(3).getReg();
12245       Register RHS2 = MI.getOperand(4).getReg();
12246       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
12247           .addReg(LHS1)
12248           .addReg(RHS1)
12249           .add(predOps(ARMCC::AL));
12250       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
12251         .addReg(LHS2).addReg(RHS2)
12252         .addImm(ARMCC::EQ).addReg(ARM::CPSR);
12253     }
12254 
12255     MachineBasicBlock *destMBB = MI.getOperand(RHSisZero ? 3 : 5).getMBB();
12256     MachineBasicBlock *exitMBB = OtherSucc(BB, destMBB);
12257     if (MI.getOperand(0).getImm() == ARMCC::NE)
12258       std::swap(destMBB, exitMBB);
12259 
12260     BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
12261       .addMBB(destMBB).addImm(ARMCC::EQ).addReg(ARM::CPSR);
12262     if (isThumb2)
12263       BuildMI(BB, dl, TII->get(ARM::t2B))
12264           .addMBB(exitMBB)
12265           .add(predOps(ARMCC::AL));
12266     else
12267       BuildMI(BB, dl, TII->get(ARM::B)) .addMBB(exitMBB);
12268 
12269     MI.eraseFromParent(); // The pseudo instruction is gone now.
12270     return BB;
12271   }
12272 
12273   case ARM::Int_eh_sjlj_setjmp:
12274   case ARM::Int_eh_sjlj_setjmp_nofp:
12275   case ARM::tInt_eh_sjlj_setjmp:
12276   case ARM::t2Int_eh_sjlj_setjmp:
12277   case ARM::t2Int_eh_sjlj_setjmp_nofp:
12278     return BB;
12279 
12280   case ARM::Int_eh_sjlj_setup_dispatch:
12281     EmitSjLjDispatchBlock(MI, BB);
12282     return BB;
12283 
12284   case ARM::ABS:
12285   case ARM::t2ABS: {
12286     // To insert an ABS instruction, we have to insert the
12287     // diamond control-flow pattern.  The incoming instruction knows the
12288     // source vreg to test against 0, the destination vreg to set,
12289     // the condition code register to branch on, the
12290     // true/false values to select between, and a branch opcode to use.
12291     // It transforms
12292     //     V1 = ABS V0
12293     // into
12294     //     V2 = MOVS V0
12295     //     BCC                      (branch to SinkBB if V0 >= 0)
12296     //     RSBBB: V3 = RSBri V2, 0  (compute ABS if V2 < 0)
12297     //     SinkBB: V1 = PHI(V2, V3)
12298     const BasicBlock *LLVM_BB = BB->getBasicBlock();
12299     MachineFunction::iterator BBI = ++BB->getIterator();
12300     MachineFunction *Fn = BB->getParent();
12301     MachineBasicBlock *RSBBB = Fn->CreateMachineBasicBlock(LLVM_BB);
12302     MachineBasicBlock *SinkBB  = Fn->CreateMachineBasicBlock(LLVM_BB);
12303     Fn->insert(BBI, RSBBB);
12304     Fn->insert(BBI, SinkBB);
12305 
12306     Register ABSSrcReg = MI.getOperand(1).getReg();
12307     Register ABSDstReg = MI.getOperand(0).getReg();
12308     bool ABSSrcKIll = MI.getOperand(1).isKill();
12309     bool isThumb2 = Subtarget->isThumb2();
12310     MachineRegisterInfo &MRI = Fn->getRegInfo();
12311     // In Thumb mode S must not be specified if source register is the SP or
12312     // PC and if destination register is the SP, so restrict register class
12313     Register NewRsbDstReg = MRI.createVirtualRegister(
12314         isThumb2 ? &ARM::rGPRRegClass : &ARM::GPRRegClass);
12315 
12316     // Transfer the remainder of BB and its successor edges to sinkMBB.
12317     SinkBB->splice(SinkBB->begin(), BB,
12318                    std::next(MachineBasicBlock::iterator(MI)), BB->end());
12319     SinkBB->transferSuccessorsAndUpdatePHIs(BB);
12320 
12321     BB->addSuccessor(RSBBB);
12322     BB->addSuccessor(SinkBB);
12323 
12324     // fall through to SinkMBB
12325     RSBBB->addSuccessor(SinkBB);
12326 
12327     // insert a cmp at the end of BB
12328     BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
12329         .addReg(ABSSrcReg)
12330         .addImm(0)
12331         .add(predOps(ARMCC::AL));
12332 
12333     // insert a bcc with opposite CC to ARMCC::MI at the end of BB
12334     BuildMI(BB, dl,
12335       TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc)).addMBB(SinkBB)
12336       .addImm(ARMCC::getOppositeCondition(ARMCC::MI)).addReg(ARM::CPSR);
12337 
12338     // insert rsbri in RSBBB
12339     // Note: BCC and rsbri will be converted into predicated rsbmi
12340     // by if-conversion pass
12341     BuildMI(*RSBBB, RSBBB->begin(), dl,
12342             TII->get(isThumb2 ? ARM::t2RSBri : ARM::RSBri), NewRsbDstReg)
12343         .addReg(ABSSrcReg, ABSSrcKIll ? RegState::Kill : 0)
12344         .addImm(0)
12345         .add(predOps(ARMCC::AL))
12346         .add(condCodeOp());
12347 
12348     // insert PHI in SinkBB,
12349     // reuse ABSDstReg to not change uses of ABS instruction
12350     BuildMI(*SinkBB, SinkBB->begin(), dl,
12351       TII->get(ARM::PHI), ABSDstReg)
12352       .addReg(NewRsbDstReg).addMBB(RSBBB)
12353       .addReg(ABSSrcReg).addMBB(BB);
12354 
12355     // remove ABS instruction
12356     MI.eraseFromParent();
12357 
12358     // return last added BB
12359     return SinkBB;
12360   }
12361   case ARM::COPY_STRUCT_BYVAL_I32:
12362     ++NumLoopByVals;
12363     return EmitStructByval(MI, BB);
12364   case ARM::WIN__CHKSTK:
12365     return EmitLowered__chkstk(MI, BB);
12366   case ARM::WIN__DBZCHK:
12367     return EmitLowered__dbzchk(MI, BB);
12368   }
12369 }
12370 
12371 /// Attaches vregs to MEMCPY that it will use as scratch registers
12372 /// when it is expanded into LDM/STM. This is done as a post-isel lowering
12373 /// instead of as a custom inserter because we need the use list from the SDNode.
attachMEMCPYScratchRegs(const ARMSubtarget * Subtarget,MachineInstr & MI,const SDNode * Node)12374 static void attachMEMCPYScratchRegs(const ARMSubtarget *Subtarget,
12375                                     MachineInstr &MI, const SDNode *Node) {
12376   bool isThumb1 = Subtarget->isThumb1Only();
12377 
12378   DebugLoc DL = MI.getDebugLoc();
12379   MachineFunction *MF = MI.getParent()->getParent();
12380   MachineRegisterInfo &MRI = MF->getRegInfo();
12381   MachineInstrBuilder MIB(*MF, MI);
12382 
12383   // If the new dst/src is unused mark it as dead.
12384   if (!Node->hasAnyUseOfValue(0)) {
12385     MI.getOperand(0).setIsDead(true);
12386   }
12387   if (!Node->hasAnyUseOfValue(1)) {
12388     MI.getOperand(1).setIsDead(true);
12389   }
12390 
12391   // The MEMCPY both defines and kills the scratch registers.
12392   for (unsigned I = 0; I != MI.getOperand(4).getImm(); ++I) {
12393     Register TmpReg = MRI.createVirtualRegister(isThumb1 ? &ARM::tGPRRegClass
12394                                                          : &ARM::GPRRegClass);
12395     MIB.addReg(TmpReg, RegState::Define|RegState::Dead);
12396   }
12397 }
12398 
AdjustInstrPostInstrSelection(MachineInstr & MI,SDNode * Node) const12399 void ARMTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
12400                                                       SDNode *Node) const {
12401   if (MI.getOpcode() == ARM::MEMCPY) {
12402     attachMEMCPYScratchRegs(Subtarget, MI, Node);
12403     return;
12404   }
12405 
12406   const MCInstrDesc *MCID = &MI.getDesc();
12407   // Adjust potentially 's' setting instructions after isel, i.e. ADC, SBC, RSB,
12408   // RSC. Coming out of isel, they have an implicit CPSR def, but the optional
12409   // operand is still set to noreg. If needed, set the optional operand's
12410   // register to CPSR, and remove the redundant implicit def.
12411   //
12412   // e.g. ADCS (..., implicit-def CPSR) -> ADC (... opt:def CPSR).
12413 
12414   // Rename pseudo opcodes.
12415   unsigned NewOpc = convertAddSubFlagsOpcode(MI.getOpcode());
12416   unsigned ccOutIdx;
12417   if (NewOpc) {
12418     const ARMBaseInstrInfo *TII = Subtarget->getInstrInfo();
12419     MCID = &TII->get(NewOpc);
12420 
12421     assert(MCID->getNumOperands() ==
12422            MI.getDesc().getNumOperands() + 5 - MI.getDesc().getSize()
12423         && "converted opcode should be the same except for cc_out"
12424            " (and, on Thumb1, pred)");
12425 
12426     MI.setDesc(*MCID);
12427 
12428     // Add the optional cc_out operand
12429     MI.addOperand(MachineOperand::CreateReg(0, /*isDef=*/true));
12430 
12431     // On Thumb1, move all input operands to the end, then add the predicate
12432     if (Subtarget->isThumb1Only()) {
12433       for (unsigned c = MCID->getNumOperands() - 4; c--;) {
12434         MI.addOperand(MI.getOperand(1));
12435         MI.removeOperand(1);
12436       }
12437 
12438       // Restore the ties
12439       for (unsigned i = MI.getNumOperands(); i--;) {
12440         const MachineOperand& op = MI.getOperand(i);
12441         if (op.isReg() && op.isUse()) {
12442           int DefIdx = MCID->getOperandConstraint(i, MCOI::TIED_TO);
12443           if (DefIdx != -1)
12444             MI.tieOperands(DefIdx, i);
12445         }
12446       }
12447 
12448       MI.addOperand(MachineOperand::CreateImm(ARMCC::AL));
12449       MI.addOperand(MachineOperand::CreateReg(0, /*isDef=*/false));
12450       ccOutIdx = 1;
12451     } else
12452       ccOutIdx = MCID->getNumOperands() - 1;
12453   } else
12454     ccOutIdx = MCID->getNumOperands() - 1;
12455 
12456   // Any ARM instruction that sets the 's' bit should specify an optional
12457   // "cc_out" operand in the last operand position.
12458   if (!MI.hasOptionalDef() || !MCID->operands()[ccOutIdx].isOptionalDef()) {
12459     assert(!NewOpc && "Optional cc_out operand required");
12460     return;
12461   }
12462   // Look for an implicit def of CPSR added by MachineInstr ctor. Remove it
12463   // since we already have an optional CPSR def.
12464   bool definesCPSR = false;
12465   bool deadCPSR = false;
12466   for (unsigned i = MCID->getNumOperands(), e = MI.getNumOperands(); i != e;
12467        ++i) {
12468     const MachineOperand &MO = MI.getOperand(i);
12469     if (MO.isReg() && MO.isDef() && MO.getReg() == ARM::CPSR) {
12470       definesCPSR = true;
12471       if (MO.isDead())
12472         deadCPSR = true;
12473       MI.removeOperand(i);
12474       break;
12475     }
12476   }
12477   if (!definesCPSR) {
12478     assert(!NewOpc && "Optional cc_out operand required");
12479     return;
12480   }
12481   assert(deadCPSR == !Node->hasAnyUseOfValue(1) && "inconsistent dead flag");
12482   if (deadCPSR) {
12483     assert(!MI.getOperand(ccOutIdx).getReg() &&
12484            "expect uninitialized optional cc_out operand");
12485     // Thumb1 instructions must have the S bit even if the CPSR is dead.
12486     if (!Subtarget->isThumb1Only())
12487       return;
12488   }
12489 
12490   // If this instruction was defined with an optional CPSR def and its dag node
12491   // had a live implicit CPSR def, then activate the optional CPSR def.
12492   MachineOperand &MO = MI.getOperand(ccOutIdx);
12493   MO.setReg(ARM::CPSR);
12494   MO.setIsDef(true);
12495 }
12496 
12497 //===----------------------------------------------------------------------===//
12498 //                           ARM Optimization Hooks
12499 //===----------------------------------------------------------------------===//
12500 
12501 // Helper function that checks if N is a null or all ones constant.
isZeroOrAllOnes(SDValue N,bool AllOnes)12502 static inline bool isZeroOrAllOnes(SDValue N, bool AllOnes) {
12503   return AllOnes ? isAllOnesConstant(N) : isNullConstant(N);
12504 }
12505 
12506 // Return true if N is conditionally 0 or all ones.
12507 // Detects these expressions where cc is an i1 value:
12508 //
12509 //   (select cc 0, y)   [AllOnes=0]
12510 //   (select cc y, 0)   [AllOnes=0]
12511 //   (zext cc)          [AllOnes=0]
12512 //   (sext cc)          [AllOnes=0/1]
12513 //   (select cc -1, y)  [AllOnes=1]
12514 //   (select cc y, -1)  [AllOnes=1]
12515 //
12516 // Invert is set when N is the null/all ones constant when CC is false.
12517 // OtherOp is set to the alternative value of N.
isConditionalZeroOrAllOnes(SDNode * N,bool AllOnes,SDValue & CC,bool & Invert,SDValue & OtherOp,SelectionDAG & DAG)12518 static bool isConditionalZeroOrAllOnes(SDNode *N, bool AllOnes,
12519                                        SDValue &CC, bool &Invert,
12520                                        SDValue &OtherOp,
12521                                        SelectionDAG &DAG) {
12522   switch (N->getOpcode()) {
12523   default: return false;
12524   case ISD::SELECT: {
12525     CC = N->getOperand(0);
12526     SDValue N1 = N->getOperand(1);
12527     SDValue N2 = N->getOperand(2);
12528     if (isZeroOrAllOnes(N1, AllOnes)) {
12529       Invert = false;
12530       OtherOp = N2;
12531       return true;
12532     }
12533     if (isZeroOrAllOnes(N2, AllOnes)) {
12534       Invert = true;
12535       OtherOp = N1;
12536       return true;
12537     }
12538     return false;
12539   }
12540   case ISD::ZERO_EXTEND:
12541     // (zext cc) can never be the all ones value.
12542     if (AllOnes)
12543       return false;
12544     [[fallthrough]];
12545   case ISD::SIGN_EXTEND: {
12546     SDLoc dl(N);
12547     EVT VT = N->getValueType(0);
12548     CC = N->getOperand(0);
12549     if (CC.getValueType() != MVT::i1 || CC.getOpcode() != ISD::SETCC)
12550       return false;
12551     Invert = !AllOnes;
12552     if (AllOnes)
12553       // When looking for an AllOnes constant, N is an sext, and the 'other'
12554       // value is 0.
12555       OtherOp = DAG.getConstant(0, dl, VT);
12556     else if (N->getOpcode() == ISD::ZERO_EXTEND)
12557       // When looking for a 0 constant, N can be zext or sext.
12558       OtherOp = DAG.getConstant(1, dl, VT);
12559     else
12560       OtherOp = DAG.getAllOnesConstant(dl, VT);
12561     return true;
12562   }
12563   }
12564 }
12565 
12566 // Combine a constant select operand into its use:
12567 //
12568 //   (add (select cc, 0, c), x)  -> (select cc, x, (add, x, c))
12569 //   (sub x, (select cc, 0, c))  -> (select cc, x, (sub, x, c))
12570 //   (and (select cc, -1, c), x) -> (select cc, x, (and, x, c))  [AllOnes=1]
12571 //   (or  (select cc, 0, c), x)  -> (select cc, x, (or, x, c))
12572 //   (xor (select cc, 0, c), x)  -> (select cc, x, (xor, x, c))
12573 //
12574 // The transform is rejected if the select doesn't have a constant operand that
12575 // is null, or all ones when AllOnes is set.
12576 //
12577 // Also recognize sext/zext from i1:
12578 //
12579 //   (add (zext cc), x) -> (select cc (add x, 1), x)
12580 //   (add (sext cc), x) -> (select cc (add x, -1), x)
12581 //
12582 // These transformations eventually create predicated instructions.
12583 //
12584 // @param N       The node to transform.
12585 // @param Slct    The N operand that is a select.
12586 // @param OtherOp The other N operand (x above).
12587 // @param DCI     Context.
12588 // @param AllOnes Require the select constant to be all ones instead of null.
12589 // @returns The new node, or SDValue() on failure.
12590 static
combineSelectAndUse(SDNode * N,SDValue Slct,SDValue OtherOp,TargetLowering::DAGCombinerInfo & DCI,bool AllOnes=false)12591 SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
12592                             TargetLowering::DAGCombinerInfo &DCI,
12593                             bool AllOnes = false) {
12594   SelectionDAG &DAG = DCI.DAG;
12595   EVT VT = N->getValueType(0);
12596   SDValue NonConstantVal;
12597   SDValue CCOp;
12598   bool SwapSelectOps;
12599   if (!isConditionalZeroOrAllOnes(Slct.getNode(), AllOnes, CCOp, SwapSelectOps,
12600                                   NonConstantVal, DAG))
12601     return SDValue();
12602 
12603   // Slct is now know to be the desired identity constant when CC is true.
12604   SDValue TrueVal = OtherOp;
12605   SDValue FalseVal = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
12606                                  OtherOp, NonConstantVal);
12607   // Unless SwapSelectOps says CC should be false.
12608   if (SwapSelectOps)
12609     std::swap(TrueVal, FalseVal);
12610 
12611   return DAG.getNode(ISD::SELECT, SDLoc(N), VT,
12612                      CCOp, TrueVal, FalseVal);
12613 }
12614 
12615 // Attempt combineSelectAndUse on each operand of a commutative operator N.
12616 static
combineSelectAndUseCommutative(SDNode * N,bool AllOnes,TargetLowering::DAGCombinerInfo & DCI)12617 SDValue combineSelectAndUseCommutative(SDNode *N, bool AllOnes,
12618                                        TargetLowering::DAGCombinerInfo &DCI) {
12619   SDValue N0 = N->getOperand(0);
12620   SDValue N1 = N->getOperand(1);
12621   if (N0.getNode()->hasOneUse())
12622     if (SDValue Result = combineSelectAndUse(N, N0, N1, DCI, AllOnes))
12623       return Result;
12624   if (N1.getNode()->hasOneUse())
12625     if (SDValue Result = combineSelectAndUse(N, N1, N0, DCI, AllOnes))
12626       return Result;
12627   return SDValue();
12628 }
12629 
IsVUZPShuffleNode(SDNode * N)12630 static bool IsVUZPShuffleNode(SDNode *N) {
12631   // VUZP shuffle node.
12632   if (N->getOpcode() == ARMISD::VUZP)
12633     return true;
12634 
12635   // "VUZP" on i32 is an alias for VTRN.
12636   if (N->getOpcode() == ARMISD::VTRN && N->getValueType(0) == MVT::v2i32)
12637     return true;
12638 
12639   return false;
12640 }
12641 
AddCombineToVPADD(SDNode * N,SDValue N0,SDValue N1,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)12642 static SDValue AddCombineToVPADD(SDNode *N, SDValue N0, SDValue N1,
12643                                  TargetLowering::DAGCombinerInfo &DCI,
12644                                  const ARMSubtarget *Subtarget) {
12645   // Look for ADD(VUZP.0, VUZP.1).
12646   if (!IsVUZPShuffleNode(N0.getNode()) || N0.getNode() != N1.getNode() ||
12647       N0 == N1)
12648    return SDValue();
12649 
12650   // Make sure the ADD is a 64-bit add; there is no 128-bit VPADD.
12651   if (!N->getValueType(0).is64BitVector())
12652     return SDValue();
12653 
12654   // Generate vpadd.
12655   SelectionDAG &DAG = DCI.DAG;
12656   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
12657   SDLoc dl(N);
12658   SDNode *Unzip = N0.getNode();
12659   EVT VT = N->getValueType(0);
12660 
12661   SmallVector<SDValue, 8> Ops;
12662   Ops.push_back(DAG.getConstant(Intrinsic::arm_neon_vpadd, dl,
12663                                 TLI.getPointerTy(DAG.getDataLayout())));
12664   Ops.push_back(Unzip->getOperand(0));
12665   Ops.push_back(Unzip->getOperand(1));
12666 
12667   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT, Ops);
12668 }
12669 
AddCombineVUZPToVPADDL(SDNode * N,SDValue N0,SDValue N1,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)12670 static SDValue AddCombineVUZPToVPADDL(SDNode *N, SDValue N0, SDValue N1,
12671                                       TargetLowering::DAGCombinerInfo &DCI,
12672                                       const ARMSubtarget *Subtarget) {
12673   // Check for two extended operands.
12674   if (!(N0.getOpcode() == ISD::SIGN_EXTEND &&
12675         N1.getOpcode() == ISD::SIGN_EXTEND) &&
12676       !(N0.getOpcode() == ISD::ZERO_EXTEND &&
12677         N1.getOpcode() == ISD::ZERO_EXTEND))
12678     return SDValue();
12679 
12680   SDValue N00 = N0.getOperand(0);
12681   SDValue N10 = N1.getOperand(0);
12682 
12683   // Look for ADD(SEXT(VUZP.0), SEXT(VUZP.1))
12684   if (!IsVUZPShuffleNode(N00.getNode()) || N00.getNode() != N10.getNode() ||
12685       N00 == N10)
12686     return SDValue();
12687 
12688   // We only recognize Q register paddl here; this can't be reached until
12689   // after type legalization.
12690   if (!N00.getValueType().is64BitVector() ||
12691       !N0.getValueType().is128BitVector())
12692     return SDValue();
12693 
12694   // Generate vpaddl.
12695   SelectionDAG &DAG = DCI.DAG;
12696   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
12697   SDLoc dl(N);
12698   EVT VT = N->getValueType(0);
12699 
12700   SmallVector<SDValue, 8> Ops;
12701   // Form vpaddl.sN or vpaddl.uN depending on the kind of extension.
12702   unsigned Opcode;
12703   if (N0.getOpcode() == ISD::SIGN_EXTEND)
12704     Opcode = Intrinsic::arm_neon_vpaddls;
12705   else
12706     Opcode = Intrinsic::arm_neon_vpaddlu;
12707   Ops.push_back(DAG.getConstant(Opcode, dl,
12708                                 TLI.getPointerTy(DAG.getDataLayout())));
12709   EVT ElemTy = N00.getValueType().getVectorElementType();
12710   unsigned NumElts = VT.getVectorNumElements();
12711   EVT ConcatVT = EVT::getVectorVT(*DAG.getContext(), ElemTy, NumElts * 2);
12712   SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), ConcatVT,
12713                                N00.getOperand(0), N00.getOperand(1));
12714   Ops.push_back(Concat);
12715 
12716   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT, Ops);
12717 }
12718 
12719 // FIXME: This function shouldn't be necessary; if we lower BUILD_VECTOR in
12720 // an appropriate manner, we end up with ADD(VUZP(ZEXT(N))), which is
12721 // much easier to match.
12722 static SDValue
AddCombineBUILD_VECTORToVPADDL(SDNode * N,SDValue N0,SDValue N1,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)12723 AddCombineBUILD_VECTORToVPADDL(SDNode *N, SDValue N0, SDValue N1,
12724                                TargetLowering::DAGCombinerInfo &DCI,
12725                                const ARMSubtarget *Subtarget) {
12726   // Only perform optimization if after legalize, and if NEON is available. We
12727   // also expected both operands to be BUILD_VECTORs.
12728   if (DCI.isBeforeLegalize() || !Subtarget->hasNEON()
12729       || N0.getOpcode() != ISD::BUILD_VECTOR
12730       || N1.getOpcode() != ISD::BUILD_VECTOR)
12731     return SDValue();
12732 
12733   // Check output type since VPADDL operand elements can only be 8, 16, or 32.
12734   EVT VT = N->getValueType(0);
12735   if (!VT.isInteger() || VT.getVectorElementType() == MVT::i64)
12736     return SDValue();
12737 
12738   // Check that the vector operands are of the right form.
12739   // N0 and N1 are BUILD_VECTOR nodes with N number of EXTRACT_VECTOR
12740   // operands, where N is the size of the formed vector.
12741   // Each EXTRACT_VECTOR should have the same input vector and odd or even
12742   // index such that we have a pair wise add pattern.
12743 
12744   // Grab the vector that all EXTRACT_VECTOR nodes should be referencing.
12745   if (N0->getOperand(0)->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
12746     return SDValue();
12747   SDValue Vec = N0->getOperand(0)->getOperand(0);
12748   SDNode *V = Vec.getNode();
12749   unsigned nextIndex = 0;
12750 
12751   // For each operands to the ADD which are BUILD_VECTORs,
12752   // check to see if each of their operands are an EXTRACT_VECTOR with
12753   // the same vector and appropriate index.
12754   for (unsigned i = 0, e = N0->getNumOperands(); i != e; ++i) {
12755     if (N0->getOperand(i)->getOpcode() == ISD::EXTRACT_VECTOR_ELT
12756         && N1->getOperand(i)->getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
12757 
12758       SDValue ExtVec0 = N0->getOperand(i);
12759       SDValue ExtVec1 = N1->getOperand(i);
12760 
12761       // First operand is the vector, verify its the same.
12762       if (V != ExtVec0->getOperand(0).getNode() ||
12763           V != ExtVec1->getOperand(0).getNode())
12764         return SDValue();
12765 
12766       // Second is the constant, verify its correct.
12767       ConstantSDNode *C0 = dyn_cast<ConstantSDNode>(ExtVec0->getOperand(1));
12768       ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(ExtVec1->getOperand(1));
12769 
12770       // For the constant, we want to see all the even or all the odd.
12771       if (!C0 || !C1 || C0->getZExtValue() != nextIndex
12772           || C1->getZExtValue() != nextIndex+1)
12773         return SDValue();
12774 
12775       // Increment index.
12776       nextIndex+=2;
12777     } else
12778       return SDValue();
12779   }
12780 
12781   // Don't generate vpaddl+vmovn; we'll match it to vpadd later. Also make sure
12782   // we're using the entire input vector, otherwise there's a size/legality
12783   // mismatch somewhere.
12784   if (nextIndex != Vec.getValueType().getVectorNumElements() ||
12785       Vec.getValueType().getVectorElementType() == VT.getVectorElementType())
12786     return SDValue();
12787 
12788   // Create VPADDL node.
12789   SelectionDAG &DAG = DCI.DAG;
12790   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
12791 
12792   SDLoc dl(N);
12793 
12794   // Build operand list.
12795   SmallVector<SDValue, 8> Ops;
12796   Ops.push_back(DAG.getConstant(Intrinsic::arm_neon_vpaddls, dl,
12797                                 TLI.getPointerTy(DAG.getDataLayout())));
12798 
12799   // Input is the vector.
12800   Ops.push_back(Vec);
12801 
12802   // Get widened type and narrowed type.
12803   MVT widenType;
12804   unsigned numElem = VT.getVectorNumElements();
12805 
12806   EVT inputLaneType = Vec.getValueType().getVectorElementType();
12807   switch (inputLaneType.getSimpleVT().SimpleTy) {
12808     case MVT::i8: widenType = MVT::getVectorVT(MVT::i16, numElem); break;
12809     case MVT::i16: widenType = MVT::getVectorVT(MVT::i32, numElem); break;
12810     case MVT::i32: widenType = MVT::getVectorVT(MVT::i64, numElem); break;
12811     default:
12812       llvm_unreachable("Invalid vector element type for padd optimization.");
12813   }
12814 
12815   SDValue tmp = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, widenType, Ops);
12816   unsigned ExtOp = VT.bitsGT(tmp.getValueType()) ? ISD::ANY_EXTEND : ISD::TRUNCATE;
12817   return DAG.getNode(ExtOp, dl, VT, tmp);
12818 }
12819 
findMUL_LOHI(SDValue V)12820 static SDValue findMUL_LOHI(SDValue V) {
12821   if (V->getOpcode() == ISD::UMUL_LOHI ||
12822       V->getOpcode() == ISD::SMUL_LOHI)
12823     return V;
12824   return SDValue();
12825 }
12826 
AddCombineTo64BitSMLAL16(SDNode * AddcNode,SDNode * AddeNode,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)12827 static SDValue AddCombineTo64BitSMLAL16(SDNode *AddcNode, SDNode *AddeNode,
12828                                         TargetLowering::DAGCombinerInfo &DCI,
12829                                         const ARMSubtarget *Subtarget) {
12830   if (!Subtarget->hasBaseDSP())
12831     return SDValue();
12832 
12833   // SMLALBB, SMLALBT, SMLALTB, SMLALTT multiply two 16-bit values and
12834   // accumulates the product into a 64-bit value. The 16-bit values will
12835   // be sign extended somehow or SRA'd into 32-bit values
12836   // (addc (adde (mul 16bit, 16bit), lo), hi)
12837   SDValue Mul = AddcNode->getOperand(0);
12838   SDValue Lo = AddcNode->getOperand(1);
12839   if (Mul.getOpcode() != ISD::MUL) {
12840     Lo = AddcNode->getOperand(0);
12841     Mul = AddcNode->getOperand(1);
12842     if (Mul.getOpcode() != ISD::MUL)
12843       return SDValue();
12844   }
12845 
12846   SDValue SRA = AddeNode->getOperand(0);
12847   SDValue Hi = AddeNode->getOperand(1);
12848   if (SRA.getOpcode() != ISD::SRA) {
12849     SRA = AddeNode->getOperand(1);
12850     Hi = AddeNode->getOperand(0);
12851     if (SRA.getOpcode() != ISD::SRA)
12852       return SDValue();
12853   }
12854   if (auto Const = dyn_cast<ConstantSDNode>(SRA.getOperand(1))) {
12855     if (Const->getZExtValue() != 31)
12856       return SDValue();
12857   } else
12858     return SDValue();
12859 
12860   if (SRA.getOperand(0) != Mul)
12861     return SDValue();
12862 
12863   SelectionDAG &DAG = DCI.DAG;
12864   SDLoc dl(AddcNode);
12865   unsigned Opcode = 0;
12866   SDValue Op0;
12867   SDValue Op1;
12868 
12869   if (isS16(Mul.getOperand(0), DAG) && isS16(Mul.getOperand(1), DAG)) {
12870     Opcode = ARMISD::SMLALBB;
12871     Op0 = Mul.getOperand(0);
12872     Op1 = Mul.getOperand(1);
12873   } else if (isS16(Mul.getOperand(0), DAG) && isSRA16(Mul.getOperand(1))) {
12874     Opcode = ARMISD::SMLALBT;
12875     Op0 = Mul.getOperand(0);
12876     Op1 = Mul.getOperand(1).getOperand(0);
12877   } else if (isSRA16(Mul.getOperand(0)) && isS16(Mul.getOperand(1), DAG)) {
12878     Opcode = ARMISD::SMLALTB;
12879     Op0 = Mul.getOperand(0).getOperand(0);
12880     Op1 = Mul.getOperand(1);
12881   } else if (isSRA16(Mul.getOperand(0)) && isSRA16(Mul.getOperand(1))) {
12882     Opcode = ARMISD::SMLALTT;
12883     Op0 = Mul->getOperand(0).getOperand(0);
12884     Op1 = Mul->getOperand(1).getOperand(0);
12885   }
12886 
12887   if (!Op0 || !Op1)
12888     return SDValue();
12889 
12890   SDValue SMLAL = DAG.getNode(Opcode, dl, DAG.getVTList(MVT::i32, MVT::i32),
12891                               Op0, Op1, Lo, Hi);
12892   // Replace the ADDs' nodes uses by the MLA node's values.
12893   SDValue HiMLALResult(SMLAL.getNode(), 1);
12894   SDValue LoMLALResult(SMLAL.getNode(), 0);
12895 
12896   DAG.ReplaceAllUsesOfValueWith(SDValue(AddcNode, 0), LoMLALResult);
12897   DAG.ReplaceAllUsesOfValueWith(SDValue(AddeNode, 0), HiMLALResult);
12898 
12899   // Return original node to notify the driver to stop replacing.
12900   SDValue resNode(AddcNode, 0);
12901   return resNode;
12902 }
12903 
AddCombineTo64bitMLAL(SDNode * AddeSubeNode,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)12904 static SDValue AddCombineTo64bitMLAL(SDNode *AddeSubeNode,
12905                                      TargetLowering::DAGCombinerInfo &DCI,
12906                                      const ARMSubtarget *Subtarget) {
12907   // Look for multiply add opportunities.
12908   // The pattern is a ISD::UMUL_LOHI followed by two add nodes, where
12909   // each add nodes consumes a value from ISD::UMUL_LOHI and there is
12910   // a glue link from the first add to the second add.
12911   // If we find this pattern, we can replace the U/SMUL_LOHI, ADDC, and ADDE by
12912   // a S/UMLAL instruction.
12913   //                  UMUL_LOHI
12914   //                 / :lo    \ :hi
12915   //                V          \          [no multiline comment]
12916   //    loAdd ->  ADDC         |
12917   //                 \ :carry /
12918   //                  V      V
12919   //                    ADDE   <- hiAdd
12920   //
12921   // In the special case where only the higher part of a signed result is used
12922   // and the add to the low part of the result of ISD::UMUL_LOHI adds or subtracts
12923   // a constant with the exact value of 0x80000000, we recognize we are dealing
12924   // with a "rounded multiply and add" (or subtract) and transform it into
12925   // either a ARMISD::SMMLAR or ARMISD::SMMLSR respectively.
12926 
12927   assert((AddeSubeNode->getOpcode() == ARMISD::ADDE ||
12928           AddeSubeNode->getOpcode() == ARMISD::SUBE) &&
12929          "Expect an ADDE or SUBE");
12930 
12931   assert(AddeSubeNode->getNumOperands() == 3 &&
12932          AddeSubeNode->getOperand(2).getValueType() == MVT::i32 &&
12933          "ADDE node has the wrong inputs");
12934 
12935   // Check that we are chained to the right ADDC or SUBC node.
12936   SDNode *AddcSubcNode = AddeSubeNode->getOperand(2).getNode();
12937   if ((AddeSubeNode->getOpcode() == ARMISD::ADDE &&
12938        AddcSubcNode->getOpcode() != ARMISD::ADDC) ||
12939       (AddeSubeNode->getOpcode() == ARMISD::SUBE &&
12940        AddcSubcNode->getOpcode() != ARMISD::SUBC))
12941     return SDValue();
12942 
12943   SDValue AddcSubcOp0 = AddcSubcNode->getOperand(0);
12944   SDValue AddcSubcOp1 = AddcSubcNode->getOperand(1);
12945 
12946   // Check if the two operands are from the same mul_lohi node.
12947   if (AddcSubcOp0.getNode() == AddcSubcOp1.getNode())
12948     return SDValue();
12949 
12950   assert(AddcSubcNode->getNumValues() == 2 &&
12951          AddcSubcNode->getValueType(0) == MVT::i32 &&
12952          "Expect ADDC with two result values. First: i32");
12953 
12954   // Check that the ADDC adds the low result of the S/UMUL_LOHI. If not, it
12955   // maybe a SMLAL which multiplies two 16-bit values.
12956   if (AddeSubeNode->getOpcode() == ARMISD::ADDE &&
12957       AddcSubcOp0->getOpcode() != ISD::UMUL_LOHI &&
12958       AddcSubcOp0->getOpcode() != ISD::SMUL_LOHI &&
12959       AddcSubcOp1->getOpcode() != ISD::UMUL_LOHI &&
12960       AddcSubcOp1->getOpcode() != ISD::SMUL_LOHI)
12961     return AddCombineTo64BitSMLAL16(AddcSubcNode, AddeSubeNode, DCI, Subtarget);
12962 
12963   // Check for the triangle shape.
12964   SDValue AddeSubeOp0 = AddeSubeNode->getOperand(0);
12965   SDValue AddeSubeOp1 = AddeSubeNode->getOperand(1);
12966 
12967   // Make sure that the ADDE/SUBE operands are not coming from the same node.
12968   if (AddeSubeOp0.getNode() == AddeSubeOp1.getNode())
12969     return SDValue();
12970 
12971   // Find the MUL_LOHI node walking up ADDE/SUBE's operands.
12972   bool IsLeftOperandMUL = false;
12973   SDValue MULOp = findMUL_LOHI(AddeSubeOp0);
12974   if (MULOp == SDValue())
12975     MULOp = findMUL_LOHI(AddeSubeOp1);
12976   else
12977     IsLeftOperandMUL = true;
12978   if (MULOp == SDValue())
12979     return SDValue();
12980 
12981   // Figure out the right opcode.
12982   unsigned Opc = MULOp->getOpcode();
12983   unsigned FinalOpc = (Opc == ISD::SMUL_LOHI) ? ARMISD::SMLAL : ARMISD::UMLAL;
12984 
12985   // Figure out the high and low input values to the MLAL node.
12986   SDValue *HiAddSub = nullptr;
12987   SDValue *LoMul = nullptr;
12988   SDValue *LowAddSub = nullptr;
12989 
12990   // Ensure that ADDE/SUBE is from high result of ISD::xMUL_LOHI.
12991   if ((AddeSubeOp0 != MULOp.getValue(1)) && (AddeSubeOp1 != MULOp.getValue(1)))
12992     return SDValue();
12993 
12994   if (IsLeftOperandMUL)
12995     HiAddSub = &AddeSubeOp1;
12996   else
12997     HiAddSub = &AddeSubeOp0;
12998 
12999   // Ensure that LoMul and LowAddSub are taken from correct ISD::SMUL_LOHI node
13000   // whose low result is fed to the ADDC/SUBC we are checking.
13001 
13002   if (AddcSubcOp0 == MULOp.getValue(0)) {
13003     LoMul = &AddcSubcOp0;
13004     LowAddSub = &AddcSubcOp1;
13005   }
13006   if (AddcSubcOp1 == MULOp.getValue(0)) {
13007     LoMul = &AddcSubcOp1;
13008     LowAddSub = &AddcSubcOp0;
13009   }
13010 
13011   if (!LoMul)
13012     return SDValue();
13013 
13014   // If HiAddSub is the same node as ADDC/SUBC or is a predecessor of ADDC/SUBC
13015   // the replacement below will create a cycle.
13016   if (AddcSubcNode == HiAddSub->getNode() ||
13017       AddcSubcNode->isPredecessorOf(HiAddSub->getNode()))
13018     return SDValue();
13019 
13020   // Create the merged node.
13021   SelectionDAG &DAG = DCI.DAG;
13022 
13023   // Start building operand list.
13024   SmallVector<SDValue, 8> Ops;
13025   Ops.push_back(LoMul->getOperand(0));
13026   Ops.push_back(LoMul->getOperand(1));
13027 
13028   // Check whether we can use SMMLAR, SMMLSR or SMMULR instead.  For this to be
13029   // the case, we must be doing signed multiplication and only use the higher
13030   // part of the result of the MLAL, furthermore the LowAddSub must be a constant
13031   // addition or subtraction with the value of 0x800000.
13032   if (Subtarget->hasV6Ops() && Subtarget->hasDSP() && Subtarget->useMulOps() &&
13033       FinalOpc == ARMISD::SMLAL && !AddeSubeNode->hasAnyUseOfValue(1) &&
13034       LowAddSub->getNode()->getOpcode() == ISD::Constant &&
13035       static_cast<ConstantSDNode *>(LowAddSub->getNode())->getZExtValue() ==
13036           0x80000000) {
13037     Ops.push_back(*HiAddSub);
13038     if (AddcSubcNode->getOpcode() == ARMISD::SUBC) {
13039       FinalOpc = ARMISD::SMMLSR;
13040     } else {
13041       FinalOpc = ARMISD::SMMLAR;
13042     }
13043     SDValue NewNode = DAG.getNode(FinalOpc, SDLoc(AddcSubcNode), MVT::i32, Ops);
13044     DAG.ReplaceAllUsesOfValueWith(SDValue(AddeSubeNode, 0), NewNode);
13045 
13046     return SDValue(AddeSubeNode, 0);
13047   } else if (AddcSubcNode->getOpcode() == ARMISD::SUBC)
13048     // SMMLS is generated during instruction selection and the rest of this
13049     // function can not handle the case where AddcSubcNode is a SUBC.
13050     return SDValue();
13051 
13052   // Finish building the operand list for {U/S}MLAL
13053   Ops.push_back(*LowAddSub);
13054   Ops.push_back(*HiAddSub);
13055 
13056   SDValue MLALNode = DAG.getNode(FinalOpc, SDLoc(AddcSubcNode),
13057                                  DAG.getVTList(MVT::i32, MVT::i32), Ops);
13058 
13059   // Replace the ADDs' nodes uses by the MLA node's values.
13060   SDValue HiMLALResult(MLALNode.getNode(), 1);
13061   DAG.ReplaceAllUsesOfValueWith(SDValue(AddeSubeNode, 0), HiMLALResult);
13062 
13063   SDValue LoMLALResult(MLALNode.getNode(), 0);
13064   DAG.ReplaceAllUsesOfValueWith(SDValue(AddcSubcNode, 0), LoMLALResult);
13065 
13066   // Return original node to notify the driver to stop replacing.
13067   return SDValue(AddeSubeNode, 0);
13068 }
13069 
AddCombineTo64bitUMAAL(SDNode * AddeNode,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13070 static SDValue AddCombineTo64bitUMAAL(SDNode *AddeNode,
13071                                       TargetLowering::DAGCombinerInfo &DCI,
13072                                       const ARMSubtarget *Subtarget) {
13073   // UMAAL is similar to UMLAL except that it adds two unsigned values.
13074   // While trying to combine for the other MLAL nodes, first search for the
13075   // chance to use UMAAL. Check if Addc uses a node which has already
13076   // been combined into a UMLAL. The other pattern is UMLAL using Addc/Adde
13077   // as the addend, and it's handled in PerformUMLALCombine.
13078 
13079   if (!Subtarget->hasV6Ops() || !Subtarget->hasDSP())
13080     return AddCombineTo64bitMLAL(AddeNode, DCI, Subtarget);
13081 
13082   // Check that we have a glued ADDC node.
13083   SDNode* AddcNode = AddeNode->getOperand(2).getNode();
13084   if (AddcNode->getOpcode() != ARMISD::ADDC)
13085     return SDValue();
13086 
13087   // Find the converted UMAAL or quit if it doesn't exist.
13088   SDNode *UmlalNode = nullptr;
13089   SDValue AddHi;
13090   if (AddcNode->getOperand(0).getOpcode() == ARMISD::UMLAL) {
13091     UmlalNode = AddcNode->getOperand(0).getNode();
13092     AddHi = AddcNode->getOperand(1);
13093   } else if (AddcNode->getOperand(1).getOpcode() == ARMISD::UMLAL) {
13094     UmlalNode = AddcNode->getOperand(1).getNode();
13095     AddHi = AddcNode->getOperand(0);
13096   } else {
13097     return AddCombineTo64bitMLAL(AddeNode, DCI, Subtarget);
13098   }
13099 
13100   // The ADDC should be glued to an ADDE node, which uses the same UMLAL as
13101   // the ADDC as well as Zero.
13102   if (!isNullConstant(UmlalNode->getOperand(3)))
13103     return SDValue();
13104 
13105   if ((isNullConstant(AddeNode->getOperand(0)) &&
13106        AddeNode->getOperand(1).getNode() == UmlalNode) ||
13107       (AddeNode->getOperand(0).getNode() == UmlalNode &&
13108        isNullConstant(AddeNode->getOperand(1)))) {
13109     SelectionDAG &DAG = DCI.DAG;
13110     SDValue Ops[] = { UmlalNode->getOperand(0), UmlalNode->getOperand(1),
13111                       UmlalNode->getOperand(2), AddHi };
13112     SDValue UMAAL =  DAG.getNode(ARMISD::UMAAL, SDLoc(AddcNode),
13113                                  DAG.getVTList(MVT::i32, MVT::i32), Ops);
13114 
13115     // Replace the ADDs' nodes uses by the UMAAL node's values.
13116     DAG.ReplaceAllUsesOfValueWith(SDValue(AddeNode, 0), SDValue(UMAAL.getNode(), 1));
13117     DAG.ReplaceAllUsesOfValueWith(SDValue(AddcNode, 0), SDValue(UMAAL.getNode(), 0));
13118 
13119     // Return original node to notify the driver to stop replacing.
13120     return SDValue(AddeNode, 0);
13121   }
13122   return SDValue();
13123 }
13124 
PerformUMLALCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)13125 static SDValue PerformUMLALCombine(SDNode *N, SelectionDAG &DAG,
13126                                    const ARMSubtarget *Subtarget) {
13127   if (!Subtarget->hasV6Ops() || !Subtarget->hasDSP())
13128     return SDValue();
13129 
13130   // Check that we have a pair of ADDC and ADDE as operands.
13131   // Both addends of the ADDE must be zero.
13132   SDNode* AddcNode = N->getOperand(2).getNode();
13133   SDNode* AddeNode = N->getOperand(3).getNode();
13134   if ((AddcNode->getOpcode() == ARMISD::ADDC) &&
13135       (AddeNode->getOpcode() == ARMISD::ADDE) &&
13136       isNullConstant(AddeNode->getOperand(0)) &&
13137       isNullConstant(AddeNode->getOperand(1)) &&
13138       (AddeNode->getOperand(2).getNode() == AddcNode))
13139     return DAG.getNode(ARMISD::UMAAL, SDLoc(N),
13140                        DAG.getVTList(MVT::i32, MVT::i32),
13141                        {N->getOperand(0), N->getOperand(1),
13142                         AddcNode->getOperand(0), AddcNode->getOperand(1)});
13143   else
13144     return SDValue();
13145 }
13146 
PerformAddcSubcCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13147 static SDValue PerformAddcSubcCombine(SDNode *N,
13148                                       TargetLowering::DAGCombinerInfo &DCI,
13149                                       const ARMSubtarget *Subtarget) {
13150   SelectionDAG &DAG(DCI.DAG);
13151 
13152   if (N->getOpcode() == ARMISD::SUBC && N->hasAnyUseOfValue(1)) {
13153     // (SUBC (ADDE 0, 0, C), 1) -> C
13154     SDValue LHS = N->getOperand(0);
13155     SDValue RHS = N->getOperand(1);
13156     if (LHS->getOpcode() == ARMISD::ADDE &&
13157         isNullConstant(LHS->getOperand(0)) &&
13158         isNullConstant(LHS->getOperand(1)) && isOneConstant(RHS)) {
13159       return DCI.CombineTo(N, SDValue(N, 0), LHS->getOperand(2));
13160     }
13161   }
13162 
13163   if (Subtarget->isThumb1Only()) {
13164     SDValue RHS = N->getOperand(1);
13165     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS)) {
13166       int32_t imm = C->getSExtValue();
13167       if (imm < 0 && imm > std::numeric_limits<int>::min()) {
13168         SDLoc DL(N);
13169         RHS = DAG.getConstant(-imm, DL, MVT::i32);
13170         unsigned Opcode = (N->getOpcode() == ARMISD::ADDC) ? ARMISD::SUBC
13171                                                            : ARMISD::ADDC;
13172         return DAG.getNode(Opcode, DL, N->getVTList(), N->getOperand(0), RHS);
13173       }
13174     }
13175   }
13176 
13177   return SDValue();
13178 }
13179 
PerformAddeSubeCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13180 static SDValue PerformAddeSubeCombine(SDNode *N,
13181                                       TargetLowering::DAGCombinerInfo &DCI,
13182                                       const ARMSubtarget *Subtarget) {
13183   if (Subtarget->isThumb1Only()) {
13184     SelectionDAG &DAG = DCI.DAG;
13185     SDValue RHS = N->getOperand(1);
13186     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(RHS)) {
13187       int64_t imm = C->getSExtValue();
13188       if (imm < 0) {
13189         SDLoc DL(N);
13190 
13191         // The with-carry-in form matches bitwise not instead of the negation.
13192         // Effectively, the inverse interpretation of the carry flag already
13193         // accounts for part of the negation.
13194         RHS = DAG.getConstant(~imm, DL, MVT::i32);
13195 
13196         unsigned Opcode = (N->getOpcode() == ARMISD::ADDE) ? ARMISD::SUBE
13197                                                            : ARMISD::ADDE;
13198         return DAG.getNode(Opcode, DL, N->getVTList(),
13199                            N->getOperand(0), RHS, N->getOperand(2));
13200       }
13201     }
13202   } else if (N->getOperand(1)->getOpcode() == ISD::SMUL_LOHI) {
13203     return AddCombineTo64bitMLAL(N, DCI, Subtarget);
13204   }
13205   return SDValue();
13206 }
13207 
PerformSELECTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13208 static SDValue PerformSELECTCombine(SDNode *N,
13209                                     TargetLowering::DAGCombinerInfo &DCI,
13210                                     const ARMSubtarget *Subtarget) {
13211   if (!Subtarget->hasMVEIntegerOps())
13212     return SDValue();
13213 
13214   SDLoc dl(N);
13215   SDValue SetCC;
13216   SDValue LHS;
13217   SDValue RHS;
13218   ISD::CondCode CC;
13219   SDValue TrueVal;
13220   SDValue FalseVal;
13221 
13222   if (N->getOpcode() == ISD::SELECT &&
13223       N->getOperand(0)->getOpcode() == ISD::SETCC) {
13224     SetCC = N->getOperand(0);
13225     LHS = SetCC->getOperand(0);
13226     RHS = SetCC->getOperand(1);
13227     CC = cast<CondCodeSDNode>(SetCC->getOperand(2))->get();
13228     TrueVal = N->getOperand(1);
13229     FalseVal = N->getOperand(2);
13230   } else if (N->getOpcode() == ISD::SELECT_CC) {
13231     LHS = N->getOperand(0);
13232     RHS = N->getOperand(1);
13233     CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
13234     TrueVal = N->getOperand(2);
13235     FalseVal = N->getOperand(3);
13236   } else {
13237     return SDValue();
13238   }
13239 
13240   unsigned int Opcode = 0;
13241   if ((TrueVal->getOpcode() == ISD::VECREDUCE_UMIN ||
13242        FalseVal->getOpcode() == ISD::VECREDUCE_UMIN) &&
13243       (CC == ISD::SETULT || CC == ISD::SETUGT)) {
13244     Opcode = ARMISD::VMINVu;
13245     if (CC == ISD::SETUGT)
13246       std::swap(TrueVal, FalseVal);
13247   } else if ((TrueVal->getOpcode() == ISD::VECREDUCE_SMIN ||
13248               FalseVal->getOpcode() == ISD::VECREDUCE_SMIN) &&
13249              (CC == ISD::SETLT || CC == ISD::SETGT)) {
13250     Opcode = ARMISD::VMINVs;
13251     if (CC == ISD::SETGT)
13252       std::swap(TrueVal, FalseVal);
13253   } else if ((TrueVal->getOpcode() == ISD::VECREDUCE_UMAX ||
13254               FalseVal->getOpcode() == ISD::VECREDUCE_UMAX) &&
13255              (CC == ISD::SETUGT || CC == ISD::SETULT)) {
13256     Opcode = ARMISD::VMAXVu;
13257     if (CC == ISD::SETULT)
13258       std::swap(TrueVal, FalseVal);
13259   } else if ((TrueVal->getOpcode() == ISD::VECREDUCE_SMAX ||
13260               FalseVal->getOpcode() == ISD::VECREDUCE_SMAX) &&
13261              (CC == ISD::SETGT || CC == ISD::SETLT)) {
13262     Opcode = ARMISD::VMAXVs;
13263     if (CC == ISD::SETLT)
13264       std::swap(TrueVal, FalseVal);
13265   } else
13266     return SDValue();
13267 
13268   // Normalise to the right hand side being the vector reduction
13269   switch (TrueVal->getOpcode()) {
13270   case ISD::VECREDUCE_UMIN:
13271   case ISD::VECREDUCE_SMIN:
13272   case ISD::VECREDUCE_UMAX:
13273   case ISD::VECREDUCE_SMAX:
13274     std::swap(LHS, RHS);
13275     std::swap(TrueVal, FalseVal);
13276     break;
13277   }
13278 
13279   EVT VectorType = FalseVal->getOperand(0).getValueType();
13280 
13281   if (VectorType != MVT::v16i8 && VectorType != MVT::v8i16 &&
13282       VectorType != MVT::v4i32)
13283     return SDValue();
13284 
13285   EVT VectorScalarType = VectorType.getVectorElementType();
13286 
13287   // The values being selected must also be the ones being compared
13288   if (TrueVal != LHS || FalseVal != RHS)
13289     return SDValue();
13290 
13291   EVT LeftType = LHS->getValueType(0);
13292   EVT RightType = RHS->getValueType(0);
13293 
13294   // The types must match the reduced type too
13295   if (LeftType != VectorScalarType || RightType != VectorScalarType)
13296     return SDValue();
13297 
13298   // Legalise the scalar to an i32
13299   if (VectorScalarType != MVT::i32)
13300     LHS = DCI.DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i32, LHS);
13301 
13302   // Generate the reduction as an i32 for legalisation purposes
13303   auto Reduction =
13304       DCI.DAG.getNode(Opcode, dl, MVT::i32, LHS, RHS->getOperand(0));
13305 
13306   // The result isn't actually an i32 so truncate it back to its original type
13307   if (VectorScalarType != MVT::i32)
13308     Reduction = DCI.DAG.getNode(ISD::TRUNCATE, dl, VectorScalarType, Reduction);
13309 
13310   return Reduction;
13311 }
13312 
13313 // A special combine for the vqdmulh family of instructions. This is one of the
13314 // potential set of patterns that could patch this instruction. The base pattern
13315 // you would expect to be min(max(ashr(mul(mul(sext(x), 2), sext(y)), 16))).
13316 // This matches the different min(max(ashr(mul(mul(sext(x), sext(y)), 2), 16))),
13317 // which llvm will have optimized to min(ashr(mul(sext(x), sext(y)), 15))) as
13318 // the max is unnecessary.
PerformVQDMULHCombine(SDNode * N,SelectionDAG & DAG)13319 static SDValue PerformVQDMULHCombine(SDNode *N, SelectionDAG &DAG) {
13320   EVT VT = N->getValueType(0);
13321   SDValue Shft;
13322   ConstantSDNode *Clamp;
13323 
13324   if (!VT.isVector() || VT.getScalarSizeInBits() > 64)
13325     return SDValue();
13326 
13327   if (N->getOpcode() == ISD::SMIN) {
13328     Shft = N->getOperand(0);
13329     Clamp = isConstOrConstSplat(N->getOperand(1));
13330   } else if (N->getOpcode() == ISD::VSELECT) {
13331     // Detect a SMIN, which for an i64 node will be a vselect/setcc, not a smin.
13332     SDValue Cmp = N->getOperand(0);
13333     if (Cmp.getOpcode() != ISD::SETCC ||
13334         cast<CondCodeSDNode>(Cmp.getOperand(2))->get() != ISD::SETLT ||
13335         Cmp.getOperand(0) != N->getOperand(1) ||
13336         Cmp.getOperand(1) != N->getOperand(2))
13337       return SDValue();
13338     Shft = N->getOperand(1);
13339     Clamp = isConstOrConstSplat(N->getOperand(2));
13340   } else
13341     return SDValue();
13342 
13343   if (!Clamp)
13344     return SDValue();
13345 
13346   MVT ScalarType;
13347   int ShftAmt = 0;
13348   switch (Clamp->getSExtValue()) {
13349   case (1 << 7) - 1:
13350     ScalarType = MVT::i8;
13351     ShftAmt = 7;
13352     break;
13353   case (1 << 15) - 1:
13354     ScalarType = MVT::i16;
13355     ShftAmt = 15;
13356     break;
13357   case (1ULL << 31) - 1:
13358     ScalarType = MVT::i32;
13359     ShftAmt = 31;
13360     break;
13361   default:
13362     return SDValue();
13363   }
13364 
13365   if (Shft.getOpcode() != ISD::SRA)
13366     return SDValue();
13367   ConstantSDNode *N1 = isConstOrConstSplat(Shft.getOperand(1));
13368   if (!N1 || N1->getSExtValue() != ShftAmt)
13369     return SDValue();
13370 
13371   SDValue Mul = Shft.getOperand(0);
13372   if (Mul.getOpcode() != ISD::MUL)
13373     return SDValue();
13374 
13375   SDValue Ext0 = Mul.getOperand(0);
13376   SDValue Ext1 = Mul.getOperand(1);
13377   if (Ext0.getOpcode() != ISD::SIGN_EXTEND ||
13378       Ext1.getOpcode() != ISD::SIGN_EXTEND)
13379     return SDValue();
13380   EVT VecVT = Ext0.getOperand(0).getValueType();
13381   if (!VecVT.isPow2VectorType() || VecVT.getVectorNumElements() == 1)
13382     return SDValue();
13383   if (Ext1.getOperand(0).getValueType() != VecVT ||
13384       VecVT.getScalarType() != ScalarType ||
13385       VT.getScalarSizeInBits() < ScalarType.getScalarSizeInBits() * 2)
13386     return SDValue();
13387 
13388   SDLoc DL(Mul);
13389   unsigned LegalLanes = 128 / (ShftAmt + 1);
13390   EVT LegalVecVT = MVT::getVectorVT(ScalarType, LegalLanes);
13391   // For types smaller than legal vectors extend to be legal and only use needed
13392   // lanes.
13393   if (VecVT.getSizeInBits() < 128) {
13394     EVT ExtVecVT =
13395         MVT::getVectorVT(MVT::getIntegerVT(128 / VecVT.getVectorNumElements()),
13396                          VecVT.getVectorNumElements());
13397     SDValue Inp0 =
13398         DAG.getNode(ISD::ANY_EXTEND, DL, ExtVecVT, Ext0.getOperand(0));
13399     SDValue Inp1 =
13400         DAG.getNode(ISD::ANY_EXTEND, DL, ExtVecVT, Ext1.getOperand(0));
13401     Inp0 = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, LegalVecVT, Inp0);
13402     Inp1 = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, LegalVecVT, Inp1);
13403     SDValue VQDMULH = DAG.getNode(ARMISD::VQDMULH, DL, LegalVecVT, Inp0, Inp1);
13404     SDValue Trunc = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, ExtVecVT, VQDMULH);
13405     Trunc = DAG.getNode(ISD::TRUNCATE, DL, VecVT, Trunc);
13406     return DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Trunc);
13407   }
13408 
13409   // For larger types, split into legal sized chunks.
13410   assert(VecVT.getSizeInBits() % 128 == 0 && "Expected a power2 type");
13411   unsigned NumParts = VecVT.getSizeInBits() / 128;
13412   SmallVector<SDValue> Parts;
13413   for (unsigned I = 0; I < NumParts; ++I) {
13414     SDValue Inp0 =
13415         DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, LegalVecVT, Ext0.getOperand(0),
13416                     DAG.getVectorIdxConstant(I * LegalLanes, DL));
13417     SDValue Inp1 =
13418         DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, LegalVecVT, Ext1.getOperand(0),
13419                     DAG.getVectorIdxConstant(I * LegalLanes, DL));
13420     SDValue VQDMULH = DAG.getNode(ARMISD::VQDMULH, DL, LegalVecVT, Inp0, Inp1);
13421     Parts.push_back(VQDMULH);
13422   }
13423   return DAG.getNode(ISD::SIGN_EXTEND, DL, VT,
13424                      DAG.getNode(ISD::CONCAT_VECTORS, DL, VecVT, Parts));
13425 }
13426 
PerformVSELECTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13427 static SDValue PerformVSELECTCombine(SDNode *N,
13428                                      TargetLowering::DAGCombinerInfo &DCI,
13429                                      const ARMSubtarget *Subtarget) {
13430   if (!Subtarget->hasMVEIntegerOps())
13431     return SDValue();
13432 
13433   if (SDValue V = PerformVQDMULHCombine(N, DCI.DAG))
13434     return V;
13435 
13436   // Transforms vselect(not(cond), lhs, rhs) into vselect(cond, rhs, lhs).
13437   //
13438   // We need to re-implement this optimization here as the implementation in the
13439   // Target-Independent DAGCombiner does not handle the kind of constant we make
13440   // (it calls isConstOrConstSplat with AllowTruncation set to false - and for
13441   // good reason, allowing truncation there would break other targets).
13442   //
13443   // Currently, this is only done for MVE, as it's the only target that benefits
13444   // from this transformation (e.g. VPNOT+VPSEL becomes a single VPSEL).
13445   if (N->getOperand(0).getOpcode() != ISD::XOR)
13446     return SDValue();
13447   SDValue XOR = N->getOperand(0);
13448 
13449   // Check if the XOR's RHS is either a 1, or a BUILD_VECTOR of 1s.
13450   // It is important to check with truncation allowed as the BUILD_VECTORs we
13451   // generate in those situations will truncate their operands.
13452   ConstantSDNode *Const =
13453       isConstOrConstSplat(XOR->getOperand(1), /*AllowUndefs*/ false,
13454                           /*AllowTruncation*/ true);
13455   if (!Const || !Const->isOne())
13456     return SDValue();
13457 
13458   // Rewrite into vselect(cond, rhs, lhs).
13459   SDValue Cond = XOR->getOperand(0);
13460   SDValue LHS = N->getOperand(1);
13461   SDValue RHS = N->getOperand(2);
13462   EVT Type = N->getValueType(0);
13463   return DCI.DAG.getNode(ISD::VSELECT, SDLoc(N), Type, Cond, RHS, LHS);
13464 }
13465 
13466 // Convert vsetcc([0,1,2,..], splat(n), ult) -> vctp n
PerformVSetCCToVCTPCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13467 static SDValue PerformVSetCCToVCTPCombine(SDNode *N,
13468                                           TargetLowering::DAGCombinerInfo &DCI,
13469                                           const ARMSubtarget *Subtarget) {
13470   SDValue Op0 = N->getOperand(0);
13471   SDValue Op1 = N->getOperand(1);
13472   ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
13473   EVT VT = N->getValueType(0);
13474 
13475   if (!Subtarget->hasMVEIntegerOps() ||
13476       !DCI.DAG.getTargetLoweringInfo().isTypeLegal(VT))
13477     return SDValue();
13478 
13479   if (CC == ISD::SETUGE) {
13480     std::swap(Op0, Op1);
13481     CC = ISD::SETULT;
13482   }
13483 
13484   if (CC != ISD::SETULT || VT.getScalarSizeInBits() != 1 ||
13485       Op0.getOpcode() != ISD::BUILD_VECTOR)
13486     return SDValue();
13487 
13488   // Check first operand is BuildVector of 0,1,2,...
13489   for (unsigned I = 0; I < VT.getVectorNumElements(); I++) {
13490     if (!Op0.getOperand(I).isUndef() &&
13491         !(isa<ConstantSDNode>(Op0.getOperand(I)) &&
13492           Op0.getConstantOperandVal(I) == I))
13493       return SDValue();
13494   }
13495 
13496   // The second is a Splat of Op1S
13497   SDValue Op1S = DCI.DAG.getSplatValue(Op1);
13498   if (!Op1S)
13499     return SDValue();
13500 
13501   unsigned Opc;
13502   switch (VT.getVectorNumElements()) {
13503   case 2:
13504     Opc = Intrinsic::arm_mve_vctp64;
13505     break;
13506   case 4:
13507     Opc = Intrinsic::arm_mve_vctp32;
13508     break;
13509   case 8:
13510     Opc = Intrinsic::arm_mve_vctp16;
13511     break;
13512   case 16:
13513     Opc = Intrinsic::arm_mve_vctp8;
13514     break;
13515   default:
13516     return SDValue();
13517   }
13518 
13519   SDLoc DL(N);
13520   return DCI.DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
13521                          DCI.DAG.getConstant(Opc, DL, MVT::i32),
13522                          DCI.DAG.getZExtOrTrunc(Op1S, DL, MVT::i32));
13523 }
13524 
13525 /// PerformADDECombine - Target-specific dag combine transform from
13526 /// ARMISD::ADDC, ARMISD::ADDE, and ISD::MUL_LOHI to MLAL or
13527 /// ARMISD::ADDC, ARMISD::ADDE and ARMISD::UMLAL to ARMISD::UMAAL
PerformADDECombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13528 static SDValue PerformADDECombine(SDNode *N,
13529                                   TargetLowering::DAGCombinerInfo &DCI,
13530                                   const ARMSubtarget *Subtarget) {
13531   // Only ARM and Thumb2 support UMLAL/SMLAL.
13532   if (Subtarget->isThumb1Only())
13533     return PerformAddeSubeCombine(N, DCI, Subtarget);
13534 
13535   // Only perform the checks after legalize when the pattern is available.
13536   if (DCI.isBeforeLegalize()) return SDValue();
13537 
13538   return AddCombineTo64bitUMAAL(N, DCI, Subtarget);
13539 }
13540 
13541 /// PerformADDCombineWithOperands - Try DAG combinations for an ADD with
13542 /// operands N0 and N1.  This is a helper for PerformADDCombine that is
13543 /// called with the default operands, and if that fails, with commuted
13544 /// operands.
PerformADDCombineWithOperands(SDNode * N,SDValue N0,SDValue N1,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)13545 static SDValue PerformADDCombineWithOperands(SDNode *N, SDValue N0, SDValue N1,
13546                                           TargetLowering::DAGCombinerInfo &DCI,
13547                                           const ARMSubtarget *Subtarget){
13548   // Attempt to create vpadd for this add.
13549   if (SDValue Result = AddCombineToVPADD(N, N0, N1, DCI, Subtarget))
13550     return Result;
13551 
13552   // Attempt to create vpaddl for this add.
13553   if (SDValue Result = AddCombineVUZPToVPADDL(N, N0, N1, DCI, Subtarget))
13554     return Result;
13555   if (SDValue Result = AddCombineBUILD_VECTORToVPADDL(N, N0, N1, DCI,
13556                                                       Subtarget))
13557     return Result;
13558 
13559   // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
13560   if (N0.getNode()->hasOneUse())
13561     if (SDValue Result = combineSelectAndUse(N, N0, N1, DCI))
13562       return Result;
13563   return SDValue();
13564 }
13565 
TryDistrubutionADDVecReduce(SDNode * N,SelectionDAG & DAG)13566 static SDValue TryDistrubutionADDVecReduce(SDNode *N, SelectionDAG &DAG) {
13567   EVT VT = N->getValueType(0);
13568   SDValue N0 = N->getOperand(0);
13569   SDValue N1 = N->getOperand(1);
13570   SDLoc dl(N);
13571 
13572   auto IsVecReduce = [](SDValue Op) {
13573     switch (Op.getOpcode()) {
13574     case ISD::VECREDUCE_ADD:
13575     case ARMISD::VADDVs:
13576     case ARMISD::VADDVu:
13577     case ARMISD::VMLAVs:
13578     case ARMISD::VMLAVu:
13579       return true;
13580     }
13581     return false;
13582   };
13583 
13584   auto DistrubuteAddAddVecReduce = [&](SDValue N0, SDValue N1) {
13585     // Distribute add(X, add(vecreduce(Y), vecreduce(Z))) ->
13586     //   add(add(X, vecreduce(Y)), vecreduce(Z))
13587     // to make better use of vaddva style instructions.
13588     if (VT == MVT::i32 && N1.getOpcode() == ISD::ADD && !IsVecReduce(N0) &&
13589         IsVecReduce(N1.getOperand(0)) && IsVecReduce(N1.getOperand(1)) &&
13590         !isa<ConstantSDNode>(N0) && N1->hasOneUse()) {
13591       SDValue Add0 = DAG.getNode(ISD::ADD, dl, VT, N0, N1.getOperand(0));
13592       return DAG.getNode(ISD::ADD, dl, VT, Add0, N1.getOperand(1));
13593     }
13594     // And turn add(add(A, reduce(B)), add(C, reduce(D))) ->
13595     //   add(add(add(A, C), reduce(B)), reduce(D))
13596     if (VT == MVT::i32 && N0.getOpcode() == ISD::ADD &&
13597         N1.getOpcode() == ISD::ADD && N0->hasOneUse() && N1->hasOneUse()) {
13598       unsigned N0RedOp = 0;
13599       if (!IsVecReduce(N0.getOperand(N0RedOp))) {
13600         N0RedOp = 1;
13601         if (!IsVecReduce(N0.getOperand(N0RedOp)))
13602           return SDValue();
13603       }
13604 
13605       unsigned N1RedOp = 0;
13606       if (!IsVecReduce(N1.getOperand(N1RedOp)))
13607         N1RedOp = 1;
13608       if (!IsVecReduce(N1.getOperand(N1RedOp)))
13609         return SDValue();
13610 
13611       SDValue Add0 = DAG.getNode(ISD::ADD, dl, VT, N0.getOperand(1 - N0RedOp),
13612                                  N1.getOperand(1 - N1RedOp));
13613       SDValue Add1 =
13614           DAG.getNode(ISD::ADD, dl, VT, Add0, N0.getOperand(N0RedOp));
13615       return DAG.getNode(ISD::ADD, dl, VT, Add1, N1.getOperand(N1RedOp));
13616     }
13617     return SDValue();
13618   };
13619   if (SDValue R = DistrubuteAddAddVecReduce(N0, N1))
13620     return R;
13621   if (SDValue R = DistrubuteAddAddVecReduce(N1, N0))
13622     return R;
13623 
13624   // Distribute add(vecreduce(load(Y)), vecreduce(load(Z)))
13625   // Or add(add(X, vecreduce(load(Y))), vecreduce(load(Z)))
13626   // by ascending load offsets. This can help cores prefetch if the order of
13627   // loads is more predictable.
13628   auto DistrubuteVecReduceLoad = [&](SDValue N0, SDValue N1, bool IsForward) {
13629     // Check if two reductions are known to load data where one is before/after
13630     // another. Return negative if N0 loads data before N1, positive if N1 is
13631     // before N0 and 0 otherwise if nothing is known.
13632     auto IsKnownOrderedLoad = [&](SDValue N0, SDValue N1) {
13633       // Look through to the first operand of a MUL, for the VMLA case.
13634       // Currently only looks at the first operand, in the hope they are equal.
13635       if (N0.getOpcode() == ISD::MUL)
13636         N0 = N0.getOperand(0);
13637       if (N1.getOpcode() == ISD::MUL)
13638         N1 = N1.getOperand(0);
13639 
13640       // Return true if the two operands are loads to the same object and the
13641       // offset of the first is known to be less than the offset of the second.
13642       LoadSDNode *Load0 = dyn_cast<LoadSDNode>(N0);
13643       LoadSDNode *Load1 = dyn_cast<LoadSDNode>(N1);
13644       if (!Load0 || !Load1 || Load0->getChain() != Load1->getChain() ||
13645           !Load0->isSimple() || !Load1->isSimple() || Load0->isIndexed() ||
13646           Load1->isIndexed())
13647         return 0;
13648 
13649       auto BaseLocDecomp0 = BaseIndexOffset::match(Load0, DAG);
13650       auto BaseLocDecomp1 = BaseIndexOffset::match(Load1, DAG);
13651 
13652       if (!BaseLocDecomp0.getBase() ||
13653           BaseLocDecomp0.getBase() != BaseLocDecomp1.getBase() ||
13654           !BaseLocDecomp0.hasValidOffset() || !BaseLocDecomp1.hasValidOffset())
13655         return 0;
13656       if (BaseLocDecomp0.getOffset() < BaseLocDecomp1.getOffset())
13657         return -1;
13658       if (BaseLocDecomp0.getOffset() > BaseLocDecomp1.getOffset())
13659         return 1;
13660       return 0;
13661     };
13662 
13663     SDValue X;
13664     if (N0.getOpcode() == ISD::ADD && N0->hasOneUse()) {
13665       if (IsVecReduce(N0.getOperand(0)) && IsVecReduce(N0.getOperand(1))) {
13666         int IsBefore = IsKnownOrderedLoad(N0.getOperand(0).getOperand(0),
13667                                          N0.getOperand(1).getOperand(0));
13668         if (IsBefore < 0) {
13669           X = N0.getOperand(0);
13670           N0 = N0.getOperand(1);
13671         } else if (IsBefore > 0) {
13672           X = N0.getOperand(1);
13673           N0 = N0.getOperand(0);
13674         } else
13675           return SDValue();
13676       } else if (IsVecReduce(N0.getOperand(0))) {
13677         X = N0.getOperand(1);
13678         N0 = N0.getOperand(0);
13679       } else if (IsVecReduce(N0.getOperand(1))) {
13680         X = N0.getOperand(0);
13681         N0 = N0.getOperand(1);
13682       } else
13683         return SDValue();
13684     } else if (IsForward && IsVecReduce(N0) && IsVecReduce(N1) &&
13685                IsKnownOrderedLoad(N0.getOperand(0), N1.getOperand(0)) < 0) {
13686       // Note this is backward to how you would expect. We create
13687       // add(reduce(load + 16), reduce(load + 0)) so that the
13688       // add(reduce(load+16), X) is combined into VADDVA(X, load+16)), leaving
13689       // the X as VADDV(load + 0)
13690       return DAG.getNode(ISD::ADD, dl, VT, N1, N0);
13691     } else
13692       return SDValue();
13693 
13694     if (!IsVecReduce(N0) || !IsVecReduce(N1))
13695       return SDValue();
13696 
13697     if (IsKnownOrderedLoad(N1.getOperand(0), N0.getOperand(0)) >= 0)
13698       return SDValue();
13699 
13700     // Switch from add(add(X, N0), N1) to add(add(X, N1), N0)
13701     SDValue Add0 = DAG.getNode(ISD::ADD, dl, VT, X, N1);
13702     return DAG.getNode(ISD::ADD, dl, VT, Add0, N0);
13703   };
13704   if (SDValue R = DistrubuteVecReduceLoad(N0, N1, true))
13705     return R;
13706   if (SDValue R = DistrubuteVecReduceLoad(N1, N0, false))
13707     return R;
13708   return SDValue();
13709 }
13710 
PerformADDVecReduce(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)13711 static SDValue PerformADDVecReduce(SDNode *N, SelectionDAG &DAG,
13712                                    const ARMSubtarget *Subtarget) {
13713   if (!Subtarget->hasMVEIntegerOps())
13714     return SDValue();
13715 
13716   if (SDValue R = TryDistrubutionADDVecReduce(N, DAG))
13717     return R;
13718 
13719   EVT VT = N->getValueType(0);
13720   SDValue N0 = N->getOperand(0);
13721   SDValue N1 = N->getOperand(1);
13722   SDLoc dl(N);
13723 
13724   if (VT != MVT::i64)
13725     return SDValue();
13726 
13727   // We are looking for a i64 add of a VADDLVx. Due to these being i64's, this
13728   // will look like:
13729   //   t1: i32,i32 = ARMISD::VADDLVs x
13730   //   t2: i64 = build_pair t1, t1:1
13731   //   t3: i64 = add t2, y
13732   // Otherwise we try to push the add up above VADDLVAx, to potentially allow
13733   // the add to be simplified separately.
13734   // We also need to check for sext / zext and commutitive adds.
13735   auto MakeVecReduce = [&](unsigned Opcode, unsigned OpcodeA, SDValue NA,
13736                            SDValue NB) {
13737     if (NB->getOpcode() != ISD::BUILD_PAIR)
13738       return SDValue();
13739     SDValue VecRed = NB->getOperand(0);
13740     if ((VecRed->getOpcode() != Opcode && VecRed->getOpcode() != OpcodeA) ||
13741         VecRed.getResNo() != 0 ||
13742         NB->getOperand(1) != SDValue(VecRed.getNode(), 1))
13743       return SDValue();
13744 
13745     if (VecRed->getOpcode() == OpcodeA) {
13746       // add(NA, VADDLVA(Inp), Y) -> VADDLVA(add(NA, Inp), Y)
13747       SDValue Inp = DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64,
13748                                 VecRed.getOperand(0), VecRed.getOperand(1));
13749       NA = DAG.getNode(ISD::ADD, dl, MVT::i64, Inp, NA);
13750     }
13751 
13752     SmallVector<SDValue, 4> Ops(2);
13753     std::tie(Ops[0], Ops[1]) = DAG.SplitScalar(NA, dl, MVT::i32, MVT::i32);
13754 
13755     unsigned S = VecRed->getOpcode() == OpcodeA ? 2 : 0;
13756     for (unsigned I = S, E = VecRed.getNumOperands(); I < E; I++)
13757       Ops.push_back(VecRed->getOperand(I));
13758     SDValue Red =
13759         DAG.getNode(OpcodeA, dl, DAG.getVTList({MVT::i32, MVT::i32}), Ops);
13760     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Red,
13761                        SDValue(Red.getNode(), 1));
13762   };
13763 
13764   if (SDValue M = MakeVecReduce(ARMISD::VADDLVs, ARMISD::VADDLVAs, N0, N1))
13765     return M;
13766   if (SDValue M = MakeVecReduce(ARMISD::VADDLVu, ARMISD::VADDLVAu, N0, N1))
13767     return M;
13768   if (SDValue M = MakeVecReduce(ARMISD::VADDLVs, ARMISD::VADDLVAs, N1, N0))
13769     return M;
13770   if (SDValue M = MakeVecReduce(ARMISD::VADDLVu, ARMISD::VADDLVAu, N1, N0))
13771     return M;
13772   if (SDValue M = MakeVecReduce(ARMISD::VADDLVps, ARMISD::VADDLVAps, N0, N1))
13773     return M;
13774   if (SDValue M = MakeVecReduce(ARMISD::VADDLVpu, ARMISD::VADDLVApu, N0, N1))
13775     return M;
13776   if (SDValue M = MakeVecReduce(ARMISD::VADDLVps, ARMISD::VADDLVAps, N1, N0))
13777     return M;
13778   if (SDValue M = MakeVecReduce(ARMISD::VADDLVpu, ARMISD::VADDLVApu, N1, N0))
13779     return M;
13780   if (SDValue M = MakeVecReduce(ARMISD::VMLALVs, ARMISD::VMLALVAs, N0, N1))
13781     return M;
13782   if (SDValue M = MakeVecReduce(ARMISD::VMLALVu, ARMISD::VMLALVAu, N0, N1))
13783     return M;
13784   if (SDValue M = MakeVecReduce(ARMISD::VMLALVs, ARMISD::VMLALVAs, N1, N0))
13785     return M;
13786   if (SDValue M = MakeVecReduce(ARMISD::VMLALVu, ARMISD::VMLALVAu, N1, N0))
13787     return M;
13788   if (SDValue M = MakeVecReduce(ARMISD::VMLALVps, ARMISD::VMLALVAps, N0, N1))
13789     return M;
13790   if (SDValue M = MakeVecReduce(ARMISD::VMLALVpu, ARMISD::VMLALVApu, N0, N1))
13791     return M;
13792   if (SDValue M = MakeVecReduce(ARMISD::VMLALVps, ARMISD::VMLALVAps, N1, N0))
13793     return M;
13794   if (SDValue M = MakeVecReduce(ARMISD::VMLALVpu, ARMISD::VMLALVApu, N1, N0))
13795     return M;
13796   return SDValue();
13797 }
13798 
13799 bool
isDesirableToCommuteWithShift(const SDNode * N,CombineLevel Level) const13800 ARMTargetLowering::isDesirableToCommuteWithShift(const SDNode *N,
13801                                                  CombineLevel Level) const {
13802   assert((N->getOpcode() == ISD::SHL || N->getOpcode() == ISD::SRA ||
13803           N->getOpcode() == ISD::SRL) &&
13804          "Expected shift op");
13805 
13806   if (Level == BeforeLegalizeTypes)
13807     return true;
13808 
13809   if (N->getOpcode() != ISD::SHL)
13810     return true;
13811 
13812   if (Subtarget->isThumb1Only()) {
13813     // Avoid making expensive immediates by commuting shifts. (This logic
13814     // only applies to Thumb1 because ARM and Thumb2 immediates can be shifted
13815     // for free.)
13816     if (N->getOpcode() != ISD::SHL)
13817       return true;
13818     SDValue N1 = N->getOperand(0);
13819     if (N1->getOpcode() != ISD::ADD && N1->getOpcode() != ISD::AND &&
13820         N1->getOpcode() != ISD::OR && N1->getOpcode() != ISD::XOR)
13821       return true;
13822     if (auto *Const = dyn_cast<ConstantSDNode>(N1->getOperand(1))) {
13823       if (Const->getAPIntValue().ult(256))
13824         return false;
13825       if (N1->getOpcode() == ISD::ADD && Const->getAPIntValue().slt(0) &&
13826           Const->getAPIntValue().sgt(-256))
13827         return false;
13828     }
13829     return true;
13830   }
13831 
13832   // Turn off commute-with-shift transform after legalization, so it doesn't
13833   // conflict with PerformSHLSimplify.  (We could try to detect when
13834   // PerformSHLSimplify would trigger more precisely, but it isn't
13835   // really necessary.)
13836   return false;
13837 }
13838 
isDesirableToCommuteXorWithShift(const SDNode * N) const13839 bool ARMTargetLowering::isDesirableToCommuteXorWithShift(
13840     const SDNode *N) const {
13841   assert(N->getOpcode() == ISD::XOR &&
13842          (N->getOperand(0).getOpcode() == ISD::SHL ||
13843           N->getOperand(0).getOpcode() == ISD::SRL) &&
13844          "Expected XOR(SHIFT) pattern");
13845 
13846   // Only commute if the entire NOT mask is a hidden shifted mask.
13847   auto *XorC = dyn_cast<ConstantSDNode>(N->getOperand(1));
13848   auto *ShiftC = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1));
13849   if (XorC && ShiftC) {
13850     unsigned MaskIdx, MaskLen;
13851     if (XorC->getAPIntValue().isShiftedMask(MaskIdx, MaskLen)) {
13852       unsigned ShiftAmt = ShiftC->getZExtValue();
13853       unsigned BitWidth = N->getValueType(0).getScalarSizeInBits();
13854       if (N->getOperand(0).getOpcode() == ISD::SHL)
13855         return MaskIdx == ShiftAmt && MaskLen == (BitWidth - ShiftAmt);
13856       return MaskIdx == 0 && MaskLen == (BitWidth - ShiftAmt);
13857     }
13858   }
13859 
13860   return false;
13861 }
13862 
shouldFoldConstantShiftPairToMask(const SDNode * N,CombineLevel Level) const13863 bool ARMTargetLowering::shouldFoldConstantShiftPairToMask(
13864     const SDNode *N, CombineLevel Level) const {
13865   assert(((N->getOpcode() == ISD::SHL &&
13866            N->getOperand(0).getOpcode() == ISD::SRL) ||
13867           (N->getOpcode() == ISD::SRL &&
13868            N->getOperand(0).getOpcode() == ISD::SHL)) &&
13869          "Expected shift-shift mask");
13870 
13871   if (!Subtarget->isThumb1Only())
13872     return true;
13873 
13874   if (Level == BeforeLegalizeTypes)
13875     return true;
13876 
13877   return false;
13878 }
13879 
shouldFoldSelectWithIdentityConstant(unsigned BinOpcode,EVT VT) const13880 bool ARMTargetLowering::shouldFoldSelectWithIdentityConstant(unsigned BinOpcode,
13881                                                              EVT VT) const {
13882   return Subtarget->hasMVEIntegerOps() && isTypeLegal(VT);
13883 }
13884 
preferIncOfAddToSubOfNot(EVT VT) const13885 bool ARMTargetLowering::preferIncOfAddToSubOfNot(EVT VT) const {
13886   if (!Subtarget->hasNEON()) {
13887     if (Subtarget->isThumb1Only())
13888       return VT.getScalarSizeInBits() <= 32;
13889     return true;
13890   }
13891   return VT.isScalarInteger();
13892 }
13893 
shouldConvertFpToSat(unsigned Op,EVT FPVT,EVT VT) const13894 bool ARMTargetLowering::shouldConvertFpToSat(unsigned Op, EVT FPVT,
13895                                              EVT VT) const {
13896   if (!isOperationLegalOrCustom(Op, VT) || !FPVT.isSimple())
13897     return false;
13898 
13899   switch (FPVT.getSimpleVT().SimpleTy) {
13900   case MVT::f16:
13901     return Subtarget->hasVFP2Base();
13902   case MVT::f32:
13903     return Subtarget->hasVFP2Base();
13904   case MVT::f64:
13905     return Subtarget->hasFP64();
13906   case MVT::v4f32:
13907   case MVT::v8f16:
13908     return Subtarget->hasMVEFloatOps();
13909   default:
13910     return false;
13911   }
13912 }
13913 
PerformSHLSimplify(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * ST)13914 static SDValue PerformSHLSimplify(SDNode *N,
13915                                 TargetLowering::DAGCombinerInfo &DCI,
13916                                 const ARMSubtarget *ST) {
13917   // Allow the generic combiner to identify potential bswaps.
13918   if (DCI.isBeforeLegalize())
13919     return SDValue();
13920 
13921   // DAG combiner will fold:
13922   // (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
13923   // (shl (or x, c1), c2) -> (or (shl x, c2), c1 << c2
13924   // Other code patterns that can be also be modified have the following form:
13925   // b + ((a << 1) | 510)
13926   // b + ((a << 1) & 510)
13927   // b + ((a << 1) ^ 510)
13928   // b + ((a << 1) + 510)
13929 
13930   // Many instructions can  perform the shift for free, but it requires both
13931   // the operands to be registers. If c1 << c2 is too large, a mov immediate
13932   // instruction will needed. So, unfold back to the original pattern if:
13933   // - if c1 and c2 are small enough that they don't require mov imms.
13934   // - the user(s) of the node can perform an shl
13935 
13936   // No shifted operands for 16-bit instructions.
13937   if (ST->isThumb() && ST->isThumb1Only())
13938     return SDValue();
13939 
13940   // Check that all the users could perform the shl themselves.
13941   for (auto *U : N->uses()) {
13942     switch(U->getOpcode()) {
13943     default:
13944       return SDValue();
13945     case ISD::SUB:
13946     case ISD::ADD:
13947     case ISD::AND:
13948     case ISD::OR:
13949     case ISD::XOR:
13950     case ISD::SETCC:
13951     case ARMISD::CMP:
13952       // Check that the user isn't already using a constant because there
13953       // aren't any instructions that support an immediate operand and a
13954       // shifted operand.
13955       if (isa<ConstantSDNode>(U->getOperand(0)) ||
13956           isa<ConstantSDNode>(U->getOperand(1)))
13957         return SDValue();
13958 
13959       // Check that it's not already using a shift.
13960       if (U->getOperand(0).getOpcode() == ISD::SHL ||
13961           U->getOperand(1).getOpcode() == ISD::SHL)
13962         return SDValue();
13963       break;
13964     }
13965   }
13966 
13967   if (N->getOpcode() != ISD::ADD && N->getOpcode() != ISD::OR &&
13968       N->getOpcode() != ISD::XOR && N->getOpcode() != ISD::AND)
13969     return SDValue();
13970 
13971   if (N->getOperand(0).getOpcode() != ISD::SHL)
13972     return SDValue();
13973 
13974   SDValue SHL = N->getOperand(0);
13975 
13976   auto *C1ShlC2 = dyn_cast<ConstantSDNode>(N->getOperand(1));
13977   auto *C2 = dyn_cast<ConstantSDNode>(SHL.getOperand(1));
13978   if (!C1ShlC2 || !C2)
13979     return SDValue();
13980 
13981   APInt C2Int = C2->getAPIntValue();
13982   APInt C1Int = C1ShlC2->getAPIntValue();
13983   unsigned C2Width = C2Int.getBitWidth();
13984   if (C2Int.uge(C2Width))
13985     return SDValue();
13986   uint64_t C2Value = C2Int.getZExtValue();
13987 
13988   // Check that performing a lshr will not lose any information.
13989   APInt Mask = APInt::getHighBitsSet(C2Width, C2Width - C2Value);
13990   if ((C1Int & Mask) != C1Int)
13991     return SDValue();
13992 
13993   // Shift the first constant.
13994   C1Int.lshrInPlace(C2Int);
13995 
13996   // The immediates are encoded as an 8-bit value that can be rotated.
13997   auto LargeImm = [](const APInt &Imm) {
13998     unsigned Zeros = Imm.countl_zero() + Imm.countr_zero();
13999     return Imm.getBitWidth() - Zeros > 8;
14000   };
14001 
14002   if (LargeImm(C1Int) || LargeImm(C2Int))
14003     return SDValue();
14004 
14005   SelectionDAG &DAG = DCI.DAG;
14006   SDLoc dl(N);
14007   SDValue X = SHL.getOperand(0);
14008   SDValue BinOp = DAG.getNode(N->getOpcode(), dl, MVT::i32, X,
14009                               DAG.getConstant(C1Int, dl, MVT::i32));
14010   // Shift left to compensate for the lshr of C1Int.
14011   SDValue Res = DAG.getNode(ISD::SHL, dl, MVT::i32, BinOp, SHL.getOperand(1));
14012 
14013   LLVM_DEBUG(dbgs() << "Simplify shl use:\n"; SHL.getOperand(0).dump();
14014              SHL.dump(); N->dump());
14015   LLVM_DEBUG(dbgs() << "Into:\n"; X.dump(); BinOp.dump(); Res.dump());
14016   return Res;
14017 }
14018 
14019 
14020 /// PerformADDCombine - Target-specific dag combine xforms for ISD::ADD.
14021 ///
PerformADDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14022 static SDValue PerformADDCombine(SDNode *N,
14023                                  TargetLowering::DAGCombinerInfo &DCI,
14024                                  const ARMSubtarget *Subtarget) {
14025   SDValue N0 = N->getOperand(0);
14026   SDValue N1 = N->getOperand(1);
14027 
14028   // Only works one way, because it needs an immediate operand.
14029   if (SDValue Result = PerformSHLSimplify(N, DCI, Subtarget))
14030     return Result;
14031 
14032   if (SDValue Result = PerformADDVecReduce(N, DCI.DAG, Subtarget))
14033     return Result;
14034 
14035   // First try with the default operand order.
14036   if (SDValue Result = PerformADDCombineWithOperands(N, N0, N1, DCI, Subtarget))
14037     return Result;
14038 
14039   // If that didn't work, try again with the operands commuted.
14040   return PerformADDCombineWithOperands(N, N1, N0, DCI, Subtarget);
14041 }
14042 
14043 // Combine (sub 0, (csinc X, Y, CC)) -> (csinv -X, Y, CC)
14044 //   providing -X is as cheap as X (currently, just a constant).
PerformSubCSINCCombine(SDNode * N,SelectionDAG & DAG)14045 static SDValue PerformSubCSINCCombine(SDNode *N, SelectionDAG &DAG) {
14046   if (N->getValueType(0) != MVT::i32 || !isNullConstant(N->getOperand(0)))
14047     return SDValue();
14048   SDValue CSINC = N->getOperand(1);
14049   if (CSINC.getOpcode() != ARMISD::CSINC || !CSINC.hasOneUse())
14050     return SDValue();
14051 
14052   ConstantSDNode *X = dyn_cast<ConstantSDNode>(CSINC.getOperand(0));
14053   if (!X)
14054     return SDValue();
14055 
14056   return DAG.getNode(ARMISD::CSINV, SDLoc(N), MVT::i32,
14057                      DAG.getNode(ISD::SUB, SDLoc(N), MVT::i32, N->getOperand(0),
14058                                  CSINC.getOperand(0)),
14059                      CSINC.getOperand(1), CSINC.getOperand(2),
14060                      CSINC.getOperand(3));
14061 }
14062 
14063 /// PerformSUBCombine - Target-specific dag combine xforms for ISD::SUB.
14064 ///
PerformSUBCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14065 static SDValue PerformSUBCombine(SDNode *N,
14066                                  TargetLowering::DAGCombinerInfo &DCI,
14067                                  const ARMSubtarget *Subtarget) {
14068   SDValue N0 = N->getOperand(0);
14069   SDValue N1 = N->getOperand(1);
14070 
14071   // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
14072   if (N1.getNode()->hasOneUse())
14073     if (SDValue Result = combineSelectAndUse(N, N1, N0, DCI))
14074       return Result;
14075 
14076   if (SDValue R = PerformSubCSINCCombine(N, DCI.DAG))
14077     return R;
14078 
14079   if (!Subtarget->hasMVEIntegerOps() || !N->getValueType(0).isVector())
14080     return SDValue();
14081 
14082   // Fold (sub (ARMvmovImm 0), (ARMvdup x)) -> (ARMvdup (sub 0, x))
14083   // so that we can readily pattern match more mve instructions which can use
14084   // a scalar operand.
14085   SDValue VDup = N->getOperand(1);
14086   if (VDup->getOpcode() != ARMISD::VDUP)
14087     return SDValue();
14088 
14089   SDValue VMov = N->getOperand(0);
14090   if (VMov->getOpcode() == ISD::BITCAST)
14091     VMov = VMov->getOperand(0);
14092 
14093   if (VMov->getOpcode() != ARMISD::VMOVIMM || !isZeroVector(VMov))
14094     return SDValue();
14095 
14096   SDLoc dl(N);
14097   SDValue Negate = DCI.DAG.getNode(ISD::SUB, dl, MVT::i32,
14098                                    DCI.DAG.getConstant(0, dl, MVT::i32),
14099                                    VDup->getOperand(0));
14100   return DCI.DAG.getNode(ARMISD::VDUP, dl, N->getValueType(0), Negate);
14101 }
14102 
14103 /// PerformVMULCombine
14104 /// Distribute (A + B) * C to (A * C) + (B * C) to take advantage of the
14105 /// special multiplier accumulator forwarding.
14106 ///   vmul d3, d0, d2
14107 ///   vmla d3, d1, d2
14108 /// is faster than
14109 ///   vadd d3, d0, d1
14110 ///   vmul d3, d3, d2
14111 //  However, for (A + B) * (A + B),
14112 //    vadd d2, d0, d1
14113 //    vmul d3, d0, d2
14114 //    vmla d3, d1, d2
14115 //  is slower than
14116 //    vadd d2, d0, d1
14117 //    vmul d3, d2, d2
PerformVMULCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14118 static SDValue PerformVMULCombine(SDNode *N,
14119                                   TargetLowering::DAGCombinerInfo &DCI,
14120                                   const ARMSubtarget *Subtarget) {
14121   if (!Subtarget->hasVMLxForwarding())
14122     return SDValue();
14123 
14124   SelectionDAG &DAG = DCI.DAG;
14125   SDValue N0 = N->getOperand(0);
14126   SDValue N1 = N->getOperand(1);
14127   unsigned Opcode = N0.getOpcode();
14128   if (Opcode != ISD::ADD && Opcode != ISD::SUB &&
14129       Opcode != ISD::FADD && Opcode != ISD::FSUB) {
14130     Opcode = N1.getOpcode();
14131     if (Opcode != ISD::ADD && Opcode != ISD::SUB &&
14132         Opcode != ISD::FADD && Opcode != ISD::FSUB)
14133       return SDValue();
14134     std::swap(N0, N1);
14135   }
14136 
14137   if (N0 == N1)
14138     return SDValue();
14139 
14140   EVT VT = N->getValueType(0);
14141   SDLoc DL(N);
14142   SDValue N00 = N0->getOperand(0);
14143   SDValue N01 = N0->getOperand(1);
14144   return DAG.getNode(Opcode, DL, VT,
14145                      DAG.getNode(ISD::MUL, DL, VT, N00, N1),
14146                      DAG.getNode(ISD::MUL, DL, VT, N01, N1));
14147 }
14148 
PerformMVEVMULLCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)14149 static SDValue PerformMVEVMULLCombine(SDNode *N, SelectionDAG &DAG,
14150                                       const ARMSubtarget *Subtarget) {
14151   EVT VT = N->getValueType(0);
14152   if (VT != MVT::v2i64)
14153     return SDValue();
14154 
14155   SDValue N0 = N->getOperand(0);
14156   SDValue N1 = N->getOperand(1);
14157 
14158   auto IsSignExt = [&](SDValue Op) {
14159     if (Op->getOpcode() != ISD::SIGN_EXTEND_INREG)
14160       return SDValue();
14161     EVT VT = cast<VTSDNode>(Op->getOperand(1))->getVT();
14162     if (VT.getScalarSizeInBits() == 32)
14163       return Op->getOperand(0);
14164     return SDValue();
14165   };
14166   auto IsZeroExt = [&](SDValue Op) {
14167     // Zero extends are a little more awkward. At the point we are matching
14168     // this, we are looking for an AND with a (-1, 0, -1, 0) buildvector mask.
14169     // That might be before of after a bitcast depending on how the and is
14170     // placed. Because this has to look through bitcasts, it is currently only
14171     // supported on LE.
14172     if (!Subtarget->isLittle())
14173       return SDValue();
14174 
14175     SDValue And = Op;
14176     if (And->getOpcode() == ISD::BITCAST)
14177       And = And->getOperand(0);
14178     if (And->getOpcode() != ISD::AND)
14179       return SDValue();
14180     SDValue Mask = And->getOperand(1);
14181     if (Mask->getOpcode() == ISD::BITCAST)
14182       Mask = Mask->getOperand(0);
14183 
14184     if (Mask->getOpcode() != ISD::BUILD_VECTOR ||
14185         Mask.getValueType() != MVT::v4i32)
14186       return SDValue();
14187     if (isAllOnesConstant(Mask->getOperand(0)) &&
14188         isNullConstant(Mask->getOperand(1)) &&
14189         isAllOnesConstant(Mask->getOperand(2)) &&
14190         isNullConstant(Mask->getOperand(3)))
14191       return And->getOperand(0);
14192     return SDValue();
14193   };
14194 
14195   SDLoc dl(N);
14196   if (SDValue Op0 = IsSignExt(N0)) {
14197     if (SDValue Op1 = IsSignExt(N1)) {
14198       SDValue New0a = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, Op0);
14199       SDValue New1a = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, Op1);
14200       return DAG.getNode(ARMISD::VMULLs, dl, VT, New0a, New1a);
14201     }
14202   }
14203   if (SDValue Op0 = IsZeroExt(N0)) {
14204     if (SDValue Op1 = IsZeroExt(N1)) {
14205       SDValue New0a = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, Op0);
14206       SDValue New1a = DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v4i32, Op1);
14207       return DAG.getNode(ARMISD::VMULLu, dl, VT, New0a, New1a);
14208     }
14209   }
14210 
14211   return SDValue();
14212 }
14213 
PerformMULCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14214 static SDValue PerformMULCombine(SDNode *N,
14215                                  TargetLowering::DAGCombinerInfo &DCI,
14216                                  const ARMSubtarget *Subtarget) {
14217   SelectionDAG &DAG = DCI.DAG;
14218 
14219   EVT VT = N->getValueType(0);
14220   if (Subtarget->hasMVEIntegerOps() && VT == MVT::v2i64)
14221     return PerformMVEVMULLCombine(N, DAG, Subtarget);
14222 
14223   if (Subtarget->isThumb1Only())
14224     return SDValue();
14225 
14226   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
14227     return SDValue();
14228 
14229   if (VT.is64BitVector() || VT.is128BitVector())
14230     return PerformVMULCombine(N, DCI, Subtarget);
14231   if (VT != MVT::i32)
14232     return SDValue();
14233 
14234   ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
14235   if (!C)
14236     return SDValue();
14237 
14238   int64_t MulAmt = C->getSExtValue();
14239   unsigned ShiftAmt = llvm::countr_zero<uint64_t>(MulAmt);
14240 
14241   ShiftAmt = ShiftAmt & (32 - 1);
14242   SDValue V = N->getOperand(0);
14243   SDLoc DL(N);
14244 
14245   SDValue Res;
14246   MulAmt >>= ShiftAmt;
14247 
14248   if (MulAmt >= 0) {
14249     if (llvm::has_single_bit<uint32_t>(MulAmt - 1)) {
14250       // (mul x, 2^N + 1) => (add (shl x, N), x)
14251       Res = DAG.getNode(ISD::ADD, DL, VT,
14252                         V,
14253                         DAG.getNode(ISD::SHL, DL, VT,
14254                                     V,
14255                                     DAG.getConstant(Log2_32(MulAmt - 1), DL,
14256                                                     MVT::i32)));
14257     } else if (llvm::has_single_bit<uint32_t>(MulAmt + 1)) {
14258       // (mul x, 2^N - 1) => (sub (shl x, N), x)
14259       Res = DAG.getNode(ISD::SUB, DL, VT,
14260                         DAG.getNode(ISD::SHL, DL, VT,
14261                                     V,
14262                                     DAG.getConstant(Log2_32(MulAmt + 1), DL,
14263                                                     MVT::i32)),
14264                         V);
14265     } else
14266       return SDValue();
14267   } else {
14268     uint64_t MulAmtAbs = -MulAmt;
14269     if (llvm::has_single_bit<uint32_t>(MulAmtAbs + 1)) {
14270       // (mul x, -(2^N - 1)) => (sub x, (shl x, N))
14271       Res = DAG.getNode(ISD::SUB, DL, VT,
14272                         V,
14273                         DAG.getNode(ISD::SHL, DL, VT,
14274                                     V,
14275                                     DAG.getConstant(Log2_32(MulAmtAbs + 1), DL,
14276                                                     MVT::i32)));
14277     } else if (llvm::has_single_bit<uint32_t>(MulAmtAbs - 1)) {
14278       // (mul x, -(2^N + 1)) => - (add (shl x, N), x)
14279       Res = DAG.getNode(ISD::ADD, DL, VT,
14280                         V,
14281                         DAG.getNode(ISD::SHL, DL, VT,
14282                                     V,
14283                                     DAG.getConstant(Log2_32(MulAmtAbs - 1), DL,
14284                                                     MVT::i32)));
14285       Res = DAG.getNode(ISD::SUB, DL, VT,
14286                         DAG.getConstant(0, DL, MVT::i32), Res);
14287     } else
14288       return SDValue();
14289   }
14290 
14291   if (ShiftAmt != 0)
14292     Res = DAG.getNode(ISD::SHL, DL, VT,
14293                       Res, DAG.getConstant(ShiftAmt, DL, MVT::i32));
14294 
14295   // Do not add new nodes to DAG combiner worklist.
14296   DCI.CombineTo(N, Res, false);
14297   return SDValue();
14298 }
14299 
CombineANDShift(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14300 static SDValue CombineANDShift(SDNode *N,
14301                                TargetLowering::DAGCombinerInfo &DCI,
14302                                const ARMSubtarget *Subtarget) {
14303   // Allow DAGCombine to pattern-match before we touch the canonical form.
14304   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
14305     return SDValue();
14306 
14307   if (N->getValueType(0) != MVT::i32)
14308     return SDValue();
14309 
14310   ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1));
14311   if (!N1C)
14312     return SDValue();
14313 
14314   uint32_t C1 = (uint32_t)N1C->getZExtValue();
14315   // Don't transform uxtb/uxth.
14316   if (C1 == 255 || C1 == 65535)
14317     return SDValue();
14318 
14319   SDNode *N0 = N->getOperand(0).getNode();
14320   if (!N0->hasOneUse())
14321     return SDValue();
14322 
14323   if (N0->getOpcode() != ISD::SHL && N0->getOpcode() != ISD::SRL)
14324     return SDValue();
14325 
14326   bool LeftShift = N0->getOpcode() == ISD::SHL;
14327 
14328   ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0->getOperand(1));
14329   if (!N01C)
14330     return SDValue();
14331 
14332   uint32_t C2 = (uint32_t)N01C->getZExtValue();
14333   if (!C2 || C2 >= 32)
14334     return SDValue();
14335 
14336   // Clear irrelevant bits in the mask.
14337   if (LeftShift)
14338     C1 &= (-1U << C2);
14339   else
14340     C1 &= (-1U >> C2);
14341 
14342   SelectionDAG &DAG = DCI.DAG;
14343   SDLoc DL(N);
14344 
14345   // We have a pattern of the form "(and (shl x, c2) c1)" or
14346   // "(and (srl x, c2) c1)", where c1 is a shifted mask. Try to
14347   // transform to a pair of shifts, to save materializing c1.
14348 
14349   // First pattern: right shift, then mask off leading bits.
14350   // FIXME: Use demanded bits?
14351   if (!LeftShift && isMask_32(C1)) {
14352     uint32_t C3 = llvm::countl_zero(C1);
14353     if (C2 < C3) {
14354       SDValue SHL = DAG.getNode(ISD::SHL, DL, MVT::i32, N0->getOperand(0),
14355                                 DAG.getConstant(C3 - C2, DL, MVT::i32));
14356       return DAG.getNode(ISD::SRL, DL, MVT::i32, SHL,
14357                          DAG.getConstant(C3, DL, MVT::i32));
14358     }
14359   }
14360 
14361   // First pattern, reversed: left shift, then mask off trailing bits.
14362   if (LeftShift && isMask_32(~C1)) {
14363     uint32_t C3 = llvm::countr_zero(C1);
14364     if (C2 < C3) {
14365       SDValue SHL = DAG.getNode(ISD::SRL, DL, MVT::i32, N0->getOperand(0),
14366                                 DAG.getConstant(C3 - C2, DL, MVT::i32));
14367       return DAG.getNode(ISD::SHL, DL, MVT::i32, SHL,
14368                          DAG.getConstant(C3, DL, MVT::i32));
14369     }
14370   }
14371 
14372   // Second pattern: left shift, then mask off leading bits.
14373   // FIXME: Use demanded bits?
14374   if (LeftShift && isShiftedMask_32(C1)) {
14375     uint32_t Trailing = llvm::countr_zero(C1);
14376     uint32_t C3 = llvm::countl_zero(C1);
14377     if (Trailing == C2 && C2 + C3 < 32) {
14378       SDValue SHL = DAG.getNode(ISD::SHL, DL, MVT::i32, N0->getOperand(0),
14379                                 DAG.getConstant(C2 + C3, DL, MVT::i32));
14380       return DAG.getNode(ISD::SRL, DL, MVT::i32, SHL,
14381                         DAG.getConstant(C3, DL, MVT::i32));
14382     }
14383   }
14384 
14385   // Second pattern, reversed: right shift, then mask off trailing bits.
14386   // FIXME: Handle other patterns of known/demanded bits.
14387   if (!LeftShift && isShiftedMask_32(C1)) {
14388     uint32_t Leading = llvm::countl_zero(C1);
14389     uint32_t C3 = llvm::countr_zero(C1);
14390     if (Leading == C2 && C2 + C3 < 32) {
14391       SDValue SHL = DAG.getNode(ISD::SRL, DL, MVT::i32, N0->getOperand(0),
14392                                 DAG.getConstant(C2 + C3, DL, MVT::i32));
14393       return DAG.getNode(ISD::SHL, DL, MVT::i32, SHL,
14394                          DAG.getConstant(C3, DL, MVT::i32));
14395     }
14396   }
14397 
14398   // Transform "(and (shl x, c2) c1)" into "(shl (and x, c1>>c2), c2)"
14399   // if "c1 >> c2" is a cheaper immediate than "c1"
14400   if (LeftShift &&
14401       HasLowerConstantMaterializationCost(C1 >> C2, C1, Subtarget)) {
14402 
14403     SDValue And = DAG.getNode(ISD::AND, DL, MVT::i32, N0->getOperand(0),
14404                               DAG.getConstant(C1 >> C2, DL, MVT::i32));
14405     return DAG.getNode(ISD::SHL, DL, MVT::i32, And,
14406                        DAG.getConstant(C2, DL, MVT::i32));
14407   }
14408 
14409   return SDValue();
14410 }
14411 
PerformANDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14412 static SDValue PerformANDCombine(SDNode *N,
14413                                  TargetLowering::DAGCombinerInfo &DCI,
14414                                  const ARMSubtarget *Subtarget) {
14415   // Attempt to use immediate-form VBIC
14416   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(1));
14417   SDLoc dl(N);
14418   EVT VT = N->getValueType(0);
14419   SelectionDAG &DAG = DCI.DAG;
14420 
14421   if (!DAG.getTargetLoweringInfo().isTypeLegal(VT) || VT == MVT::v2i1 ||
14422       VT == MVT::v4i1 || VT == MVT::v8i1 || VT == MVT::v16i1)
14423     return SDValue();
14424 
14425   APInt SplatBits, SplatUndef;
14426   unsigned SplatBitSize;
14427   bool HasAnyUndefs;
14428   if (BVN && (Subtarget->hasNEON() || Subtarget->hasMVEIntegerOps()) &&
14429       BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
14430     if (SplatBitSize == 8 || SplatBitSize == 16 || SplatBitSize == 32 ||
14431         SplatBitSize == 64) {
14432       EVT VbicVT;
14433       SDValue Val = isVMOVModifiedImm((~SplatBits).getZExtValue(),
14434                                       SplatUndef.getZExtValue(), SplatBitSize,
14435                                       DAG, dl, VbicVT, VT, OtherModImm);
14436       if (Val.getNode()) {
14437         SDValue Input =
14438           DAG.getNode(ISD::BITCAST, dl, VbicVT, N->getOperand(0));
14439         SDValue Vbic = DAG.getNode(ARMISD::VBICIMM, dl, VbicVT, Input, Val);
14440         return DAG.getNode(ISD::BITCAST, dl, VT, Vbic);
14441       }
14442     }
14443   }
14444 
14445   if (!Subtarget->isThumb1Only()) {
14446     // fold (and (select cc, -1, c), x) -> (select cc, x, (and, x, c))
14447     if (SDValue Result = combineSelectAndUseCommutative(N, true, DCI))
14448       return Result;
14449 
14450     if (SDValue Result = PerformSHLSimplify(N, DCI, Subtarget))
14451       return Result;
14452   }
14453 
14454   if (Subtarget->isThumb1Only())
14455     if (SDValue Result = CombineANDShift(N, DCI, Subtarget))
14456       return Result;
14457 
14458   return SDValue();
14459 }
14460 
14461 // Try combining OR nodes to SMULWB, SMULWT.
PerformORCombineToSMULWBT(SDNode * OR,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14462 static SDValue PerformORCombineToSMULWBT(SDNode *OR,
14463                                          TargetLowering::DAGCombinerInfo &DCI,
14464                                          const ARMSubtarget *Subtarget) {
14465   if (!Subtarget->hasV6Ops() ||
14466       (Subtarget->isThumb() &&
14467        (!Subtarget->hasThumb2() || !Subtarget->hasDSP())))
14468     return SDValue();
14469 
14470   SDValue SRL = OR->getOperand(0);
14471   SDValue SHL = OR->getOperand(1);
14472 
14473   if (SRL.getOpcode() != ISD::SRL || SHL.getOpcode() != ISD::SHL) {
14474     SRL = OR->getOperand(1);
14475     SHL = OR->getOperand(0);
14476   }
14477   if (!isSRL16(SRL) || !isSHL16(SHL))
14478     return SDValue();
14479 
14480   // The first operands to the shifts need to be the two results from the
14481   // same smul_lohi node.
14482   if ((SRL.getOperand(0).getNode() != SHL.getOperand(0).getNode()) ||
14483        SRL.getOperand(0).getOpcode() != ISD::SMUL_LOHI)
14484     return SDValue();
14485 
14486   SDNode *SMULLOHI = SRL.getOperand(0).getNode();
14487   if (SRL.getOperand(0) != SDValue(SMULLOHI, 0) ||
14488       SHL.getOperand(0) != SDValue(SMULLOHI, 1))
14489     return SDValue();
14490 
14491   // Now we have:
14492   // (or (srl (smul_lohi ?, ?), 16), (shl (smul_lohi ?, ?), 16)))
14493   // For SMUL[B|T] smul_lohi will take a 32-bit and a 16-bit arguments.
14494   // For SMUWB the 16-bit value will signed extended somehow.
14495   // For SMULWT only the SRA is required.
14496   // Check both sides of SMUL_LOHI
14497   SDValue OpS16 = SMULLOHI->getOperand(0);
14498   SDValue OpS32 = SMULLOHI->getOperand(1);
14499 
14500   SelectionDAG &DAG = DCI.DAG;
14501   if (!isS16(OpS16, DAG) && !isSRA16(OpS16)) {
14502     OpS16 = OpS32;
14503     OpS32 = SMULLOHI->getOperand(0);
14504   }
14505 
14506   SDLoc dl(OR);
14507   unsigned Opcode = 0;
14508   if (isS16(OpS16, DAG))
14509     Opcode = ARMISD::SMULWB;
14510   else if (isSRA16(OpS16)) {
14511     Opcode = ARMISD::SMULWT;
14512     OpS16 = OpS16->getOperand(0);
14513   }
14514   else
14515     return SDValue();
14516 
14517   SDValue Res = DAG.getNode(Opcode, dl, MVT::i32, OpS32, OpS16);
14518   DAG.ReplaceAllUsesOfValueWith(SDValue(OR, 0), Res);
14519   return SDValue(OR, 0);
14520 }
14521 
PerformORCombineToBFI(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14522 static SDValue PerformORCombineToBFI(SDNode *N,
14523                                      TargetLowering::DAGCombinerInfo &DCI,
14524                                      const ARMSubtarget *Subtarget) {
14525   // BFI is only available on V6T2+
14526   if (Subtarget->isThumb1Only() || !Subtarget->hasV6T2Ops())
14527     return SDValue();
14528 
14529   EVT VT = N->getValueType(0);
14530   SDValue N0 = N->getOperand(0);
14531   SDValue N1 = N->getOperand(1);
14532   SelectionDAG &DAG = DCI.DAG;
14533   SDLoc DL(N);
14534   // 1) or (and A, mask), val => ARMbfi A, val, mask
14535   //      iff (val & mask) == val
14536   //
14537   // 2) or (and A, mask), (and B, mask2) => ARMbfi A, (lsr B, amt), mask
14538   //  2a) iff isBitFieldInvertedMask(mask) && isBitFieldInvertedMask(~mask2)
14539   //          && mask == ~mask2
14540   //  2b) iff isBitFieldInvertedMask(~mask) && isBitFieldInvertedMask(mask2)
14541   //          && ~mask == mask2
14542   //  (i.e., copy a bitfield value into another bitfield of the same width)
14543 
14544   if (VT != MVT::i32)
14545     return SDValue();
14546 
14547   SDValue N00 = N0.getOperand(0);
14548 
14549   // The value and the mask need to be constants so we can verify this is
14550   // actually a bitfield set. If the mask is 0xffff, we can do better
14551   // via a movt instruction, so don't use BFI in that case.
14552   SDValue MaskOp = N0.getOperand(1);
14553   ConstantSDNode *MaskC = dyn_cast<ConstantSDNode>(MaskOp);
14554   if (!MaskC)
14555     return SDValue();
14556   unsigned Mask = MaskC->getZExtValue();
14557   if (Mask == 0xffff)
14558     return SDValue();
14559   SDValue Res;
14560   // Case (1): or (and A, mask), val => ARMbfi A, val, mask
14561   ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
14562   if (N1C) {
14563     unsigned Val = N1C->getZExtValue();
14564     if ((Val & ~Mask) != Val)
14565       return SDValue();
14566 
14567     if (ARM::isBitFieldInvertedMask(Mask)) {
14568       Val >>= llvm::countr_zero(~Mask);
14569 
14570       Res = DAG.getNode(ARMISD::BFI, DL, VT, N00,
14571                         DAG.getConstant(Val, DL, MVT::i32),
14572                         DAG.getConstant(Mask, DL, MVT::i32));
14573 
14574       DCI.CombineTo(N, Res, false);
14575       // Return value from the original node to inform the combiner than N is
14576       // now dead.
14577       return SDValue(N, 0);
14578     }
14579   } else if (N1.getOpcode() == ISD::AND) {
14580     // case (2) or (and A, mask), (and B, mask2) => ARMbfi A, (lsr B, amt), mask
14581     ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
14582     if (!N11C)
14583       return SDValue();
14584     unsigned Mask2 = N11C->getZExtValue();
14585 
14586     // Mask and ~Mask2 (or reverse) must be equivalent for the BFI pattern
14587     // as is to match.
14588     if (ARM::isBitFieldInvertedMask(Mask) &&
14589         (Mask == ~Mask2)) {
14590       // The pack halfword instruction works better for masks that fit it,
14591       // so use that when it's available.
14592       if (Subtarget->hasDSP() &&
14593           (Mask == 0xffff || Mask == 0xffff0000))
14594         return SDValue();
14595       // 2a
14596       unsigned amt = llvm::countr_zero(Mask2);
14597       Res = DAG.getNode(ISD::SRL, DL, VT, N1.getOperand(0),
14598                         DAG.getConstant(amt, DL, MVT::i32));
14599       Res = DAG.getNode(ARMISD::BFI, DL, VT, N00, Res,
14600                         DAG.getConstant(Mask, DL, MVT::i32));
14601       DCI.CombineTo(N, Res, false);
14602       // Return value from the original node to inform the combiner than N is
14603       // now dead.
14604       return SDValue(N, 0);
14605     } else if (ARM::isBitFieldInvertedMask(~Mask) &&
14606                (~Mask == Mask2)) {
14607       // The pack halfword instruction works better for masks that fit it,
14608       // so use that when it's available.
14609       if (Subtarget->hasDSP() &&
14610           (Mask2 == 0xffff || Mask2 == 0xffff0000))
14611         return SDValue();
14612       // 2b
14613       unsigned lsb = llvm::countr_zero(Mask);
14614       Res = DAG.getNode(ISD::SRL, DL, VT, N00,
14615                         DAG.getConstant(lsb, DL, MVT::i32));
14616       Res = DAG.getNode(ARMISD::BFI, DL, VT, N1.getOperand(0), Res,
14617                         DAG.getConstant(Mask2, DL, MVT::i32));
14618       DCI.CombineTo(N, Res, false);
14619       // Return value from the original node to inform the combiner than N is
14620       // now dead.
14621       return SDValue(N, 0);
14622     }
14623   }
14624 
14625   if (DAG.MaskedValueIsZero(N1, MaskC->getAPIntValue()) &&
14626       N00.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N00.getOperand(1)) &&
14627       ARM::isBitFieldInvertedMask(~Mask)) {
14628     // Case (3): or (and (shl A, #shamt), mask), B => ARMbfi B, A, ~mask
14629     // where lsb(mask) == #shamt and masked bits of B are known zero.
14630     SDValue ShAmt = N00.getOperand(1);
14631     unsigned ShAmtC = ShAmt->getAsZExtVal();
14632     unsigned LSB = llvm::countr_zero(Mask);
14633     if (ShAmtC != LSB)
14634       return SDValue();
14635 
14636     Res = DAG.getNode(ARMISD::BFI, DL, VT, N1, N00.getOperand(0),
14637                       DAG.getConstant(~Mask, DL, MVT::i32));
14638 
14639     DCI.CombineTo(N, Res, false);
14640     // Return value from the original node to inform the combiner than N is
14641     // now dead.
14642     return SDValue(N, 0);
14643   }
14644 
14645   return SDValue();
14646 }
14647 
isValidMVECond(unsigned CC,bool IsFloat)14648 static bool isValidMVECond(unsigned CC, bool IsFloat) {
14649   switch (CC) {
14650   case ARMCC::EQ:
14651   case ARMCC::NE:
14652   case ARMCC::LE:
14653   case ARMCC::GT:
14654   case ARMCC::GE:
14655   case ARMCC::LT:
14656     return true;
14657   case ARMCC::HS:
14658   case ARMCC::HI:
14659     return !IsFloat;
14660   default:
14661     return false;
14662   };
14663 }
14664 
getVCMPCondCode(SDValue N)14665 static ARMCC::CondCodes getVCMPCondCode(SDValue N) {
14666   if (N->getOpcode() == ARMISD::VCMP)
14667     return (ARMCC::CondCodes)N->getConstantOperandVal(2);
14668   else if (N->getOpcode() == ARMISD::VCMPZ)
14669     return (ARMCC::CondCodes)N->getConstantOperandVal(1);
14670   else
14671     llvm_unreachable("Not a VCMP/VCMPZ!");
14672 }
14673 
CanInvertMVEVCMP(SDValue N)14674 static bool CanInvertMVEVCMP(SDValue N) {
14675   ARMCC::CondCodes CC = ARMCC::getOppositeCondition(getVCMPCondCode(N));
14676   return isValidMVECond(CC, N->getOperand(0).getValueType().isFloatingPoint());
14677 }
14678 
PerformORCombine_i1(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)14679 static SDValue PerformORCombine_i1(SDNode *N, SelectionDAG &DAG,
14680                                    const ARMSubtarget *Subtarget) {
14681   // Try to invert "or A, B" -> "and ~A, ~B", as the "and" is easier to chain
14682   // together with predicates
14683   EVT VT = N->getValueType(0);
14684   SDLoc DL(N);
14685   SDValue N0 = N->getOperand(0);
14686   SDValue N1 = N->getOperand(1);
14687 
14688   auto IsFreelyInvertable = [&](SDValue V) {
14689     if (V->getOpcode() == ARMISD::VCMP || V->getOpcode() == ARMISD::VCMPZ)
14690       return CanInvertMVEVCMP(V);
14691     return false;
14692   };
14693 
14694   // At least one operand must be freely invertable.
14695   if (!(IsFreelyInvertable(N0) || IsFreelyInvertable(N1)))
14696     return SDValue();
14697 
14698   SDValue NewN0 = DAG.getLogicalNOT(DL, N0, VT);
14699   SDValue NewN1 = DAG.getLogicalNOT(DL, N1, VT);
14700   SDValue And = DAG.getNode(ISD::AND, DL, VT, NewN0, NewN1);
14701   return DAG.getLogicalNOT(DL, And, VT);
14702 }
14703 
14704 /// PerformORCombine - Target-specific dag combine xforms for ISD::OR
PerformORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14705 static SDValue PerformORCombine(SDNode *N,
14706                                 TargetLowering::DAGCombinerInfo &DCI,
14707                                 const ARMSubtarget *Subtarget) {
14708   // Attempt to use immediate-form VORR
14709   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(1));
14710   SDLoc dl(N);
14711   EVT VT = N->getValueType(0);
14712   SelectionDAG &DAG = DCI.DAG;
14713 
14714   if(!DAG.getTargetLoweringInfo().isTypeLegal(VT))
14715     return SDValue();
14716 
14717   if (Subtarget->hasMVEIntegerOps() && (VT == MVT::v2i1 || VT == MVT::v4i1 ||
14718                                         VT == MVT::v8i1 || VT == MVT::v16i1))
14719     return PerformORCombine_i1(N, DAG, Subtarget);
14720 
14721   APInt SplatBits, SplatUndef;
14722   unsigned SplatBitSize;
14723   bool HasAnyUndefs;
14724   if (BVN && (Subtarget->hasNEON() || Subtarget->hasMVEIntegerOps()) &&
14725       BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
14726     if (SplatBitSize == 8 || SplatBitSize == 16 || SplatBitSize == 32 ||
14727         SplatBitSize == 64) {
14728       EVT VorrVT;
14729       SDValue Val =
14730           isVMOVModifiedImm(SplatBits.getZExtValue(), SplatUndef.getZExtValue(),
14731                             SplatBitSize, DAG, dl, VorrVT, VT, OtherModImm);
14732       if (Val.getNode()) {
14733         SDValue Input =
14734           DAG.getNode(ISD::BITCAST, dl, VorrVT, N->getOperand(0));
14735         SDValue Vorr = DAG.getNode(ARMISD::VORRIMM, dl, VorrVT, Input, Val);
14736         return DAG.getNode(ISD::BITCAST, dl, VT, Vorr);
14737       }
14738     }
14739   }
14740 
14741   if (!Subtarget->isThumb1Only()) {
14742     // fold (or (select cc, 0, c), x) -> (select cc, x, (or, x, c))
14743     if (SDValue Result = combineSelectAndUseCommutative(N, false, DCI))
14744       return Result;
14745     if (SDValue Result = PerformORCombineToSMULWBT(N, DCI, Subtarget))
14746       return Result;
14747   }
14748 
14749   SDValue N0 = N->getOperand(0);
14750   SDValue N1 = N->getOperand(1);
14751 
14752   // (or (and B, A), (and C, ~A)) => (VBSL A, B, C) when A is a constant.
14753   if (Subtarget->hasNEON() && N1.getOpcode() == ISD::AND && VT.isVector() &&
14754       DAG.getTargetLoweringInfo().isTypeLegal(VT)) {
14755 
14756     // The code below optimizes (or (and X, Y), Z).
14757     // The AND operand needs to have a single user to make these optimizations
14758     // profitable.
14759     if (N0.getOpcode() != ISD::AND || !N0.hasOneUse())
14760       return SDValue();
14761 
14762     APInt SplatUndef;
14763     unsigned SplatBitSize;
14764     bool HasAnyUndefs;
14765 
14766     APInt SplatBits0, SplatBits1;
14767     BuildVectorSDNode *BVN0 = dyn_cast<BuildVectorSDNode>(N0->getOperand(1));
14768     BuildVectorSDNode *BVN1 = dyn_cast<BuildVectorSDNode>(N1->getOperand(1));
14769     // Ensure that the second operand of both ands are constants
14770     if (BVN0 && BVN0->isConstantSplat(SplatBits0, SplatUndef, SplatBitSize,
14771                                       HasAnyUndefs) && !HasAnyUndefs) {
14772         if (BVN1 && BVN1->isConstantSplat(SplatBits1, SplatUndef, SplatBitSize,
14773                                           HasAnyUndefs) && !HasAnyUndefs) {
14774             // Ensure that the bit width of the constants are the same and that
14775             // the splat arguments are logical inverses as per the pattern we
14776             // are trying to simplify.
14777             if (SplatBits0.getBitWidth() == SplatBits1.getBitWidth() &&
14778                 SplatBits0 == ~SplatBits1) {
14779                 // Canonicalize the vector type to make instruction selection
14780                 // simpler.
14781                 EVT CanonicalVT = VT.is128BitVector() ? MVT::v4i32 : MVT::v2i32;
14782                 SDValue Result = DAG.getNode(ARMISD::VBSP, dl, CanonicalVT,
14783                                              N0->getOperand(1),
14784                                              N0->getOperand(0),
14785                                              N1->getOperand(0));
14786                 return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, Result);
14787             }
14788         }
14789     }
14790   }
14791 
14792   // Try to use the ARM/Thumb2 BFI (bitfield insert) instruction when
14793   // reasonable.
14794   if (N0.getOpcode() == ISD::AND && N0.hasOneUse()) {
14795     if (SDValue Res = PerformORCombineToBFI(N, DCI, Subtarget))
14796       return Res;
14797   }
14798 
14799   if (SDValue Result = PerformSHLSimplify(N, DCI, Subtarget))
14800     return Result;
14801 
14802   return SDValue();
14803 }
14804 
PerformXORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)14805 static SDValue PerformXORCombine(SDNode *N,
14806                                  TargetLowering::DAGCombinerInfo &DCI,
14807                                  const ARMSubtarget *Subtarget) {
14808   EVT VT = N->getValueType(0);
14809   SelectionDAG &DAG = DCI.DAG;
14810 
14811   if(!DAG.getTargetLoweringInfo().isTypeLegal(VT))
14812     return SDValue();
14813 
14814   if (!Subtarget->isThumb1Only()) {
14815     // fold (xor (select cc, 0, c), x) -> (select cc, x, (xor, x, c))
14816     if (SDValue Result = combineSelectAndUseCommutative(N, false, DCI))
14817       return Result;
14818 
14819     if (SDValue Result = PerformSHLSimplify(N, DCI, Subtarget))
14820       return Result;
14821   }
14822 
14823   if (Subtarget->hasMVEIntegerOps()) {
14824     // fold (xor(vcmp/z, 1)) into a vcmp with the opposite condition.
14825     SDValue N0 = N->getOperand(0);
14826     SDValue N1 = N->getOperand(1);
14827     const TargetLowering *TLI = Subtarget->getTargetLowering();
14828     if (TLI->isConstTrueVal(N1) &&
14829         (N0->getOpcode() == ARMISD::VCMP || N0->getOpcode() == ARMISD::VCMPZ)) {
14830       if (CanInvertMVEVCMP(N0)) {
14831         SDLoc DL(N0);
14832         ARMCC::CondCodes CC = ARMCC::getOppositeCondition(getVCMPCondCode(N0));
14833 
14834         SmallVector<SDValue, 4> Ops;
14835         Ops.push_back(N0->getOperand(0));
14836         if (N0->getOpcode() == ARMISD::VCMP)
14837           Ops.push_back(N0->getOperand(1));
14838         Ops.push_back(DAG.getConstant(CC, DL, MVT::i32));
14839         return DAG.getNode(N0->getOpcode(), DL, N0->getValueType(0), Ops);
14840       }
14841     }
14842   }
14843 
14844   return SDValue();
14845 }
14846 
14847 // ParseBFI - given a BFI instruction in N, extract the "from" value (Rn) and return it,
14848 // and fill in FromMask and ToMask with (consecutive) bits in "from" to be extracted and
14849 // their position in "to" (Rd).
ParseBFI(SDNode * N,APInt & ToMask,APInt & FromMask)14850 static SDValue ParseBFI(SDNode *N, APInt &ToMask, APInt &FromMask) {
14851   assert(N->getOpcode() == ARMISD::BFI);
14852 
14853   SDValue From = N->getOperand(1);
14854   ToMask = ~N->getConstantOperandAPInt(2);
14855   FromMask = APInt::getLowBitsSet(ToMask.getBitWidth(), ToMask.popcount());
14856 
14857   // If the Base came from a SHR #C, we can deduce that it is really testing bit
14858   // #C in the base of the SHR.
14859   if (From->getOpcode() == ISD::SRL &&
14860       isa<ConstantSDNode>(From->getOperand(1))) {
14861     APInt Shift = From->getConstantOperandAPInt(1);
14862     assert(Shift.getLimitedValue() < 32 && "Shift too large!");
14863     FromMask <<= Shift.getLimitedValue(31);
14864     From = From->getOperand(0);
14865   }
14866 
14867   return From;
14868 }
14869 
14870 // If A and B contain one contiguous set of bits, does A | B == A . B?
14871 //
14872 // Neither A nor B must be zero.
BitsProperlyConcatenate(const APInt & A,const APInt & B)14873 static bool BitsProperlyConcatenate(const APInt &A, const APInt &B) {
14874   unsigned LastActiveBitInA = A.countr_zero();
14875   unsigned FirstActiveBitInB = B.getBitWidth() - B.countl_zero() - 1;
14876   return LastActiveBitInA - 1 == FirstActiveBitInB;
14877 }
14878 
FindBFIToCombineWith(SDNode * N)14879 static SDValue FindBFIToCombineWith(SDNode *N) {
14880   // We have a BFI in N. Find a BFI it can combine with, if one exists.
14881   APInt ToMask, FromMask;
14882   SDValue From = ParseBFI(N, ToMask, FromMask);
14883   SDValue To = N->getOperand(0);
14884 
14885   SDValue V = To;
14886   if (V.getOpcode() != ARMISD::BFI)
14887     return SDValue();
14888 
14889   APInt NewToMask, NewFromMask;
14890   SDValue NewFrom = ParseBFI(V.getNode(), NewToMask, NewFromMask);
14891   if (NewFrom != From)
14892     return SDValue();
14893 
14894   // Do the written bits conflict with any we've seen so far?
14895   if ((NewToMask & ToMask).getBoolValue())
14896     // Conflicting bits.
14897     return SDValue();
14898 
14899   // Are the new bits contiguous when combined with the old bits?
14900   if (BitsProperlyConcatenate(ToMask, NewToMask) &&
14901       BitsProperlyConcatenate(FromMask, NewFromMask))
14902     return V;
14903   if (BitsProperlyConcatenate(NewToMask, ToMask) &&
14904       BitsProperlyConcatenate(NewFromMask, FromMask))
14905     return V;
14906 
14907   return SDValue();
14908 }
14909 
PerformBFICombine(SDNode * N,SelectionDAG & DAG)14910 static SDValue PerformBFICombine(SDNode *N, SelectionDAG &DAG) {
14911   SDValue N0 = N->getOperand(0);
14912   SDValue N1 = N->getOperand(1);
14913 
14914   if (N1.getOpcode() == ISD::AND) {
14915     // (bfi A, (and B, Mask1), Mask2) -> (bfi A, B, Mask2) iff
14916     // the bits being cleared by the AND are not demanded by the BFI.
14917     ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
14918     if (!N11C)
14919       return SDValue();
14920     unsigned InvMask = N->getConstantOperandVal(2);
14921     unsigned LSB = llvm::countr_zero(~InvMask);
14922     unsigned Width = llvm::bit_width<unsigned>(~InvMask) - LSB;
14923     assert(Width <
14924                static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
14925            "undefined behavior");
14926     unsigned Mask = (1u << Width) - 1;
14927     unsigned Mask2 = N11C->getZExtValue();
14928     if ((Mask & (~Mask2)) == 0)
14929       return DAG.getNode(ARMISD::BFI, SDLoc(N), N->getValueType(0),
14930                          N->getOperand(0), N1.getOperand(0), N->getOperand(2));
14931     return SDValue();
14932   }
14933 
14934   // Look for another BFI to combine with.
14935   if (SDValue CombineBFI = FindBFIToCombineWith(N)) {
14936     // We've found a BFI.
14937     APInt ToMask1, FromMask1;
14938     SDValue From1 = ParseBFI(N, ToMask1, FromMask1);
14939 
14940     APInt ToMask2, FromMask2;
14941     SDValue From2 = ParseBFI(CombineBFI.getNode(), ToMask2, FromMask2);
14942     assert(From1 == From2);
14943     (void)From2;
14944 
14945     // Create a new BFI, combining the two together.
14946     APInt NewFromMask = FromMask1 | FromMask2;
14947     APInt NewToMask = ToMask1 | ToMask2;
14948 
14949     EVT VT = N->getValueType(0);
14950     SDLoc dl(N);
14951 
14952     if (NewFromMask[0] == 0)
14953       From1 = DAG.getNode(ISD::SRL, dl, VT, From1,
14954                           DAG.getConstant(NewFromMask.countr_zero(), dl, VT));
14955     return DAG.getNode(ARMISD::BFI, dl, VT, CombineBFI.getOperand(0), From1,
14956                        DAG.getConstant(~NewToMask, dl, VT));
14957   }
14958 
14959   // Reassociate BFI(BFI (A, B, M1), C, M2) to BFI(BFI (A, C, M2), B, M1) so
14960   // that lower bit insertions are performed first, providing that M1 and M2
14961   // do no overlap. This can allow multiple BFI instructions to be combined
14962   // together by the other folds above.
14963   if (N->getOperand(0).getOpcode() == ARMISD::BFI) {
14964     APInt ToMask1 = ~N->getConstantOperandAPInt(2);
14965     APInt ToMask2 = ~N0.getConstantOperandAPInt(2);
14966 
14967     if (!N0.hasOneUse() || (ToMask1 & ToMask2) != 0 ||
14968         ToMask1.countl_zero() < ToMask2.countl_zero())
14969       return SDValue();
14970 
14971     EVT VT = N->getValueType(0);
14972     SDLoc dl(N);
14973     SDValue BFI1 = DAG.getNode(ARMISD::BFI, dl, VT, N0.getOperand(0),
14974                                N->getOperand(1), N->getOperand(2));
14975     return DAG.getNode(ARMISD::BFI, dl, VT, BFI1, N0.getOperand(1),
14976                        N0.getOperand(2));
14977   }
14978 
14979   return SDValue();
14980 }
14981 
14982 // Check that N is CMPZ(CSINC(0, 0, CC, X)),
14983 //              or CMPZ(CMOV(1, 0, CC, $cpsr, X))
14984 // return X if valid.
IsCMPZCSINC(SDNode * Cmp,ARMCC::CondCodes & CC)14985 static SDValue IsCMPZCSINC(SDNode *Cmp, ARMCC::CondCodes &CC) {
14986   if (Cmp->getOpcode() != ARMISD::CMPZ || !isNullConstant(Cmp->getOperand(1)))
14987     return SDValue();
14988   SDValue CSInc = Cmp->getOperand(0);
14989 
14990   // Ignore any `And 1` nodes that may not yet have been removed. We are
14991   // looking for a value that produces 1/0, so these have no effect on the
14992   // code.
14993   while (CSInc.getOpcode() == ISD::AND &&
14994          isa<ConstantSDNode>(CSInc.getOperand(1)) &&
14995          CSInc.getConstantOperandVal(1) == 1 && CSInc->hasOneUse())
14996     CSInc = CSInc.getOperand(0);
14997 
14998   if (CSInc.getOpcode() == ARMISD::CSINC &&
14999       isNullConstant(CSInc.getOperand(0)) &&
15000       isNullConstant(CSInc.getOperand(1)) && CSInc->hasOneUse()) {
15001     CC = (ARMCC::CondCodes)CSInc.getConstantOperandVal(2);
15002     return CSInc.getOperand(3);
15003   }
15004   if (CSInc.getOpcode() == ARMISD::CMOV && isOneConstant(CSInc.getOperand(0)) &&
15005       isNullConstant(CSInc.getOperand(1)) && CSInc->hasOneUse()) {
15006     CC = (ARMCC::CondCodes)CSInc.getConstantOperandVal(2);
15007     return CSInc.getOperand(4);
15008   }
15009   if (CSInc.getOpcode() == ARMISD::CMOV && isOneConstant(CSInc.getOperand(1)) &&
15010       isNullConstant(CSInc.getOperand(0)) && CSInc->hasOneUse()) {
15011     CC = ARMCC::getOppositeCondition(
15012         (ARMCC::CondCodes)CSInc.getConstantOperandVal(2));
15013     return CSInc.getOperand(4);
15014   }
15015   return SDValue();
15016 }
15017 
PerformCMPZCombine(SDNode * N,SelectionDAG & DAG)15018 static SDValue PerformCMPZCombine(SDNode *N, SelectionDAG &DAG) {
15019   // Given CMPZ(CSINC(C, 0, 0, EQ), 0), we can just use C directly. As in
15020   //       t92: glue = ARMISD::CMPZ t74, 0
15021   //     t93: i32 = ARMISD::CSINC 0, 0, 1, t92
15022   //   t96: glue = ARMISD::CMPZ t93, 0
15023   // t114: i32 = ARMISD::CSINV 0, 0, 0, t96
15024   ARMCC::CondCodes Cond;
15025   if (SDValue C = IsCMPZCSINC(N, Cond))
15026     if (Cond == ARMCC::EQ)
15027       return C;
15028   return SDValue();
15029 }
15030 
PerformCSETCombine(SDNode * N,SelectionDAG & DAG)15031 static SDValue PerformCSETCombine(SDNode *N, SelectionDAG &DAG) {
15032   // Fold away an unneccessary CMPZ/CSINC
15033   // CSXYZ A, B, C1 (CMPZ (CSINC 0, 0, C2, D), 0) ->
15034   // if C1==EQ -> CSXYZ A, B, C2, D
15035   // if C1==NE -> CSXYZ A, B, NOT(C2), D
15036   ARMCC::CondCodes Cond;
15037   if (SDValue C = IsCMPZCSINC(N->getOperand(3).getNode(), Cond)) {
15038     if (N->getConstantOperandVal(2) == ARMCC::EQ)
15039       return DAG.getNode(N->getOpcode(), SDLoc(N), MVT::i32, N->getOperand(0),
15040                          N->getOperand(1),
15041                          DAG.getConstant(Cond, SDLoc(N), MVT::i32), C);
15042     if (N->getConstantOperandVal(2) == ARMCC::NE)
15043       return DAG.getNode(
15044           N->getOpcode(), SDLoc(N), MVT::i32, N->getOperand(0),
15045           N->getOperand(1),
15046           DAG.getConstant(ARMCC::getOppositeCondition(Cond), SDLoc(N), MVT::i32), C);
15047   }
15048   return SDValue();
15049 }
15050 
15051 /// PerformVMOVRRDCombine - Target-specific dag combine xforms for
15052 /// ARMISD::VMOVRRD.
PerformVMOVRRDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)15053 static SDValue PerformVMOVRRDCombine(SDNode *N,
15054                                      TargetLowering::DAGCombinerInfo &DCI,
15055                                      const ARMSubtarget *Subtarget) {
15056   // vmovrrd(vmovdrr x, y) -> x,y
15057   SDValue InDouble = N->getOperand(0);
15058   if (InDouble.getOpcode() == ARMISD::VMOVDRR && Subtarget->hasFP64())
15059     return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
15060 
15061   // vmovrrd(load f64) -> (load i32), (load i32)
15062   SDNode *InNode = InDouble.getNode();
15063   if (ISD::isNormalLoad(InNode) && InNode->hasOneUse() &&
15064       InNode->getValueType(0) == MVT::f64 &&
15065       InNode->getOperand(1).getOpcode() == ISD::FrameIndex &&
15066       !cast<LoadSDNode>(InNode)->isVolatile()) {
15067     // TODO: Should this be done for non-FrameIndex operands?
15068     LoadSDNode *LD = cast<LoadSDNode>(InNode);
15069 
15070     SelectionDAG &DAG = DCI.DAG;
15071     SDLoc DL(LD);
15072     SDValue BasePtr = LD->getBasePtr();
15073     SDValue NewLD1 =
15074         DAG.getLoad(MVT::i32, DL, LD->getChain(), BasePtr, LD->getPointerInfo(),
15075                     LD->getAlign(), LD->getMemOperand()->getFlags());
15076 
15077     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i32, BasePtr,
15078                                     DAG.getConstant(4, DL, MVT::i32));
15079 
15080     SDValue NewLD2 = DAG.getLoad(MVT::i32, DL, LD->getChain(), OffsetPtr,
15081                                  LD->getPointerInfo().getWithOffset(4),
15082                                  commonAlignment(LD->getAlign(), 4),
15083                                  LD->getMemOperand()->getFlags());
15084 
15085     DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), NewLD2.getValue(1));
15086     if (DCI.DAG.getDataLayout().isBigEndian())
15087       std::swap (NewLD1, NewLD2);
15088     SDValue Result = DCI.CombineTo(N, NewLD1, NewLD2);
15089     return Result;
15090   }
15091 
15092   // VMOVRRD(extract(..(build_vector(a, b, c, d)))) -> a,b or c,d
15093   // VMOVRRD(extract(insert_vector(insert_vector(.., a, l1), b, l2))) -> a,b
15094   if (InDouble.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
15095       isa<ConstantSDNode>(InDouble.getOperand(1))) {
15096     SDValue BV = InDouble.getOperand(0);
15097     // Look up through any nop bitcasts and vector_reg_casts. bitcasts may
15098     // change lane order under big endian.
15099     bool BVSwap = BV.getOpcode() == ISD::BITCAST;
15100     while (
15101         (BV.getOpcode() == ISD::BITCAST ||
15102          BV.getOpcode() == ARMISD::VECTOR_REG_CAST) &&
15103         (BV.getValueType() == MVT::v2f64 || BV.getValueType() == MVT::v2i64)) {
15104       BVSwap = BV.getOpcode() == ISD::BITCAST;
15105       BV = BV.getOperand(0);
15106     }
15107     if (BV.getValueType() != MVT::v4i32)
15108       return SDValue();
15109 
15110     // Handle buildvectors, pulling out the correct lane depending on
15111     // endianness.
15112     unsigned Offset = InDouble.getConstantOperandVal(1) == 1 ? 2 : 0;
15113     if (BV.getOpcode() == ISD::BUILD_VECTOR) {
15114       SDValue Op0 = BV.getOperand(Offset);
15115       SDValue Op1 = BV.getOperand(Offset + 1);
15116       if (!Subtarget->isLittle() && BVSwap)
15117         std::swap(Op0, Op1);
15118 
15119       return DCI.DAG.getMergeValues({Op0, Op1}, SDLoc(N));
15120     }
15121 
15122     // A chain of insert_vectors, grabbing the correct value of the chain of
15123     // inserts.
15124     SDValue Op0, Op1;
15125     while (BV.getOpcode() == ISD::INSERT_VECTOR_ELT) {
15126       if (isa<ConstantSDNode>(BV.getOperand(2))) {
15127         if (BV.getConstantOperandVal(2) == Offset)
15128           Op0 = BV.getOperand(1);
15129         if (BV.getConstantOperandVal(2) == Offset + 1)
15130           Op1 = BV.getOperand(1);
15131       }
15132       BV = BV.getOperand(0);
15133     }
15134     if (!Subtarget->isLittle() && BVSwap)
15135       std::swap(Op0, Op1);
15136     if (Op0 && Op1)
15137       return DCI.DAG.getMergeValues({Op0, Op1}, SDLoc(N));
15138   }
15139 
15140   return SDValue();
15141 }
15142 
15143 /// PerformVMOVDRRCombine - Target-specific dag combine xforms for
15144 /// ARMISD::VMOVDRR.  This is also used for BUILD_VECTORs with 2 operands.
PerformVMOVDRRCombine(SDNode * N,SelectionDAG & DAG)15145 static SDValue PerformVMOVDRRCombine(SDNode *N, SelectionDAG &DAG) {
15146   // N=vmovrrd(X); vmovdrr(N:0, N:1) -> bit_convert(X)
15147   SDValue Op0 = N->getOperand(0);
15148   SDValue Op1 = N->getOperand(1);
15149   if (Op0.getOpcode() == ISD::BITCAST)
15150     Op0 = Op0.getOperand(0);
15151   if (Op1.getOpcode() == ISD::BITCAST)
15152     Op1 = Op1.getOperand(0);
15153   if (Op0.getOpcode() == ARMISD::VMOVRRD &&
15154       Op0.getNode() == Op1.getNode() &&
15155       Op0.getResNo() == 0 && Op1.getResNo() == 1)
15156     return DAG.getNode(ISD::BITCAST, SDLoc(N),
15157                        N->getValueType(0), Op0.getOperand(0));
15158   return SDValue();
15159 }
15160 
PerformVMOVhrCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15161 static SDValue PerformVMOVhrCombine(SDNode *N,
15162                                     TargetLowering::DAGCombinerInfo &DCI) {
15163   SDValue Op0 = N->getOperand(0);
15164 
15165   // VMOVhr (VMOVrh (X)) -> X
15166   if (Op0->getOpcode() == ARMISD::VMOVrh)
15167     return Op0->getOperand(0);
15168 
15169   // FullFP16: half values are passed in S-registers, and we don't
15170   // need any of the bitcast and moves:
15171   //
15172   //     t2: f32,ch1,gl1? = CopyFromReg ch, Register:f32 %0, gl?
15173   //   t5: i32 = bitcast t2
15174   // t18: f16 = ARMISD::VMOVhr t5
15175   // =>
15176   // tN: f16,ch2,gl2? = CopyFromReg ch, Register::f32 %0, gl?
15177   if (Op0->getOpcode() == ISD::BITCAST) {
15178     SDValue Copy = Op0->getOperand(0);
15179     if (Copy.getValueType() == MVT::f32 &&
15180         Copy->getOpcode() == ISD::CopyFromReg) {
15181       bool HasGlue = Copy->getNumOperands() == 3;
15182       SDValue Ops[] = {Copy->getOperand(0), Copy->getOperand(1),
15183                        HasGlue ? Copy->getOperand(2) : SDValue()};
15184       EVT OutTys[] = {N->getValueType(0), MVT::Other, MVT::Glue};
15185       SDValue NewCopy =
15186           DCI.DAG.getNode(ISD::CopyFromReg, SDLoc(N),
15187                           DCI.DAG.getVTList(ArrayRef(OutTys, HasGlue ? 3 : 2)),
15188                           ArrayRef(Ops, HasGlue ? 3 : 2));
15189 
15190       // Update Users, Chains, and Potential Glue.
15191       DCI.DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), NewCopy.getValue(0));
15192       DCI.DAG.ReplaceAllUsesOfValueWith(Copy.getValue(1), NewCopy.getValue(1));
15193       if (HasGlue)
15194         DCI.DAG.ReplaceAllUsesOfValueWith(Copy.getValue(2),
15195                                           NewCopy.getValue(2));
15196 
15197       return NewCopy;
15198     }
15199   }
15200 
15201   // fold (VMOVhr (load x)) -> (load (f16*)x)
15202   if (LoadSDNode *LN0 = dyn_cast<LoadSDNode>(Op0)) {
15203     if (LN0->hasOneUse() && LN0->isUnindexed() &&
15204         LN0->getMemoryVT() == MVT::i16) {
15205       SDValue Load =
15206           DCI.DAG.getLoad(N->getValueType(0), SDLoc(N), LN0->getChain(),
15207                           LN0->getBasePtr(), LN0->getMemOperand());
15208       DCI.DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Load.getValue(0));
15209       DCI.DAG.ReplaceAllUsesOfValueWith(Op0.getValue(1), Load.getValue(1));
15210       return Load;
15211     }
15212   }
15213 
15214   // Only the bottom 16 bits of the source register are used.
15215   APInt DemandedMask = APInt::getLowBitsSet(32, 16);
15216   const TargetLowering &TLI = DCI.DAG.getTargetLoweringInfo();
15217   if (TLI.SimplifyDemandedBits(Op0, DemandedMask, DCI))
15218     return SDValue(N, 0);
15219 
15220   return SDValue();
15221 }
15222 
PerformVMOVrhCombine(SDNode * N,SelectionDAG & DAG)15223 static SDValue PerformVMOVrhCombine(SDNode *N, SelectionDAG &DAG) {
15224   SDValue N0 = N->getOperand(0);
15225   EVT VT = N->getValueType(0);
15226 
15227   // fold (VMOVrh (fpconst x)) -> const x
15228   if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N0)) {
15229     APFloat V = C->getValueAPF();
15230     return DAG.getConstant(V.bitcastToAPInt().getZExtValue(), SDLoc(N), VT);
15231   }
15232 
15233   // fold (VMOVrh (load x)) -> (zextload (i16*)x)
15234   if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse()) {
15235     LoadSDNode *LN0 = cast<LoadSDNode>(N0);
15236 
15237     SDValue Load =
15238         DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT, LN0->getChain(),
15239                        LN0->getBasePtr(), MVT::i16, LN0->getMemOperand());
15240     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Load.getValue(0));
15241     DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
15242     return Load;
15243   }
15244 
15245   // Fold VMOVrh(extract(x, n)) -> vgetlaneu(x, n)
15246   if (N0->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
15247       isa<ConstantSDNode>(N0->getOperand(1)))
15248     return DAG.getNode(ARMISD::VGETLANEu, SDLoc(N), VT, N0->getOperand(0),
15249                        N0->getOperand(1));
15250 
15251   return SDValue();
15252 }
15253 
15254 /// hasNormalLoadOperand - Check if any of the operands of a BUILD_VECTOR node
15255 /// are normal, non-volatile loads.  If so, it is profitable to bitcast an
15256 /// i64 vector to have f64 elements, since the value can then be loaded
15257 /// directly into a VFP register.
hasNormalLoadOperand(SDNode * N)15258 static bool hasNormalLoadOperand(SDNode *N) {
15259   unsigned NumElts = N->getValueType(0).getVectorNumElements();
15260   for (unsigned i = 0; i < NumElts; ++i) {
15261     SDNode *Elt = N->getOperand(i).getNode();
15262     if (ISD::isNormalLoad(Elt) && !cast<LoadSDNode>(Elt)->isVolatile())
15263       return true;
15264   }
15265   return false;
15266 }
15267 
15268 /// PerformBUILD_VECTORCombine - Target-specific dag combine xforms for
15269 /// ISD::BUILD_VECTOR.
PerformBUILD_VECTORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)15270 static SDValue PerformBUILD_VECTORCombine(SDNode *N,
15271                                           TargetLowering::DAGCombinerInfo &DCI,
15272                                           const ARMSubtarget *Subtarget) {
15273   // build_vector(N=ARMISD::VMOVRRD(X), N:1) -> bit_convert(X):
15274   // VMOVRRD is introduced when legalizing i64 types.  It forces the i64 value
15275   // into a pair of GPRs, which is fine when the value is used as a scalar,
15276   // but if the i64 value is converted to a vector, we need to undo the VMOVRRD.
15277   SelectionDAG &DAG = DCI.DAG;
15278   if (N->getNumOperands() == 2)
15279     if (SDValue RV = PerformVMOVDRRCombine(N, DAG))
15280       return RV;
15281 
15282   // Load i64 elements as f64 values so that type legalization does not split
15283   // them up into i32 values.
15284   EVT VT = N->getValueType(0);
15285   if (VT.getVectorElementType() != MVT::i64 || !hasNormalLoadOperand(N))
15286     return SDValue();
15287   SDLoc dl(N);
15288   SmallVector<SDValue, 8> Ops;
15289   unsigned NumElts = VT.getVectorNumElements();
15290   for (unsigned i = 0; i < NumElts; ++i) {
15291     SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::f64, N->getOperand(i));
15292     Ops.push_back(V);
15293     // Make the DAGCombiner fold the bitcast.
15294     DCI.AddToWorklist(V.getNode());
15295   }
15296   EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64, NumElts);
15297   SDValue BV = DAG.getBuildVector(FloatVT, dl, Ops);
15298   return DAG.getNode(ISD::BITCAST, dl, VT, BV);
15299 }
15300 
15301 /// Target-specific dag combine xforms for ARMISD::BUILD_VECTOR.
15302 static SDValue
PerformARMBUILD_VECTORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15303 PerformARMBUILD_VECTORCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
15304   // ARMISD::BUILD_VECTOR is introduced when legalizing ISD::BUILD_VECTOR.
15305   // At that time, we may have inserted bitcasts from integer to float.
15306   // If these bitcasts have survived DAGCombine, change the lowering of this
15307   // BUILD_VECTOR in something more vector friendly, i.e., that does not
15308   // force to use floating point types.
15309 
15310   // Make sure we can change the type of the vector.
15311   // This is possible iff:
15312   // 1. The vector is only used in a bitcast to a integer type. I.e.,
15313   //    1.1. Vector is used only once.
15314   //    1.2. Use is a bit convert to an integer type.
15315   // 2. The size of its operands are 32-bits (64-bits are not legal).
15316   EVT VT = N->getValueType(0);
15317   EVT EltVT = VT.getVectorElementType();
15318 
15319   // Check 1.1. and 2.
15320   if (EltVT.getSizeInBits() != 32 || !N->hasOneUse())
15321     return SDValue();
15322 
15323   // By construction, the input type must be float.
15324   assert(EltVT == MVT::f32 && "Unexpected type!");
15325 
15326   // Check 1.2.
15327   SDNode *Use = *N->use_begin();
15328   if (Use->getOpcode() != ISD::BITCAST ||
15329       Use->getValueType(0).isFloatingPoint())
15330     return SDValue();
15331 
15332   // Check profitability.
15333   // Model is, if more than half of the relevant operands are bitcast from
15334   // i32, turn the build_vector into a sequence of insert_vector_elt.
15335   // Relevant operands are everything that is not statically
15336   // (i.e., at compile time) bitcasted.
15337   unsigned NumOfBitCastedElts = 0;
15338   unsigned NumElts = VT.getVectorNumElements();
15339   unsigned NumOfRelevantElts = NumElts;
15340   for (unsigned Idx = 0; Idx < NumElts; ++Idx) {
15341     SDValue Elt = N->getOperand(Idx);
15342     if (Elt->getOpcode() == ISD::BITCAST) {
15343       // Assume only bit cast to i32 will go away.
15344       if (Elt->getOperand(0).getValueType() == MVT::i32)
15345         ++NumOfBitCastedElts;
15346     } else if (Elt.isUndef() || isa<ConstantSDNode>(Elt))
15347       // Constants are statically casted, thus do not count them as
15348       // relevant operands.
15349       --NumOfRelevantElts;
15350   }
15351 
15352   // Check if more than half of the elements require a non-free bitcast.
15353   if (NumOfBitCastedElts <= NumOfRelevantElts / 2)
15354     return SDValue();
15355 
15356   SelectionDAG &DAG = DCI.DAG;
15357   // Create the new vector type.
15358   EVT VecVT = EVT::getVectorVT(*DAG.getContext(), MVT::i32, NumElts);
15359   // Check if the type is legal.
15360   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
15361   if (!TLI.isTypeLegal(VecVT))
15362     return SDValue();
15363 
15364   // Combine:
15365   // ARMISD::BUILD_VECTOR E1, E2, ..., EN.
15366   // => BITCAST INSERT_VECTOR_ELT
15367   //                      (INSERT_VECTOR_ELT (...), (BITCAST EN-1), N-1),
15368   //                      (BITCAST EN), N.
15369   SDValue Vec = DAG.getUNDEF(VecVT);
15370   SDLoc dl(N);
15371   for (unsigned Idx = 0 ; Idx < NumElts; ++Idx) {
15372     SDValue V = N->getOperand(Idx);
15373     if (V.isUndef())
15374       continue;
15375     if (V.getOpcode() == ISD::BITCAST &&
15376         V->getOperand(0).getValueType() == MVT::i32)
15377       // Fold obvious case.
15378       V = V.getOperand(0);
15379     else {
15380       V = DAG.getNode(ISD::BITCAST, SDLoc(V), MVT::i32, V);
15381       // Make the DAGCombiner fold the bitcasts.
15382       DCI.AddToWorklist(V.getNode());
15383     }
15384     SDValue LaneIdx = DAG.getConstant(Idx, dl, MVT::i32);
15385     Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VecVT, Vec, V, LaneIdx);
15386   }
15387   Vec = DAG.getNode(ISD::BITCAST, dl, VT, Vec);
15388   // Make the DAGCombiner fold the bitcasts.
15389   DCI.AddToWorklist(Vec.getNode());
15390   return Vec;
15391 }
15392 
15393 static SDValue
PerformPREDICATE_CASTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15394 PerformPREDICATE_CASTCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
15395   EVT VT = N->getValueType(0);
15396   SDValue Op = N->getOperand(0);
15397   SDLoc dl(N);
15398 
15399   // PREDICATE_CAST(PREDICATE_CAST(x)) == PREDICATE_CAST(x)
15400   if (Op->getOpcode() == ARMISD::PREDICATE_CAST) {
15401     // If the valuetypes are the same, we can remove the cast entirely.
15402     if (Op->getOperand(0).getValueType() == VT)
15403       return Op->getOperand(0);
15404     return DCI.DAG.getNode(ARMISD::PREDICATE_CAST, dl, VT, Op->getOperand(0));
15405   }
15406 
15407   // Turn pred_cast(xor x, -1) into xor(pred_cast x, -1), in order to produce
15408   // more VPNOT which might get folded as else predicates.
15409   if (Op.getValueType() == MVT::i32 && isBitwiseNot(Op)) {
15410     SDValue X =
15411         DCI.DAG.getNode(ARMISD::PREDICATE_CAST, dl, VT, Op->getOperand(0));
15412     SDValue C = DCI.DAG.getNode(ARMISD::PREDICATE_CAST, dl, VT,
15413                                 DCI.DAG.getConstant(65535, dl, MVT::i32));
15414     return DCI.DAG.getNode(ISD::XOR, dl, VT, X, C);
15415   }
15416 
15417   // Only the bottom 16 bits of the source register are used.
15418   if (Op.getValueType() == MVT::i32) {
15419     APInt DemandedMask = APInt::getLowBitsSet(32, 16);
15420     const TargetLowering &TLI = DCI.DAG.getTargetLoweringInfo();
15421     if (TLI.SimplifyDemandedBits(Op, DemandedMask, DCI))
15422       return SDValue(N, 0);
15423   }
15424   return SDValue();
15425 }
15426 
PerformVECTOR_REG_CASTCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)15427 static SDValue PerformVECTOR_REG_CASTCombine(SDNode *N, SelectionDAG &DAG,
15428                                              const ARMSubtarget *ST) {
15429   EVT VT = N->getValueType(0);
15430   SDValue Op = N->getOperand(0);
15431   SDLoc dl(N);
15432 
15433   // Under Little endian, a VECTOR_REG_CAST is equivalent to a BITCAST
15434   if (ST->isLittle())
15435     return DAG.getNode(ISD::BITCAST, dl, VT, Op);
15436 
15437   // VECTOR_REG_CAST undef -> undef
15438   if (Op.isUndef())
15439     return DAG.getUNDEF(VT);
15440 
15441   // VECTOR_REG_CAST(VECTOR_REG_CAST(x)) == VECTOR_REG_CAST(x)
15442   if (Op->getOpcode() == ARMISD::VECTOR_REG_CAST) {
15443     // If the valuetypes are the same, we can remove the cast entirely.
15444     if (Op->getOperand(0).getValueType() == VT)
15445       return Op->getOperand(0);
15446     return DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, VT, Op->getOperand(0));
15447   }
15448 
15449   return SDValue();
15450 }
15451 
PerformVCMPCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)15452 static SDValue PerformVCMPCombine(SDNode *N, SelectionDAG &DAG,
15453                                   const ARMSubtarget *Subtarget) {
15454   if (!Subtarget->hasMVEIntegerOps())
15455     return SDValue();
15456 
15457   EVT VT = N->getValueType(0);
15458   SDValue Op0 = N->getOperand(0);
15459   SDValue Op1 = N->getOperand(1);
15460   ARMCC::CondCodes Cond = (ARMCC::CondCodes)N->getConstantOperandVal(2);
15461   SDLoc dl(N);
15462 
15463   // vcmp X, 0, cc -> vcmpz X, cc
15464   if (isZeroVector(Op1))
15465     return DAG.getNode(ARMISD::VCMPZ, dl, VT, Op0, N->getOperand(2));
15466 
15467   unsigned SwappedCond = getSwappedCondition(Cond);
15468   if (isValidMVECond(SwappedCond, VT.isFloatingPoint())) {
15469     // vcmp 0, X, cc -> vcmpz X, reversed(cc)
15470     if (isZeroVector(Op0))
15471       return DAG.getNode(ARMISD::VCMPZ, dl, VT, Op1,
15472                          DAG.getConstant(SwappedCond, dl, MVT::i32));
15473     // vcmp vdup(Y), X, cc -> vcmp X, vdup(Y), reversed(cc)
15474     if (Op0->getOpcode() == ARMISD::VDUP && Op1->getOpcode() != ARMISD::VDUP)
15475       return DAG.getNode(ARMISD::VCMP, dl, VT, Op1, Op0,
15476                          DAG.getConstant(SwappedCond, dl, MVT::i32));
15477   }
15478 
15479   return SDValue();
15480 }
15481 
15482 /// PerformInsertEltCombine - Target-specific dag combine xforms for
15483 /// ISD::INSERT_VECTOR_ELT.
PerformInsertEltCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15484 static SDValue PerformInsertEltCombine(SDNode *N,
15485                                        TargetLowering::DAGCombinerInfo &DCI) {
15486   // Bitcast an i64 load inserted into a vector to f64.
15487   // Otherwise, the i64 value will be legalized to a pair of i32 values.
15488   EVT VT = N->getValueType(0);
15489   SDNode *Elt = N->getOperand(1).getNode();
15490   if (VT.getVectorElementType() != MVT::i64 ||
15491       !ISD::isNormalLoad(Elt) || cast<LoadSDNode>(Elt)->isVolatile())
15492     return SDValue();
15493 
15494   SelectionDAG &DAG = DCI.DAG;
15495   SDLoc dl(N);
15496   EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64,
15497                                  VT.getVectorNumElements());
15498   SDValue Vec = DAG.getNode(ISD::BITCAST, dl, FloatVT, N->getOperand(0));
15499   SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::f64, N->getOperand(1));
15500   // Make the DAGCombiner fold the bitcasts.
15501   DCI.AddToWorklist(Vec.getNode());
15502   DCI.AddToWorklist(V.getNode());
15503   SDValue InsElt = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, FloatVT,
15504                                Vec, V, N->getOperand(2));
15505   return DAG.getNode(ISD::BITCAST, dl, VT, InsElt);
15506 }
15507 
15508 // Convert a pair of extracts from the same base vector to a VMOVRRD. Either
15509 // directly or bitcast to an integer if the original is a float vector.
15510 // extract(x, n); extract(x, n+1)  ->  VMOVRRD(extract v2f64 x, n/2)
15511 // bitcast(extract(x, n)); bitcast(extract(x, n+1))  ->  VMOVRRD(extract x, n/2)
15512 static SDValue
PerformExtractEltToVMOVRRD(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15513 PerformExtractEltToVMOVRRD(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
15514   EVT VT = N->getValueType(0);
15515   SDLoc dl(N);
15516 
15517   if (!DCI.isAfterLegalizeDAG() || VT != MVT::i32 ||
15518       !DCI.DAG.getTargetLoweringInfo().isTypeLegal(MVT::f64))
15519     return SDValue();
15520 
15521   SDValue Ext = SDValue(N, 0);
15522   if (Ext.getOpcode() == ISD::BITCAST &&
15523       Ext.getOperand(0).getValueType() == MVT::f32)
15524     Ext = Ext.getOperand(0);
15525   if (Ext.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
15526       !isa<ConstantSDNode>(Ext.getOperand(1)) ||
15527       Ext.getConstantOperandVal(1) % 2 != 0)
15528     return SDValue();
15529   if (Ext->use_size() == 1 &&
15530       (Ext->use_begin()->getOpcode() == ISD::SINT_TO_FP ||
15531        Ext->use_begin()->getOpcode() == ISD::UINT_TO_FP))
15532     return SDValue();
15533 
15534   SDValue Op0 = Ext.getOperand(0);
15535   EVT VecVT = Op0.getValueType();
15536   unsigned ResNo = Op0.getResNo();
15537   unsigned Lane = Ext.getConstantOperandVal(1);
15538   if (VecVT.getVectorNumElements() != 4)
15539     return SDValue();
15540 
15541   // Find another extract, of Lane + 1
15542   auto OtherIt = find_if(Op0->uses(), [&](SDNode *V) {
15543     return V->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
15544            isa<ConstantSDNode>(V->getOperand(1)) &&
15545            V->getConstantOperandVal(1) == Lane + 1 &&
15546            V->getOperand(0).getResNo() == ResNo;
15547   });
15548   if (OtherIt == Op0->uses().end())
15549     return SDValue();
15550 
15551   // For float extracts, we need to be converting to a i32 for both vector
15552   // lanes.
15553   SDValue OtherExt(*OtherIt, 0);
15554   if (OtherExt.getValueType() != MVT::i32) {
15555     if (OtherExt->use_size() != 1 ||
15556         OtherExt->use_begin()->getOpcode() != ISD::BITCAST ||
15557         OtherExt->use_begin()->getValueType(0) != MVT::i32)
15558       return SDValue();
15559     OtherExt = SDValue(*OtherExt->use_begin(), 0);
15560   }
15561 
15562   // Convert the type to a f64 and extract with a VMOVRRD.
15563   SDValue F64 = DCI.DAG.getNode(
15564       ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64,
15565       DCI.DAG.getNode(ARMISD::VECTOR_REG_CAST, dl, MVT::v2f64, Op0),
15566       DCI.DAG.getConstant(Ext.getConstantOperandVal(1) / 2, dl, MVT::i32));
15567   SDValue VMOVRRD =
15568       DCI.DAG.getNode(ARMISD::VMOVRRD, dl, {MVT::i32, MVT::i32}, F64);
15569 
15570   DCI.CombineTo(OtherExt.getNode(), SDValue(VMOVRRD.getNode(), 1));
15571   return VMOVRRD;
15572 }
15573 
PerformExtractEltCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * ST)15574 static SDValue PerformExtractEltCombine(SDNode *N,
15575                                         TargetLowering::DAGCombinerInfo &DCI,
15576                                         const ARMSubtarget *ST) {
15577   SDValue Op0 = N->getOperand(0);
15578   EVT VT = N->getValueType(0);
15579   SDLoc dl(N);
15580 
15581   // extract (vdup x) -> x
15582   if (Op0->getOpcode() == ARMISD::VDUP) {
15583     SDValue X = Op0->getOperand(0);
15584     if (VT == MVT::f16 && X.getValueType() == MVT::i32)
15585       return DCI.DAG.getNode(ARMISD::VMOVhr, dl, VT, X);
15586     if (VT == MVT::i32 && X.getValueType() == MVT::f16)
15587       return DCI.DAG.getNode(ARMISD::VMOVrh, dl, VT, X);
15588     if (VT == MVT::f32 && X.getValueType() == MVT::i32)
15589       return DCI.DAG.getNode(ISD::BITCAST, dl, VT, X);
15590 
15591     while (X.getValueType() != VT && X->getOpcode() == ISD::BITCAST)
15592       X = X->getOperand(0);
15593     if (X.getValueType() == VT)
15594       return X;
15595   }
15596 
15597   // extract ARM_BUILD_VECTOR -> x
15598   if (Op0->getOpcode() == ARMISD::BUILD_VECTOR &&
15599       isa<ConstantSDNode>(N->getOperand(1)) &&
15600       N->getConstantOperandVal(1) < Op0.getNumOperands()) {
15601     return Op0.getOperand(N->getConstantOperandVal(1));
15602   }
15603 
15604   // extract(bitcast(BUILD_VECTOR(VMOVDRR(a, b), ..))) -> a or b
15605   if (Op0.getValueType() == MVT::v4i32 &&
15606       isa<ConstantSDNode>(N->getOperand(1)) &&
15607       Op0.getOpcode() == ISD::BITCAST &&
15608       Op0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
15609       Op0.getOperand(0).getValueType() == MVT::v2f64) {
15610     SDValue BV = Op0.getOperand(0);
15611     unsigned Offset = N->getConstantOperandVal(1);
15612     SDValue MOV = BV.getOperand(Offset < 2 ? 0 : 1);
15613     if (MOV.getOpcode() == ARMISD::VMOVDRR)
15614       return MOV.getOperand(ST->isLittle() ? Offset % 2 : 1 - Offset % 2);
15615   }
15616 
15617   // extract x, n; extract x, n+1  ->  VMOVRRD x
15618   if (SDValue R = PerformExtractEltToVMOVRRD(N, DCI))
15619     return R;
15620 
15621   // extract (MVETrunc(x)) -> extract x
15622   if (Op0->getOpcode() == ARMISD::MVETRUNC) {
15623     unsigned Idx = N->getConstantOperandVal(1);
15624     unsigned Vec =
15625         Idx / Op0->getOperand(0).getValueType().getVectorNumElements();
15626     unsigned SubIdx =
15627         Idx % Op0->getOperand(0).getValueType().getVectorNumElements();
15628     return DCI.DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT, Op0.getOperand(Vec),
15629                            DCI.DAG.getConstant(SubIdx, dl, MVT::i32));
15630   }
15631 
15632   return SDValue();
15633 }
15634 
PerformSignExtendInregCombine(SDNode * N,SelectionDAG & DAG)15635 static SDValue PerformSignExtendInregCombine(SDNode *N, SelectionDAG &DAG) {
15636   SDValue Op = N->getOperand(0);
15637   EVT VT = N->getValueType(0);
15638 
15639   // sext_inreg(VGETLANEu) -> VGETLANEs
15640   if (Op.getOpcode() == ARMISD::VGETLANEu &&
15641       cast<VTSDNode>(N->getOperand(1))->getVT() ==
15642           Op.getOperand(0).getValueType().getScalarType())
15643     return DAG.getNode(ARMISD::VGETLANEs, SDLoc(N), VT, Op.getOperand(0),
15644                        Op.getOperand(1));
15645 
15646   return SDValue();
15647 }
15648 
15649 static SDValue
PerformInsertSubvectorCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)15650 PerformInsertSubvectorCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
15651   SDValue Vec = N->getOperand(0);
15652   SDValue SubVec = N->getOperand(1);
15653   uint64_t IdxVal = N->getConstantOperandVal(2);
15654   EVT VecVT = Vec.getValueType();
15655   EVT SubVT = SubVec.getValueType();
15656 
15657   // Only do this for legal fixed vector types.
15658   if (!VecVT.isFixedLengthVector() ||
15659       !DCI.DAG.getTargetLoweringInfo().isTypeLegal(VecVT) ||
15660       !DCI.DAG.getTargetLoweringInfo().isTypeLegal(SubVT))
15661     return SDValue();
15662 
15663   // Ignore widening patterns.
15664   if (IdxVal == 0 && Vec.isUndef())
15665     return SDValue();
15666 
15667   // Subvector must be half the width and an "aligned" insertion.
15668   unsigned NumSubElts = SubVT.getVectorNumElements();
15669   if ((SubVT.getSizeInBits() * 2) != VecVT.getSizeInBits() ||
15670       (IdxVal != 0 && IdxVal != NumSubElts))
15671     return SDValue();
15672 
15673   // Fold insert_subvector -> concat_vectors
15674   // insert_subvector(Vec,Sub,lo) -> concat_vectors(Sub,extract(Vec,hi))
15675   // insert_subvector(Vec,Sub,hi) -> concat_vectors(extract(Vec,lo),Sub)
15676   SDLoc DL(N);
15677   SDValue Lo, Hi;
15678   if (IdxVal == 0) {
15679     Lo = SubVec;
15680     Hi = DCI.DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT, Vec,
15681                          DCI.DAG.getVectorIdxConstant(NumSubElts, DL));
15682   } else {
15683     Lo = DCI.DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVT, Vec,
15684                          DCI.DAG.getVectorIdxConstant(0, DL));
15685     Hi = SubVec;
15686   }
15687   return DCI.DAG.getNode(ISD::CONCAT_VECTORS, DL, VecVT, Lo, Hi);
15688 }
15689 
15690 // shuffle(MVETrunc(x, y)) -> VMOVN(x, y)
PerformShuffleVMOVNCombine(ShuffleVectorSDNode * N,SelectionDAG & DAG)15691 static SDValue PerformShuffleVMOVNCombine(ShuffleVectorSDNode *N,
15692                                           SelectionDAG &DAG) {
15693   SDValue Trunc = N->getOperand(0);
15694   EVT VT = Trunc.getValueType();
15695   if (Trunc.getOpcode() != ARMISD::MVETRUNC || !N->getOperand(1).isUndef())
15696     return SDValue();
15697 
15698   SDLoc DL(Trunc);
15699   if (isVMOVNTruncMask(N->getMask(), VT, false))
15700     return DAG.getNode(
15701         ARMISD::VMOVN, DL, VT,
15702         DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, Trunc.getOperand(0)),
15703         DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, Trunc.getOperand(1)),
15704         DAG.getConstant(1, DL, MVT::i32));
15705   else if (isVMOVNTruncMask(N->getMask(), VT, true))
15706     return DAG.getNode(
15707         ARMISD::VMOVN, DL, VT,
15708         DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, Trunc.getOperand(1)),
15709         DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, Trunc.getOperand(0)),
15710         DAG.getConstant(1, DL, MVT::i32));
15711   return SDValue();
15712 }
15713 
15714 /// PerformVECTOR_SHUFFLECombine - Target-specific dag combine xforms for
15715 /// ISD::VECTOR_SHUFFLE.
PerformVECTOR_SHUFFLECombine(SDNode * N,SelectionDAG & DAG)15716 static SDValue PerformVECTOR_SHUFFLECombine(SDNode *N, SelectionDAG &DAG) {
15717   if (SDValue R = PerformShuffleVMOVNCombine(cast<ShuffleVectorSDNode>(N), DAG))
15718     return R;
15719 
15720   // The LLVM shufflevector instruction does not require the shuffle mask
15721   // length to match the operand vector length, but ISD::VECTOR_SHUFFLE does
15722   // have that requirement.  When translating to ISD::VECTOR_SHUFFLE, if the
15723   // operands do not match the mask length, they are extended by concatenating
15724   // them with undef vectors.  That is probably the right thing for other
15725   // targets, but for NEON it is better to concatenate two double-register
15726   // size vector operands into a single quad-register size vector.  Do that
15727   // transformation here:
15728   //   shuffle(concat(v1, undef), concat(v2, undef)) ->
15729   //   shuffle(concat(v1, v2), undef)
15730   SDValue Op0 = N->getOperand(0);
15731   SDValue Op1 = N->getOperand(1);
15732   if (Op0.getOpcode() != ISD::CONCAT_VECTORS ||
15733       Op1.getOpcode() != ISD::CONCAT_VECTORS ||
15734       Op0.getNumOperands() != 2 ||
15735       Op1.getNumOperands() != 2)
15736     return SDValue();
15737   SDValue Concat0Op1 = Op0.getOperand(1);
15738   SDValue Concat1Op1 = Op1.getOperand(1);
15739   if (!Concat0Op1.isUndef() || !Concat1Op1.isUndef())
15740     return SDValue();
15741   // Skip the transformation if any of the types are illegal.
15742   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
15743   EVT VT = N->getValueType(0);
15744   if (!TLI.isTypeLegal(VT) ||
15745       !TLI.isTypeLegal(Concat0Op1.getValueType()) ||
15746       !TLI.isTypeLegal(Concat1Op1.getValueType()))
15747     return SDValue();
15748 
15749   SDValue NewConcat = DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT,
15750                                   Op0.getOperand(0), Op1.getOperand(0));
15751   // Translate the shuffle mask.
15752   SmallVector<int, 16> NewMask;
15753   unsigned NumElts = VT.getVectorNumElements();
15754   unsigned HalfElts = NumElts/2;
15755   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
15756   for (unsigned n = 0; n < NumElts; ++n) {
15757     int MaskElt = SVN->getMaskElt(n);
15758     int NewElt = -1;
15759     if (MaskElt < (int)HalfElts)
15760       NewElt = MaskElt;
15761     else if (MaskElt >= (int)NumElts && MaskElt < (int)(NumElts + HalfElts))
15762       NewElt = HalfElts + MaskElt - NumElts;
15763     NewMask.push_back(NewElt);
15764   }
15765   return DAG.getVectorShuffle(VT, SDLoc(N), NewConcat,
15766                               DAG.getUNDEF(VT), NewMask);
15767 }
15768 
15769 /// Load/store instruction that can be merged with a base address
15770 /// update
15771 struct BaseUpdateTarget {
15772   SDNode *N;
15773   bool isIntrinsic;
15774   bool isStore;
15775   unsigned AddrOpIdx;
15776 };
15777 
15778 struct BaseUpdateUser {
15779   /// Instruction that updates a pointer
15780   SDNode *N;
15781   /// Pointer increment operand
15782   SDValue Inc;
15783   /// Pointer increment value if it is a constant, or 0 otherwise
15784   unsigned ConstInc;
15785 };
15786 
TryCombineBaseUpdate(struct BaseUpdateTarget & Target,struct BaseUpdateUser & User,bool SimpleConstIncOnly,TargetLowering::DAGCombinerInfo & DCI)15787 static bool TryCombineBaseUpdate(struct BaseUpdateTarget &Target,
15788                                  struct BaseUpdateUser &User,
15789                                  bool SimpleConstIncOnly,
15790                                  TargetLowering::DAGCombinerInfo &DCI) {
15791   SelectionDAG &DAG = DCI.DAG;
15792   SDNode *N = Target.N;
15793   MemSDNode *MemN = cast<MemSDNode>(N);
15794   SDLoc dl(N);
15795 
15796   // Find the new opcode for the updating load/store.
15797   bool isLoadOp = true;
15798   bool isLaneOp = false;
15799   // Workaround for vst1x and vld1x intrinsics which do not have alignment
15800   // as an operand.
15801   bool hasAlignment = true;
15802   unsigned NewOpc = 0;
15803   unsigned NumVecs = 0;
15804   if (Target.isIntrinsic) {
15805     unsigned IntNo = N->getConstantOperandVal(1);
15806     switch (IntNo) {
15807     default:
15808       llvm_unreachable("unexpected intrinsic for Neon base update");
15809     case Intrinsic::arm_neon_vld1:
15810       NewOpc = ARMISD::VLD1_UPD;
15811       NumVecs = 1;
15812       break;
15813     case Intrinsic::arm_neon_vld2:
15814       NewOpc = ARMISD::VLD2_UPD;
15815       NumVecs = 2;
15816       break;
15817     case Intrinsic::arm_neon_vld3:
15818       NewOpc = ARMISD::VLD3_UPD;
15819       NumVecs = 3;
15820       break;
15821     case Intrinsic::arm_neon_vld4:
15822       NewOpc = ARMISD::VLD4_UPD;
15823       NumVecs = 4;
15824       break;
15825     case Intrinsic::arm_neon_vld1x2:
15826       NewOpc = ARMISD::VLD1x2_UPD;
15827       NumVecs = 2;
15828       hasAlignment = false;
15829       break;
15830     case Intrinsic::arm_neon_vld1x3:
15831       NewOpc = ARMISD::VLD1x3_UPD;
15832       NumVecs = 3;
15833       hasAlignment = false;
15834       break;
15835     case Intrinsic::arm_neon_vld1x4:
15836       NewOpc = ARMISD::VLD1x4_UPD;
15837       NumVecs = 4;
15838       hasAlignment = false;
15839       break;
15840     case Intrinsic::arm_neon_vld2dup:
15841       NewOpc = ARMISD::VLD2DUP_UPD;
15842       NumVecs = 2;
15843       break;
15844     case Intrinsic::arm_neon_vld3dup:
15845       NewOpc = ARMISD::VLD3DUP_UPD;
15846       NumVecs = 3;
15847       break;
15848     case Intrinsic::arm_neon_vld4dup:
15849       NewOpc = ARMISD::VLD4DUP_UPD;
15850       NumVecs = 4;
15851       break;
15852     case Intrinsic::arm_neon_vld2lane:
15853       NewOpc = ARMISD::VLD2LN_UPD;
15854       NumVecs = 2;
15855       isLaneOp = true;
15856       break;
15857     case Intrinsic::arm_neon_vld3lane:
15858       NewOpc = ARMISD::VLD3LN_UPD;
15859       NumVecs = 3;
15860       isLaneOp = true;
15861       break;
15862     case Intrinsic::arm_neon_vld4lane:
15863       NewOpc = ARMISD::VLD4LN_UPD;
15864       NumVecs = 4;
15865       isLaneOp = true;
15866       break;
15867     case Intrinsic::arm_neon_vst1:
15868       NewOpc = ARMISD::VST1_UPD;
15869       NumVecs = 1;
15870       isLoadOp = false;
15871       break;
15872     case Intrinsic::arm_neon_vst2:
15873       NewOpc = ARMISD::VST2_UPD;
15874       NumVecs = 2;
15875       isLoadOp = false;
15876       break;
15877     case Intrinsic::arm_neon_vst3:
15878       NewOpc = ARMISD::VST3_UPD;
15879       NumVecs = 3;
15880       isLoadOp = false;
15881       break;
15882     case Intrinsic::arm_neon_vst4:
15883       NewOpc = ARMISD::VST4_UPD;
15884       NumVecs = 4;
15885       isLoadOp = false;
15886       break;
15887     case Intrinsic::arm_neon_vst2lane:
15888       NewOpc = ARMISD::VST2LN_UPD;
15889       NumVecs = 2;
15890       isLoadOp = false;
15891       isLaneOp = true;
15892       break;
15893     case Intrinsic::arm_neon_vst3lane:
15894       NewOpc = ARMISD::VST3LN_UPD;
15895       NumVecs = 3;
15896       isLoadOp = false;
15897       isLaneOp = true;
15898       break;
15899     case Intrinsic::arm_neon_vst4lane:
15900       NewOpc = ARMISD::VST4LN_UPD;
15901       NumVecs = 4;
15902       isLoadOp = false;
15903       isLaneOp = true;
15904       break;
15905     case Intrinsic::arm_neon_vst1x2:
15906       NewOpc = ARMISD::VST1x2_UPD;
15907       NumVecs = 2;
15908       isLoadOp = false;
15909       hasAlignment = false;
15910       break;
15911     case Intrinsic::arm_neon_vst1x3:
15912       NewOpc = ARMISD::VST1x3_UPD;
15913       NumVecs = 3;
15914       isLoadOp = false;
15915       hasAlignment = false;
15916       break;
15917     case Intrinsic::arm_neon_vst1x4:
15918       NewOpc = ARMISD::VST1x4_UPD;
15919       NumVecs = 4;
15920       isLoadOp = false;
15921       hasAlignment = false;
15922       break;
15923     }
15924   } else {
15925     isLaneOp = true;
15926     switch (N->getOpcode()) {
15927     default:
15928       llvm_unreachable("unexpected opcode for Neon base update");
15929     case ARMISD::VLD1DUP:
15930       NewOpc = ARMISD::VLD1DUP_UPD;
15931       NumVecs = 1;
15932       break;
15933     case ARMISD::VLD2DUP:
15934       NewOpc = ARMISD::VLD2DUP_UPD;
15935       NumVecs = 2;
15936       break;
15937     case ARMISD::VLD3DUP:
15938       NewOpc = ARMISD::VLD3DUP_UPD;
15939       NumVecs = 3;
15940       break;
15941     case ARMISD::VLD4DUP:
15942       NewOpc = ARMISD::VLD4DUP_UPD;
15943       NumVecs = 4;
15944       break;
15945     case ISD::LOAD:
15946       NewOpc = ARMISD::VLD1_UPD;
15947       NumVecs = 1;
15948       isLaneOp = false;
15949       break;
15950     case ISD::STORE:
15951       NewOpc = ARMISD::VST1_UPD;
15952       NumVecs = 1;
15953       isLaneOp = false;
15954       isLoadOp = false;
15955       break;
15956     }
15957   }
15958 
15959   // Find the size of memory referenced by the load/store.
15960   EVT VecTy;
15961   if (isLoadOp) {
15962     VecTy = N->getValueType(0);
15963   } else if (Target.isIntrinsic) {
15964     VecTy = N->getOperand(Target.AddrOpIdx + 1).getValueType();
15965   } else {
15966     assert(Target.isStore &&
15967            "Node has to be a load, a store, or an intrinsic!");
15968     VecTy = N->getOperand(1).getValueType();
15969   }
15970 
15971   bool isVLDDUPOp =
15972       NewOpc == ARMISD::VLD1DUP_UPD || NewOpc == ARMISD::VLD2DUP_UPD ||
15973       NewOpc == ARMISD::VLD3DUP_UPD || NewOpc == ARMISD::VLD4DUP_UPD;
15974 
15975   unsigned NumBytes = NumVecs * VecTy.getSizeInBits() / 8;
15976   if (isLaneOp || isVLDDUPOp)
15977     NumBytes /= VecTy.getVectorNumElements();
15978 
15979   if (NumBytes >= 3 * 16 && User.ConstInc != NumBytes) {
15980     // VLD3/4 and VST3/4 for 128-bit vectors are implemented with two
15981     // separate instructions that make it harder to use a non-constant update.
15982     return false;
15983   }
15984 
15985   if (SimpleConstIncOnly && User.ConstInc != NumBytes)
15986     return false;
15987 
15988   // OK, we found an ADD we can fold into the base update.
15989   // Now, create a _UPD node, taking care of not breaking alignment.
15990 
15991   EVT AlignedVecTy = VecTy;
15992   Align Alignment = MemN->getAlign();
15993 
15994   // If this is a less-than-standard-aligned load/store, change the type to
15995   // match the standard alignment.
15996   // The alignment is overlooked when selecting _UPD variants; and it's
15997   // easier to introduce bitcasts here than fix that.
15998   // There are 3 ways to get to this base-update combine:
15999   // - intrinsics: they are assumed to be properly aligned (to the standard
16000   //   alignment of the memory type), so we don't need to do anything.
16001   // - ARMISD::VLDx nodes: they are only generated from the aforementioned
16002   //   intrinsics, so, likewise, there's nothing to do.
16003   // - generic load/store instructions: the alignment is specified as an
16004   //   explicit operand, rather than implicitly as the standard alignment
16005   //   of the memory type (like the intrisics).  We need to change the
16006   //   memory type to match the explicit alignment.  That way, we don't
16007   //   generate non-standard-aligned ARMISD::VLDx nodes.
16008   if (isa<LSBaseSDNode>(N)) {
16009     if (Alignment.value() < VecTy.getScalarSizeInBits() / 8) {
16010       MVT EltTy = MVT::getIntegerVT(Alignment.value() * 8);
16011       assert(NumVecs == 1 && "Unexpected multi-element generic load/store.");
16012       assert(!isLaneOp && "Unexpected generic load/store lane.");
16013       unsigned NumElts = NumBytes / (EltTy.getSizeInBits() / 8);
16014       AlignedVecTy = MVT::getVectorVT(EltTy, NumElts);
16015     }
16016     // Don't set an explicit alignment on regular load/stores that we want
16017     // to transform to VLD/VST 1_UPD nodes.
16018     // This matches the behavior of regular load/stores, which only get an
16019     // explicit alignment if the MMO alignment is larger than the standard
16020     // alignment of the memory type.
16021     // Intrinsics, however, always get an explicit alignment, set to the
16022     // alignment of the MMO.
16023     Alignment = Align(1);
16024   }
16025 
16026   // Create the new updating load/store node.
16027   // First, create an SDVTList for the new updating node's results.
16028   EVT Tys[6];
16029   unsigned NumResultVecs = (isLoadOp ? NumVecs : 0);
16030   unsigned n;
16031   for (n = 0; n < NumResultVecs; ++n)
16032     Tys[n] = AlignedVecTy;
16033   Tys[n++] = MVT::i32;
16034   Tys[n] = MVT::Other;
16035   SDVTList SDTys = DAG.getVTList(ArrayRef(Tys, NumResultVecs + 2));
16036 
16037   // Then, gather the new node's operands.
16038   SmallVector<SDValue, 8> Ops;
16039   Ops.push_back(N->getOperand(0)); // incoming chain
16040   Ops.push_back(N->getOperand(Target.AddrOpIdx));
16041   Ops.push_back(User.Inc);
16042 
16043   if (StoreSDNode *StN = dyn_cast<StoreSDNode>(N)) {
16044     // Try to match the intrinsic's signature
16045     Ops.push_back(StN->getValue());
16046   } else {
16047     // Loads (and of course intrinsics) match the intrinsics' signature,
16048     // so just add all but the alignment operand.
16049     unsigned LastOperand =
16050         hasAlignment ? N->getNumOperands() - 1 : N->getNumOperands();
16051     for (unsigned i = Target.AddrOpIdx + 1; i < LastOperand; ++i)
16052       Ops.push_back(N->getOperand(i));
16053   }
16054 
16055   // For all node types, the alignment operand is always the last one.
16056   Ops.push_back(DAG.getConstant(Alignment.value(), dl, MVT::i32));
16057 
16058   // If this is a non-standard-aligned STORE, the penultimate operand is the
16059   // stored value.  Bitcast it to the aligned type.
16060   if (AlignedVecTy != VecTy && N->getOpcode() == ISD::STORE) {
16061     SDValue &StVal = Ops[Ops.size() - 2];
16062     StVal = DAG.getNode(ISD::BITCAST, dl, AlignedVecTy, StVal);
16063   }
16064 
16065   EVT LoadVT = isLaneOp ? VecTy.getVectorElementType() : AlignedVecTy;
16066   SDValue UpdN = DAG.getMemIntrinsicNode(NewOpc, dl, SDTys, Ops, LoadVT,
16067                                          MemN->getMemOperand());
16068 
16069   // Update the uses.
16070   SmallVector<SDValue, 5> NewResults;
16071   for (unsigned i = 0; i < NumResultVecs; ++i)
16072     NewResults.push_back(SDValue(UpdN.getNode(), i));
16073 
16074   // If this is an non-standard-aligned LOAD, the first result is the loaded
16075   // value.  Bitcast it to the expected result type.
16076   if (AlignedVecTy != VecTy && N->getOpcode() == ISD::LOAD) {
16077     SDValue &LdVal = NewResults[0];
16078     LdVal = DAG.getNode(ISD::BITCAST, dl, VecTy, LdVal);
16079   }
16080 
16081   NewResults.push_back(SDValue(UpdN.getNode(), NumResultVecs + 1)); // chain
16082   DCI.CombineTo(N, NewResults);
16083   DCI.CombineTo(User.N, SDValue(UpdN.getNode(), NumResultVecs));
16084 
16085   return true;
16086 }
16087 
16088 // If (opcode ptr inc) is and ADD-like instruction, return the
16089 // increment value. Otherwise return 0.
getPointerConstIncrement(unsigned Opcode,SDValue Ptr,SDValue Inc,const SelectionDAG & DAG)16090 static unsigned getPointerConstIncrement(unsigned Opcode, SDValue Ptr,
16091                                          SDValue Inc, const SelectionDAG &DAG) {
16092   ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode());
16093   if (!CInc)
16094     return 0;
16095 
16096   switch (Opcode) {
16097   case ARMISD::VLD1_UPD:
16098   case ISD::ADD:
16099     return CInc->getZExtValue();
16100   case ISD::OR: {
16101     if (DAG.haveNoCommonBitsSet(Ptr, Inc)) {
16102       // (OR ptr inc) is the same as (ADD ptr inc)
16103       return CInc->getZExtValue();
16104     }
16105     return 0;
16106   }
16107   default:
16108     return 0;
16109   }
16110 }
16111 
findPointerConstIncrement(SDNode * N,SDValue * Ptr,SDValue * CInc)16112 static bool findPointerConstIncrement(SDNode *N, SDValue *Ptr, SDValue *CInc) {
16113   switch (N->getOpcode()) {
16114   case ISD::ADD:
16115   case ISD::OR: {
16116     if (isa<ConstantSDNode>(N->getOperand(1))) {
16117       *Ptr = N->getOperand(0);
16118       *CInc = N->getOperand(1);
16119       return true;
16120     }
16121     return false;
16122   }
16123   case ARMISD::VLD1_UPD: {
16124     if (isa<ConstantSDNode>(N->getOperand(2))) {
16125       *Ptr = N->getOperand(1);
16126       *CInc = N->getOperand(2);
16127       return true;
16128     }
16129     return false;
16130   }
16131   default:
16132     return false;
16133   }
16134 }
16135 
isValidBaseUpdate(SDNode * N,SDNode * User)16136 static bool isValidBaseUpdate(SDNode *N, SDNode *User) {
16137   // Check that the add is independent of the load/store.
16138   // Otherwise, folding it would create a cycle. Search through Addr
16139   // as well, since the User may not be a direct user of Addr and
16140   // only share a base pointer.
16141   SmallPtrSet<const SDNode *, 32> Visited;
16142   SmallVector<const SDNode *, 16> Worklist;
16143   Worklist.push_back(N);
16144   Worklist.push_back(User);
16145   if (SDNode::hasPredecessorHelper(N, Visited, Worklist) ||
16146       SDNode::hasPredecessorHelper(User, Visited, Worklist))
16147     return false;
16148   return true;
16149 }
16150 
16151 /// CombineBaseUpdate - Target-specific DAG combine function for VLDDUP,
16152 /// NEON load/store intrinsics, and generic vector load/stores, to merge
16153 /// base address updates.
16154 /// For generic load/stores, the memory type is assumed to be a vector.
16155 /// The caller is assumed to have checked legality.
CombineBaseUpdate(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)16156 static SDValue CombineBaseUpdate(SDNode *N,
16157                                  TargetLowering::DAGCombinerInfo &DCI) {
16158   const bool isIntrinsic = (N->getOpcode() == ISD::INTRINSIC_VOID ||
16159                             N->getOpcode() == ISD::INTRINSIC_W_CHAIN);
16160   const bool isStore = N->getOpcode() == ISD::STORE;
16161   const unsigned AddrOpIdx = ((isIntrinsic || isStore) ? 2 : 1);
16162   BaseUpdateTarget Target = {N, isIntrinsic, isStore, AddrOpIdx};
16163 
16164   SDValue Addr = N->getOperand(AddrOpIdx);
16165 
16166   SmallVector<BaseUpdateUser, 8> BaseUpdates;
16167 
16168   // Search for a use of the address operand that is an increment.
16169   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(),
16170          UE = Addr.getNode()->use_end(); UI != UE; ++UI) {
16171     SDNode *User = *UI;
16172     if (UI.getUse().getResNo() != Addr.getResNo() ||
16173         User->getNumOperands() != 2)
16174       continue;
16175 
16176     SDValue Inc = User->getOperand(UI.getOperandNo() == 1 ? 0 : 1);
16177     unsigned ConstInc =
16178         getPointerConstIncrement(User->getOpcode(), Addr, Inc, DCI.DAG);
16179 
16180     if (ConstInc || User->getOpcode() == ISD::ADD)
16181       BaseUpdates.push_back({User, Inc, ConstInc});
16182   }
16183 
16184   // If the address is a constant pointer increment itself, find
16185   // another constant increment that has the same base operand
16186   SDValue Base;
16187   SDValue CInc;
16188   if (findPointerConstIncrement(Addr.getNode(), &Base, &CInc)) {
16189     unsigned Offset =
16190         getPointerConstIncrement(Addr->getOpcode(), Base, CInc, DCI.DAG);
16191     for (SDNode::use_iterator UI = Base->use_begin(), UE = Base->use_end();
16192          UI != UE; ++UI) {
16193 
16194       SDNode *User = *UI;
16195       if (UI.getUse().getResNo() != Base.getResNo() || User == Addr.getNode() ||
16196           User->getNumOperands() != 2)
16197         continue;
16198 
16199       SDValue UserInc = User->getOperand(UI.getOperandNo() == 0 ? 1 : 0);
16200       unsigned UserOffset =
16201           getPointerConstIncrement(User->getOpcode(), Base, UserInc, DCI.DAG);
16202 
16203       if (!UserOffset || UserOffset <= Offset)
16204         continue;
16205 
16206       unsigned NewConstInc = UserOffset - Offset;
16207       SDValue NewInc = DCI.DAG.getConstant(NewConstInc, SDLoc(N), MVT::i32);
16208       BaseUpdates.push_back({User, NewInc, NewConstInc});
16209     }
16210   }
16211 
16212   // Try to fold the load/store with an update that matches memory
16213   // access size. This should work well for sequential loads.
16214   //
16215   // Filter out invalid updates as well.
16216   unsigned NumValidUpd = BaseUpdates.size();
16217   for (unsigned I = 0; I < NumValidUpd;) {
16218     BaseUpdateUser &User = BaseUpdates[I];
16219     if (!isValidBaseUpdate(N, User.N)) {
16220       --NumValidUpd;
16221       std::swap(BaseUpdates[I], BaseUpdates[NumValidUpd]);
16222       continue;
16223     }
16224 
16225     if (TryCombineBaseUpdate(Target, User, /*SimpleConstIncOnly=*/true, DCI))
16226       return SDValue();
16227     ++I;
16228   }
16229   BaseUpdates.resize(NumValidUpd);
16230 
16231   // Try to fold with other users. Non-constant updates are considered
16232   // first, and constant updates are sorted to not break a sequence of
16233   // strided accesses (if there is any).
16234   std::stable_sort(BaseUpdates.begin(), BaseUpdates.end(),
16235                    [](const BaseUpdateUser &LHS, const BaseUpdateUser &RHS) {
16236                      return LHS.ConstInc < RHS.ConstInc;
16237                    });
16238   for (BaseUpdateUser &User : BaseUpdates) {
16239     if (TryCombineBaseUpdate(Target, User, /*SimpleConstIncOnly=*/false, DCI))
16240       return SDValue();
16241   }
16242   return SDValue();
16243 }
16244 
PerformVLDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)16245 static SDValue PerformVLDCombine(SDNode *N,
16246                                  TargetLowering::DAGCombinerInfo &DCI) {
16247   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
16248     return SDValue();
16249 
16250   return CombineBaseUpdate(N, DCI);
16251 }
16252 
PerformMVEVLDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)16253 static SDValue PerformMVEVLDCombine(SDNode *N,
16254                                     TargetLowering::DAGCombinerInfo &DCI) {
16255   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
16256     return SDValue();
16257 
16258   SelectionDAG &DAG = DCI.DAG;
16259   SDValue Addr = N->getOperand(2);
16260   MemSDNode *MemN = cast<MemSDNode>(N);
16261   SDLoc dl(N);
16262 
16263   // For the stores, where there are multiple intrinsics we only actually want
16264   // to post-inc the last of the them.
16265   unsigned IntNo = N->getConstantOperandVal(1);
16266   if (IntNo == Intrinsic::arm_mve_vst2q && N->getConstantOperandVal(5) != 1)
16267     return SDValue();
16268   if (IntNo == Intrinsic::arm_mve_vst4q && N->getConstantOperandVal(7) != 3)
16269     return SDValue();
16270 
16271   // Search for a use of the address operand that is an increment.
16272   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(),
16273                             UE = Addr.getNode()->use_end();
16274        UI != UE; ++UI) {
16275     SDNode *User = *UI;
16276     if (User->getOpcode() != ISD::ADD ||
16277         UI.getUse().getResNo() != Addr.getResNo())
16278       continue;
16279 
16280     // Check that the add is independent of the load/store.  Otherwise, folding
16281     // it would create a cycle. We can avoid searching through Addr as it's a
16282     // predecessor to both.
16283     SmallPtrSet<const SDNode *, 32> Visited;
16284     SmallVector<const SDNode *, 16> Worklist;
16285     Visited.insert(Addr.getNode());
16286     Worklist.push_back(N);
16287     Worklist.push_back(User);
16288     if (SDNode::hasPredecessorHelper(N, Visited, Worklist) ||
16289         SDNode::hasPredecessorHelper(User, Visited, Worklist))
16290       continue;
16291 
16292     // Find the new opcode for the updating load/store.
16293     bool isLoadOp = true;
16294     unsigned NewOpc = 0;
16295     unsigned NumVecs = 0;
16296     switch (IntNo) {
16297     default:
16298       llvm_unreachable("unexpected intrinsic for MVE VLDn combine");
16299     case Intrinsic::arm_mve_vld2q:
16300       NewOpc = ARMISD::VLD2_UPD;
16301       NumVecs = 2;
16302       break;
16303     case Intrinsic::arm_mve_vld4q:
16304       NewOpc = ARMISD::VLD4_UPD;
16305       NumVecs = 4;
16306       break;
16307     case Intrinsic::arm_mve_vst2q:
16308       NewOpc = ARMISD::VST2_UPD;
16309       NumVecs = 2;
16310       isLoadOp = false;
16311       break;
16312     case Intrinsic::arm_mve_vst4q:
16313       NewOpc = ARMISD::VST4_UPD;
16314       NumVecs = 4;
16315       isLoadOp = false;
16316       break;
16317     }
16318 
16319     // Find the size of memory referenced by the load/store.
16320     EVT VecTy;
16321     if (isLoadOp) {
16322       VecTy = N->getValueType(0);
16323     } else {
16324       VecTy = N->getOperand(3).getValueType();
16325     }
16326 
16327     unsigned NumBytes = NumVecs * VecTy.getSizeInBits() / 8;
16328 
16329     // If the increment is a constant, it must match the memory ref size.
16330     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
16331     ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode());
16332     if (!CInc || CInc->getZExtValue() != NumBytes)
16333       continue;
16334 
16335     // Create the new updating load/store node.
16336     // First, create an SDVTList for the new updating node's results.
16337     EVT Tys[6];
16338     unsigned NumResultVecs = (isLoadOp ? NumVecs : 0);
16339     unsigned n;
16340     for (n = 0; n < NumResultVecs; ++n)
16341       Tys[n] = VecTy;
16342     Tys[n++] = MVT::i32;
16343     Tys[n] = MVT::Other;
16344     SDVTList SDTys = DAG.getVTList(ArrayRef(Tys, NumResultVecs + 2));
16345 
16346     // Then, gather the new node's operands.
16347     SmallVector<SDValue, 8> Ops;
16348     Ops.push_back(N->getOperand(0)); // incoming chain
16349     Ops.push_back(N->getOperand(2)); // ptr
16350     Ops.push_back(Inc);
16351 
16352     for (unsigned i = 3; i < N->getNumOperands(); ++i)
16353       Ops.push_back(N->getOperand(i));
16354 
16355     SDValue UpdN = DAG.getMemIntrinsicNode(NewOpc, dl, SDTys, Ops, VecTy,
16356                                            MemN->getMemOperand());
16357 
16358     // Update the uses.
16359     SmallVector<SDValue, 5> NewResults;
16360     for (unsigned i = 0; i < NumResultVecs; ++i)
16361       NewResults.push_back(SDValue(UpdN.getNode(), i));
16362 
16363     NewResults.push_back(SDValue(UpdN.getNode(), NumResultVecs + 1)); // chain
16364     DCI.CombineTo(N, NewResults);
16365     DCI.CombineTo(User, SDValue(UpdN.getNode(), NumResultVecs));
16366 
16367     break;
16368   }
16369 
16370   return SDValue();
16371 }
16372 
16373 /// CombineVLDDUP - For a VDUPLANE node N, check if its source operand is a
16374 /// vldN-lane (N > 1) intrinsic, and if all the other uses of that intrinsic
16375 /// are also VDUPLANEs.  If so, combine them to a vldN-dup operation and
16376 /// return true.
CombineVLDDUP(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)16377 static bool CombineVLDDUP(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
16378   SelectionDAG &DAG = DCI.DAG;
16379   EVT VT = N->getValueType(0);
16380   // vldN-dup instructions only support 64-bit vectors for N > 1.
16381   if (!VT.is64BitVector())
16382     return false;
16383 
16384   // Check if the VDUPLANE operand is a vldN-dup intrinsic.
16385   SDNode *VLD = N->getOperand(0).getNode();
16386   if (VLD->getOpcode() != ISD::INTRINSIC_W_CHAIN)
16387     return false;
16388   unsigned NumVecs = 0;
16389   unsigned NewOpc = 0;
16390   unsigned IntNo = VLD->getConstantOperandVal(1);
16391   if (IntNo == Intrinsic::arm_neon_vld2lane) {
16392     NumVecs = 2;
16393     NewOpc = ARMISD::VLD2DUP;
16394   } else if (IntNo == Intrinsic::arm_neon_vld3lane) {
16395     NumVecs = 3;
16396     NewOpc = ARMISD::VLD3DUP;
16397   } else if (IntNo == Intrinsic::arm_neon_vld4lane) {
16398     NumVecs = 4;
16399     NewOpc = ARMISD::VLD4DUP;
16400   } else {
16401     return false;
16402   }
16403 
16404   // First check that all the vldN-lane uses are VDUPLANEs and that the lane
16405   // numbers match the load.
16406   unsigned VLDLaneNo = VLD->getConstantOperandVal(NumVecs + 3);
16407   for (SDNode::use_iterator UI = VLD->use_begin(), UE = VLD->use_end();
16408        UI != UE; ++UI) {
16409     // Ignore uses of the chain result.
16410     if (UI.getUse().getResNo() == NumVecs)
16411       continue;
16412     SDNode *User = *UI;
16413     if (User->getOpcode() != ARMISD::VDUPLANE ||
16414         VLDLaneNo != User->getConstantOperandVal(1))
16415       return false;
16416   }
16417 
16418   // Create the vldN-dup node.
16419   EVT Tys[5];
16420   unsigned n;
16421   for (n = 0; n < NumVecs; ++n)
16422     Tys[n] = VT;
16423   Tys[n] = MVT::Other;
16424   SDVTList SDTys = DAG.getVTList(ArrayRef(Tys, NumVecs + 1));
16425   SDValue Ops[] = { VLD->getOperand(0), VLD->getOperand(2) };
16426   MemIntrinsicSDNode *VLDMemInt = cast<MemIntrinsicSDNode>(VLD);
16427   SDValue VLDDup = DAG.getMemIntrinsicNode(NewOpc, SDLoc(VLD), SDTys,
16428                                            Ops, VLDMemInt->getMemoryVT(),
16429                                            VLDMemInt->getMemOperand());
16430 
16431   // Update the uses.
16432   for (SDNode::use_iterator UI = VLD->use_begin(), UE = VLD->use_end();
16433        UI != UE; ++UI) {
16434     unsigned ResNo = UI.getUse().getResNo();
16435     // Ignore uses of the chain result.
16436     if (ResNo == NumVecs)
16437       continue;
16438     SDNode *User = *UI;
16439     DCI.CombineTo(User, SDValue(VLDDup.getNode(), ResNo));
16440   }
16441 
16442   // Now the vldN-lane intrinsic is dead except for its chain result.
16443   // Update uses of the chain.
16444   std::vector<SDValue> VLDDupResults;
16445   for (unsigned n = 0; n < NumVecs; ++n)
16446     VLDDupResults.push_back(SDValue(VLDDup.getNode(), n));
16447   VLDDupResults.push_back(SDValue(VLDDup.getNode(), NumVecs));
16448   DCI.CombineTo(VLD, VLDDupResults);
16449 
16450   return true;
16451 }
16452 
16453 /// PerformVDUPLANECombine - Target-specific dag combine xforms for
16454 /// ARMISD::VDUPLANE.
PerformVDUPLANECombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)16455 static SDValue PerformVDUPLANECombine(SDNode *N,
16456                                       TargetLowering::DAGCombinerInfo &DCI,
16457                                       const ARMSubtarget *Subtarget) {
16458   SDValue Op = N->getOperand(0);
16459   EVT VT = N->getValueType(0);
16460 
16461   // On MVE, we just convert the VDUPLANE to a VDUP with an extract.
16462   if (Subtarget->hasMVEIntegerOps()) {
16463     EVT ExtractVT = VT.getVectorElementType();
16464     // We need to ensure we are creating a legal type.
16465     if (!DCI.DAG.getTargetLoweringInfo().isTypeLegal(ExtractVT))
16466       ExtractVT = MVT::i32;
16467     SDValue Extract = DCI.DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), ExtractVT,
16468                               N->getOperand(0), N->getOperand(1));
16469     return DCI.DAG.getNode(ARMISD::VDUP, SDLoc(N), VT, Extract);
16470   }
16471 
16472   // If the source is a vldN-lane (N > 1) intrinsic, and all the other uses
16473   // of that intrinsic are also VDUPLANEs, combine them to a vldN-dup operation.
16474   if (CombineVLDDUP(N, DCI))
16475     return SDValue(N, 0);
16476 
16477   // If the source is already a VMOVIMM or VMVNIMM splat, the VDUPLANE is
16478   // redundant.  Ignore bit_converts for now; element sizes are checked below.
16479   while (Op.getOpcode() == ISD::BITCAST)
16480     Op = Op.getOperand(0);
16481   if (Op.getOpcode() != ARMISD::VMOVIMM && Op.getOpcode() != ARMISD::VMVNIMM)
16482     return SDValue();
16483 
16484   // Make sure the VMOV element size is not bigger than the VDUPLANE elements.
16485   unsigned EltSize = Op.getScalarValueSizeInBits();
16486   // The canonical VMOV for a zero vector uses a 32-bit element size.
16487   unsigned Imm = Op.getConstantOperandVal(0);
16488   unsigned EltBits;
16489   if (ARM_AM::decodeVMOVModImm(Imm, EltBits) == 0)
16490     EltSize = 8;
16491   if (EltSize > VT.getScalarSizeInBits())
16492     return SDValue();
16493 
16494   return DCI.DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Op);
16495 }
16496 
16497 /// PerformVDUPCombine - Target-specific dag combine xforms for ARMISD::VDUP.
PerformVDUPCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)16498 static SDValue PerformVDUPCombine(SDNode *N, SelectionDAG &DAG,
16499                                   const ARMSubtarget *Subtarget) {
16500   SDValue Op = N->getOperand(0);
16501   SDLoc dl(N);
16502 
16503   if (Subtarget->hasMVEIntegerOps()) {
16504     // Convert VDUP f32 -> VDUP BITCAST i32 under MVE, as we know the value will
16505     // need to come from a GPR.
16506     if (Op.getValueType() == MVT::f32)
16507       return DAG.getNode(ARMISD::VDUP, dl, N->getValueType(0),
16508                          DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op));
16509     else if (Op.getValueType() == MVT::f16)
16510       return DAG.getNode(ARMISD::VDUP, dl, N->getValueType(0),
16511                          DAG.getNode(ARMISD::VMOVrh, dl, MVT::i32, Op));
16512   }
16513 
16514   if (!Subtarget->hasNEON())
16515     return SDValue();
16516 
16517   // Match VDUP(LOAD) -> VLD1DUP.
16518   // We match this pattern here rather than waiting for isel because the
16519   // transform is only legal for unindexed loads.
16520   LoadSDNode *LD = dyn_cast<LoadSDNode>(Op.getNode());
16521   if (LD && Op.hasOneUse() && LD->isUnindexed() &&
16522       LD->getMemoryVT() == N->getValueType(0).getVectorElementType()) {
16523     SDValue Ops[] = {LD->getOperand(0), LD->getOperand(1),
16524                      DAG.getConstant(LD->getAlign().value(), SDLoc(N), MVT::i32)};
16525     SDVTList SDTys = DAG.getVTList(N->getValueType(0), MVT::Other);
16526     SDValue VLDDup =
16527         DAG.getMemIntrinsicNode(ARMISD::VLD1DUP, SDLoc(N), SDTys, Ops,
16528                                 LD->getMemoryVT(), LD->getMemOperand());
16529     DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), VLDDup.getValue(1));
16530     return VLDDup;
16531   }
16532 
16533   return SDValue();
16534 }
16535 
PerformLOADCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)16536 static SDValue PerformLOADCombine(SDNode *N,
16537                                   TargetLowering::DAGCombinerInfo &DCI,
16538                                   const ARMSubtarget *Subtarget) {
16539   EVT VT = N->getValueType(0);
16540 
16541   // If this is a legal vector load, try to combine it into a VLD1_UPD.
16542   if (Subtarget->hasNEON() && ISD::isNormalLoad(N) && VT.isVector() &&
16543       DCI.DAG.getTargetLoweringInfo().isTypeLegal(VT))
16544     return CombineBaseUpdate(N, DCI);
16545 
16546   return SDValue();
16547 }
16548 
16549 // Optimize trunc store (of multiple scalars) to shuffle and store.  First,
16550 // pack all of the elements in one place.  Next, store to memory in fewer
16551 // chunks.
PerformTruncatingStoreCombine(StoreSDNode * St,SelectionDAG & DAG)16552 static SDValue PerformTruncatingStoreCombine(StoreSDNode *St,
16553                                              SelectionDAG &DAG) {
16554   SDValue StVal = St->getValue();
16555   EVT VT = StVal.getValueType();
16556   if (!St->isTruncatingStore() || !VT.isVector())
16557     return SDValue();
16558   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
16559   EVT StVT = St->getMemoryVT();
16560   unsigned NumElems = VT.getVectorNumElements();
16561   assert(StVT != VT && "Cannot truncate to the same type");
16562   unsigned FromEltSz = VT.getScalarSizeInBits();
16563   unsigned ToEltSz = StVT.getScalarSizeInBits();
16564 
16565   // From, To sizes and ElemCount must be pow of two
16566   if (!isPowerOf2_32(NumElems * FromEltSz * ToEltSz))
16567     return SDValue();
16568 
16569   // We are going to use the original vector elt for storing.
16570   // Accumulated smaller vector elements must be a multiple of the store size.
16571   if (0 != (NumElems * FromEltSz) % ToEltSz)
16572     return SDValue();
16573 
16574   unsigned SizeRatio = FromEltSz / ToEltSz;
16575   assert(SizeRatio * NumElems * ToEltSz == VT.getSizeInBits());
16576 
16577   // Create a type on which we perform the shuffle.
16578   EVT WideVecVT = EVT::getVectorVT(*DAG.getContext(), StVT.getScalarType(),
16579                                    NumElems * SizeRatio);
16580   assert(WideVecVT.getSizeInBits() == VT.getSizeInBits());
16581 
16582   SDLoc DL(St);
16583   SDValue WideVec = DAG.getNode(ISD::BITCAST, DL, WideVecVT, StVal);
16584   SmallVector<int, 8> ShuffleVec(NumElems * SizeRatio, -1);
16585   for (unsigned i = 0; i < NumElems; ++i)
16586     ShuffleVec[i] = DAG.getDataLayout().isBigEndian() ? (i + 1) * SizeRatio - 1
16587                                                       : i * SizeRatio;
16588 
16589   // Can't shuffle using an illegal type.
16590   if (!TLI.isTypeLegal(WideVecVT))
16591     return SDValue();
16592 
16593   SDValue Shuff = DAG.getVectorShuffle(
16594       WideVecVT, DL, WideVec, DAG.getUNDEF(WideVec.getValueType()), ShuffleVec);
16595   // At this point all of the data is stored at the bottom of the
16596   // register. We now need to save it to mem.
16597 
16598   // Find the largest store unit
16599   MVT StoreType = MVT::i8;
16600   for (MVT Tp : MVT::integer_valuetypes()) {
16601     if (TLI.isTypeLegal(Tp) && Tp.getSizeInBits() <= NumElems * ToEltSz)
16602       StoreType = Tp;
16603   }
16604   // Didn't find a legal store type.
16605   if (!TLI.isTypeLegal(StoreType))
16606     return SDValue();
16607 
16608   // Bitcast the original vector into a vector of store-size units
16609   EVT StoreVecVT =
16610       EVT::getVectorVT(*DAG.getContext(), StoreType,
16611                        VT.getSizeInBits() / EVT(StoreType).getSizeInBits());
16612   assert(StoreVecVT.getSizeInBits() == VT.getSizeInBits());
16613   SDValue ShuffWide = DAG.getNode(ISD::BITCAST, DL, StoreVecVT, Shuff);
16614   SmallVector<SDValue, 8> Chains;
16615   SDValue Increment = DAG.getConstant(StoreType.getSizeInBits() / 8, DL,
16616                                       TLI.getPointerTy(DAG.getDataLayout()));
16617   SDValue BasePtr = St->getBasePtr();
16618 
16619   // Perform one or more big stores into memory.
16620   unsigned E = (ToEltSz * NumElems) / StoreType.getSizeInBits();
16621   for (unsigned I = 0; I < E; I++) {
16622     SDValue SubVec = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, StoreType,
16623                                  ShuffWide, DAG.getIntPtrConstant(I, DL));
16624     SDValue Ch =
16625         DAG.getStore(St->getChain(), DL, SubVec, BasePtr, St->getPointerInfo(),
16626                      St->getAlign(), St->getMemOperand()->getFlags());
16627     BasePtr =
16628         DAG.getNode(ISD::ADD, DL, BasePtr.getValueType(), BasePtr, Increment);
16629     Chains.push_back(Ch);
16630   }
16631   return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
16632 }
16633 
16634 // Try taking a single vector store from an fpround (which would otherwise turn
16635 // into an expensive buildvector) and splitting it into a series of narrowing
16636 // stores.
PerformSplittingToNarrowingStores(StoreSDNode * St,SelectionDAG & DAG)16637 static SDValue PerformSplittingToNarrowingStores(StoreSDNode *St,
16638                                                  SelectionDAG &DAG) {
16639   if (!St->isSimple() || St->isTruncatingStore() || !St->isUnindexed())
16640     return SDValue();
16641   SDValue Trunc = St->getValue();
16642   if (Trunc->getOpcode() != ISD::FP_ROUND)
16643     return SDValue();
16644   EVT FromVT = Trunc->getOperand(0).getValueType();
16645   EVT ToVT = Trunc.getValueType();
16646   if (!ToVT.isVector())
16647     return SDValue();
16648   assert(FromVT.getVectorNumElements() == ToVT.getVectorNumElements());
16649   EVT ToEltVT = ToVT.getVectorElementType();
16650   EVT FromEltVT = FromVT.getVectorElementType();
16651 
16652   if (FromEltVT != MVT::f32 || ToEltVT != MVT::f16)
16653     return SDValue();
16654 
16655   unsigned NumElements = 4;
16656   if (FromVT.getVectorNumElements() % NumElements != 0)
16657     return SDValue();
16658 
16659   // Test if the Trunc will be convertable to a VMOVN with a shuffle, and if so
16660   // use the VMOVN over splitting the store. We are looking for patterns of:
16661   // !rev: 0 N 1 N+1 2 N+2 ...
16662   //  rev: N 0 N+1 1 N+2 2 ...
16663   // The shuffle may either be a single source (in which case N = NumElts/2) or
16664   // two inputs extended with concat to the same size (in which case N =
16665   // NumElts).
16666   auto isVMOVNShuffle = [&](ShuffleVectorSDNode *SVN, bool Rev) {
16667     ArrayRef<int> M = SVN->getMask();
16668     unsigned NumElts = ToVT.getVectorNumElements();
16669     if (SVN->getOperand(1).isUndef())
16670       NumElts /= 2;
16671 
16672     unsigned Off0 = Rev ? NumElts : 0;
16673     unsigned Off1 = Rev ? 0 : NumElts;
16674 
16675     for (unsigned I = 0; I < NumElts; I += 2) {
16676       if (M[I] >= 0 && M[I] != (int)(Off0 + I / 2))
16677         return false;
16678       if (M[I + 1] >= 0 && M[I + 1] != (int)(Off1 + I / 2))
16679         return false;
16680     }
16681 
16682     return true;
16683   };
16684 
16685   if (auto *Shuffle = dyn_cast<ShuffleVectorSDNode>(Trunc.getOperand(0)))
16686     if (isVMOVNShuffle(Shuffle, false) || isVMOVNShuffle(Shuffle, true))
16687       return SDValue();
16688 
16689   LLVMContext &C = *DAG.getContext();
16690   SDLoc DL(St);
16691   // Details about the old store
16692   SDValue Ch = St->getChain();
16693   SDValue BasePtr = St->getBasePtr();
16694   Align Alignment = St->getOriginalAlign();
16695   MachineMemOperand::Flags MMOFlags = St->getMemOperand()->getFlags();
16696   AAMDNodes AAInfo = St->getAAInfo();
16697 
16698   // We split the store into slices of NumElements. fp16 trunc stores are vcvt
16699   // and then stored as truncating integer stores.
16700   EVT NewFromVT = EVT::getVectorVT(C, FromEltVT, NumElements);
16701   EVT NewToVT = EVT::getVectorVT(
16702       C, EVT::getIntegerVT(C, ToEltVT.getSizeInBits()), NumElements);
16703 
16704   SmallVector<SDValue, 4> Stores;
16705   for (unsigned i = 0; i < FromVT.getVectorNumElements() / NumElements; i++) {
16706     unsigned NewOffset = i * NumElements * ToEltVT.getSizeInBits() / 8;
16707     SDValue NewPtr =
16708         DAG.getObjectPtrOffset(DL, BasePtr, TypeSize::getFixed(NewOffset));
16709 
16710     SDValue Extract =
16711         DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, NewFromVT, Trunc.getOperand(0),
16712                     DAG.getConstant(i * NumElements, DL, MVT::i32));
16713 
16714     SDValue FPTrunc =
16715         DAG.getNode(ARMISD::VCVTN, DL, MVT::v8f16, DAG.getUNDEF(MVT::v8f16),
16716                     Extract, DAG.getConstant(0, DL, MVT::i32));
16717     Extract = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, MVT::v4i32, FPTrunc);
16718 
16719     SDValue Store = DAG.getTruncStore(
16720         Ch, DL, Extract, NewPtr, St->getPointerInfo().getWithOffset(NewOffset),
16721         NewToVT, Alignment, MMOFlags, AAInfo);
16722     Stores.push_back(Store);
16723   }
16724   return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Stores);
16725 }
16726 
16727 // Try taking a single vector store from an MVETRUNC (which would otherwise turn
16728 // into an expensive buildvector) and splitting it into a series of narrowing
16729 // stores.
PerformSplittingMVETruncToNarrowingStores(StoreSDNode * St,SelectionDAG & DAG)16730 static SDValue PerformSplittingMVETruncToNarrowingStores(StoreSDNode *St,
16731                                                          SelectionDAG &DAG) {
16732   if (!St->isSimple() || St->isTruncatingStore() || !St->isUnindexed())
16733     return SDValue();
16734   SDValue Trunc = St->getValue();
16735   if (Trunc->getOpcode() != ARMISD::MVETRUNC)
16736     return SDValue();
16737   EVT FromVT = Trunc->getOperand(0).getValueType();
16738   EVT ToVT = Trunc.getValueType();
16739 
16740   LLVMContext &C = *DAG.getContext();
16741   SDLoc DL(St);
16742   // Details about the old store
16743   SDValue Ch = St->getChain();
16744   SDValue BasePtr = St->getBasePtr();
16745   Align Alignment = St->getOriginalAlign();
16746   MachineMemOperand::Flags MMOFlags = St->getMemOperand()->getFlags();
16747   AAMDNodes AAInfo = St->getAAInfo();
16748 
16749   EVT NewToVT = EVT::getVectorVT(C, ToVT.getVectorElementType(),
16750                                  FromVT.getVectorNumElements());
16751 
16752   SmallVector<SDValue, 4> Stores;
16753   for (unsigned i = 0; i < Trunc.getNumOperands(); i++) {
16754     unsigned NewOffset =
16755         i * FromVT.getVectorNumElements() * ToVT.getScalarSizeInBits() / 8;
16756     SDValue NewPtr =
16757         DAG.getObjectPtrOffset(DL, BasePtr, TypeSize::getFixed(NewOffset));
16758 
16759     SDValue Extract = Trunc.getOperand(i);
16760     SDValue Store = DAG.getTruncStore(
16761         Ch, DL, Extract, NewPtr, St->getPointerInfo().getWithOffset(NewOffset),
16762         NewToVT, Alignment, MMOFlags, AAInfo);
16763     Stores.push_back(Store);
16764   }
16765   return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Stores);
16766 }
16767 
16768 // Given a floating point store from an extracted vector, with an integer
16769 // VGETLANE that already exists, store the existing VGETLANEu directly. This can
16770 // help reduce fp register pressure, doesn't require the fp extract and allows
16771 // use of more integer post-inc stores not available with vstr.
PerformExtractFpToIntStores(StoreSDNode * St,SelectionDAG & DAG)16772 static SDValue PerformExtractFpToIntStores(StoreSDNode *St, SelectionDAG &DAG) {
16773   if (!St->isSimple() || St->isTruncatingStore() || !St->isUnindexed())
16774     return SDValue();
16775   SDValue Extract = St->getValue();
16776   EVT VT = Extract.getValueType();
16777   // For now only uses f16. This may be useful for f32 too, but that will
16778   // be bitcast(extract), not the VGETLANEu we currently check here.
16779   if (VT != MVT::f16 || Extract->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
16780     return SDValue();
16781 
16782   SDNode *GetLane =
16783       DAG.getNodeIfExists(ARMISD::VGETLANEu, DAG.getVTList(MVT::i32),
16784                           {Extract.getOperand(0), Extract.getOperand(1)});
16785   if (!GetLane)
16786     return SDValue();
16787 
16788   LLVMContext &C = *DAG.getContext();
16789   SDLoc DL(St);
16790   // Create a new integer store to replace the existing floating point version.
16791   SDValue Ch = St->getChain();
16792   SDValue BasePtr = St->getBasePtr();
16793   Align Alignment = St->getOriginalAlign();
16794   MachineMemOperand::Flags MMOFlags = St->getMemOperand()->getFlags();
16795   AAMDNodes AAInfo = St->getAAInfo();
16796   EVT NewToVT = EVT::getIntegerVT(C, VT.getSizeInBits());
16797   SDValue Store = DAG.getTruncStore(Ch, DL, SDValue(GetLane, 0), BasePtr,
16798                                     St->getPointerInfo(), NewToVT, Alignment,
16799                                     MMOFlags, AAInfo);
16800 
16801   return Store;
16802 }
16803 
16804 /// PerformSTORECombine - Target-specific dag combine xforms for
16805 /// ISD::STORE.
PerformSTORECombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * Subtarget)16806 static SDValue PerformSTORECombine(SDNode *N,
16807                                    TargetLowering::DAGCombinerInfo &DCI,
16808                                    const ARMSubtarget *Subtarget) {
16809   StoreSDNode *St = cast<StoreSDNode>(N);
16810   if (St->isVolatile())
16811     return SDValue();
16812   SDValue StVal = St->getValue();
16813   EVT VT = StVal.getValueType();
16814 
16815   if (Subtarget->hasNEON())
16816     if (SDValue Store = PerformTruncatingStoreCombine(St, DCI.DAG))
16817       return Store;
16818 
16819   if (Subtarget->hasMVEFloatOps())
16820     if (SDValue NewToken = PerformSplittingToNarrowingStores(St, DCI.DAG))
16821       return NewToken;
16822 
16823   if (Subtarget->hasMVEIntegerOps()) {
16824     if (SDValue NewChain = PerformExtractFpToIntStores(St, DCI.DAG))
16825       return NewChain;
16826     if (SDValue NewToken =
16827             PerformSplittingMVETruncToNarrowingStores(St, DCI.DAG))
16828       return NewToken;
16829   }
16830 
16831   if (!ISD::isNormalStore(St))
16832     return SDValue();
16833 
16834   // Split a store of a VMOVDRR into two integer stores to avoid mixing NEON and
16835   // ARM stores of arguments in the same cache line.
16836   if (StVal.getNode()->getOpcode() == ARMISD::VMOVDRR &&
16837       StVal.getNode()->hasOneUse()) {
16838     SelectionDAG  &DAG = DCI.DAG;
16839     bool isBigEndian = DAG.getDataLayout().isBigEndian();
16840     SDLoc DL(St);
16841     SDValue BasePtr = St->getBasePtr();
16842     SDValue NewST1 = DAG.getStore(
16843         St->getChain(), DL, StVal.getNode()->getOperand(isBigEndian ? 1 : 0),
16844         BasePtr, St->getPointerInfo(), St->getOriginalAlign(),
16845         St->getMemOperand()->getFlags());
16846 
16847     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i32, BasePtr,
16848                                     DAG.getConstant(4, DL, MVT::i32));
16849     return DAG.getStore(NewST1.getValue(0), DL,
16850                         StVal.getNode()->getOperand(isBigEndian ? 0 : 1),
16851                         OffsetPtr, St->getPointerInfo().getWithOffset(4),
16852                         St->getOriginalAlign(),
16853                         St->getMemOperand()->getFlags());
16854   }
16855 
16856   if (StVal.getValueType() == MVT::i64 &&
16857       StVal.getNode()->getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
16858 
16859     // Bitcast an i64 store extracted from a vector to f64.
16860     // Otherwise, the i64 value will be legalized to a pair of i32 values.
16861     SelectionDAG &DAG = DCI.DAG;
16862     SDLoc dl(StVal);
16863     SDValue IntVec = StVal.getOperand(0);
16864     EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64,
16865                                    IntVec.getValueType().getVectorNumElements());
16866     SDValue Vec = DAG.getNode(ISD::BITCAST, dl, FloatVT, IntVec);
16867     SDValue ExtElt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64,
16868                                  Vec, StVal.getOperand(1));
16869     dl = SDLoc(N);
16870     SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::i64, ExtElt);
16871     // Make the DAGCombiner fold the bitcasts.
16872     DCI.AddToWorklist(Vec.getNode());
16873     DCI.AddToWorklist(ExtElt.getNode());
16874     DCI.AddToWorklist(V.getNode());
16875     return DAG.getStore(St->getChain(), dl, V, St->getBasePtr(),
16876                         St->getPointerInfo(), St->getAlign(),
16877                         St->getMemOperand()->getFlags(), St->getAAInfo());
16878   }
16879 
16880   // If this is a legal vector store, try to combine it into a VST1_UPD.
16881   if (Subtarget->hasNEON() && ISD::isNormalStore(N) && VT.isVector() &&
16882       DCI.DAG.getTargetLoweringInfo().isTypeLegal(VT))
16883     return CombineBaseUpdate(N, DCI);
16884 
16885   return SDValue();
16886 }
16887 
16888 /// PerformVCVTCombine - VCVT (floating-point to fixed-point, Advanced SIMD)
16889 /// can replace combinations of VMUL and VCVT (floating-point to integer)
16890 /// when the VMUL has a constant operand that is a power of 2.
16891 ///
16892 /// Example (assume d17 = <float 8.000000e+00, float 8.000000e+00>):
16893 ///  vmul.f32        d16, d17, d16
16894 ///  vcvt.s32.f32    d16, d16
16895 /// becomes:
16896 ///  vcvt.s32.f32    d16, d16, #3
PerformVCVTCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)16897 static SDValue PerformVCVTCombine(SDNode *N, SelectionDAG &DAG,
16898                                   const ARMSubtarget *Subtarget) {
16899   if (!Subtarget->hasNEON())
16900     return SDValue();
16901 
16902   SDValue Op = N->getOperand(0);
16903   if (!Op.getValueType().isVector() || !Op.getValueType().isSimple() ||
16904       Op.getOpcode() != ISD::FMUL)
16905     return SDValue();
16906 
16907   SDValue ConstVec = Op->getOperand(1);
16908   if (!isa<BuildVectorSDNode>(ConstVec))
16909     return SDValue();
16910 
16911   MVT FloatTy = Op.getSimpleValueType().getVectorElementType();
16912   uint32_t FloatBits = FloatTy.getSizeInBits();
16913   MVT IntTy = N->getSimpleValueType(0).getVectorElementType();
16914   uint32_t IntBits = IntTy.getSizeInBits();
16915   unsigned NumLanes = Op.getValueType().getVectorNumElements();
16916   if (FloatBits != 32 || IntBits > 32 || (NumLanes != 4 && NumLanes != 2)) {
16917     // These instructions only exist converting from f32 to i32. We can handle
16918     // smaller integers by generating an extra truncate, but larger ones would
16919     // be lossy. We also can't handle anything other than 2 or 4 lanes, since
16920     // these intructions only support v2i32/v4i32 types.
16921     return SDValue();
16922   }
16923 
16924   BitVector UndefElements;
16925   BuildVectorSDNode *BV = cast<BuildVectorSDNode>(ConstVec);
16926   int32_t C = BV->getConstantFPSplatPow2ToLog2Int(&UndefElements, 33);
16927   if (C == -1 || C == 0 || C > 32)
16928     return SDValue();
16929 
16930   SDLoc dl(N);
16931   bool isSigned = N->getOpcode() == ISD::FP_TO_SINT;
16932   unsigned IntrinsicOpcode = isSigned ? Intrinsic::arm_neon_vcvtfp2fxs :
16933     Intrinsic::arm_neon_vcvtfp2fxu;
16934   SDValue FixConv = DAG.getNode(
16935       ISD::INTRINSIC_WO_CHAIN, dl, NumLanes == 2 ? MVT::v2i32 : MVT::v4i32,
16936       DAG.getConstant(IntrinsicOpcode, dl, MVT::i32), Op->getOperand(0),
16937       DAG.getConstant(C, dl, MVT::i32));
16938 
16939   if (IntBits < FloatBits)
16940     FixConv = DAG.getNode(ISD::TRUNCATE, dl, N->getValueType(0), FixConv);
16941 
16942   return FixConv;
16943 }
16944 
PerformFAddVSelectCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)16945 static SDValue PerformFAddVSelectCombine(SDNode *N, SelectionDAG &DAG,
16946                                          const ARMSubtarget *Subtarget) {
16947   if (!Subtarget->hasMVEFloatOps())
16948     return SDValue();
16949 
16950   // Turn (fadd x, (vselect c, y, -0.0)) into (vselect c, (fadd x, y), x)
16951   // The second form can be more easily turned into a predicated vadd, and
16952   // possibly combined into a fma to become a predicated vfma.
16953   SDValue Op0 = N->getOperand(0);
16954   SDValue Op1 = N->getOperand(1);
16955   EVT VT = N->getValueType(0);
16956   SDLoc DL(N);
16957 
16958   // The identity element for a fadd is -0.0 or +0.0 when the nsz flag is set,
16959   // which these VMOV's represent.
16960   auto isIdentitySplat = [&](SDValue Op, bool NSZ) {
16961     if (Op.getOpcode() != ISD::BITCAST ||
16962         Op.getOperand(0).getOpcode() != ARMISD::VMOVIMM)
16963       return false;
16964     uint64_t ImmVal = Op.getOperand(0).getConstantOperandVal(0);
16965     if (VT == MVT::v4f32 && (ImmVal == 1664 || (ImmVal == 0 && NSZ)))
16966       return true;
16967     if (VT == MVT::v8f16 && (ImmVal == 2688 || (ImmVal == 0 && NSZ)))
16968       return true;
16969     return false;
16970   };
16971 
16972   if (Op0.getOpcode() == ISD::VSELECT && Op1.getOpcode() != ISD::VSELECT)
16973     std::swap(Op0, Op1);
16974 
16975   if (Op1.getOpcode() != ISD::VSELECT)
16976     return SDValue();
16977 
16978   SDNodeFlags FaddFlags = N->getFlags();
16979   bool NSZ = FaddFlags.hasNoSignedZeros();
16980   if (!isIdentitySplat(Op1.getOperand(2), NSZ))
16981     return SDValue();
16982 
16983   SDValue FAdd =
16984       DAG.getNode(ISD::FADD, DL, VT, Op0, Op1.getOperand(1), FaddFlags);
16985   return DAG.getNode(ISD::VSELECT, DL, VT, Op1.getOperand(0), FAdd, Op0, FaddFlags);
16986 }
16987 
PerformFADDVCMLACombine(SDNode * N,SelectionDAG & DAG)16988 static SDValue PerformFADDVCMLACombine(SDNode *N, SelectionDAG &DAG) {
16989   SDValue LHS = N->getOperand(0);
16990   SDValue RHS = N->getOperand(1);
16991   EVT VT = N->getValueType(0);
16992   SDLoc DL(N);
16993 
16994   if (!N->getFlags().hasAllowReassociation())
16995     return SDValue();
16996 
16997   // Combine fadd(a, vcmla(b, c, d)) -> vcmla(fadd(a, b), b, c)
16998   auto ReassocComplex = [&](SDValue A, SDValue B) {
16999     if (A.getOpcode() != ISD::INTRINSIC_WO_CHAIN)
17000       return SDValue();
17001     unsigned Opc = A.getConstantOperandVal(0);
17002     if (Opc != Intrinsic::arm_mve_vcmlaq)
17003       return SDValue();
17004     SDValue VCMLA = DAG.getNode(
17005         ISD::INTRINSIC_WO_CHAIN, DL, VT, A.getOperand(0), A.getOperand(1),
17006         DAG.getNode(ISD::FADD, DL, VT, A.getOperand(2), B, N->getFlags()),
17007         A.getOperand(3), A.getOperand(4));
17008     VCMLA->setFlags(A->getFlags());
17009     return VCMLA;
17010   };
17011   if (SDValue R = ReassocComplex(LHS, RHS))
17012     return R;
17013   if (SDValue R = ReassocComplex(RHS, LHS))
17014     return R;
17015 
17016   return SDValue();
17017 }
17018 
PerformFADDCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)17019 static SDValue PerformFADDCombine(SDNode *N, SelectionDAG &DAG,
17020                                   const ARMSubtarget *Subtarget) {
17021   if (SDValue S = PerformFAddVSelectCombine(N, DAG, Subtarget))
17022     return S;
17023   if (SDValue S = PerformFADDVCMLACombine(N, DAG))
17024     return S;
17025   return SDValue();
17026 }
17027 
17028 /// PerformVMulVCTPCombine - VCVT (fixed-point to floating-point, Advanced SIMD)
17029 /// can replace combinations of VCVT (integer to floating-point) and VMUL
17030 /// when the VMUL has a constant operand that is a power of 2.
17031 ///
17032 /// Example (assume d17 = <float 0.125, float 0.125>):
17033 ///  vcvt.f32.s32    d16, d16
17034 ///  vmul.f32        d16, d16, d17
17035 /// becomes:
17036 ///  vcvt.f32.s32    d16, d16, #3
PerformVMulVCTPCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * Subtarget)17037 static SDValue PerformVMulVCTPCombine(SDNode *N, SelectionDAG &DAG,
17038                                       const ARMSubtarget *Subtarget) {
17039   if (!Subtarget->hasNEON())
17040     return SDValue();
17041 
17042   SDValue Op = N->getOperand(0);
17043   unsigned OpOpcode = Op.getNode()->getOpcode();
17044   if (!N->getValueType(0).isVector() || !N->getValueType(0).isSimple() ||
17045       (OpOpcode != ISD::SINT_TO_FP && OpOpcode != ISD::UINT_TO_FP))
17046     return SDValue();
17047 
17048   SDValue ConstVec = N->getOperand(1);
17049   if (!isa<BuildVectorSDNode>(ConstVec))
17050     return SDValue();
17051 
17052   MVT FloatTy = N->getSimpleValueType(0).getVectorElementType();
17053   uint32_t FloatBits = FloatTy.getSizeInBits();
17054   MVT IntTy = Op.getOperand(0).getSimpleValueType().getVectorElementType();
17055   uint32_t IntBits = IntTy.getSizeInBits();
17056   unsigned NumLanes = Op.getValueType().getVectorNumElements();
17057   if (FloatBits != 32 || IntBits > 32 || (NumLanes != 4 && NumLanes != 2)) {
17058     // These instructions only exist converting from i32 to f32. We can handle
17059     // smaller integers by generating an extra extend, but larger ones would
17060     // be lossy. We also can't handle anything other than 2 or 4 lanes, since
17061     // these intructions only support v2i32/v4i32 types.
17062     return SDValue();
17063   }
17064 
17065   ConstantFPSDNode *CN = isConstOrConstSplatFP(ConstVec, true);
17066   APFloat Recip(0.0f);
17067   if (!CN || !CN->getValueAPF().getExactInverse(&Recip))
17068     return SDValue();
17069 
17070   bool IsExact;
17071   APSInt IntVal(33);
17072   if (Recip.convertToInteger(IntVal, APFloat::rmTowardZero, &IsExact) !=
17073           APFloat::opOK ||
17074       !IsExact)
17075     return SDValue();
17076 
17077   int32_t C = IntVal.exactLogBase2();
17078   if (C == -1 || C == 0 || C > 32)
17079     return SDValue();
17080 
17081   SDLoc DL(N);
17082   bool isSigned = OpOpcode == ISD::SINT_TO_FP;
17083   SDValue ConvInput = Op.getOperand(0);
17084   if (IntBits < FloatBits)
17085     ConvInput = DAG.getNode(isSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND, DL,
17086                             NumLanes == 2 ? MVT::v2i32 : MVT::v4i32, ConvInput);
17087 
17088   unsigned IntrinsicOpcode = isSigned ? Intrinsic::arm_neon_vcvtfxs2fp
17089                                       : Intrinsic::arm_neon_vcvtfxu2fp;
17090   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, Op.getValueType(),
17091                      DAG.getConstant(IntrinsicOpcode, DL, MVT::i32), ConvInput,
17092                      DAG.getConstant(C, DL, MVT::i32));
17093 }
17094 
PerformVECREDUCE_ADDCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)17095 static SDValue PerformVECREDUCE_ADDCombine(SDNode *N, SelectionDAG &DAG,
17096                                            const ARMSubtarget *ST) {
17097   if (!ST->hasMVEIntegerOps())
17098     return SDValue();
17099 
17100   assert(N->getOpcode() == ISD::VECREDUCE_ADD);
17101   EVT ResVT = N->getValueType(0);
17102   SDValue N0 = N->getOperand(0);
17103   SDLoc dl(N);
17104 
17105   // Try to turn vecreduce_add(add(x, y)) into vecreduce(x) + vecreduce(y)
17106   if (ResVT == MVT::i32 && N0.getOpcode() == ISD::ADD &&
17107       (N0.getValueType() == MVT::v4i32 || N0.getValueType() == MVT::v8i16 ||
17108        N0.getValueType() == MVT::v16i8)) {
17109     SDValue Red0 = DAG.getNode(ISD::VECREDUCE_ADD, dl, ResVT, N0.getOperand(0));
17110     SDValue Red1 = DAG.getNode(ISD::VECREDUCE_ADD, dl, ResVT, N0.getOperand(1));
17111     return DAG.getNode(ISD::ADD, dl, ResVT, Red0, Red1);
17112   }
17113 
17114   // We are looking for something that will have illegal types if left alone,
17115   // but that we can convert to a single instruction under MVE. For example
17116   // vecreduce_add(sext(A, v8i32)) => VADDV.s16 A
17117   // or
17118   // vecreduce_add(mul(zext(A, v16i32), zext(B, v16i32))) => VMLADAV.u8 A, B
17119 
17120   // The legal cases are:
17121   //   VADDV u/s 8/16/32
17122   //   VMLAV u/s 8/16/32
17123   //   VADDLV u/s 32
17124   //   VMLALV u/s 16/32
17125 
17126   // If the input vector is smaller than legal (v4i8/v4i16 for example) we can
17127   // extend it and use v4i32 instead.
17128   auto ExtTypeMatches = [](SDValue A, ArrayRef<MVT> ExtTypes) {
17129     EVT AVT = A.getValueType();
17130     return any_of(ExtTypes, [&](MVT Ty) {
17131       return AVT.getVectorNumElements() == Ty.getVectorNumElements() &&
17132              AVT.bitsLE(Ty);
17133     });
17134   };
17135   auto ExtendIfNeeded = [&](SDValue A, unsigned ExtendCode) {
17136     EVT AVT = A.getValueType();
17137     if (!AVT.is128BitVector())
17138       A = DAG.getNode(ExtendCode, dl,
17139                       AVT.changeVectorElementType(MVT::getIntegerVT(
17140                           128 / AVT.getVectorMinNumElements())),
17141                       A);
17142     return A;
17143   };
17144   auto IsVADDV = [&](MVT RetTy, unsigned ExtendCode, ArrayRef<MVT> ExtTypes) {
17145     if (ResVT != RetTy || N0->getOpcode() != ExtendCode)
17146       return SDValue();
17147     SDValue A = N0->getOperand(0);
17148     if (ExtTypeMatches(A, ExtTypes))
17149       return ExtendIfNeeded(A, ExtendCode);
17150     return SDValue();
17151   };
17152   auto IsPredVADDV = [&](MVT RetTy, unsigned ExtendCode,
17153                          ArrayRef<MVT> ExtTypes, SDValue &Mask) {
17154     if (ResVT != RetTy || N0->getOpcode() != ISD::VSELECT ||
17155         !ISD::isBuildVectorAllZeros(N0->getOperand(2).getNode()))
17156       return SDValue();
17157     Mask = N0->getOperand(0);
17158     SDValue Ext = N0->getOperand(1);
17159     if (Ext->getOpcode() != ExtendCode)
17160       return SDValue();
17161     SDValue A = Ext->getOperand(0);
17162     if (ExtTypeMatches(A, ExtTypes))
17163       return ExtendIfNeeded(A, ExtendCode);
17164     return SDValue();
17165   };
17166   auto IsVMLAV = [&](MVT RetTy, unsigned ExtendCode, ArrayRef<MVT> ExtTypes,
17167                      SDValue &A, SDValue &B) {
17168     // For a vmla we are trying to match a larger pattern:
17169     // ExtA = sext/zext A
17170     // ExtB = sext/zext B
17171     // Mul = mul ExtA, ExtB
17172     // vecreduce.add Mul
17173     // There might also be en extra extend between the mul and the addreduce, so
17174     // long as the bitwidth is high enough to make them equivalent (for example
17175     // original v8i16 might be mul at v8i32 and the reduce happens at v8i64).
17176     if (ResVT != RetTy)
17177       return false;
17178     SDValue Mul = N0;
17179     if (Mul->getOpcode() == ExtendCode &&
17180         Mul->getOperand(0).getScalarValueSizeInBits() * 2 >=
17181             ResVT.getScalarSizeInBits())
17182       Mul = Mul->getOperand(0);
17183     if (Mul->getOpcode() != ISD::MUL)
17184       return false;
17185     SDValue ExtA = Mul->getOperand(0);
17186     SDValue ExtB = Mul->getOperand(1);
17187     if (ExtA->getOpcode() != ExtendCode || ExtB->getOpcode() != ExtendCode)
17188       return false;
17189     A = ExtA->getOperand(0);
17190     B = ExtB->getOperand(0);
17191     if (ExtTypeMatches(A, ExtTypes) && ExtTypeMatches(B, ExtTypes)) {
17192       A = ExtendIfNeeded(A, ExtendCode);
17193       B = ExtendIfNeeded(B, ExtendCode);
17194       return true;
17195     }
17196     return false;
17197   };
17198   auto IsPredVMLAV = [&](MVT RetTy, unsigned ExtendCode, ArrayRef<MVT> ExtTypes,
17199                      SDValue &A, SDValue &B, SDValue &Mask) {
17200     // Same as the pattern above with a select for the zero predicated lanes
17201     // ExtA = sext/zext A
17202     // ExtB = sext/zext B
17203     // Mul = mul ExtA, ExtB
17204     // N0 = select Mask, Mul, 0
17205     // vecreduce.add N0
17206     if (ResVT != RetTy || N0->getOpcode() != ISD::VSELECT ||
17207         !ISD::isBuildVectorAllZeros(N0->getOperand(2).getNode()))
17208       return false;
17209     Mask = N0->getOperand(0);
17210     SDValue Mul = N0->getOperand(1);
17211     if (Mul->getOpcode() == ExtendCode &&
17212         Mul->getOperand(0).getScalarValueSizeInBits() * 2 >=
17213             ResVT.getScalarSizeInBits())
17214       Mul = Mul->getOperand(0);
17215     if (Mul->getOpcode() != ISD::MUL)
17216       return false;
17217     SDValue ExtA = Mul->getOperand(0);
17218     SDValue ExtB = Mul->getOperand(1);
17219     if (ExtA->getOpcode() != ExtendCode || ExtB->getOpcode() != ExtendCode)
17220       return false;
17221     A = ExtA->getOperand(0);
17222     B = ExtB->getOperand(0);
17223     if (ExtTypeMatches(A, ExtTypes) && ExtTypeMatches(B, ExtTypes)) {
17224       A = ExtendIfNeeded(A, ExtendCode);
17225       B = ExtendIfNeeded(B, ExtendCode);
17226       return true;
17227     }
17228     return false;
17229   };
17230   auto Create64bitNode = [&](unsigned Opcode, ArrayRef<SDValue> Ops) {
17231     // Split illegal MVT::v16i8->i64 vector reductions into two legal v8i16->i64
17232     // reductions. The operands are extended with MVEEXT, but as they are
17233     // reductions the lane orders do not matter. MVEEXT may be combined with
17234     // loads to produce two extending loads, or else they will be expanded to
17235     // VREV/VMOVL.
17236     EVT VT = Ops[0].getValueType();
17237     if (VT == MVT::v16i8) {
17238       assert((Opcode == ARMISD::VMLALVs || Opcode == ARMISD::VMLALVu) &&
17239              "Unexpected illegal long reduction opcode");
17240       bool IsUnsigned = Opcode == ARMISD::VMLALVu;
17241 
17242       SDValue Ext0 =
17243           DAG.getNode(IsUnsigned ? ARMISD::MVEZEXT : ARMISD::MVESEXT, dl,
17244                       DAG.getVTList(MVT::v8i16, MVT::v8i16), Ops[0]);
17245       SDValue Ext1 =
17246           DAG.getNode(IsUnsigned ? ARMISD::MVEZEXT : ARMISD::MVESEXT, dl,
17247                       DAG.getVTList(MVT::v8i16, MVT::v8i16), Ops[1]);
17248 
17249       SDValue MLA0 = DAG.getNode(Opcode, dl, DAG.getVTList(MVT::i32, MVT::i32),
17250                                  Ext0, Ext1);
17251       SDValue MLA1 =
17252           DAG.getNode(IsUnsigned ? ARMISD::VMLALVAu : ARMISD::VMLALVAs, dl,
17253                       DAG.getVTList(MVT::i32, MVT::i32), MLA0, MLA0.getValue(1),
17254                       Ext0.getValue(1), Ext1.getValue(1));
17255       return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, MLA1, MLA1.getValue(1));
17256     }
17257     SDValue Node = DAG.getNode(Opcode, dl, {MVT::i32, MVT::i32}, Ops);
17258     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Node,
17259                        SDValue(Node.getNode(), 1));
17260   };
17261 
17262   SDValue A, B;
17263   SDValue Mask;
17264   if (IsVMLAV(MVT::i32, ISD::SIGN_EXTEND, {MVT::v8i16, MVT::v16i8}, A, B))
17265     return DAG.getNode(ARMISD::VMLAVs, dl, ResVT, A, B);
17266   if (IsVMLAV(MVT::i32, ISD::ZERO_EXTEND, {MVT::v8i16, MVT::v16i8}, A, B))
17267     return DAG.getNode(ARMISD::VMLAVu, dl, ResVT, A, B);
17268   if (IsVMLAV(MVT::i64, ISD::SIGN_EXTEND, {MVT::v16i8, MVT::v8i16, MVT::v4i32},
17269               A, B))
17270     return Create64bitNode(ARMISD::VMLALVs, {A, B});
17271   if (IsVMLAV(MVT::i64, ISD::ZERO_EXTEND, {MVT::v16i8, MVT::v8i16, MVT::v4i32},
17272               A, B))
17273     return Create64bitNode(ARMISD::VMLALVu, {A, B});
17274   if (IsVMLAV(MVT::i16, ISD::SIGN_EXTEND, {MVT::v16i8}, A, B))
17275     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17276                        DAG.getNode(ARMISD::VMLAVs, dl, MVT::i32, A, B));
17277   if (IsVMLAV(MVT::i16, ISD::ZERO_EXTEND, {MVT::v16i8}, A, B))
17278     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17279                        DAG.getNode(ARMISD::VMLAVu, dl, MVT::i32, A, B));
17280 
17281   if (IsPredVMLAV(MVT::i32, ISD::SIGN_EXTEND, {MVT::v8i16, MVT::v16i8}, A, B,
17282                   Mask))
17283     return DAG.getNode(ARMISD::VMLAVps, dl, ResVT, A, B, Mask);
17284   if (IsPredVMLAV(MVT::i32, ISD::ZERO_EXTEND, {MVT::v8i16, MVT::v16i8}, A, B,
17285                   Mask))
17286     return DAG.getNode(ARMISD::VMLAVpu, dl, ResVT, A, B, Mask);
17287   if (IsPredVMLAV(MVT::i64, ISD::SIGN_EXTEND, {MVT::v8i16, MVT::v4i32}, A, B,
17288                   Mask))
17289     return Create64bitNode(ARMISD::VMLALVps, {A, B, Mask});
17290   if (IsPredVMLAV(MVT::i64, ISD::ZERO_EXTEND, {MVT::v8i16, MVT::v4i32}, A, B,
17291                   Mask))
17292     return Create64bitNode(ARMISD::VMLALVpu, {A, B, Mask});
17293   if (IsPredVMLAV(MVT::i16, ISD::SIGN_EXTEND, {MVT::v16i8}, A, B, Mask))
17294     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17295                        DAG.getNode(ARMISD::VMLAVps, dl, MVT::i32, A, B, Mask));
17296   if (IsPredVMLAV(MVT::i16, ISD::ZERO_EXTEND, {MVT::v16i8}, A, B, Mask))
17297     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17298                        DAG.getNode(ARMISD::VMLAVpu, dl, MVT::i32, A, B, Mask));
17299 
17300   if (SDValue A = IsVADDV(MVT::i32, ISD::SIGN_EXTEND, {MVT::v8i16, MVT::v16i8}))
17301     return DAG.getNode(ARMISD::VADDVs, dl, ResVT, A);
17302   if (SDValue A = IsVADDV(MVT::i32, ISD::ZERO_EXTEND, {MVT::v8i16, MVT::v16i8}))
17303     return DAG.getNode(ARMISD::VADDVu, dl, ResVT, A);
17304   if (SDValue A = IsVADDV(MVT::i64, ISD::SIGN_EXTEND, {MVT::v4i32}))
17305     return Create64bitNode(ARMISD::VADDLVs, {A});
17306   if (SDValue A = IsVADDV(MVT::i64, ISD::ZERO_EXTEND, {MVT::v4i32}))
17307     return Create64bitNode(ARMISD::VADDLVu, {A});
17308   if (SDValue A = IsVADDV(MVT::i16, ISD::SIGN_EXTEND, {MVT::v16i8}))
17309     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17310                        DAG.getNode(ARMISD::VADDVs, dl, MVT::i32, A));
17311   if (SDValue A = IsVADDV(MVT::i16, ISD::ZERO_EXTEND, {MVT::v16i8}))
17312     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17313                        DAG.getNode(ARMISD::VADDVu, dl, MVT::i32, A));
17314 
17315   if (SDValue A = IsPredVADDV(MVT::i32, ISD::SIGN_EXTEND, {MVT::v8i16, MVT::v16i8}, Mask))
17316     return DAG.getNode(ARMISD::VADDVps, dl, ResVT, A, Mask);
17317   if (SDValue A = IsPredVADDV(MVT::i32, ISD::ZERO_EXTEND, {MVT::v8i16, MVT::v16i8}, Mask))
17318     return DAG.getNode(ARMISD::VADDVpu, dl, ResVT, A, Mask);
17319   if (SDValue A = IsPredVADDV(MVT::i64, ISD::SIGN_EXTEND, {MVT::v4i32}, Mask))
17320     return Create64bitNode(ARMISD::VADDLVps, {A, Mask});
17321   if (SDValue A = IsPredVADDV(MVT::i64, ISD::ZERO_EXTEND, {MVT::v4i32}, Mask))
17322     return Create64bitNode(ARMISD::VADDLVpu, {A, Mask});
17323   if (SDValue A = IsPredVADDV(MVT::i16, ISD::SIGN_EXTEND, {MVT::v16i8}, Mask))
17324     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17325                        DAG.getNode(ARMISD::VADDVps, dl, MVT::i32, A, Mask));
17326   if (SDValue A = IsPredVADDV(MVT::i16, ISD::ZERO_EXTEND, {MVT::v16i8}, Mask))
17327     return DAG.getNode(ISD::TRUNCATE, dl, ResVT,
17328                        DAG.getNode(ARMISD::VADDVpu, dl, MVT::i32, A, Mask));
17329 
17330   // Some complications. We can get a case where the two inputs of the mul are
17331   // the same, then the output sext will have been helpfully converted to a
17332   // zext. Turn it back.
17333   SDValue Op = N0;
17334   if (Op->getOpcode() == ISD::VSELECT)
17335     Op = Op->getOperand(1);
17336   if (Op->getOpcode() == ISD::ZERO_EXTEND &&
17337       Op->getOperand(0)->getOpcode() == ISD::MUL) {
17338     SDValue Mul = Op->getOperand(0);
17339     if (Mul->getOperand(0) == Mul->getOperand(1) &&
17340         Mul->getOperand(0)->getOpcode() == ISD::SIGN_EXTEND) {
17341       SDValue Ext = DAG.getNode(ISD::SIGN_EXTEND, dl, N0->getValueType(0), Mul);
17342       if (Op != N0)
17343         Ext = DAG.getNode(ISD::VSELECT, dl, N0->getValueType(0),
17344                           N0->getOperand(0), Ext, N0->getOperand(2));
17345       return DAG.getNode(ISD::VECREDUCE_ADD, dl, ResVT, Ext);
17346     }
17347   }
17348 
17349   return SDValue();
17350 }
17351 
17352 // Looks for vaddv(shuffle) or vmlav(shuffle, shuffle), with a shuffle where all
17353 // the lanes are used. Due to the reduction being commutative the shuffle can be
17354 // removed.
PerformReduceShuffleCombine(SDNode * N,SelectionDAG & DAG)17355 static SDValue PerformReduceShuffleCombine(SDNode *N, SelectionDAG &DAG) {
17356   unsigned VecOp = N->getOperand(0).getValueType().isVector() ? 0 : 2;
17357   auto *Shuf = dyn_cast<ShuffleVectorSDNode>(N->getOperand(VecOp));
17358   if (!Shuf || !Shuf->getOperand(1).isUndef())
17359     return SDValue();
17360 
17361   // Check all elements are used once in the mask.
17362   ArrayRef<int> Mask = Shuf->getMask();
17363   APInt SetElts(Mask.size(), 0);
17364   for (int E : Mask) {
17365     if (E < 0 || E >= (int)Mask.size())
17366       return SDValue();
17367     SetElts.setBit(E);
17368   }
17369   if (!SetElts.isAllOnes())
17370     return SDValue();
17371 
17372   if (N->getNumOperands() != VecOp + 1) {
17373     auto *Shuf2 = dyn_cast<ShuffleVectorSDNode>(N->getOperand(VecOp + 1));
17374     if (!Shuf2 || !Shuf2->getOperand(1).isUndef() || Shuf2->getMask() != Mask)
17375       return SDValue();
17376   }
17377 
17378   SmallVector<SDValue> Ops;
17379   for (SDValue Op : N->ops()) {
17380     if (Op.getValueType().isVector())
17381       Ops.push_back(Op.getOperand(0));
17382     else
17383       Ops.push_back(Op);
17384   }
17385   return DAG.getNode(N->getOpcode(), SDLoc(N), N->getVTList(), Ops);
17386 }
17387 
PerformVMOVNCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)17388 static SDValue PerformVMOVNCombine(SDNode *N,
17389                                    TargetLowering::DAGCombinerInfo &DCI) {
17390   SDValue Op0 = N->getOperand(0);
17391   SDValue Op1 = N->getOperand(1);
17392   unsigned IsTop = N->getConstantOperandVal(2);
17393 
17394   // VMOVNT a undef -> a
17395   // VMOVNB a undef -> a
17396   // VMOVNB undef a -> a
17397   if (Op1->isUndef())
17398     return Op0;
17399   if (Op0->isUndef() && !IsTop)
17400     return Op1;
17401 
17402   // VMOVNt(c, VQMOVNb(a, b)) => VQMOVNt(c, b)
17403   // VMOVNb(c, VQMOVNb(a, b)) => VQMOVNb(c, b)
17404   if ((Op1->getOpcode() == ARMISD::VQMOVNs ||
17405        Op1->getOpcode() == ARMISD::VQMOVNu) &&
17406       Op1->getConstantOperandVal(2) == 0)
17407     return DCI.DAG.getNode(Op1->getOpcode(), SDLoc(Op1), N->getValueType(0),
17408                            Op0, Op1->getOperand(1), N->getOperand(2));
17409 
17410   // Only the bottom lanes from Qm (Op1) and either the top or bottom lanes from
17411   // Qd (Op0) are demanded from a VMOVN, depending on whether we are inserting
17412   // into the top or bottom lanes.
17413   unsigned NumElts = N->getValueType(0).getVectorNumElements();
17414   APInt Op1DemandedElts = APInt::getSplat(NumElts, APInt::getLowBitsSet(2, 1));
17415   APInt Op0DemandedElts =
17416       IsTop ? Op1DemandedElts
17417             : APInt::getSplat(NumElts, APInt::getHighBitsSet(2, 1));
17418 
17419   const TargetLowering &TLI = DCI.DAG.getTargetLoweringInfo();
17420   if (TLI.SimplifyDemandedVectorElts(Op0, Op0DemandedElts, DCI))
17421     return SDValue(N, 0);
17422   if (TLI.SimplifyDemandedVectorElts(Op1, Op1DemandedElts, DCI))
17423     return SDValue(N, 0);
17424 
17425   return SDValue();
17426 }
17427 
PerformVQMOVNCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)17428 static SDValue PerformVQMOVNCombine(SDNode *N,
17429                                     TargetLowering::DAGCombinerInfo &DCI) {
17430   SDValue Op0 = N->getOperand(0);
17431   unsigned IsTop = N->getConstantOperandVal(2);
17432 
17433   unsigned NumElts = N->getValueType(0).getVectorNumElements();
17434   APInt Op0DemandedElts =
17435       APInt::getSplat(NumElts, IsTop ? APInt::getLowBitsSet(2, 1)
17436                                      : APInt::getHighBitsSet(2, 1));
17437 
17438   const TargetLowering &TLI = DCI.DAG.getTargetLoweringInfo();
17439   if (TLI.SimplifyDemandedVectorElts(Op0, Op0DemandedElts, DCI))
17440     return SDValue(N, 0);
17441   return SDValue();
17442 }
17443 
PerformVQDMULHCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)17444 static SDValue PerformVQDMULHCombine(SDNode *N,
17445                                      TargetLowering::DAGCombinerInfo &DCI) {
17446   EVT VT = N->getValueType(0);
17447   SDValue LHS = N->getOperand(0);
17448   SDValue RHS = N->getOperand(1);
17449 
17450   auto *Shuf0 = dyn_cast<ShuffleVectorSDNode>(LHS);
17451   auto *Shuf1 = dyn_cast<ShuffleVectorSDNode>(RHS);
17452   // Turn VQDMULH(shuffle, shuffle) -> shuffle(VQDMULH)
17453   if (Shuf0 && Shuf1 && Shuf0->getMask().equals(Shuf1->getMask()) &&
17454       LHS.getOperand(1).isUndef() && RHS.getOperand(1).isUndef() &&
17455       (LHS.hasOneUse() || RHS.hasOneUse() || LHS == RHS)) {
17456     SDLoc DL(N);
17457     SDValue NewBinOp = DCI.DAG.getNode(N->getOpcode(), DL, VT,
17458                                        LHS.getOperand(0), RHS.getOperand(0));
17459     SDValue UndefV = LHS.getOperand(1);
17460     return DCI.DAG.getVectorShuffle(VT, DL, NewBinOp, UndefV, Shuf0->getMask());
17461   }
17462   return SDValue();
17463 }
17464 
PerformLongShiftCombine(SDNode * N,SelectionDAG & DAG)17465 static SDValue PerformLongShiftCombine(SDNode *N, SelectionDAG &DAG) {
17466   SDLoc DL(N);
17467   SDValue Op0 = N->getOperand(0);
17468   SDValue Op1 = N->getOperand(1);
17469 
17470   // Turn X << -C -> X >> C and viceversa. The negative shifts can come up from
17471   // uses of the intrinsics.
17472   if (auto C = dyn_cast<ConstantSDNode>(N->getOperand(2))) {
17473     int ShiftAmt = C->getSExtValue();
17474     if (ShiftAmt == 0) {
17475       SDValue Merge = DAG.getMergeValues({Op0, Op1}, DL);
17476       DAG.ReplaceAllUsesWith(N, Merge.getNode());
17477       return SDValue();
17478     }
17479 
17480     if (ShiftAmt >= -32 && ShiftAmt < 0) {
17481       unsigned NewOpcode =
17482           N->getOpcode() == ARMISD::LSLL ? ARMISD::LSRL : ARMISD::LSLL;
17483       SDValue NewShift = DAG.getNode(NewOpcode, DL, N->getVTList(), Op0, Op1,
17484                                      DAG.getConstant(-ShiftAmt, DL, MVT::i32));
17485       DAG.ReplaceAllUsesWith(N, NewShift.getNode());
17486       return NewShift;
17487     }
17488   }
17489 
17490   return SDValue();
17491 }
17492 
17493 /// PerformIntrinsicCombine - ARM-specific DAG combining for intrinsics.
PerformIntrinsicCombine(SDNode * N,DAGCombinerInfo & DCI) const17494 SDValue ARMTargetLowering::PerformIntrinsicCombine(SDNode *N,
17495                                                    DAGCombinerInfo &DCI) const {
17496   SelectionDAG &DAG = DCI.DAG;
17497   unsigned IntNo = N->getConstantOperandVal(0);
17498   switch (IntNo) {
17499   default:
17500     // Don't do anything for most intrinsics.
17501     break;
17502 
17503   // Vector shifts: check for immediate versions and lower them.
17504   // Note: This is done during DAG combining instead of DAG legalizing because
17505   // the build_vectors for 64-bit vector element shift counts are generally
17506   // not legal, and it is hard to see their values after they get legalized to
17507   // loads from a constant pool.
17508   case Intrinsic::arm_neon_vshifts:
17509   case Intrinsic::arm_neon_vshiftu:
17510   case Intrinsic::arm_neon_vrshifts:
17511   case Intrinsic::arm_neon_vrshiftu:
17512   case Intrinsic::arm_neon_vrshiftn:
17513   case Intrinsic::arm_neon_vqshifts:
17514   case Intrinsic::arm_neon_vqshiftu:
17515   case Intrinsic::arm_neon_vqshiftsu:
17516   case Intrinsic::arm_neon_vqshiftns:
17517   case Intrinsic::arm_neon_vqshiftnu:
17518   case Intrinsic::arm_neon_vqshiftnsu:
17519   case Intrinsic::arm_neon_vqrshiftns:
17520   case Intrinsic::arm_neon_vqrshiftnu:
17521   case Intrinsic::arm_neon_vqrshiftnsu: {
17522     EVT VT = N->getOperand(1).getValueType();
17523     int64_t Cnt;
17524     unsigned VShiftOpc = 0;
17525 
17526     switch (IntNo) {
17527     case Intrinsic::arm_neon_vshifts:
17528     case Intrinsic::arm_neon_vshiftu:
17529       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt)) {
17530         VShiftOpc = ARMISD::VSHLIMM;
17531         break;
17532       }
17533       if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt)) {
17534         VShiftOpc = (IntNo == Intrinsic::arm_neon_vshifts ? ARMISD::VSHRsIMM
17535                                                           : ARMISD::VSHRuIMM);
17536         break;
17537       }
17538       return SDValue();
17539 
17540     case Intrinsic::arm_neon_vrshifts:
17541     case Intrinsic::arm_neon_vrshiftu:
17542       if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt))
17543         break;
17544       return SDValue();
17545 
17546     case Intrinsic::arm_neon_vqshifts:
17547     case Intrinsic::arm_neon_vqshiftu:
17548       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
17549         break;
17550       return SDValue();
17551 
17552     case Intrinsic::arm_neon_vqshiftsu:
17553       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
17554         break;
17555       llvm_unreachable("invalid shift count for vqshlu intrinsic");
17556 
17557     case Intrinsic::arm_neon_vrshiftn:
17558     case Intrinsic::arm_neon_vqshiftns:
17559     case Intrinsic::arm_neon_vqshiftnu:
17560     case Intrinsic::arm_neon_vqshiftnsu:
17561     case Intrinsic::arm_neon_vqrshiftns:
17562     case Intrinsic::arm_neon_vqrshiftnu:
17563     case Intrinsic::arm_neon_vqrshiftnsu:
17564       // Narrowing shifts require an immediate right shift.
17565       if (isVShiftRImm(N->getOperand(2), VT, true, true, Cnt))
17566         break;
17567       llvm_unreachable("invalid shift count for narrowing vector shift "
17568                        "intrinsic");
17569 
17570     default:
17571       llvm_unreachable("unhandled vector shift");
17572     }
17573 
17574     switch (IntNo) {
17575     case Intrinsic::arm_neon_vshifts:
17576     case Intrinsic::arm_neon_vshiftu:
17577       // Opcode already set above.
17578       break;
17579     case Intrinsic::arm_neon_vrshifts:
17580       VShiftOpc = ARMISD::VRSHRsIMM;
17581       break;
17582     case Intrinsic::arm_neon_vrshiftu:
17583       VShiftOpc = ARMISD::VRSHRuIMM;
17584       break;
17585     case Intrinsic::arm_neon_vrshiftn:
17586       VShiftOpc = ARMISD::VRSHRNIMM;
17587       break;
17588     case Intrinsic::arm_neon_vqshifts:
17589       VShiftOpc = ARMISD::VQSHLsIMM;
17590       break;
17591     case Intrinsic::arm_neon_vqshiftu:
17592       VShiftOpc = ARMISD::VQSHLuIMM;
17593       break;
17594     case Intrinsic::arm_neon_vqshiftsu:
17595       VShiftOpc = ARMISD::VQSHLsuIMM;
17596       break;
17597     case Intrinsic::arm_neon_vqshiftns:
17598       VShiftOpc = ARMISD::VQSHRNsIMM;
17599       break;
17600     case Intrinsic::arm_neon_vqshiftnu:
17601       VShiftOpc = ARMISD::VQSHRNuIMM;
17602       break;
17603     case Intrinsic::arm_neon_vqshiftnsu:
17604       VShiftOpc = ARMISD::VQSHRNsuIMM;
17605       break;
17606     case Intrinsic::arm_neon_vqrshiftns:
17607       VShiftOpc = ARMISD::VQRSHRNsIMM;
17608       break;
17609     case Intrinsic::arm_neon_vqrshiftnu:
17610       VShiftOpc = ARMISD::VQRSHRNuIMM;
17611       break;
17612     case Intrinsic::arm_neon_vqrshiftnsu:
17613       VShiftOpc = ARMISD::VQRSHRNsuIMM;
17614       break;
17615     }
17616 
17617     SDLoc dl(N);
17618     return DAG.getNode(VShiftOpc, dl, N->getValueType(0),
17619                        N->getOperand(1), DAG.getConstant(Cnt, dl, MVT::i32));
17620   }
17621 
17622   case Intrinsic::arm_neon_vshiftins: {
17623     EVT VT = N->getOperand(1).getValueType();
17624     int64_t Cnt;
17625     unsigned VShiftOpc = 0;
17626 
17627     if (isVShiftLImm(N->getOperand(3), VT, false, Cnt))
17628       VShiftOpc = ARMISD::VSLIIMM;
17629     else if (isVShiftRImm(N->getOperand(3), VT, false, true, Cnt))
17630       VShiftOpc = ARMISD::VSRIIMM;
17631     else {
17632       llvm_unreachable("invalid shift count for vsli/vsri intrinsic");
17633     }
17634 
17635     SDLoc dl(N);
17636     return DAG.getNode(VShiftOpc, dl, N->getValueType(0),
17637                        N->getOperand(1), N->getOperand(2),
17638                        DAG.getConstant(Cnt, dl, MVT::i32));
17639   }
17640 
17641   case Intrinsic::arm_neon_vqrshifts:
17642   case Intrinsic::arm_neon_vqrshiftu:
17643     // No immediate versions of these to check for.
17644     break;
17645 
17646   case Intrinsic::arm_mve_vqdmlah:
17647   case Intrinsic::arm_mve_vqdmlash:
17648   case Intrinsic::arm_mve_vqrdmlah:
17649   case Intrinsic::arm_mve_vqrdmlash:
17650   case Intrinsic::arm_mve_vmla_n_predicated:
17651   case Intrinsic::arm_mve_vmlas_n_predicated:
17652   case Intrinsic::arm_mve_vqdmlah_predicated:
17653   case Intrinsic::arm_mve_vqdmlash_predicated:
17654   case Intrinsic::arm_mve_vqrdmlah_predicated:
17655   case Intrinsic::arm_mve_vqrdmlash_predicated: {
17656     // These intrinsics all take an i32 scalar operand which is narrowed to the
17657     // size of a single lane of the vector type they return. So we don't need
17658     // any bits of that operand above that point, which allows us to eliminate
17659     // uxth/sxth.
17660     unsigned BitWidth = N->getValueType(0).getScalarSizeInBits();
17661     APInt DemandedMask = APInt::getLowBitsSet(32, BitWidth);
17662     if (SimplifyDemandedBits(N->getOperand(3), DemandedMask, DCI))
17663       return SDValue();
17664     break;
17665   }
17666 
17667   case Intrinsic::arm_mve_minv:
17668   case Intrinsic::arm_mve_maxv:
17669   case Intrinsic::arm_mve_minav:
17670   case Intrinsic::arm_mve_maxav:
17671   case Intrinsic::arm_mve_minv_predicated:
17672   case Intrinsic::arm_mve_maxv_predicated:
17673   case Intrinsic::arm_mve_minav_predicated:
17674   case Intrinsic::arm_mve_maxav_predicated: {
17675     // These intrinsics all take an i32 scalar operand which is narrowed to the
17676     // size of a single lane of the vector type they take as the other input.
17677     unsigned BitWidth = N->getOperand(2)->getValueType(0).getScalarSizeInBits();
17678     APInt DemandedMask = APInt::getLowBitsSet(32, BitWidth);
17679     if (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI))
17680       return SDValue();
17681     break;
17682   }
17683 
17684   case Intrinsic::arm_mve_addv: {
17685     // Turn this intrinsic straight into the appropriate ARMISD::VADDV node,
17686     // which allow PerformADDVecReduce to turn it into VADDLV when possible.
17687     bool Unsigned = N->getConstantOperandVal(2);
17688     unsigned Opc = Unsigned ? ARMISD::VADDVu : ARMISD::VADDVs;
17689     return DAG.getNode(Opc, SDLoc(N), N->getVTList(), N->getOperand(1));
17690   }
17691 
17692   case Intrinsic::arm_mve_addlv:
17693   case Intrinsic::arm_mve_addlv_predicated: {
17694     // Same for these, but ARMISD::VADDLV has to be followed by a BUILD_PAIR
17695     // which recombines the two outputs into an i64
17696     bool Unsigned = N->getConstantOperandVal(2);
17697     unsigned Opc = IntNo == Intrinsic::arm_mve_addlv ?
17698                     (Unsigned ? ARMISD::VADDLVu : ARMISD::VADDLVs) :
17699                     (Unsigned ? ARMISD::VADDLVpu : ARMISD::VADDLVps);
17700 
17701     SmallVector<SDValue, 4> Ops;
17702     for (unsigned i = 1, e = N->getNumOperands(); i < e; i++)
17703       if (i != 2)                      // skip the unsigned flag
17704         Ops.push_back(N->getOperand(i));
17705 
17706     SDLoc dl(N);
17707     SDValue val = DAG.getNode(Opc, dl, {MVT::i32, MVT::i32}, Ops);
17708     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, val.getValue(0),
17709                        val.getValue(1));
17710   }
17711   }
17712 
17713   return SDValue();
17714 }
17715 
17716 /// PerformShiftCombine - Checks for immediate versions of vector shifts and
17717 /// lowers them.  As with the vector shift intrinsics, this is done during DAG
17718 /// combining instead of DAG legalizing because the build_vectors for 64-bit
17719 /// vector element shift counts are generally not legal, and it is hard to see
17720 /// their values after they get legalized to loads from a constant pool.
PerformShiftCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * ST)17721 static SDValue PerformShiftCombine(SDNode *N,
17722                                    TargetLowering::DAGCombinerInfo &DCI,
17723                                    const ARMSubtarget *ST) {
17724   SelectionDAG &DAG = DCI.DAG;
17725   EVT VT = N->getValueType(0);
17726 
17727   if (ST->isThumb1Only() && N->getOpcode() == ISD::SHL && VT == MVT::i32 &&
17728       N->getOperand(0)->getOpcode() == ISD::AND &&
17729       N->getOperand(0)->hasOneUse()) {
17730     if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
17731       return SDValue();
17732     // Look for the pattern (shl (and x, AndMask), ShiftAmt). This doesn't
17733     // usually show up because instcombine prefers to canonicalize it to
17734     // (and (shl x, ShiftAmt) (shl AndMask, ShiftAmt)), but the shift can come
17735     // out of GEP lowering in some cases.
17736     SDValue N0 = N->getOperand(0);
17737     ConstantSDNode *ShiftAmtNode = dyn_cast<ConstantSDNode>(N->getOperand(1));
17738     if (!ShiftAmtNode)
17739       return SDValue();
17740     uint32_t ShiftAmt = static_cast<uint32_t>(ShiftAmtNode->getZExtValue());
17741     ConstantSDNode *AndMaskNode = dyn_cast<ConstantSDNode>(N0->getOperand(1));
17742     if (!AndMaskNode)
17743       return SDValue();
17744     uint32_t AndMask = static_cast<uint32_t>(AndMaskNode->getZExtValue());
17745     // Don't transform uxtb/uxth.
17746     if (AndMask == 255 || AndMask == 65535)
17747       return SDValue();
17748     if (isMask_32(AndMask)) {
17749       uint32_t MaskedBits = llvm::countl_zero(AndMask);
17750       if (MaskedBits > ShiftAmt) {
17751         SDLoc DL(N);
17752         SDValue SHL = DAG.getNode(ISD::SHL, DL, MVT::i32, N0->getOperand(0),
17753                                   DAG.getConstant(MaskedBits, DL, MVT::i32));
17754         return DAG.getNode(
17755             ISD::SRL, DL, MVT::i32, SHL,
17756             DAG.getConstant(MaskedBits - ShiftAmt, DL, MVT::i32));
17757       }
17758     }
17759   }
17760 
17761   // Nothing to be done for scalar shifts.
17762   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
17763   if (!VT.isVector() || !TLI.isTypeLegal(VT))
17764     return SDValue();
17765   if (ST->hasMVEIntegerOps())
17766     return SDValue();
17767 
17768   int64_t Cnt;
17769 
17770   switch (N->getOpcode()) {
17771   default: llvm_unreachable("unexpected shift opcode");
17772 
17773   case ISD::SHL:
17774     if (isVShiftLImm(N->getOperand(1), VT, false, Cnt)) {
17775       SDLoc dl(N);
17776       return DAG.getNode(ARMISD::VSHLIMM, dl, VT, N->getOperand(0),
17777                          DAG.getConstant(Cnt, dl, MVT::i32));
17778     }
17779     break;
17780 
17781   case ISD::SRA:
17782   case ISD::SRL:
17783     if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
17784       unsigned VShiftOpc =
17785           (N->getOpcode() == ISD::SRA ? ARMISD::VSHRsIMM : ARMISD::VSHRuIMM);
17786       SDLoc dl(N);
17787       return DAG.getNode(VShiftOpc, dl, VT, N->getOperand(0),
17788                          DAG.getConstant(Cnt, dl, MVT::i32));
17789     }
17790   }
17791   return SDValue();
17792 }
17793 
17794 // Look for a sign/zero/fpextend extend of a larger than legal load. This can be
17795 // split into multiple extending loads, which are simpler to deal with than an
17796 // arbitrary extend. For fp extends we use an integer extending load and a VCVTL
17797 // to convert the type to an f32.
PerformSplittingToWideningLoad(SDNode * N,SelectionDAG & DAG)17798 static SDValue PerformSplittingToWideningLoad(SDNode *N, SelectionDAG &DAG) {
17799   SDValue N0 = N->getOperand(0);
17800   if (N0.getOpcode() != ISD::LOAD)
17801     return SDValue();
17802   LoadSDNode *LD = cast<LoadSDNode>(N0.getNode());
17803   if (!LD->isSimple() || !N0.hasOneUse() || LD->isIndexed() ||
17804       LD->getExtensionType() != ISD::NON_EXTLOAD)
17805     return SDValue();
17806   EVT FromVT = LD->getValueType(0);
17807   EVT ToVT = N->getValueType(0);
17808   if (!ToVT.isVector())
17809     return SDValue();
17810   assert(FromVT.getVectorNumElements() == ToVT.getVectorNumElements());
17811   EVT ToEltVT = ToVT.getVectorElementType();
17812   EVT FromEltVT = FromVT.getVectorElementType();
17813 
17814   unsigned NumElements = 0;
17815   if (ToEltVT == MVT::i32 && FromEltVT == MVT::i8)
17816     NumElements = 4;
17817   if (ToEltVT == MVT::f32 && FromEltVT == MVT::f16)
17818     NumElements = 4;
17819   if (NumElements == 0 ||
17820       (FromEltVT != MVT::f16 && FromVT.getVectorNumElements() == NumElements) ||
17821       FromVT.getVectorNumElements() % NumElements != 0 ||
17822       !isPowerOf2_32(NumElements))
17823     return SDValue();
17824 
17825   LLVMContext &C = *DAG.getContext();
17826   SDLoc DL(LD);
17827   // Details about the old load
17828   SDValue Ch = LD->getChain();
17829   SDValue BasePtr = LD->getBasePtr();
17830   Align Alignment = LD->getOriginalAlign();
17831   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
17832   AAMDNodes AAInfo = LD->getAAInfo();
17833 
17834   ISD::LoadExtType NewExtType =
17835       N->getOpcode() == ISD::SIGN_EXTEND ? ISD::SEXTLOAD : ISD::ZEXTLOAD;
17836   SDValue Offset = DAG.getUNDEF(BasePtr.getValueType());
17837   EVT NewFromVT = EVT::getVectorVT(
17838       C, EVT::getIntegerVT(C, FromEltVT.getScalarSizeInBits()), NumElements);
17839   EVT NewToVT = EVT::getVectorVT(
17840       C, EVT::getIntegerVT(C, ToEltVT.getScalarSizeInBits()), NumElements);
17841 
17842   SmallVector<SDValue, 4> Loads;
17843   SmallVector<SDValue, 4> Chains;
17844   for (unsigned i = 0; i < FromVT.getVectorNumElements() / NumElements; i++) {
17845     unsigned NewOffset = (i * NewFromVT.getSizeInBits()) / 8;
17846     SDValue NewPtr =
17847         DAG.getObjectPtrOffset(DL, BasePtr, TypeSize::getFixed(NewOffset));
17848 
17849     SDValue NewLoad =
17850         DAG.getLoad(ISD::UNINDEXED, NewExtType, NewToVT, DL, Ch, NewPtr, Offset,
17851                     LD->getPointerInfo().getWithOffset(NewOffset), NewFromVT,
17852                     Alignment, MMOFlags, AAInfo);
17853     Loads.push_back(NewLoad);
17854     Chains.push_back(SDValue(NewLoad.getNode(), 1));
17855   }
17856 
17857   // Float truncs need to extended with VCVTB's into their floating point types.
17858   if (FromEltVT == MVT::f16) {
17859     SmallVector<SDValue, 4> Extends;
17860 
17861     for (unsigned i = 0; i < Loads.size(); i++) {
17862       SDValue LoadBC =
17863           DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, MVT::v8f16, Loads[i]);
17864       SDValue FPExt = DAG.getNode(ARMISD::VCVTL, DL, MVT::v4f32, LoadBC,
17865                                   DAG.getConstant(0, DL, MVT::i32));
17866       Extends.push_back(FPExt);
17867     }
17868 
17869     Loads = Extends;
17870   }
17871 
17872   SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
17873   DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), NewChain);
17874   return DAG.getNode(ISD::CONCAT_VECTORS, DL, ToVT, Loads);
17875 }
17876 
17877 /// PerformExtendCombine - Target-specific DAG combining for ISD::SIGN_EXTEND,
17878 /// ISD::ZERO_EXTEND, and ISD::ANY_EXTEND.
PerformExtendCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)17879 static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
17880                                     const ARMSubtarget *ST) {
17881   SDValue N0 = N->getOperand(0);
17882 
17883   // Check for sign- and zero-extensions of vector extract operations of 8- and
17884   // 16-bit vector elements. NEON and MVE support these directly. They are
17885   // handled during DAG combining because type legalization will promote them
17886   // to 32-bit types and it is messy to recognize the operations after that.
17887   if ((ST->hasNEON() || ST->hasMVEIntegerOps()) &&
17888       N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
17889     SDValue Vec = N0.getOperand(0);
17890     SDValue Lane = N0.getOperand(1);
17891     EVT VT = N->getValueType(0);
17892     EVT EltVT = N0.getValueType();
17893     const TargetLowering &TLI = DAG.getTargetLoweringInfo();
17894 
17895     if (VT == MVT::i32 &&
17896         (EltVT == MVT::i8 || EltVT == MVT::i16) &&
17897         TLI.isTypeLegal(Vec.getValueType()) &&
17898         isa<ConstantSDNode>(Lane)) {
17899 
17900       unsigned Opc = 0;
17901       switch (N->getOpcode()) {
17902       default: llvm_unreachable("unexpected opcode");
17903       case ISD::SIGN_EXTEND:
17904         Opc = ARMISD::VGETLANEs;
17905         break;
17906       case ISD::ZERO_EXTEND:
17907       case ISD::ANY_EXTEND:
17908         Opc = ARMISD::VGETLANEu;
17909         break;
17910       }
17911       return DAG.getNode(Opc, SDLoc(N), VT, Vec, Lane);
17912     }
17913   }
17914 
17915   if (ST->hasMVEIntegerOps())
17916     if (SDValue NewLoad = PerformSplittingToWideningLoad(N, DAG))
17917       return NewLoad;
17918 
17919   return SDValue();
17920 }
17921 
PerformFPExtendCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)17922 static SDValue PerformFPExtendCombine(SDNode *N, SelectionDAG &DAG,
17923                                       const ARMSubtarget *ST) {
17924   if (ST->hasMVEFloatOps())
17925     if (SDValue NewLoad = PerformSplittingToWideningLoad(N, DAG))
17926       return NewLoad;
17927 
17928   return SDValue();
17929 }
17930 
17931 // Lower smin(smax(x, C1), C2) to ssat or usat, if they have saturating
17932 // constant bounds.
PerformMinMaxToSatCombine(SDValue Op,SelectionDAG & DAG,const ARMSubtarget * Subtarget)17933 static SDValue PerformMinMaxToSatCombine(SDValue Op, SelectionDAG &DAG,
17934                                          const ARMSubtarget *Subtarget) {
17935   if ((Subtarget->isThumb() || !Subtarget->hasV6Ops()) &&
17936       !Subtarget->isThumb2())
17937     return SDValue();
17938 
17939   EVT VT = Op.getValueType();
17940   SDValue Op0 = Op.getOperand(0);
17941 
17942   if (VT != MVT::i32 ||
17943       (Op0.getOpcode() != ISD::SMIN && Op0.getOpcode() != ISD::SMAX) ||
17944       !isa<ConstantSDNode>(Op.getOperand(1)) ||
17945       !isa<ConstantSDNode>(Op0.getOperand(1)))
17946     return SDValue();
17947 
17948   SDValue Min = Op;
17949   SDValue Max = Op0;
17950   SDValue Input = Op0.getOperand(0);
17951   if (Min.getOpcode() == ISD::SMAX)
17952     std::swap(Min, Max);
17953 
17954   APInt MinC = Min.getConstantOperandAPInt(1);
17955   APInt MaxC = Max.getConstantOperandAPInt(1);
17956 
17957   if (Min.getOpcode() != ISD::SMIN || Max.getOpcode() != ISD::SMAX ||
17958       !(MinC + 1).isPowerOf2())
17959     return SDValue();
17960 
17961   SDLoc DL(Op);
17962   if (MinC == ~MaxC)
17963     return DAG.getNode(ARMISD::SSAT, DL, VT, Input,
17964                        DAG.getConstant(MinC.countr_one(), DL, VT));
17965   if (MaxC == 0)
17966     return DAG.getNode(ARMISD::USAT, DL, VT, Input,
17967                        DAG.getConstant(MinC.countr_one(), DL, VT));
17968 
17969   return SDValue();
17970 }
17971 
17972 /// PerformMinMaxCombine - Target-specific DAG combining for creating truncating
17973 /// saturates.
PerformMinMaxCombine(SDNode * N,SelectionDAG & DAG,const ARMSubtarget * ST)17974 static SDValue PerformMinMaxCombine(SDNode *N, SelectionDAG &DAG,
17975                                     const ARMSubtarget *ST) {
17976   EVT VT = N->getValueType(0);
17977   SDValue N0 = N->getOperand(0);
17978 
17979   if (VT == MVT::i32)
17980     return PerformMinMaxToSatCombine(SDValue(N, 0), DAG, ST);
17981 
17982   if (!ST->hasMVEIntegerOps())
17983     return SDValue();
17984 
17985   if (SDValue V = PerformVQDMULHCombine(N, DAG))
17986     return V;
17987 
17988   if (VT != MVT::v4i32 && VT != MVT::v8i16)
17989     return SDValue();
17990 
17991   auto IsSignedSaturate = [&](SDNode *Min, SDNode *Max) {
17992     // Check one is a smin and the other is a smax
17993     if (Min->getOpcode() != ISD::SMIN)
17994       std::swap(Min, Max);
17995     if (Min->getOpcode() != ISD::SMIN || Max->getOpcode() != ISD::SMAX)
17996       return false;
17997 
17998     APInt SaturateC;
17999     if (VT == MVT::v4i32)
18000       SaturateC = APInt(32, (1 << 15) - 1, true);
18001     else //if (VT == MVT::v8i16)
18002       SaturateC = APInt(16, (1 << 7) - 1, true);
18003 
18004     APInt MinC, MaxC;
18005     if (!ISD::isConstantSplatVector(Min->getOperand(1).getNode(), MinC) ||
18006         MinC != SaturateC)
18007       return false;
18008     if (!ISD::isConstantSplatVector(Max->getOperand(1).getNode(), MaxC) ||
18009         MaxC != ~SaturateC)
18010       return false;
18011     return true;
18012   };
18013 
18014   if (IsSignedSaturate(N, N0.getNode())) {
18015     SDLoc DL(N);
18016     MVT ExtVT, HalfVT;
18017     if (VT == MVT::v4i32) {
18018       HalfVT = MVT::v8i16;
18019       ExtVT = MVT::v4i16;
18020     } else { // if (VT == MVT::v8i16)
18021       HalfVT = MVT::v16i8;
18022       ExtVT = MVT::v8i8;
18023     }
18024 
18025     // Create a VQMOVNB with undef top lanes, then signed extended into the top
18026     // half. That extend will hopefully be removed if only the bottom bits are
18027     // demanded (though a truncating store, for example).
18028     SDValue VQMOVN =
18029         DAG.getNode(ARMISD::VQMOVNs, DL, HalfVT, DAG.getUNDEF(HalfVT),
18030                     N0->getOperand(0), DAG.getConstant(0, DL, MVT::i32));
18031     SDValue Bitcast = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, VQMOVN);
18032     return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Bitcast,
18033                        DAG.getValueType(ExtVT));
18034   }
18035 
18036   auto IsUnsignedSaturate = [&](SDNode *Min) {
18037     // For unsigned, we just need to check for <= 0xffff
18038     if (Min->getOpcode() != ISD::UMIN)
18039       return false;
18040 
18041     APInt SaturateC;
18042     if (VT == MVT::v4i32)
18043       SaturateC = APInt(32, (1 << 16) - 1, true);
18044     else //if (VT == MVT::v8i16)
18045       SaturateC = APInt(16, (1 << 8) - 1, true);
18046 
18047     APInt MinC;
18048     if (!ISD::isConstantSplatVector(Min->getOperand(1).getNode(), MinC) ||
18049         MinC != SaturateC)
18050       return false;
18051     return true;
18052   };
18053 
18054   if (IsUnsignedSaturate(N)) {
18055     SDLoc DL(N);
18056     MVT HalfVT;
18057     unsigned ExtConst;
18058     if (VT == MVT::v4i32) {
18059       HalfVT = MVT::v8i16;
18060       ExtConst = 0x0000FFFF;
18061     } else { //if (VT == MVT::v8i16)
18062       HalfVT = MVT::v16i8;
18063       ExtConst = 0x00FF;
18064     }
18065 
18066     // Create a VQMOVNB with undef top lanes, then ZExt into the top half with
18067     // an AND. That extend will hopefully be removed if only the bottom bits are
18068     // demanded (though a truncating store, for example).
18069     SDValue VQMOVN =
18070         DAG.getNode(ARMISD::VQMOVNu, DL, HalfVT, DAG.getUNDEF(HalfVT), N0,
18071                     DAG.getConstant(0, DL, MVT::i32));
18072     SDValue Bitcast = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, VQMOVN);
18073     return DAG.getNode(ISD::AND, DL, VT, Bitcast,
18074                        DAG.getConstant(ExtConst, DL, VT));
18075   }
18076 
18077   return SDValue();
18078 }
18079 
isPowerOf2Constant(SDValue V)18080 static const APInt *isPowerOf2Constant(SDValue V) {
18081   ConstantSDNode *C = dyn_cast<ConstantSDNode>(V);
18082   if (!C)
18083     return nullptr;
18084   const APInt *CV = &C->getAPIntValue();
18085   return CV->isPowerOf2() ? CV : nullptr;
18086 }
18087 
PerformCMOVToBFICombine(SDNode * CMOV,SelectionDAG & DAG) const18088 SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &DAG) const {
18089   // If we have a CMOV, OR and AND combination such as:
18090   //   if (x & CN)
18091   //     y |= CM;
18092   //
18093   // And:
18094   //   * CN is a single bit;
18095   //   * All bits covered by CM are known zero in y
18096   //
18097   // Then we can convert this into a sequence of BFI instructions. This will
18098   // always be a win if CM is a single bit, will always be no worse than the
18099   // TST&OR sequence if CM is two bits, and for thumb will be no worse if CM is
18100   // three bits (due to the extra IT instruction).
18101 
18102   SDValue Op0 = CMOV->getOperand(0);
18103   SDValue Op1 = CMOV->getOperand(1);
18104   auto CC = CMOV->getConstantOperandAPInt(2).getLimitedValue();
18105   SDValue CmpZ = CMOV->getOperand(4);
18106 
18107   // The compare must be against zero.
18108   if (!isNullConstant(CmpZ->getOperand(1)))
18109     return SDValue();
18110 
18111   assert(CmpZ->getOpcode() == ARMISD::CMPZ);
18112   SDValue And = CmpZ->getOperand(0);
18113   if (And->getOpcode() != ISD::AND)
18114     return SDValue();
18115   const APInt *AndC = isPowerOf2Constant(And->getOperand(1));
18116   if (!AndC)
18117     return SDValue();
18118   SDValue X = And->getOperand(0);
18119 
18120   if (CC == ARMCC::EQ) {
18121     // We're performing an "equal to zero" compare. Swap the operands so we
18122     // canonicalize on a "not equal to zero" compare.
18123     std::swap(Op0, Op1);
18124   } else {
18125     assert(CC == ARMCC::NE && "How can a CMPZ node not be EQ or NE?");
18126   }
18127 
18128   if (Op1->getOpcode() != ISD::OR)
18129     return SDValue();
18130 
18131   ConstantSDNode *OrC = dyn_cast<ConstantSDNode>(Op1->getOperand(1));
18132   if (!OrC)
18133     return SDValue();
18134   SDValue Y = Op1->getOperand(0);
18135 
18136   if (Op0 != Y)
18137     return SDValue();
18138 
18139   // Now, is it profitable to continue?
18140   APInt OrCI = OrC->getAPIntValue();
18141   unsigned Heuristic = Subtarget->isThumb() ? 3 : 2;
18142   if (OrCI.popcount() > Heuristic)
18143     return SDValue();
18144 
18145   // Lastly, can we determine that the bits defined by OrCI
18146   // are zero in Y?
18147   KnownBits Known = DAG.computeKnownBits(Y);
18148   if ((OrCI & Known.Zero) != OrCI)
18149     return SDValue();
18150 
18151   // OK, we can do the combine.
18152   SDValue V = Y;
18153   SDLoc dl(X);
18154   EVT VT = X.getValueType();
18155   unsigned BitInX = AndC->logBase2();
18156 
18157   if (BitInX != 0) {
18158     // We must shift X first.
18159     X = DAG.getNode(ISD::SRL, dl, VT, X,
18160                     DAG.getConstant(BitInX, dl, VT));
18161   }
18162 
18163   for (unsigned BitInY = 0, NumActiveBits = OrCI.getActiveBits();
18164        BitInY < NumActiveBits; ++BitInY) {
18165     if (OrCI[BitInY] == 0)
18166       continue;
18167     APInt Mask(VT.getSizeInBits(), 0);
18168     Mask.setBit(BitInY);
18169     V = DAG.getNode(ARMISD::BFI, dl, VT, V, X,
18170                     // Confusingly, the operand is an *inverted* mask.
18171                     DAG.getConstant(~Mask, dl, VT));
18172   }
18173 
18174   return V;
18175 }
18176 
18177 // Given N, the value controlling the conditional branch, search for the loop
18178 // intrinsic, returning it, along with how the value is used. We need to handle
18179 // patterns such as the following:
18180 // (brcond (xor (setcc (loop.decrement), 0, ne), 1), exit)
18181 // (brcond (setcc (loop.decrement), 0, eq), exit)
18182 // (brcond (setcc (loop.decrement), 0, ne), header)
SearchLoopIntrinsic(SDValue N,ISD::CondCode & CC,int & Imm,bool & Negate)18183 static SDValue SearchLoopIntrinsic(SDValue N, ISD::CondCode &CC, int &Imm,
18184                                    bool &Negate) {
18185   switch (N->getOpcode()) {
18186   default:
18187     break;
18188   case ISD::XOR: {
18189     if (!isa<ConstantSDNode>(N.getOperand(1)))
18190       return SDValue();
18191     if (!cast<ConstantSDNode>(N.getOperand(1))->isOne())
18192       return SDValue();
18193     Negate = !Negate;
18194     return SearchLoopIntrinsic(N.getOperand(0), CC, Imm, Negate);
18195   }
18196   case ISD::SETCC: {
18197     auto *Const = dyn_cast<ConstantSDNode>(N.getOperand(1));
18198     if (!Const)
18199       return SDValue();
18200     if (Const->isZero())
18201       Imm = 0;
18202     else if (Const->isOne())
18203       Imm = 1;
18204     else
18205       return SDValue();
18206     CC = cast<CondCodeSDNode>(N.getOperand(2))->get();
18207     return SearchLoopIntrinsic(N->getOperand(0), CC, Imm, Negate);
18208   }
18209   case ISD::INTRINSIC_W_CHAIN: {
18210     unsigned IntOp = N.getConstantOperandVal(1);
18211     if (IntOp != Intrinsic::test_start_loop_iterations &&
18212         IntOp != Intrinsic::loop_decrement_reg)
18213       return SDValue();
18214     return N;
18215   }
18216   }
18217   return SDValue();
18218 }
18219 
PerformHWLoopCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * ST)18220 static SDValue PerformHWLoopCombine(SDNode *N,
18221                                     TargetLowering::DAGCombinerInfo &DCI,
18222                                     const ARMSubtarget *ST) {
18223 
18224   // The hwloop intrinsics that we're interested are used for control-flow,
18225   // either for entering or exiting the loop:
18226   // - test.start.loop.iterations will test whether its operand is zero. If it
18227   //   is zero, the proceeding branch should not enter the loop.
18228   // - loop.decrement.reg also tests whether its operand is zero. If it is
18229   //   zero, the proceeding branch should not branch back to the beginning of
18230   //   the loop.
18231   // So here, we need to check that how the brcond is using the result of each
18232   // of the intrinsics to ensure that we're branching to the right place at the
18233   // right time.
18234 
18235   ISD::CondCode CC;
18236   SDValue Cond;
18237   int Imm = 1;
18238   bool Negate = false;
18239   SDValue Chain = N->getOperand(0);
18240   SDValue Dest;
18241 
18242   if (N->getOpcode() == ISD::BRCOND) {
18243     CC = ISD::SETEQ;
18244     Cond = N->getOperand(1);
18245     Dest = N->getOperand(2);
18246   } else {
18247     assert(N->getOpcode() == ISD::BR_CC && "Expected BRCOND or BR_CC!");
18248     CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
18249     Cond = N->getOperand(2);
18250     Dest = N->getOperand(4);
18251     if (auto *Const = dyn_cast<ConstantSDNode>(N->getOperand(3))) {
18252       if (!Const->isOne() && !Const->isZero())
18253         return SDValue();
18254       Imm = Const->getZExtValue();
18255     } else
18256       return SDValue();
18257   }
18258 
18259   SDValue Int = SearchLoopIntrinsic(Cond, CC, Imm, Negate);
18260   if (!Int)
18261     return SDValue();
18262 
18263   if (Negate)
18264     CC = ISD::getSetCCInverse(CC, /* Integer inverse */ MVT::i32);
18265 
18266   auto IsTrueIfZero = [](ISD::CondCode CC, int Imm) {
18267     return (CC == ISD::SETEQ && Imm == 0) ||
18268            (CC == ISD::SETNE && Imm == 1) ||
18269            (CC == ISD::SETLT && Imm == 1) ||
18270            (CC == ISD::SETULT && Imm == 1);
18271   };
18272 
18273   auto IsFalseIfZero = [](ISD::CondCode CC, int Imm) {
18274     return (CC == ISD::SETEQ && Imm == 1) ||
18275            (CC == ISD::SETNE && Imm == 0) ||
18276            (CC == ISD::SETGT && Imm == 0) ||
18277            (CC == ISD::SETUGT && Imm == 0) ||
18278            (CC == ISD::SETGE && Imm == 1) ||
18279            (CC == ISD::SETUGE && Imm == 1);
18280   };
18281 
18282   assert((IsTrueIfZero(CC, Imm) || IsFalseIfZero(CC, Imm)) &&
18283          "unsupported condition");
18284 
18285   SDLoc dl(Int);
18286   SelectionDAG &DAG = DCI.DAG;
18287   SDValue Elements = Int.getOperand(2);
18288   unsigned IntOp = Int->getConstantOperandVal(1);
18289   assert((N->hasOneUse() && N->use_begin()->getOpcode() == ISD::BR)
18290           && "expected single br user");
18291   SDNode *Br = *N->use_begin();
18292   SDValue OtherTarget = Br->getOperand(1);
18293 
18294   // Update the unconditional branch to branch to the given Dest.
18295   auto UpdateUncondBr = [](SDNode *Br, SDValue Dest, SelectionDAG &DAG) {
18296     SDValue NewBrOps[] = { Br->getOperand(0), Dest };
18297     SDValue NewBr = DAG.getNode(ISD::BR, SDLoc(Br), MVT::Other, NewBrOps);
18298     DAG.ReplaceAllUsesOfValueWith(SDValue(Br, 0), NewBr);
18299   };
18300 
18301   if (IntOp == Intrinsic::test_start_loop_iterations) {
18302     SDValue Res;
18303     SDValue Setup = DAG.getNode(ARMISD::WLSSETUP, dl, MVT::i32, Elements);
18304     // We expect this 'instruction' to branch when the counter is zero.
18305     if (IsTrueIfZero(CC, Imm)) {
18306       SDValue Ops[] = {Chain, Setup, Dest};
18307       Res = DAG.getNode(ARMISD::WLS, dl, MVT::Other, Ops);
18308     } else {
18309       // The logic is the reverse of what we need for WLS, so find the other
18310       // basic block target: the target of the proceeding br.
18311       UpdateUncondBr(Br, Dest, DAG);
18312 
18313       SDValue Ops[] = {Chain, Setup, OtherTarget};
18314       Res = DAG.getNode(ARMISD::WLS, dl, MVT::Other, Ops);
18315     }
18316     // Update LR count to the new value
18317     DAG.ReplaceAllUsesOfValueWith(Int.getValue(0), Setup);
18318     // Update chain
18319     DAG.ReplaceAllUsesOfValueWith(Int.getValue(2), Int.getOperand(0));
18320     return Res;
18321   } else {
18322     SDValue Size =
18323         DAG.getTargetConstant(Int.getConstantOperandVal(3), dl, MVT::i32);
18324     SDValue Args[] = { Int.getOperand(0), Elements, Size, };
18325     SDValue LoopDec = DAG.getNode(ARMISD::LOOP_DEC, dl,
18326                                   DAG.getVTList(MVT::i32, MVT::Other), Args);
18327     DAG.ReplaceAllUsesWith(Int.getNode(), LoopDec.getNode());
18328 
18329     // We expect this instruction to branch when the count is not zero.
18330     SDValue Target = IsFalseIfZero(CC, Imm) ? Dest : OtherTarget;
18331 
18332     // Update the unconditional branch to target the loop preheader if we've
18333     // found the condition has been reversed.
18334     if (Target == OtherTarget)
18335       UpdateUncondBr(Br, Dest, DAG);
18336 
18337     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
18338                         SDValue(LoopDec.getNode(), 1), Chain);
18339 
18340     SDValue EndArgs[] = { Chain, SDValue(LoopDec.getNode(), 0), Target };
18341     return DAG.getNode(ARMISD::LE, dl, MVT::Other, EndArgs);
18342   }
18343   return SDValue();
18344 }
18345 
18346 /// PerformBRCONDCombine - Target-specific DAG combining for ARMISD::BRCOND.
18347 SDValue
PerformBRCONDCombine(SDNode * N,SelectionDAG & DAG) const18348 ARMTargetLowering::PerformBRCONDCombine(SDNode *N, SelectionDAG &DAG) const {
18349   SDValue Cmp = N->getOperand(4);
18350   if (Cmp.getOpcode() != ARMISD::CMPZ)
18351     // Only looking at NE cases.
18352     return SDValue();
18353 
18354   EVT VT = N->getValueType(0);
18355   SDLoc dl(N);
18356   SDValue LHS = Cmp.getOperand(0);
18357   SDValue RHS = Cmp.getOperand(1);
18358   SDValue Chain = N->getOperand(0);
18359   SDValue BB = N->getOperand(1);
18360   SDValue ARMcc = N->getOperand(2);
18361   ARMCC::CondCodes CC = (ARMCC::CondCodes)ARMcc->getAsZExtVal();
18362 
18363   // (brcond Chain BB ne CPSR (cmpz (and (cmov 0 1 CC CPSR Cmp) 1) 0))
18364   // -> (brcond Chain BB CC CPSR Cmp)
18365   if (CC == ARMCC::NE && LHS.getOpcode() == ISD::AND && LHS->hasOneUse() &&
18366       LHS->getOperand(0)->getOpcode() == ARMISD::CMOV &&
18367       LHS->getOperand(0)->hasOneUse() &&
18368       isNullConstant(LHS->getOperand(0)->getOperand(0)) &&
18369       isOneConstant(LHS->getOperand(0)->getOperand(1)) &&
18370       isOneConstant(LHS->getOperand(1)) && isNullConstant(RHS)) {
18371     return DAG.getNode(
18372         ARMISD::BRCOND, dl, VT, Chain, BB, LHS->getOperand(0)->getOperand(2),
18373         LHS->getOperand(0)->getOperand(3), LHS->getOperand(0)->getOperand(4));
18374   }
18375 
18376   return SDValue();
18377 }
18378 
18379 /// PerformCMOVCombine - Target-specific DAG combining for ARMISD::CMOV.
18380 SDValue
PerformCMOVCombine(SDNode * N,SelectionDAG & DAG) const18381 ARMTargetLowering::PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const {
18382   SDValue Cmp = N->getOperand(4);
18383   if (Cmp.getOpcode() != ARMISD::CMPZ)
18384     // Only looking at EQ and NE cases.
18385     return SDValue();
18386 
18387   EVT VT = N->getValueType(0);
18388   SDLoc dl(N);
18389   SDValue LHS = Cmp.getOperand(0);
18390   SDValue RHS = Cmp.getOperand(1);
18391   SDValue FalseVal = N->getOperand(0);
18392   SDValue TrueVal = N->getOperand(1);
18393   SDValue ARMcc = N->getOperand(2);
18394   ARMCC::CondCodes CC = (ARMCC::CondCodes)ARMcc->getAsZExtVal();
18395 
18396   // BFI is only available on V6T2+.
18397   if (!Subtarget->isThumb1Only() && Subtarget->hasV6T2Ops()) {
18398     SDValue R = PerformCMOVToBFICombine(N, DAG);
18399     if (R)
18400       return R;
18401   }
18402 
18403   // Simplify
18404   //   mov     r1, r0
18405   //   cmp     r1, x
18406   //   mov     r0, y
18407   //   moveq   r0, x
18408   // to
18409   //   cmp     r0, x
18410   //   movne   r0, y
18411   //
18412   //   mov     r1, r0
18413   //   cmp     r1, x
18414   //   mov     r0, x
18415   //   movne   r0, y
18416   // to
18417   //   cmp     r0, x
18418   //   movne   r0, y
18419   /// FIXME: Turn this into a target neutral optimization?
18420   SDValue Res;
18421   if (CC == ARMCC::NE && FalseVal == RHS && FalseVal != LHS) {
18422     Res = DAG.getNode(ARMISD::CMOV, dl, VT, LHS, TrueVal, ARMcc,
18423                       N->getOperand(3), Cmp);
18424   } else if (CC == ARMCC::EQ && TrueVal == RHS) {
18425     SDValue ARMcc;
18426     SDValue NewCmp = getARMCmp(LHS, RHS, ISD::SETNE, ARMcc, DAG, dl);
18427     Res = DAG.getNode(ARMISD::CMOV, dl, VT, LHS, FalseVal, ARMcc,
18428                       N->getOperand(3), NewCmp);
18429   }
18430 
18431   // (cmov F T ne CPSR (cmpz (cmov 0 1 CC CPSR Cmp) 0))
18432   // -> (cmov F T CC CPSR Cmp)
18433   if (CC == ARMCC::NE && LHS.getOpcode() == ARMISD::CMOV && LHS->hasOneUse() &&
18434       isNullConstant(LHS->getOperand(0)) && isOneConstant(LHS->getOperand(1)) &&
18435       isNullConstant(RHS)) {
18436     return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal,
18437                        LHS->getOperand(2), LHS->getOperand(3),
18438                        LHS->getOperand(4));
18439   }
18440 
18441   if (!VT.isInteger())
18442       return SDValue();
18443 
18444   // Fold away an unneccessary CMPZ/CMOV
18445   // CMOV A, B, C1, $cpsr, (CMPZ (CMOV 1, 0, C2, D), 0) ->
18446   // if C1==EQ -> CMOV A, B, C2, $cpsr, D
18447   // if C1==NE -> CMOV A, B, NOT(C2), $cpsr, D
18448   if (N->getConstantOperandVal(2) == ARMCC::EQ ||
18449       N->getConstantOperandVal(2) == ARMCC::NE) {
18450     ARMCC::CondCodes Cond;
18451     if (SDValue C = IsCMPZCSINC(N->getOperand(4).getNode(), Cond)) {
18452       if (N->getConstantOperandVal(2) == ARMCC::NE)
18453         Cond = ARMCC::getOppositeCondition(Cond);
18454       return DAG.getNode(N->getOpcode(), SDLoc(N), MVT::i32, N->getOperand(0),
18455                          N->getOperand(1),
18456                          DAG.getTargetConstant(Cond, SDLoc(N), MVT::i32),
18457                          N->getOperand(3), C);
18458     }
18459   }
18460 
18461   // Materialize a boolean comparison for integers so we can avoid branching.
18462   if (isNullConstant(FalseVal)) {
18463     if (CC == ARMCC::EQ && isOneConstant(TrueVal)) {
18464       if (!Subtarget->isThumb1Only() && Subtarget->hasV5TOps()) {
18465         // If x == y then x - y == 0 and ARM's CLZ will return 32, shifting it
18466         // right 5 bits will make that 32 be 1, otherwise it will be 0.
18467         // CMOV 0, 1, ==, (CMPZ x, y) -> SRL (CTLZ (SUB x, y)), 5
18468         SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, LHS, RHS);
18469         Res = DAG.getNode(ISD::SRL, dl, VT, DAG.getNode(ISD::CTLZ, dl, VT, Sub),
18470                           DAG.getConstant(5, dl, MVT::i32));
18471       } else {
18472         // CMOV 0, 1, ==, (CMPZ x, y) ->
18473         //     (UADDO_CARRY (SUB x, y), t:0, t:1)
18474         // where t = (USUBO_CARRY 0, (SUB x, y), 0)
18475         //
18476         // The USUBO_CARRY computes 0 - (x - y) and this will give a borrow when
18477         // x != y. In other words, a carry C == 1 when x == y, C == 0
18478         // otherwise.
18479         // The final UADDO_CARRY computes
18480         //     x - y + (0 - (x - y)) + C == C
18481         SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, LHS, RHS);
18482         SDVTList VTs = DAG.getVTList(VT, MVT::i32);
18483         SDValue Neg = DAG.getNode(ISD::USUBO, dl, VTs, FalseVal, Sub);
18484         // ISD::USUBO_CARRY returns a borrow but we want the carry here
18485         // actually.
18486         SDValue Carry =
18487             DAG.getNode(ISD::SUB, dl, MVT::i32,
18488                         DAG.getConstant(1, dl, MVT::i32), Neg.getValue(1));
18489         Res = DAG.getNode(ISD::UADDO_CARRY, dl, VTs, Sub, Neg, Carry);
18490       }
18491     } else if (CC == ARMCC::NE && !isNullConstant(RHS) &&
18492                (!Subtarget->isThumb1Only() || isPowerOf2Constant(TrueVal))) {
18493       // This seems pointless but will allow us to combine it further below.
18494       // CMOV 0, z, !=, (CMPZ x, y) -> CMOV (SUBC x, y), z, !=, (SUBC x, y):1
18495       SDValue Sub =
18496           DAG.getNode(ARMISD::SUBC, dl, DAG.getVTList(VT, MVT::i32), LHS, RHS);
18497       SDValue CPSRGlue = DAG.getCopyToReg(DAG.getEntryNode(), dl, ARM::CPSR,
18498                                           Sub.getValue(1), SDValue());
18499       Res = DAG.getNode(ARMISD::CMOV, dl, VT, Sub, TrueVal, ARMcc,
18500                         N->getOperand(3), CPSRGlue.getValue(1));
18501       FalseVal = Sub;
18502     }
18503   } else if (isNullConstant(TrueVal)) {
18504     if (CC == ARMCC::EQ && !isNullConstant(RHS) &&
18505         (!Subtarget->isThumb1Only() || isPowerOf2Constant(FalseVal))) {
18506       // This seems pointless but will allow us to combine it further below
18507       // Note that we change == for != as this is the dual for the case above.
18508       // CMOV z, 0, ==, (CMPZ x, y) -> CMOV (SUBC x, y), z, !=, (SUBC x, y):1
18509       SDValue Sub =
18510           DAG.getNode(ARMISD::SUBC, dl, DAG.getVTList(VT, MVT::i32), LHS, RHS);
18511       SDValue CPSRGlue = DAG.getCopyToReg(DAG.getEntryNode(), dl, ARM::CPSR,
18512                                           Sub.getValue(1), SDValue());
18513       Res = DAG.getNode(ARMISD::CMOV, dl, VT, Sub, FalseVal,
18514                         DAG.getConstant(ARMCC::NE, dl, MVT::i32),
18515                         N->getOperand(3), CPSRGlue.getValue(1));
18516       FalseVal = Sub;
18517     }
18518   }
18519 
18520   // On Thumb1, the DAG above may be further combined if z is a power of 2
18521   // (z == 2 ^ K).
18522   // CMOV (SUBC x, y), z, !=, (SUBC x, y):1 ->
18523   // t1 = (USUBO (SUB x, y), 1)
18524   // t2 = (USUBO_CARRY (SUB x, y), t1:0, t1:1)
18525   // Result = if K != 0 then (SHL t2:0, K) else t2:0
18526   //
18527   // This also handles the special case of comparing against zero; it's
18528   // essentially, the same pattern, except there's no SUBC:
18529   // CMOV x, z, !=, (CMPZ x, 0) ->
18530   // t1 = (USUBO x, 1)
18531   // t2 = (USUBO_CARRY x, t1:0, t1:1)
18532   // Result = if K != 0 then (SHL t2:0, K) else t2:0
18533   const APInt *TrueConst;
18534   if (Subtarget->isThumb1Only() && CC == ARMCC::NE &&
18535       ((FalseVal.getOpcode() == ARMISD::SUBC && FalseVal.getOperand(0) == LHS &&
18536         FalseVal.getOperand(1) == RHS) ||
18537        (FalseVal == LHS && isNullConstant(RHS))) &&
18538       (TrueConst = isPowerOf2Constant(TrueVal))) {
18539     SDVTList VTs = DAG.getVTList(VT, MVT::i32);
18540     unsigned ShiftAmount = TrueConst->logBase2();
18541     if (ShiftAmount)
18542       TrueVal = DAG.getConstant(1, dl, VT);
18543     SDValue Subc = DAG.getNode(ISD::USUBO, dl, VTs, FalseVal, TrueVal);
18544     Res = DAG.getNode(ISD::USUBO_CARRY, dl, VTs, FalseVal, Subc,
18545                       Subc.getValue(1));
18546 
18547     if (ShiftAmount)
18548       Res = DAG.getNode(ISD::SHL, dl, VT, Res,
18549                         DAG.getConstant(ShiftAmount, dl, MVT::i32));
18550   }
18551 
18552   if (Res.getNode()) {
18553     KnownBits Known = DAG.computeKnownBits(SDValue(N,0));
18554     // Capture demanded bits information that would be otherwise lost.
18555     if (Known.Zero == 0xfffffffe)
18556       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
18557                         DAG.getValueType(MVT::i1));
18558     else if (Known.Zero == 0xffffff00)
18559       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
18560                         DAG.getValueType(MVT::i8));
18561     else if (Known.Zero == 0xffff0000)
18562       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
18563                         DAG.getValueType(MVT::i16));
18564   }
18565 
18566   return Res;
18567 }
18568 
PerformBITCASTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const ARMSubtarget * ST)18569 static SDValue PerformBITCASTCombine(SDNode *N,
18570                                      TargetLowering::DAGCombinerInfo &DCI,
18571                                      const ARMSubtarget *ST) {
18572   SelectionDAG &DAG = DCI.DAG;
18573   SDValue Src = N->getOperand(0);
18574   EVT DstVT = N->getValueType(0);
18575 
18576   // Convert v4f32 bitcast (v4i32 vdup (i32)) -> v4f32 vdup (i32) under MVE.
18577   if (ST->hasMVEIntegerOps() && Src.getOpcode() == ARMISD::VDUP) {
18578     EVT SrcVT = Src.getValueType();
18579     if (SrcVT.getScalarSizeInBits() == DstVT.getScalarSizeInBits())
18580       return DAG.getNode(ARMISD::VDUP, SDLoc(N), DstVT, Src.getOperand(0));
18581   }
18582 
18583   // We may have a bitcast of something that has already had this bitcast
18584   // combine performed on it, so skip past any VECTOR_REG_CASTs.
18585   while (Src.getOpcode() == ARMISD::VECTOR_REG_CAST)
18586     Src = Src.getOperand(0);
18587 
18588   // Bitcast from element-wise VMOV or VMVN doesn't need VREV if the VREV that
18589   // would be generated is at least the width of the element type.
18590   EVT SrcVT = Src.getValueType();
18591   if ((Src.getOpcode() == ARMISD::VMOVIMM ||
18592        Src.getOpcode() == ARMISD::VMVNIMM ||
18593        Src.getOpcode() == ARMISD::VMOVFPIMM) &&
18594       SrcVT.getScalarSizeInBits() <= DstVT.getScalarSizeInBits() &&
18595       DAG.getDataLayout().isBigEndian())
18596     return DAG.getNode(ARMISD::VECTOR_REG_CAST, SDLoc(N), DstVT, Src);
18597 
18598   // bitcast(extract(x, n)); bitcast(extract(x, n+1))  ->  VMOVRRD x
18599   if (SDValue R = PerformExtractEltToVMOVRRD(N, DCI))
18600     return R;
18601 
18602   return SDValue();
18603 }
18604 
18605 // Some combines for the MVETrunc truncations legalizer helper. Also lowers the
18606 // node into stack operations after legalizeOps.
PerformMVETruncCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI) const18607 SDValue ARMTargetLowering::PerformMVETruncCombine(
18608     SDNode *N, TargetLowering::DAGCombinerInfo &DCI) const {
18609   SelectionDAG &DAG = DCI.DAG;
18610   EVT VT = N->getValueType(0);
18611   SDLoc DL(N);
18612 
18613   // MVETrunc(Undef, Undef) -> Undef
18614   if (all_of(N->ops(), [](SDValue Op) { return Op.isUndef(); }))
18615     return DAG.getUNDEF(VT);
18616 
18617   // MVETrunc(MVETrunc a b, MVETrunc c, d) -> MVETrunc
18618   if (N->getNumOperands() == 2 &&
18619       N->getOperand(0).getOpcode() == ARMISD::MVETRUNC &&
18620       N->getOperand(1).getOpcode() == ARMISD::MVETRUNC)
18621     return DAG.getNode(ARMISD::MVETRUNC, DL, VT, N->getOperand(0).getOperand(0),
18622                        N->getOperand(0).getOperand(1),
18623                        N->getOperand(1).getOperand(0),
18624                        N->getOperand(1).getOperand(1));
18625 
18626   // MVETrunc(shuffle, shuffle) -> VMOVN
18627   if (N->getNumOperands() == 2 &&
18628       N->getOperand(0).getOpcode() == ISD::VECTOR_SHUFFLE &&
18629       N->getOperand(1).getOpcode() == ISD::VECTOR_SHUFFLE) {
18630     auto *S0 = cast<ShuffleVectorSDNode>(N->getOperand(0).getNode());
18631     auto *S1 = cast<ShuffleVectorSDNode>(N->getOperand(1).getNode());
18632 
18633     if (S0->getOperand(0) == S1->getOperand(0) &&
18634         S0->getOperand(1) == S1->getOperand(1)) {
18635       // Construct complete shuffle mask
18636       SmallVector<int, 8> Mask(S0->getMask());
18637       Mask.append(S1->getMask().begin(), S1->getMask().end());
18638 
18639       if (isVMOVNTruncMask(Mask, VT, false))
18640         return DAG.getNode(
18641             ARMISD::VMOVN, DL, VT,
18642             DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, S0->getOperand(0)),
18643             DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, S0->getOperand(1)),
18644             DAG.getConstant(1, DL, MVT::i32));
18645       if (isVMOVNTruncMask(Mask, VT, true))
18646         return DAG.getNode(
18647             ARMISD::VMOVN, DL, VT,
18648             DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, S0->getOperand(1)),
18649             DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, S0->getOperand(0)),
18650             DAG.getConstant(1, DL, MVT::i32));
18651     }
18652   }
18653 
18654   // For MVETrunc of a buildvector or shuffle, it can be beneficial to lower the
18655   // truncate to a buildvector to allow the generic optimisations to kick in.
18656   if (all_of(N->ops(), [](SDValue Op) {
18657         return Op.getOpcode() == ISD::BUILD_VECTOR ||
18658                Op.getOpcode() == ISD::VECTOR_SHUFFLE ||
18659                (Op.getOpcode() == ISD::BITCAST &&
18660                 Op.getOperand(0).getOpcode() == ISD::BUILD_VECTOR);
18661       })) {
18662     SmallVector<SDValue, 8> Extracts;
18663     for (unsigned Op = 0; Op < N->getNumOperands(); Op++) {
18664       SDValue O = N->getOperand(Op);
18665       for (unsigned i = 0; i < O.getValueType().getVectorNumElements(); i++) {
18666         SDValue Ext = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::i32, O,
18667                                   DAG.getConstant(i, DL, MVT::i32));
18668         Extracts.push_back(Ext);
18669       }
18670     }
18671     return DAG.getBuildVector(VT, DL, Extracts);
18672   }
18673 
18674   // If we are late in the legalization process and nothing has optimised
18675   // the trunc to anything better, lower it to a stack store and reload,
18676   // performing the truncation whilst keeping the lanes in the correct order:
18677   //   VSTRH.32 a, stack; VSTRH.32 b, stack+8; VLDRW.32 stack;
18678   if (!DCI.isAfterLegalizeDAG())
18679     return SDValue();
18680 
18681   SDValue StackPtr = DAG.CreateStackTemporary(TypeSize::getFixed(16), Align(4));
18682   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
18683   int NumIns = N->getNumOperands();
18684   assert((NumIns == 2 || NumIns == 4) &&
18685          "Expected 2 or 4 inputs to an MVETrunc");
18686   EVT StoreVT = VT.getHalfNumVectorElementsVT(*DAG.getContext());
18687   if (N->getNumOperands() == 4)
18688     StoreVT = StoreVT.getHalfNumVectorElementsVT(*DAG.getContext());
18689 
18690   SmallVector<SDValue> Chains;
18691   for (int I = 0; I < NumIns; I++) {
18692     SDValue Ptr = DAG.getNode(
18693         ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
18694         DAG.getConstant(I * 16 / NumIns, DL, StackPtr.getValueType()));
18695     MachinePointerInfo MPI = MachinePointerInfo::getFixedStack(
18696         DAG.getMachineFunction(), SPFI, I * 16 / NumIns);
18697     SDValue Ch = DAG.getTruncStore(DAG.getEntryNode(), DL, N->getOperand(I),
18698                                    Ptr, MPI, StoreVT, Align(4));
18699     Chains.push_back(Ch);
18700   }
18701 
18702   SDValue Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
18703   MachinePointerInfo MPI =
18704       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI, 0);
18705   return DAG.getLoad(VT, DL, Chain, StackPtr, MPI, Align(4));
18706 }
18707 
18708 // Take a MVEEXT(load x) and split that into (extload x, extload x+8)
PerformSplittingMVEEXTToWideningLoad(SDNode * N,SelectionDAG & DAG)18709 static SDValue PerformSplittingMVEEXTToWideningLoad(SDNode *N,
18710                                                     SelectionDAG &DAG) {
18711   SDValue N0 = N->getOperand(0);
18712   LoadSDNode *LD = dyn_cast<LoadSDNode>(N0.getNode());
18713   if (!LD || !LD->isSimple() || !N0.hasOneUse() || LD->isIndexed())
18714     return SDValue();
18715 
18716   EVT FromVT = LD->getMemoryVT();
18717   EVT ToVT = N->getValueType(0);
18718   if (!ToVT.isVector())
18719     return SDValue();
18720   assert(FromVT.getVectorNumElements() == ToVT.getVectorNumElements() * 2);
18721   EVT ToEltVT = ToVT.getVectorElementType();
18722   EVT FromEltVT = FromVT.getVectorElementType();
18723 
18724   unsigned NumElements = 0;
18725   if (ToEltVT == MVT::i32 && (FromEltVT == MVT::i16 || FromEltVT == MVT::i8))
18726     NumElements = 4;
18727   if (ToEltVT == MVT::i16 && FromEltVT == MVT::i8)
18728     NumElements = 8;
18729   assert(NumElements != 0);
18730 
18731   ISD::LoadExtType NewExtType =
18732       N->getOpcode() == ARMISD::MVESEXT ? ISD::SEXTLOAD : ISD::ZEXTLOAD;
18733   if (LD->getExtensionType() != ISD::NON_EXTLOAD &&
18734       LD->getExtensionType() != ISD::EXTLOAD &&
18735       LD->getExtensionType() != NewExtType)
18736     return SDValue();
18737 
18738   LLVMContext &C = *DAG.getContext();
18739   SDLoc DL(LD);
18740   // Details about the old load
18741   SDValue Ch = LD->getChain();
18742   SDValue BasePtr = LD->getBasePtr();
18743   Align Alignment = LD->getOriginalAlign();
18744   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
18745   AAMDNodes AAInfo = LD->getAAInfo();
18746 
18747   SDValue Offset = DAG.getUNDEF(BasePtr.getValueType());
18748   EVT NewFromVT = EVT::getVectorVT(
18749       C, EVT::getIntegerVT(C, FromEltVT.getScalarSizeInBits()), NumElements);
18750   EVT NewToVT = EVT::getVectorVT(
18751       C, EVT::getIntegerVT(C, ToEltVT.getScalarSizeInBits()), NumElements);
18752 
18753   SmallVector<SDValue, 4> Loads;
18754   SmallVector<SDValue, 4> Chains;
18755   for (unsigned i = 0; i < FromVT.getVectorNumElements() / NumElements; i++) {
18756     unsigned NewOffset = (i * NewFromVT.getSizeInBits()) / 8;
18757     SDValue NewPtr =
18758         DAG.getObjectPtrOffset(DL, BasePtr, TypeSize::getFixed(NewOffset));
18759 
18760     SDValue NewLoad =
18761         DAG.getLoad(ISD::UNINDEXED, NewExtType, NewToVT, DL, Ch, NewPtr, Offset,
18762                     LD->getPointerInfo().getWithOffset(NewOffset), NewFromVT,
18763                     Alignment, MMOFlags, AAInfo);
18764     Loads.push_back(NewLoad);
18765     Chains.push_back(SDValue(NewLoad.getNode(), 1));
18766   }
18767 
18768   SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
18769   DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), NewChain);
18770   return DAG.getMergeValues(Loads, DL);
18771 }
18772 
18773 // Perform combines for MVEEXT. If it has not be optimized to anything better
18774 // before lowering, it gets converted to stack store and extloads performing the
18775 // extend whilst still keeping the same lane ordering.
PerformMVEExtCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI) const18776 SDValue ARMTargetLowering::PerformMVEExtCombine(
18777     SDNode *N, TargetLowering::DAGCombinerInfo &DCI) const {
18778   SelectionDAG &DAG = DCI.DAG;
18779   EVT VT = N->getValueType(0);
18780   SDLoc DL(N);
18781   assert(N->getNumValues() == 2 && "Expected MVEEXT with 2 elements");
18782   assert((VT == MVT::v4i32 || VT == MVT::v8i16) && "Unexpected MVEEXT type");
18783 
18784   EVT ExtVT = N->getOperand(0).getValueType().getHalfNumVectorElementsVT(
18785       *DAG.getContext());
18786   auto Extend = [&](SDValue V) {
18787     SDValue VVT = DAG.getNode(ARMISD::VECTOR_REG_CAST, DL, VT, V);
18788     return N->getOpcode() == ARMISD::MVESEXT
18789                ? DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, VVT,
18790                              DAG.getValueType(ExtVT))
18791                : DAG.getZeroExtendInReg(VVT, DL, ExtVT);
18792   };
18793 
18794   // MVEEXT(VDUP) -> SIGN_EXTEND_INREG(VDUP)
18795   if (N->getOperand(0).getOpcode() == ARMISD::VDUP) {
18796     SDValue Ext = Extend(N->getOperand(0));
18797     return DAG.getMergeValues({Ext, Ext}, DL);
18798   }
18799 
18800   // MVEEXT(shuffle) -> SIGN_EXTEND_INREG/ZERO_EXTEND_INREG
18801   if (auto *SVN = dyn_cast<ShuffleVectorSDNode>(N->getOperand(0))) {
18802     ArrayRef<int> Mask = SVN->getMask();
18803     assert(Mask.size() == 2 * VT.getVectorNumElements());
18804     assert(Mask.size() == SVN->getValueType(0).getVectorNumElements());
18805     unsigned Rev = VT == MVT::v4i32 ? ARMISD::VREV32 : ARMISD::VREV16;
18806     SDValue Op0 = SVN->getOperand(0);
18807     SDValue Op1 = SVN->getOperand(1);
18808 
18809     auto CheckInregMask = [&](int Start, int Offset) {
18810       for (int Idx = 0, E = VT.getVectorNumElements(); Idx < E; ++Idx)
18811         if (Mask[Start + Idx] >= 0 && Mask[Start + Idx] != Idx * 2 + Offset)
18812           return false;
18813       return true;
18814     };
18815     SDValue V0 = SDValue(N, 0);
18816     SDValue V1 = SDValue(N, 1);
18817     if (CheckInregMask(0, 0))
18818       V0 = Extend(Op0);
18819     else if (CheckInregMask(0, 1))
18820       V0 = Extend(DAG.getNode(Rev, DL, SVN->getValueType(0), Op0));
18821     else if (CheckInregMask(0, Mask.size()))
18822       V0 = Extend(Op1);
18823     else if (CheckInregMask(0, Mask.size() + 1))
18824       V0 = Extend(DAG.getNode(Rev, DL, SVN->getValueType(0), Op1));
18825 
18826     if (CheckInregMask(VT.getVectorNumElements(), Mask.size()))
18827       V1 = Extend(Op1);
18828     else if (CheckInregMask(VT.getVectorNumElements(), Mask.size() + 1))
18829       V1 = Extend(DAG.getNode(Rev, DL, SVN->getValueType(0), Op1));
18830     else if (CheckInregMask(VT.getVectorNumElements(), 0))
18831       V1 = Extend(Op0);
18832     else if (CheckInregMask(VT.getVectorNumElements(), 1))
18833       V1 = Extend(DAG.getNode(Rev, DL, SVN->getValueType(0), Op0));
18834 
18835     if (V0.getNode() != N || V1.getNode() != N)
18836       return DAG.getMergeValues({V0, V1}, DL);
18837   }
18838 
18839   // MVEEXT(load) -> extload, extload
18840   if (N->getOperand(0)->getOpcode() == ISD::LOAD)
18841     if (SDValue L = PerformSplittingMVEEXTToWideningLoad(N, DAG))
18842       return L;
18843 
18844   if (!DCI.isAfterLegalizeDAG())
18845     return SDValue();
18846 
18847   // Lower to a stack store and reload:
18848   //  VSTRW.32 a, stack; VLDRH.32 stack; VLDRH.32 stack+8;
18849   SDValue StackPtr = DAG.CreateStackTemporary(TypeSize::getFixed(16), Align(4));
18850   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
18851   int NumOuts = N->getNumValues();
18852   assert((NumOuts == 2 || NumOuts == 4) &&
18853          "Expected 2 or 4 outputs to an MVEEXT");
18854   EVT LoadVT = N->getOperand(0).getValueType().getHalfNumVectorElementsVT(
18855       *DAG.getContext());
18856   if (N->getNumOperands() == 4)
18857     LoadVT = LoadVT.getHalfNumVectorElementsVT(*DAG.getContext());
18858 
18859   MachinePointerInfo MPI =
18860       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI, 0);
18861   SDValue Chain = DAG.getStore(DAG.getEntryNode(), DL, N->getOperand(0),
18862                                StackPtr, MPI, Align(4));
18863 
18864   SmallVector<SDValue> Loads;
18865   for (int I = 0; I < NumOuts; I++) {
18866     SDValue Ptr = DAG.getNode(
18867         ISD::ADD, DL, StackPtr.getValueType(), StackPtr,
18868         DAG.getConstant(I * 16 / NumOuts, DL, StackPtr.getValueType()));
18869     MachinePointerInfo MPI = MachinePointerInfo::getFixedStack(
18870         DAG.getMachineFunction(), SPFI, I * 16 / NumOuts);
18871     SDValue Load = DAG.getExtLoad(
18872         N->getOpcode() == ARMISD::MVESEXT ? ISD::SEXTLOAD : ISD::ZEXTLOAD, DL,
18873         VT, Chain, Ptr, MPI, LoadVT, Align(4));
18874     Loads.push_back(Load);
18875   }
18876 
18877   return DAG.getMergeValues(Loads, DL);
18878 }
18879 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const18880 SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
18881                                              DAGCombinerInfo &DCI) const {
18882   switch (N->getOpcode()) {
18883   default: break;
18884   case ISD::SELECT_CC:
18885   case ISD::SELECT:     return PerformSELECTCombine(N, DCI, Subtarget);
18886   case ISD::VSELECT:    return PerformVSELECTCombine(N, DCI, Subtarget);
18887   case ISD::SETCC:      return PerformVSetCCToVCTPCombine(N, DCI, Subtarget);
18888   case ARMISD::ADDE:    return PerformADDECombine(N, DCI, Subtarget);
18889   case ARMISD::UMLAL:   return PerformUMLALCombine(N, DCI.DAG, Subtarget);
18890   case ISD::ADD:        return PerformADDCombine(N, DCI, Subtarget);
18891   case ISD::SUB:        return PerformSUBCombine(N, DCI, Subtarget);
18892   case ISD::MUL:        return PerformMULCombine(N, DCI, Subtarget);
18893   case ISD::OR:         return PerformORCombine(N, DCI, Subtarget);
18894   case ISD::XOR:        return PerformXORCombine(N, DCI, Subtarget);
18895   case ISD::AND:        return PerformANDCombine(N, DCI, Subtarget);
18896   case ISD::BRCOND:
18897   case ISD::BR_CC:      return PerformHWLoopCombine(N, DCI, Subtarget);
18898   case ARMISD::ADDC:
18899   case ARMISD::SUBC:    return PerformAddcSubcCombine(N, DCI, Subtarget);
18900   case ARMISD::SUBE:    return PerformAddeSubeCombine(N, DCI, Subtarget);
18901   case ARMISD::BFI:     return PerformBFICombine(N, DCI.DAG);
18902   case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI, Subtarget);
18903   case ARMISD::VMOVDRR: return PerformVMOVDRRCombine(N, DCI.DAG);
18904   case ARMISD::VMOVhr:  return PerformVMOVhrCombine(N, DCI);
18905   case ARMISD::VMOVrh:  return PerformVMOVrhCombine(N, DCI.DAG);
18906   case ISD::STORE:      return PerformSTORECombine(N, DCI, Subtarget);
18907   case ISD::BUILD_VECTOR: return PerformBUILD_VECTORCombine(N, DCI, Subtarget);
18908   case ISD::INSERT_VECTOR_ELT: return PerformInsertEltCombine(N, DCI);
18909   case ISD::EXTRACT_VECTOR_ELT:
18910     return PerformExtractEltCombine(N, DCI, Subtarget);
18911   case ISD::SIGN_EXTEND_INREG: return PerformSignExtendInregCombine(N, DCI.DAG);
18912   case ISD::INSERT_SUBVECTOR: return PerformInsertSubvectorCombine(N, DCI);
18913   case ISD::VECTOR_SHUFFLE: return PerformVECTOR_SHUFFLECombine(N, DCI.DAG);
18914   case ARMISD::VDUPLANE: return PerformVDUPLANECombine(N, DCI, Subtarget);
18915   case ARMISD::VDUP: return PerformVDUPCombine(N, DCI.DAG, Subtarget);
18916   case ISD::FP_TO_SINT:
18917   case ISD::FP_TO_UINT:
18918     return PerformVCVTCombine(N, DCI.DAG, Subtarget);
18919   case ISD::FADD:
18920     return PerformFADDCombine(N, DCI.DAG, Subtarget);
18921   case ISD::FMUL:
18922     return PerformVMulVCTPCombine(N, DCI.DAG, Subtarget);
18923   case ISD::INTRINSIC_WO_CHAIN:
18924     return PerformIntrinsicCombine(N, DCI);
18925   case ISD::SHL:
18926   case ISD::SRA:
18927   case ISD::SRL:
18928     return PerformShiftCombine(N, DCI, Subtarget);
18929   case ISD::SIGN_EXTEND:
18930   case ISD::ZERO_EXTEND:
18931   case ISD::ANY_EXTEND:
18932     return PerformExtendCombine(N, DCI.DAG, Subtarget);
18933   case ISD::FP_EXTEND:
18934     return PerformFPExtendCombine(N, DCI.DAG, Subtarget);
18935   case ISD::SMIN:
18936   case ISD::UMIN:
18937   case ISD::SMAX:
18938   case ISD::UMAX:
18939     return PerformMinMaxCombine(N, DCI.DAG, Subtarget);
18940   case ARMISD::CMOV:
18941     return PerformCMOVCombine(N, DCI.DAG);
18942   case ARMISD::BRCOND:
18943     return PerformBRCONDCombine(N, DCI.DAG);
18944   case ARMISD::CMPZ:
18945     return PerformCMPZCombine(N, DCI.DAG);
18946   case ARMISD::CSINC:
18947   case ARMISD::CSINV:
18948   case ARMISD::CSNEG:
18949     return PerformCSETCombine(N, DCI.DAG);
18950   case ISD::LOAD:
18951     return PerformLOADCombine(N, DCI, Subtarget);
18952   case ARMISD::VLD1DUP:
18953   case ARMISD::VLD2DUP:
18954   case ARMISD::VLD3DUP:
18955   case ARMISD::VLD4DUP:
18956     return PerformVLDCombine(N, DCI);
18957   case ARMISD::BUILD_VECTOR:
18958     return PerformARMBUILD_VECTORCombine(N, DCI);
18959   case ISD::BITCAST:
18960     return PerformBITCASTCombine(N, DCI, Subtarget);
18961   case ARMISD::PREDICATE_CAST:
18962     return PerformPREDICATE_CASTCombine(N, DCI);
18963   case ARMISD::VECTOR_REG_CAST:
18964     return PerformVECTOR_REG_CASTCombine(N, DCI.DAG, Subtarget);
18965   case ARMISD::MVETRUNC:
18966     return PerformMVETruncCombine(N, DCI);
18967   case ARMISD::MVESEXT:
18968   case ARMISD::MVEZEXT:
18969     return PerformMVEExtCombine(N, DCI);
18970   case ARMISD::VCMP:
18971     return PerformVCMPCombine(N, DCI.DAG, Subtarget);
18972   case ISD::VECREDUCE_ADD:
18973     return PerformVECREDUCE_ADDCombine(N, DCI.DAG, Subtarget);
18974   case ARMISD::VADDVs:
18975   case ARMISD::VADDVu:
18976   case ARMISD::VADDLVs:
18977   case ARMISD::VADDLVu:
18978   case ARMISD::VADDLVAs:
18979   case ARMISD::VADDLVAu:
18980   case ARMISD::VMLAVs:
18981   case ARMISD::VMLAVu:
18982   case ARMISD::VMLALVs:
18983   case ARMISD::VMLALVu:
18984   case ARMISD::VMLALVAs:
18985   case ARMISD::VMLALVAu:
18986     return PerformReduceShuffleCombine(N, DCI.DAG);
18987   case ARMISD::VMOVN:
18988     return PerformVMOVNCombine(N, DCI);
18989   case ARMISD::VQMOVNs:
18990   case ARMISD::VQMOVNu:
18991     return PerformVQMOVNCombine(N, DCI);
18992   case ARMISD::VQDMULH:
18993     return PerformVQDMULHCombine(N, DCI);
18994   case ARMISD::ASRL:
18995   case ARMISD::LSRL:
18996   case ARMISD::LSLL:
18997     return PerformLongShiftCombine(N, DCI.DAG);
18998   case ARMISD::SMULWB: {
18999     unsigned BitWidth = N->getValueType(0).getSizeInBits();
19000     APInt DemandedMask = APInt::getLowBitsSet(BitWidth, 16);
19001     if (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI))
19002       return SDValue();
19003     break;
19004   }
19005   case ARMISD::SMULWT: {
19006     unsigned BitWidth = N->getValueType(0).getSizeInBits();
19007     APInt DemandedMask = APInt::getHighBitsSet(BitWidth, 16);
19008     if (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI))
19009       return SDValue();
19010     break;
19011   }
19012   case ARMISD::SMLALBB:
19013   case ARMISD::QADD16b:
19014   case ARMISD::QSUB16b:
19015   case ARMISD::UQADD16b:
19016   case ARMISD::UQSUB16b: {
19017     unsigned BitWidth = N->getValueType(0).getSizeInBits();
19018     APInt DemandedMask = APInt::getLowBitsSet(BitWidth, 16);
19019     if ((SimplifyDemandedBits(N->getOperand(0), DemandedMask, DCI)) ||
19020         (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI)))
19021       return SDValue();
19022     break;
19023   }
19024   case ARMISD::SMLALBT: {
19025     unsigned LowWidth = N->getOperand(0).getValueType().getSizeInBits();
19026     APInt LowMask = APInt::getLowBitsSet(LowWidth, 16);
19027     unsigned HighWidth = N->getOperand(1).getValueType().getSizeInBits();
19028     APInt HighMask = APInt::getHighBitsSet(HighWidth, 16);
19029     if ((SimplifyDemandedBits(N->getOperand(0), LowMask, DCI)) ||
19030         (SimplifyDemandedBits(N->getOperand(1), HighMask, DCI)))
19031       return SDValue();
19032     break;
19033   }
19034   case ARMISD::SMLALTB: {
19035     unsigned HighWidth = N->getOperand(0).getValueType().getSizeInBits();
19036     APInt HighMask = APInt::getHighBitsSet(HighWidth, 16);
19037     unsigned LowWidth = N->getOperand(1).getValueType().getSizeInBits();
19038     APInt LowMask = APInt::getLowBitsSet(LowWidth, 16);
19039     if ((SimplifyDemandedBits(N->getOperand(0), HighMask, DCI)) ||
19040         (SimplifyDemandedBits(N->getOperand(1), LowMask, DCI)))
19041       return SDValue();
19042     break;
19043   }
19044   case ARMISD::SMLALTT: {
19045     unsigned BitWidth = N->getValueType(0).getSizeInBits();
19046     APInt DemandedMask = APInt::getHighBitsSet(BitWidth, 16);
19047     if ((SimplifyDemandedBits(N->getOperand(0), DemandedMask, DCI)) ||
19048         (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI)))
19049       return SDValue();
19050     break;
19051   }
19052   case ARMISD::QADD8b:
19053   case ARMISD::QSUB8b:
19054   case ARMISD::UQADD8b:
19055   case ARMISD::UQSUB8b: {
19056     unsigned BitWidth = N->getValueType(0).getSizeInBits();
19057     APInt DemandedMask = APInt::getLowBitsSet(BitWidth, 8);
19058     if ((SimplifyDemandedBits(N->getOperand(0), DemandedMask, DCI)) ||
19059         (SimplifyDemandedBits(N->getOperand(1), DemandedMask, DCI)))
19060       return SDValue();
19061     break;
19062   }
19063   case ISD::INTRINSIC_VOID:
19064   case ISD::INTRINSIC_W_CHAIN:
19065     switch (N->getConstantOperandVal(1)) {
19066     case Intrinsic::arm_neon_vld1:
19067     case Intrinsic::arm_neon_vld1x2:
19068     case Intrinsic::arm_neon_vld1x3:
19069     case Intrinsic::arm_neon_vld1x4:
19070     case Intrinsic::arm_neon_vld2:
19071     case Intrinsic::arm_neon_vld3:
19072     case Intrinsic::arm_neon_vld4:
19073     case Intrinsic::arm_neon_vld2lane:
19074     case Intrinsic::arm_neon_vld3lane:
19075     case Intrinsic::arm_neon_vld4lane:
19076     case Intrinsic::arm_neon_vld2dup:
19077     case Intrinsic::arm_neon_vld3dup:
19078     case Intrinsic::arm_neon_vld4dup:
19079     case Intrinsic::arm_neon_vst1:
19080     case Intrinsic::arm_neon_vst1x2:
19081     case Intrinsic::arm_neon_vst1x3:
19082     case Intrinsic::arm_neon_vst1x4:
19083     case Intrinsic::arm_neon_vst2:
19084     case Intrinsic::arm_neon_vst3:
19085     case Intrinsic::arm_neon_vst4:
19086     case Intrinsic::arm_neon_vst2lane:
19087     case Intrinsic::arm_neon_vst3lane:
19088     case Intrinsic::arm_neon_vst4lane:
19089       return PerformVLDCombine(N, DCI);
19090     case Intrinsic::arm_mve_vld2q:
19091     case Intrinsic::arm_mve_vld4q:
19092     case Intrinsic::arm_mve_vst2q:
19093     case Intrinsic::arm_mve_vst4q:
19094       return PerformMVEVLDCombine(N, DCI);
19095     default: break;
19096     }
19097     break;
19098   }
19099   return SDValue();
19100 }
19101 
isDesirableToTransformToIntegerOp(unsigned Opc,EVT VT) const19102 bool ARMTargetLowering::isDesirableToTransformToIntegerOp(unsigned Opc,
19103                                                           EVT VT) const {
19104   return (VT == MVT::f32) && (Opc == ISD::LOAD || Opc == ISD::STORE);
19105 }
19106 
allowsMisalignedMemoryAccesses(EVT VT,unsigned,Align Alignment,MachineMemOperand::Flags,unsigned * Fast) const19107 bool ARMTargetLowering::allowsMisalignedMemoryAccesses(EVT VT, unsigned,
19108                                                        Align Alignment,
19109                                                        MachineMemOperand::Flags,
19110                                                        unsigned *Fast) const {
19111   // Depends what it gets converted into if the type is weird.
19112   if (!VT.isSimple())
19113     return false;
19114 
19115   // The AllowsUnaligned flag models the SCTLR.A setting in ARM cpus
19116   bool AllowsUnaligned = Subtarget->allowsUnalignedMem();
19117   auto Ty = VT.getSimpleVT().SimpleTy;
19118 
19119   if (Ty == MVT::i8 || Ty == MVT::i16 || Ty == MVT::i32) {
19120     // Unaligned access can use (for example) LRDB, LRDH, LDR
19121     if (AllowsUnaligned) {
19122       if (Fast)
19123         *Fast = Subtarget->hasV7Ops();
19124       return true;
19125     }
19126   }
19127 
19128   if (Ty == MVT::f64 || Ty == MVT::v2f64) {
19129     // For any little-endian targets with neon, we can support unaligned ld/st
19130     // of D and Q (e.g. {D0,D1}) registers by using vld1.i8/vst1.i8.
19131     // A big-endian target may also explicitly support unaligned accesses
19132     if (Subtarget->hasNEON() && (AllowsUnaligned || Subtarget->isLittle())) {
19133       if (Fast)
19134         *Fast = 1;
19135       return true;
19136     }
19137   }
19138 
19139   if (!Subtarget->hasMVEIntegerOps())
19140     return false;
19141 
19142   // These are for predicates
19143   if ((Ty == MVT::v16i1 || Ty == MVT::v8i1 || Ty == MVT::v4i1 ||
19144        Ty == MVT::v2i1)) {
19145     if (Fast)
19146       *Fast = 1;
19147     return true;
19148   }
19149 
19150   // These are for truncated stores/narrowing loads. They are fine so long as
19151   // the alignment is at least the size of the item being loaded
19152   if ((Ty == MVT::v4i8 || Ty == MVT::v8i8 || Ty == MVT::v4i16) &&
19153       Alignment >= VT.getScalarSizeInBits() / 8) {
19154     if (Fast)
19155       *Fast = true;
19156     return true;
19157   }
19158 
19159   // In little-endian MVE, the store instructions VSTRB.U8, VSTRH.U16 and
19160   // VSTRW.U32 all store the vector register in exactly the same format, and
19161   // differ only in the range of their immediate offset field and the required
19162   // alignment. So there is always a store that can be used, regardless of
19163   // actual type.
19164   //
19165   // For big endian, that is not the case. But can still emit a (VSTRB.U8;
19166   // VREV64.8) pair and get the same effect. This will likely be better than
19167   // aligning the vector through the stack.
19168   if (Ty == MVT::v16i8 || Ty == MVT::v8i16 || Ty == MVT::v8f16 ||
19169       Ty == MVT::v4i32 || Ty == MVT::v4f32 || Ty == MVT::v2i64 ||
19170       Ty == MVT::v2f64) {
19171     if (Fast)
19172       *Fast = 1;
19173     return true;
19174   }
19175 
19176   return false;
19177 }
19178 
19179 
getOptimalMemOpType(const MemOp & Op,const AttributeList & FuncAttributes) const19180 EVT ARMTargetLowering::getOptimalMemOpType(
19181     const MemOp &Op, const AttributeList &FuncAttributes) const {
19182   // See if we can use NEON instructions for this...
19183   if ((Op.isMemcpy() || Op.isZeroMemset()) && Subtarget->hasNEON() &&
19184       !FuncAttributes.hasFnAttr(Attribute::NoImplicitFloat)) {
19185     unsigned Fast;
19186     if (Op.size() >= 16 &&
19187         (Op.isAligned(Align(16)) ||
19188          (allowsMisalignedMemoryAccesses(MVT::v2f64, 0, Align(1),
19189                                          MachineMemOperand::MONone, &Fast) &&
19190           Fast))) {
19191       return MVT::v2f64;
19192     } else if (Op.size() >= 8 &&
19193                (Op.isAligned(Align(8)) ||
19194                 (allowsMisalignedMemoryAccesses(
19195                      MVT::f64, 0, Align(1), MachineMemOperand::MONone, &Fast) &&
19196                  Fast))) {
19197       return MVT::f64;
19198     }
19199   }
19200 
19201   // Let the target-independent logic figure it out.
19202   return MVT::Other;
19203 }
19204 
19205 // 64-bit integers are split into their high and low parts and held in two
19206 // different registers, so the trunc is free since the low register can just
19207 // be used.
isTruncateFree(Type * SrcTy,Type * DstTy) const19208 bool ARMTargetLowering::isTruncateFree(Type *SrcTy, Type *DstTy) const {
19209   if (!SrcTy->isIntegerTy() || !DstTy->isIntegerTy())
19210     return false;
19211   unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();
19212   unsigned DestBits = DstTy->getPrimitiveSizeInBits();
19213   return (SrcBits == 64 && DestBits == 32);
19214 }
19215 
isTruncateFree(EVT SrcVT,EVT DstVT) const19216 bool ARMTargetLowering::isTruncateFree(EVT SrcVT, EVT DstVT) const {
19217   if (SrcVT.isVector() || DstVT.isVector() || !SrcVT.isInteger() ||
19218       !DstVT.isInteger())
19219     return false;
19220   unsigned SrcBits = SrcVT.getSizeInBits();
19221   unsigned DestBits = DstVT.getSizeInBits();
19222   return (SrcBits == 64 && DestBits == 32);
19223 }
19224 
isZExtFree(SDValue Val,EVT VT2) const19225 bool ARMTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
19226   if (Val.getOpcode() != ISD::LOAD)
19227     return false;
19228 
19229   EVT VT1 = Val.getValueType();
19230   if (!VT1.isSimple() || !VT1.isInteger() ||
19231       !VT2.isSimple() || !VT2.isInteger())
19232     return false;
19233 
19234   switch (VT1.getSimpleVT().SimpleTy) {
19235   default: break;
19236   case MVT::i1:
19237   case MVT::i8:
19238   case MVT::i16:
19239     // 8-bit and 16-bit loads implicitly zero-extend to 32-bits.
19240     return true;
19241   }
19242 
19243   return false;
19244 }
19245 
isFNegFree(EVT VT) const19246 bool ARMTargetLowering::isFNegFree(EVT VT) const {
19247   if (!VT.isSimple())
19248     return false;
19249 
19250   // There are quite a few FP16 instructions (e.g. VNMLA, VNMLS, etc.) that
19251   // negate values directly (fneg is free). So, we don't want to let the DAG
19252   // combiner rewrite fneg into xors and some other instructions.  For f16 and
19253   // FullFP16 argument passing, some bitcast nodes may be introduced,
19254   // triggering this DAG combine rewrite, so we are avoiding that with this.
19255   switch (VT.getSimpleVT().SimpleTy) {
19256   default: break;
19257   case MVT::f16:
19258     return Subtarget->hasFullFP16();
19259   }
19260 
19261   return false;
19262 }
19263 
19264 /// Check if Ext1 and Ext2 are extends of the same type, doubling the bitwidth
19265 /// of the vector elements.
areExtractExts(Value * Ext1,Value * Ext2)19266 static bool areExtractExts(Value *Ext1, Value *Ext2) {
19267   auto areExtDoubled = [](Instruction *Ext) {
19268     return Ext->getType()->getScalarSizeInBits() ==
19269            2 * Ext->getOperand(0)->getType()->getScalarSizeInBits();
19270   };
19271 
19272   if (!match(Ext1, m_ZExtOrSExt(m_Value())) ||
19273       !match(Ext2, m_ZExtOrSExt(m_Value())) ||
19274       !areExtDoubled(cast<Instruction>(Ext1)) ||
19275       !areExtDoubled(cast<Instruction>(Ext2)))
19276     return false;
19277 
19278   return true;
19279 }
19280 
19281 /// Check if sinking \p I's operands to I's basic block is profitable, because
19282 /// the operands can be folded into a target instruction, e.g.
19283 /// sext/zext can be folded into vsubl.
shouldSinkOperands(Instruction * I,SmallVectorImpl<Use * > & Ops) const19284 bool ARMTargetLowering::shouldSinkOperands(Instruction *I,
19285                                            SmallVectorImpl<Use *> &Ops) const {
19286   if (!I->getType()->isVectorTy())
19287     return false;
19288 
19289   if (Subtarget->hasNEON()) {
19290     switch (I->getOpcode()) {
19291     case Instruction::Sub:
19292     case Instruction::Add: {
19293       if (!areExtractExts(I->getOperand(0), I->getOperand(1)))
19294         return false;
19295       Ops.push_back(&I->getOperandUse(0));
19296       Ops.push_back(&I->getOperandUse(1));
19297       return true;
19298     }
19299     default:
19300       return false;
19301     }
19302   }
19303 
19304   if (!Subtarget->hasMVEIntegerOps())
19305     return false;
19306 
19307   auto IsFMSMul = [&](Instruction *I) {
19308     if (!I->hasOneUse())
19309       return false;
19310     auto *Sub = cast<Instruction>(*I->users().begin());
19311     return Sub->getOpcode() == Instruction::FSub && Sub->getOperand(1) == I;
19312   };
19313   auto IsFMS = [&](Instruction *I) {
19314     if (match(I->getOperand(0), m_FNeg(m_Value())) ||
19315         match(I->getOperand(1), m_FNeg(m_Value())))
19316       return true;
19317     return false;
19318   };
19319 
19320   auto IsSinker = [&](Instruction *I, int Operand) {
19321     switch (I->getOpcode()) {
19322     case Instruction::Add:
19323     case Instruction::Mul:
19324     case Instruction::FAdd:
19325     case Instruction::ICmp:
19326     case Instruction::FCmp:
19327       return true;
19328     case Instruction::FMul:
19329       return !IsFMSMul(I);
19330     case Instruction::Sub:
19331     case Instruction::FSub:
19332     case Instruction::Shl:
19333     case Instruction::LShr:
19334     case Instruction::AShr:
19335       return Operand == 1;
19336     case Instruction::Call:
19337       if (auto *II = dyn_cast<IntrinsicInst>(I)) {
19338         switch (II->getIntrinsicID()) {
19339         case Intrinsic::fma:
19340           return !IsFMS(I);
19341         case Intrinsic::sadd_sat:
19342         case Intrinsic::uadd_sat:
19343         case Intrinsic::arm_mve_add_predicated:
19344         case Intrinsic::arm_mve_mul_predicated:
19345         case Intrinsic::arm_mve_qadd_predicated:
19346         case Intrinsic::arm_mve_vhadd:
19347         case Intrinsic::arm_mve_hadd_predicated:
19348         case Intrinsic::arm_mve_vqdmull:
19349         case Intrinsic::arm_mve_vqdmull_predicated:
19350         case Intrinsic::arm_mve_vqdmulh:
19351         case Intrinsic::arm_mve_qdmulh_predicated:
19352         case Intrinsic::arm_mve_vqrdmulh:
19353         case Intrinsic::arm_mve_qrdmulh_predicated:
19354         case Intrinsic::arm_mve_fma_predicated:
19355           return true;
19356         case Intrinsic::ssub_sat:
19357         case Intrinsic::usub_sat:
19358         case Intrinsic::arm_mve_sub_predicated:
19359         case Intrinsic::arm_mve_qsub_predicated:
19360         case Intrinsic::arm_mve_hsub_predicated:
19361         case Intrinsic::arm_mve_vhsub:
19362           return Operand == 1;
19363         default:
19364           return false;
19365         }
19366       }
19367       return false;
19368     default:
19369       return false;
19370     }
19371   };
19372 
19373   for (auto OpIdx : enumerate(I->operands())) {
19374     Instruction *Op = dyn_cast<Instruction>(OpIdx.value().get());
19375     // Make sure we are not already sinking this operand
19376     if (!Op || any_of(Ops, [&](Use *U) { return U->get() == Op; }))
19377       continue;
19378 
19379     Instruction *Shuffle = Op;
19380     if (Shuffle->getOpcode() == Instruction::BitCast)
19381       Shuffle = dyn_cast<Instruction>(Shuffle->getOperand(0));
19382     // We are looking for a splat that can be sunk.
19383     if (!Shuffle ||
19384         !match(Shuffle, m_Shuffle(
19385                             m_InsertElt(m_Undef(), m_Value(), m_ZeroInt()),
19386                             m_Undef(), m_ZeroMask())))
19387       continue;
19388     if (!IsSinker(I, OpIdx.index()))
19389       continue;
19390 
19391     // All uses of the shuffle should be sunk to avoid duplicating it across gpr
19392     // and vector registers
19393     for (Use &U : Op->uses()) {
19394       Instruction *Insn = cast<Instruction>(U.getUser());
19395       if (!IsSinker(Insn, U.getOperandNo()))
19396         return false;
19397     }
19398 
19399     Ops.push_back(&Shuffle->getOperandUse(0));
19400     if (Shuffle != Op)
19401       Ops.push_back(&Op->getOperandUse(0));
19402     Ops.push_back(&OpIdx.value());
19403   }
19404   return true;
19405 }
19406 
shouldConvertSplatType(ShuffleVectorInst * SVI) const19407 Type *ARMTargetLowering::shouldConvertSplatType(ShuffleVectorInst *SVI) const {
19408   if (!Subtarget->hasMVEIntegerOps())
19409     return nullptr;
19410   Type *SVIType = SVI->getType();
19411   Type *ScalarType = SVIType->getScalarType();
19412 
19413   if (ScalarType->isFloatTy())
19414     return Type::getInt32Ty(SVIType->getContext());
19415   if (ScalarType->isHalfTy())
19416     return Type::getInt16Ty(SVIType->getContext());
19417   return nullptr;
19418 }
19419 
isVectorLoadExtDesirable(SDValue ExtVal) const19420 bool ARMTargetLowering::isVectorLoadExtDesirable(SDValue ExtVal) const {
19421   EVT VT = ExtVal.getValueType();
19422 
19423   if (!isTypeLegal(VT))
19424     return false;
19425 
19426   if (auto *Ld = dyn_cast<MaskedLoadSDNode>(ExtVal.getOperand(0))) {
19427     if (Ld->isExpandingLoad())
19428       return false;
19429   }
19430 
19431   if (Subtarget->hasMVEIntegerOps())
19432     return true;
19433 
19434   // Don't create a loadext if we can fold the extension into a wide/long
19435   // instruction.
19436   // If there's more than one user instruction, the loadext is desirable no
19437   // matter what.  There can be two uses by the same instruction.
19438   if (ExtVal->use_empty() ||
19439       !ExtVal->use_begin()->isOnlyUserOf(ExtVal.getNode()))
19440     return true;
19441 
19442   SDNode *U = *ExtVal->use_begin();
19443   if ((U->getOpcode() == ISD::ADD || U->getOpcode() == ISD::SUB ||
19444        U->getOpcode() == ISD::SHL || U->getOpcode() == ARMISD::VSHLIMM))
19445     return false;
19446 
19447   return true;
19448 }
19449 
allowTruncateForTailCall(Type * Ty1,Type * Ty2) const19450 bool ARMTargetLowering::allowTruncateForTailCall(Type *Ty1, Type *Ty2) const {
19451   if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
19452     return false;
19453 
19454   if (!isTypeLegal(EVT::getEVT(Ty1)))
19455     return false;
19456 
19457   assert(Ty1->getPrimitiveSizeInBits() <= 64 && "i128 is probably not a noop");
19458 
19459   // Assuming the caller doesn't have a zeroext or signext return parameter,
19460   // truncation all the way down to i1 is valid.
19461   return true;
19462 }
19463 
19464 /// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
19465 /// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
19466 /// expanded to FMAs when this method returns true, otherwise fmuladd is
19467 /// expanded to fmul + fadd.
19468 ///
19469 /// ARM supports both fused and unfused multiply-add operations; we already
19470 /// lower a pair of fmul and fadd to the latter so it's not clear that there
19471 /// would be a gain or that the gain would be worthwhile enough to risk
19472 /// correctness bugs.
19473 ///
19474 /// For MVE, we set this to true as it helps simplify the need for some
19475 /// patterns (and we don't have the non-fused floating point instruction).
isFMAFasterThanFMulAndFAdd(const MachineFunction & MF,EVT VT) const19476 bool ARMTargetLowering::isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
19477                                                    EVT VT) const {
19478   if (!VT.isSimple())
19479     return false;
19480 
19481   switch (VT.getSimpleVT().SimpleTy) {
19482   case MVT::v4f32:
19483   case MVT::v8f16:
19484     return Subtarget->hasMVEFloatOps();
19485   case MVT::f16:
19486     return Subtarget->useFPVFMx16();
19487   case MVT::f32:
19488     return Subtarget->useFPVFMx();
19489   case MVT::f64:
19490     return Subtarget->useFPVFMx64();
19491   default:
19492     break;
19493   }
19494 
19495   return false;
19496 }
19497 
isLegalT1AddressImmediate(int64_t V,EVT VT)19498 static bool isLegalT1AddressImmediate(int64_t V, EVT VT) {
19499   if (V < 0)
19500     return false;
19501 
19502   unsigned Scale = 1;
19503   switch (VT.getSimpleVT().SimpleTy) {
19504   case MVT::i1:
19505   case MVT::i8:
19506     // Scale == 1;
19507     break;
19508   case MVT::i16:
19509     // Scale == 2;
19510     Scale = 2;
19511     break;
19512   default:
19513     // On thumb1 we load most things (i32, i64, floats, etc) with a LDR
19514     // Scale == 4;
19515     Scale = 4;
19516     break;
19517   }
19518 
19519   if ((V & (Scale - 1)) != 0)
19520     return false;
19521   return isUInt<5>(V / Scale);
19522 }
19523 
isLegalT2AddressImmediate(int64_t V,EVT VT,const ARMSubtarget * Subtarget)19524 static bool isLegalT2AddressImmediate(int64_t V, EVT VT,
19525                                       const ARMSubtarget *Subtarget) {
19526   if (!VT.isInteger() && !VT.isFloatingPoint())
19527     return false;
19528   if (VT.isVector() && Subtarget->hasNEON())
19529     return false;
19530   if (VT.isVector() && VT.isFloatingPoint() && Subtarget->hasMVEIntegerOps() &&
19531       !Subtarget->hasMVEFloatOps())
19532     return false;
19533 
19534   bool IsNeg = false;
19535   if (V < 0) {
19536     IsNeg = true;
19537     V = -V;
19538   }
19539 
19540   unsigned NumBytes = std::max((unsigned)VT.getSizeInBits() / 8, 1U);
19541 
19542   // MVE: size * imm7
19543   if (VT.isVector() && Subtarget->hasMVEIntegerOps()) {
19544     switch (VT.getSimpleVT().getVectorElementType().SimpleTy) {
19545     case MVT::i32:
19546     case MVT::f32:
19547       return isShiftedUInt<7,2>(V);
19548     case MVT::i16:
19549     case MVT::f16:
19550       return isShiftedUInt<7,1>(V);
19551     case MVT::i8:
19552       return isUInt<7>(V);
19553     default:
19554       return false;
19555     }
19556   }
19557 
19558   // half VLDR: 2 * imm8
19559   if (VT.isFloatingPoint() && NumBytes == 2 && Subtarget->hasFPRegs16())
19560     return isShiftedUInt<8, 1>(V);
19561   // VLDR and LDRD: 4 * imm8
19562   if ((VT.isFloatingPoint() && Subtarget->hasVFP2Base()) || NumBytes == 8)
19563     return isShiftedUInt<8, 2>(V);
19564 
19565   if (NumBytes == 1 || NumBytes == 2 || NumBytes == 4) {
19566     // + imm12 or - imm8
19567     if (IsNeg)
19568       return isUInt<8>(V);
19569     return isUInt<12>(V);
19570   }
19571 
19572   return false;
19573 }
19574 
19575 /// isLegalAddressImmediate - Return true if the integer value can be used
19576 /// as the offset of the target addressing mode for load / store of the
19577 /// given type.
isLegalAddressImmediate(int64_t V,EVT VT,const ARMSubtarget * Subtarget)19578 static bool isLegalAddressImmediate(int64_t V, EVT VT,
19579                                     const ARMSubtarget *Subtarget) {
19580   if (V == 0)
19581     return true;
19582 
19583   if (!VT.isSimple())
19584     return false;
19585 
19586   if (Subtarget->isThumb1Only())
19587     return isLegalT1AddressImmediate(V, VT);
19588   else if (Subtarget->isThumb2())
19589     return isLegalT2AddressImmediate(V, VT, Subtarget);
19590 
19591   // ARM mode.
19592   if (V < 0)
19593     V = - V;
19594   switch (VT.getSimpleVT().SimpleTy) {
19595   default: return false;
19596   case MVT::i1:
19597   case MVT::i8:
19598   case MVT::i32:
19599     // +- imm12
19600     return isUInt<12>(V);
19601   case MVT::i16:
19602     // +- imm8
19603     return isUInt<8>(V);
19604   case MVT::f32:
19605   case MVT::f64:
19606     if (!Subtarget->hasVFP2Base()) // FIXME: NEON?
19607       return false;
19608     return isShiftedUInt<8, 2>(V);
19609   }
19610 }
19611 
isLegalT2ScaledAddressingMode(const AddrMode & AM,EVT VT) const19612 bool ARMTargetLowering::isLegalT2ScaledAddressingMode(const AddrMode &AM,
19613                                                       EVT VT) const {
19614   int Scale = AM.Scale;
19615   if (Scale < 0)
19616     return false;
19617 
19618   switch (VT.getSimpleVT().SimpleTy) {
19619   default: return false;
19620   case MVT::i1:
19621   case MVT::i8:
19622   case MVT::i16:
19623   case MVT::i32:
19624     if (Scale == 1)
19625       return true;
19626     // r + r << imm
19627     Scale = Scale & ~1;
19628     return Scale == 2 || Scale == 4 || Scale == 8;
19629   case MVT::i64:
19630     // FIXME: What are we trying to model here? ldrd doesn't have an r + r
19631     // version in Thumb mode.
19632     // r + r
19633     if (Scale == 1)
19634       return true;
19635     // r * 2 (this can be lowered to r + r).
19636     if (!AM.HasBaseReg && Scale == 2)
19637       return true;
19638     return false;
19639   case MVT::isVoid:
19640     // Note, we allow "void" uses (basically, uses that aren't loads or
19641     // stores), because arm allows folding a scale into many arithmetic
19642     // operations.  This should be made more precise and revisited later.
19643 
19644     // Allow r << imm, but the imm has to be a multiple of two.
19645     if (Scale & 1) return false;
19646     return isPowerOf2_32(Scale);
19647   }
19648 }
19649 
isLegalT1ScaledAddressingMode(const AddrMode & AM,EVT VT) const19650 bool ARMTargetLowering::isLegalT1ScaledAddressingMode(const AddrMode &AM,
19651                                                       EVT VT) const {
19652   const int Scale = AM.Scale;
19653 
19654   // Negative scales are not supported in Thumb1.
19655   if (Scale < 0)
19656     return false;
19657 
19658   // Thumb1 addressing modes do not support register scaling excepting the
19659   // following cases:
19660   // 1. Scale == 1 means no scaling.
19661   // 2. Scale == 2 this can be lowered to r + r if there is no base register.
19662   return (Scale == 1) || (!AM.HasBaseReg && Scale == 2);
19663 }
19664 
19665 /// isLegalAddressingMode - Return true if the addressing mode represented
19666 /// by AM is legal for this target, for a load/store of the specified type.
isLegalAddressingMode(const DataLayout & DL,const AddrMode & AM,Type * Ty,unsigned AS,Instruction * I) const19667 bool ARMTargetLowering::isLegalAddressingMode(const DataLayout &DL,
19668                                               const AddrMode &AM, Type *Ty,
19669                                               unsigned AS, Instruction *I) const {
19670   EVT VT = getValueType(DL, Ty, true);
19671   if (!isLegalAddressImmediate(AM.BaseOffs, VT, Subtarget))
19672     return false;
19673 
19674   // Can never fold addr of global into load/store.
19675   if (AM.BaseGV)
19676     return false;
19677 
19678   switch (AM.Scale) {
19679   case 0:  // no scale reg, must be "r+i" or "r", or "i".
19680     break;
19681   default:
19682     // ARM doesn't support any R+R*scale+imm addr modes.
19683     if (AM.BaseOffs)
19684       return false;
19685 
19686     if (!VT.isSimple())
19687       return false;
19688 
19689     if (Subtarget->isThumb1Only())
19690       return isLegalT1ScaledAddressingMode(AM, VT);
19691 
19692     if (Subtarget->isThumb2())
19693       return isLegalT2ScaledAddressingMode(AM, VT);
19694 
19695     int Scale = AM.Scale;
19696     switch (VT.getSimpleVT().SimpleTy) {
19697     default: return false;
19698     case MVT::i1:
19699     case MVT::i8:
19700     case MVT::i32:
19701       if (Scale < 0) Scale = -Scale;
19702       if (Scale == 1)
19703         return true;
19704       // r + r << imm
19705       return isPowerOf2_32(Scale & ~1);
19706     case MVT::i16:
19707     case MVT::i64:
19708       // r +/- r
19709       if (Scale == 1 || (AM.HasBaseReg && Scale == -1))
19710         return true;
19711       // r * 2 (this can be lowered to r + r).
19712       if (!AM.HasBaseReg && Scale == 2)
19713         return true;
19714       return false;
19715 
19716     case MVT::isVoid:
19717       // Note, we allow "void" uses (basically, uses that aren't loads or
19718       // stores), because arm allows folding a scale into many arithmetic
19719       // operations.  This should be made more precise and revisited later.
19720 
19721       // Allow r << imm, but the imm has to be a multiple of two.
19722       if (Scale & 1) return false;
19723       return isPowerOf2_32(Scale);
19724     }
19725   }
19726   return true;
19727 }
19728 
19729 /// isLegalICmpImmediate - Return true if the specified immediate is legal
19730 /// icmp immediate, that is the target has icmp instructions which can compare
19731 /// a register against the immediate without having to materialize the
19732 /// immediate into a register.
isLegalICmpImmediate(int64_t Imm) const19733 bool ARMTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
19734   // Thumb2 and ARM modes can use cmn for negative immediates.
19735   if (!Subtarget->isThumb())
19736     return ARM_AM::getSOImmVal((uint32_t)Imm) != -1 ||
19737            ARM_AM::getSOImmVal(-(uint32_t)Imm) != -1;
19738   if (Subtarget->isThumb2())
19739     return ARM_AM::getT2SOImmVal((uint32_t)Imm) != -1 ||
19740            ARM_AM::getT2SOImmVal(-(uint32_t)Imm) != -1;
19741   // Thumb1 doesn't have cmn, and only 8-bit immediates.
19742   return Imm >= 0 && Imm <= 255;
19743 }
19744 
19745 /// isLegalAddImmediate - Return true if the specified immediate is a legal add
19746 /// *or sub* immediate, that is the target has add or sub instructions which can
19747 /// add a register with the immediate without having to materialize the
19748 /// immediate into a register.
isLegalAddImmediate(int64_t Imm) const19749 bool ARMTargetLowering::isLegalAddImmediate(int64_t Imm) const {
19750   // Same encoding for add/sub, just flip the sign.
19751   int64_t AbsImm = std::abs(Imm);
19752   if (!Subtarget->isThumb())
19753     return ARM_AM::getSOImmVal(AbsImm) != -1;
19754   if (Subtarget->isThumb2())
19755     return ARM_AM::getT2SOImmVal(AbsImm) != -1;
19756   // Thumb1 only has 8-bit unsigned immediate.
19757   return AbsImm >= 0 && AbsImm <= 255;
19758 }
19759 
19760 // Return false to prevent folding
19761 // (mul (add r, c0), c1) -> (add (mul r, c1), c0*c1) in DAGCombine,
19762 // if the folding leads to worse code.
isMulAddWithConstProfitable(SDValue AddNode,SDValue ConstNode) const19763 bool ARMTargetLowering::isMulAddWithConstProfitable(SDValue AddNode,
19764                                                     SDValue ConstNode) const {
19765   // Let the DAGCombiner decide for vector types and large types.
19766   const EVT VT = AddNode.getValueType();
19767   if (VT.isVector() || VT.getScalarSizeInBits() > 32)
19768     return true;
19769 
19770   // It is worse if c0 is legal add immediate, while c1*c0 is not
19771   // and has to be composed by at least two instructions.
19772   const ConstantSDNode *C0Node = cast<ConstantSDNode>(AddNode.getOperand(1));
19773   const ConstantSDNode *C1Node = cast<ConstantSDNode>(ConstNode);
19774   const int64_t C0 = C0Node->getSExtValue();
19775   APInt CA = C0Node->getAPIntValue() * C1Node->getAPIntValue();
19776   if (!isLegalAddImmediate(C0) || isLegalAddImmediate(CA.getSExtValue()))
19777     return true;
19778   if (ConstantMaterializationCost((unsigned)CA.getZExtValue(), Subtarget) > 1)
19779     return false;
19780 
19781   // Default to true and let the DAGCombiner decide.
19782   return true;
19783 }
19784 
getARMIndexedAddressParts(SDNode * Ptr,EVT VT,bool isSEXTLoad,SDValue & Base,SDValue & Offset,bool & isInc,SelectionDAG & DAG)19785 static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT,
19786                                       bool isSEXTLoad, SDValue &Base,
19787                                       SDValue &Offset, bool &isInc,
19788                                       SelectionDAG &DAG) {
19789   if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
19790     return false;
19791 
19792   if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
19793     // AddressingMode 3
19794     Base = Ptr->getOperand(0);
19795     if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
19796       int RHSC = (int)RHS->getZExtValue();
19797       if (RHSC < 0 && RHSC > -256) {
19798         assert(Ptr->getOpcode() == ISD::ADD);
19799         isInc = false;
19800         Offset = DAG.getConstant(-RHSC, SDLoc(Ptr), RHS->getValueType(0));
19801         return true;
19802       }
19803     }
19804     isInc = (Ptr->getOpcode() == ISD::ADD);
19805     Offset = Ptr->getOperand(1);
19806     return true;
19807   } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
19808     // AddressingMode 2
19809     if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
19810       int RHSC = (int)RHS->getZExtValue();
19811       if (RHSC < 0 && RHSC > -0x1000) {
19812         assert(Ptr->getOpcode() == ISD::ADD);
19813         isInc = false;
19814         Offset = DAG.getConstant(-RHSC, SDLoc(Ptr), RHS->getValueType(0));
19815         Base = Ptr->getOperand(0);
19816         return true;
19817       }
19818     }
19819 
19820     if (Ptr->getOpcode() == ISD::ADD) {
19821       isInc = true;
19822       ARM_AM::ShiftOpc ShOpcVal=
19823         ARM_AM::getShiftOpcForNode(Ptr->getOperand(0).getOpcode());
19824       if (ShOpcVal != ARM_AM::no_shift) {
19825         Base = Ptr->getOperand(1);
19826         Offset = Ptr->getOperand(0);
19827       } else {
19828         Base = Ptr->getOperand(0);
19829         Offset = Ptr->getOperand(1);
19830       }
19831       return true;
19832     }
19833 
19834     isInc = (Ptr->getOpcode() == ISD::ADD);
19835     Base = Ptr->getOperand(0);
19836     Offset = Ptr->getOperand(1);
19837     return true;
19838   }
19839 
19840   // FIXME: Use VLDM / VSTM to emulate indexed FP load / store.
19841   return false;
19842 }
19843 
getT2IndexedAddressParts(SDNode * Ptr,EVT VT,bool isSEXTLoad,SDValue & Base,SDValue & Offset,bool & isInc,SelectionDAG & DAG)19844 static bool getT2IndexedAddressParts(SDNode *Ptr, EVT VT,
19845                                      bool isSEXTLoad, SDValue &Base,
19846                                      SDValue &Offset, bool &isInc,
19847                                      SelectionDAG &DAG) {
19848   if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
19849     return false;
19850 
19851   Base = Ptr->getOperand(0);
19852   if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
19853     int RHSC = (int)RHS->getZExtValue();
19854     if (RHSC < 0 && RHSC > -0x100) { // 8 bits.
19855       assert(Ptr->getOpcode() == ISD::ADD);
19856       isInc = false;
19857       Offset = DAG.getConstant(-RHSC, SDLoc(Ptr), RHS->getValueType(0));
19858       return true;
19859     } else if (RHSC > 0 && RHSC < 0x100) { // 8 bit, no zero.
19860       isInc = Ptr->getOpcode() == ISD::ADD;
19861       Offset = DAG.getConstant(RHSC, SDLoc(Ptr), RHS->getValueType(0));
19862       return true;
19863     }
19864   }
19865 
19866   return false;
19867 }
19868 
getMVEIndexedAddressParts(SDNode * Ptr,EVT VT,Align Alignment,bool isSEXTLoad,bool IsMasked,bool isLE,SDValue & Base,SDValue & Offset,bool & isInc,SelectionDAG & DAG)19869 static bool getMVEIndexedAddressParts(SDNode *Ptr, EVT VT, Align Alignment,
19870                                       bool isSEXTLoad, bool IsMasked, bool isLE,
19871                                       SDValue &Base, SDValue &Offset,
19872                                       bool &isInc, SelectionDAG &DAG) {
19873   if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
19874     return false;
19875   if (!isa<ConstantSDNode>(Ptr->getOperand(1)))
19876     return false;
19877 
19878   // We allow LE non-masked loads to change the type (for example use a vldrb.8
19879   // as opposed to a vldrw.32). This can allow extra addressing modes or
19880   // alignments for what is otherwise an equivalent instruction.
19881   bool CanChangeType = isLE && !IsMasked;
19882 
19883   ConstantSDNode *RHS = cast<ConstantSDNode>(Ptr->getOperand(1));
19884   int RHSC = (int)RHS->getZExtValue();
19885 
19886   auto IsInRange = [&](int RHSC, int Limit, int Scale) {
19887     if (RHSC < 0 && RHSC > -Limit * Scale && RHSC % Scale == 0) {
19888       assert(Ptr->getOpcode() == ISD::ADD);
19889       isInc = false;
19890       Offset = DAG.getConstant(-RHSC, SDLoc(Ptr), RHS->getValueType(0));
19891       return true;
19892     } else if (RHSC > 0 && RHSC < Limit * Scale && RHSC % Scale == 0) {
19893       isInc = Ptr->getOpcode() == ISD::ADD;
19894       Offset = DAG.getConstant(RHSC, SDLoc(Ptr), RHS->getValueType(0));
19895       return true;
19896     }
19897     return false;
19898   };
19899 
19900   // Try to find a matching instruction based on s/zext, Alignment, Offset and
19901   // (in BE/masked) type.
19902   Base = Ptr->getOperand(0);
19903   if (VT == MVT::v4i16) {
19904     if (Alignment >= 2 && IsInRange(RHSC, 0x80, 2))
19905       return true;
19906   } else if (VT == MVT::v4i8 || VT == MVT::v8i8) {
19907     if (IsInRange(RHSC, 0x80, 1))
19908       return true;
19909   } else if (Alignment >= 4 &&
19910              (CanChangeType || VT == MVT::v4i32 || VT == MVT::v4f32) &&
19911              IsInRange(RHSC, 0x80, 4))
19912     return true;
19913   else if (Alignment >= 2 &&
19914            (CanChangeType || VT == MVT::v8i16 || VT == MVT::v8f16) &&
19915            IsInRange(RHSC, 0x80, 2))
19916     return true;
19917   else if ((CanChangeType || VT == MVT::v16i8) && IsInRange(RHSC, 0x80, 1))
19918     return true;
19919   return false;
19920 }
19921 
19922 /// getPreIndexedAddressParts - returns true by value, base pointer and
19923 /// offset pointer and addressing mode by reference if the node's address
19924 /// can be legally represented as pre-indexed load / store address.
19925 bool
getPreIndexedAddressParts(SDNode * N,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const19926 ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
19927                                              SDValue &Offset,
19928                                              ISD::MemIndexedMode &AM,
19929                                              SelectionDAG &DAG) const {
19930   if (Subtarget->isThumb1Only())
19931     return false;
19932 
19933   EVT VT;
19934   SDValue Ptr;
19935   Align Alignment;
19936   bool isSEXTLoad = false;
19937   bool IsMasked = false;
19938   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
19939     Ptr = LD->getBasePtr();
19940     VT = LD->getMemoryVT();
19941     Alignment = LD->getAlign();
19942     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
19943   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
19944     Ptr = ST->getBasePtr();
19945     VT = ST->getMemoryVT();
19946     Alignment = ST->getAlign();
19947   } else if (MaskedLoadSDNode *LD = dyn_cast<MaskedLoadSDNode>(N)) {
19948     Ptr = LD->getBasePtr();
19949     VT = LD->getMemoryVT();
19950     Alignment = LD->getAlign();
19951     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
19952     IsMasked = true;
19953   } else if (MaskedStoreSDNode *ST = dyn_cast<MaskedStoreSDNode>(N)) {
19954     Ptr = ST->getBasePtr();
19955     VT = ST->getMemoryVT();
19956     Alignment = ST->getAlign();
19957     IsMasked = true;
19958   } else
19959     return false;
19960 
19961   bool isInc;
19962   bool isLegal = false;
19963   if (VT.isVector())
19964     isLegal = Subtarget->hasMVEIntegerOps() &&
19965               getMVEIndexedAddressParts(
19966                   Ptr.getNode(), VT, Alignment, isSEXTLoad, IsMasked,
19967                   Subtarget->isLittle(), Base, Offset, isInc, DAG);
19968   else {
19969     if (Subtarget->isThumb2())
19970       isLegal = getT2IndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
19971                                          Offset, isInc, DAG);
19972     else
19973       isLegal = getARMIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
19974                                           Offset, isInc, DAG);
19975   }
19976   if (!isLegal)
19977     return false;
19978 
19979   AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
19980   return true;
19981 }
19982 
19983 /// getPostIndexedAddressParts - returns true by value, base pointer and
19984 /// offset pointer and addressing mode by reference if this node can be
19985 /// combined with a load / store to form a post-indexed load / store.
getPostIndexedAddressParts(SDNode * N,SDNode * Op,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const19986 bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
19987                                                    SDValue &Base,
19988                                                    SDValue &Offset,
19989                                                    ISD::MemIndexedMode &AM,
19990                                                    SelectionDAG &DAG) const {
19991   EVT VT;
19992   SDValue Ptr;
19993   Align Alignment;
19994   bool isSEXTLoad = false, isNonExt;
19995   bool IsMasked = false;
19996   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
19997     VT = LD->getMemoryVT();
19998     Ptr = LD->getBasePtr();
19999     Alignment = LD->getAlign();
20000     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
20001     isNonExt = LD->getExtensionType() == ISD::NON_EXTLOAD;
20002   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
20003     VT = ST->getMemoryVT();
20004     Ptr = ST->getBasePtr();
20005     Alignment = ST->getAlign();
20006     isNonExt = !ST->isTruncatingStore();
20007   } else if (MaskedLoadSDNode *LD = dyn_cast<MaskedLoadSDNode>(N)) {
20008     VT = LD->getMemoryVT();
20009     Ptr = LD->getBasePtr();
20010     Alignment = LD->getAlign();
20011     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
20012     isNonExt = LD->getExtensionType() == ISD::NON_EXTLOAD;
20013     IsMasked = true;
20014   } else if (MaskedStoreSDNode *ST = dyn_cast<MaskedStoreSDNode>(N)) {
20015     VT = ST->getMemoryVT();
20016     Ptr = ST->getBasePtr();
20017     Alignment = ST->getAlign();
20018     isNonExt = !ST->isTruncatingStore();
20019     IsMasked = true;
20020   } else
20021     return false;
20022 
20023   if (Subtarget->isThumb1Only()) {
20024     // Thumb-1 can do a limited post-inc load or store as an updating LDM. It
20025     // must be non-extending/truncating, i32, with an offset of 4.
20026     assert(Op->getValueType(0) == MVT::i32 && "Non-i32 post-inc op?!");
20027     if (Op->getOpcode() != ISD::ADD || !isNonExt)
20028       return false;
20029     auto *RHS = dyn_cast<ConstantSDNode>(Op->getOperand(1));
20030     if (!RHS || RHS->getZExtValue() != 4)
20031       return false;
20032     if (Alignment < Align(4))
20033       return false;
20034 
20035     Offset = Op->getOperand(1);
20036     Base = Op->getOperand(0);
20037     AM = ISD::POST_INC;
20038     return true;
20039   }
20040 
20041   bool isInc;
20042   bool isLegal = false;
20043   if (VT.isVector())
20044     isLegal = Subtarget->hasMVEIntegerOps() &&
20045               getMVEIndexedAddressParts(Op, VT, Alignment, isSEXTLoad, IsMasked,
20046                                         Subtarget->isLittle(), Base, Offset,
20047                                         isInc, DAG);
20048   else {
20049     if (Subtarget->isThumb2())
20050       isLegal = getT2IndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
20051                                          isInc, DAG);
20052     else
20053       isLegal = getARMIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
20054                                           isInc, DAG);
20055   }
20056   if (!isLegal)
20057     return false;
20058 
20059   if (Ptr != Base) {
20060     // Swap base ptr and offset to catch more post-index load / store when
20061     // it's legal. In Thumb2 mode, offset must be an immediate.
20062     if (Ptr == Offset && Op->getOpcode() == ISD::ADD &&
20063         !Subtarget->isThumb2())
20064       std::swap(Base, Offset);
20065 
20066     // Post-indexed load / store update the base pointer.
20067     if (Ptr != Base)
20068       return false;
20069   }
20070 
20071   AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
20072   return true;
20073 }
20074 
computeKnownBitsForTargetNode(const SDValue Op,KnownBits & Known,const APInt & DemandedElts,const SelectionDAG & DAG,unsigned Depth) const20075 void ARMTargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
20076                                                       KnownBits &Known,
20077                                                       const APInt &DemandedElts,
20078                                                       const SelectionDAG &DAG,
20079                                                       unsigned Depth) const {
20080   unsigned BitWidth = Known.getBitWidth();
20081   Known.resetAll();
20082   switch (Op.getOpcode()) {
20083   default: break;
20084   case ARMISD::ADDC:
20085   case ARMISD::ADDE:
20086   case ARMISD::SUBC:
20087   case ARMISD::SUBE:
20088     // Special cases when we convert a carry to a boolean.
20089     if (Op.getResNo() == 0) {
20090       SDValue LHS = Op.getOperand(0);
20091       SDValue RHS = Op.getOperand(1);
20092       // (ADDE 0, 0, C) will give us a single bit.
20093       if (Op->getOpcode() == ARMISD::ADDE && isNullConstant(LHS) &&
20094           isNullConstant(RHS)) {
20095         Known.Zero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
20096         return;
20097       }
20098     }
20099     break;
20100   case ARMISD::CMOV: {
20101     // Bits are known zero/one if known on the LHS and RHS.
20102     Known = DAG.computeKnownBits(Op.getOperand(0), Depth+1);
20103     if (Known.isUnknown())
20104       return;
20105 
20106     KnownBits KnownRHS = DAG.computeKnownBits(Op.getOperand(1), Depth+1);
20107     Known = Known.intersectWith(KnownRHS);
20108     return;
20109   }
20110   case ISD::INTRINSIC_W_CHAIN: {
20111     Intrinsic::ID IntID =
20112         static_cast<Intrinsic::ID>(Op->getConstantOperandVal(1));
20113     switch (IntID) {
20114     default: return;
20115     case Intrinsic::arm_ldaex:
20116     case Intrinsic::arm_ldrex: {
20117       EVT VT = cast<MemIntrinsicSDNode>(Op)->getMemoryVT();
20118       unsigned MemBits = VT.getScalarSizeInBits();
20119       Known.Zero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits);
20120       return;
20121     }
20122     }
20123   }
20124   case ARMISD::BFI: {
20125     // Conservatively, we can recurse down the first operand
20126     // and just mask out all affected bits.
20127     Known = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
20128 
20129     // The operand to BFI is already a mask suitable for removing the bits it
20130     // sets.
20131     const APInt &Mask = Op.getConstantOperandAPInt(2);
20132     Known.Zero &= Mask;
20133     Known.One &= Mask;
20134     return;
20135   }
20136   case ARMISD::VGETLANEs:
20137   case ARMISD::VGETLANEu: {
20138     const SDValue &SrcSV = Op.getOperand(0);
20139     EVT VecVT = SrcSV.getValueType();
20140     assert(VecVT.isVector() && "VGETLANE expected a vector type");
20141     const unsigned NumSrcElts = VecVT.getVectorNumElements();
20142     ConstantSDNode *Pos = cast<ConstantSDNode>(Op.getOperand(1).getNode());
20143     assert(Pos->getAPIntValue().ult(NumSrcElts) &&
20144            "VGETLANE index out of bounds");
20145     unsigned Idx = Pos->getZExtValue();
20146     APInt DemandedElt = APInt::getOneBitSet(NumSrcElts, Idx);
20147     Known = DAG.computeKnownBits(SrcSV, DemandedElt, Depth + 1);
20148 
20149     EVT VT = Op.getValueType();
20150     const unsigned DstSz = VT.getScalarSizeInBits();
20151     const unsigned SrcSz = VecVT.getVectorElementType().getSizeInBits();
20152     (void)SrcSz;
20153     assert(SrcSz == Known.getBitWidth());
20154     assert(DstSz > SrcSz);
20155     if (Op.getOpcode() == ARMISD::VGETLANEs)
20156       Known = Known.sext(DstSz);
20157     else {
20158       Known = Known.zext(DstSz);
20159     }
20160     assert(DstSz == Known.getBitWidth());
20161     break;
20162   }
20163   case ARMISD::VMOVrh: {
20164     KnownBits KnownOp = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
20165     assert(KnownOp.getBitWidth() == 16);
20166     Known = KnownOp.zext(32);
20167     break;
20168   }
20169   case ARMISD::CSINC:
20170   case ARMISD::CSINV:
20171   case ARMISD::CSNEG: {
20172     KnownBits KnownOp0 = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
20173     KnownBits KnownOp1 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
20174 
20175     // The result is either:
20176     // CSINC: KnownOp0 or KnownOp1 + 1
20177     // CSINV: KnownOp0 or ~KnownOp1
20178     // CSNEG: KnownOp0 or KnownOp1 * -1
20179     if (Op.getOpcode() == ARMISD::CSINC)
20180       KnownOp1 = KnownBits::computeForAddSub(
20181           /*Add=*/true, /*NSW=*/false, /*NUW=*/false, KnownOp1,
20182           KnownBits::makeConstant(APInt(32, 1)));
20183     else if (Op.getOpcode() == ARMISD::CSINV)
20184       std::swap(KnownOp1.Zero, KnownOp1.One);
20185     else if (Op.getOpcode() == ARMISD::CSNEG)
20186       KnownOp1 = KnownBits::mul(
20187           KnownOp1, KnownBits::makeConstant(APInt(32, -1)));
20188 
20189     Known = KnownOp0.intersectWith(KnownOp1);
20190     break;
20191   }
20192   }
20193 }
20194 
targetShrinkDemandedConstant(SDValue Op,const APInt & DemandedBits,const APInt & DemandedElts,TargetLoweringOpt & TLO) const20195 bool ARMTargetLowering::targetShrinkDemandedConstant(
20196     SDValue Op, const APInt &DemandedBits, const APInt &DemandedElts,
20197     TargetLoweringOpt &TLO) const {
20198   // Delay optimization, so we don't have to deal with illegal types, or block
20199   // optimizations.
20200   if (!TLO.LegalOps)
20201     return false;
20202 
20203   // Only optimize AND for now.
20204   if (Op.getOpcode() != ISD::AND)
20205     return false;
20206 
20207   EVT VT = Op.getValueType();
20208 
20209   // Ignore vectors.
20210   if (VT.isVector())
20211     return false;
20212 
20213   assert(VT == MVT::i32 && "Unexpected integer type");
20214 
20215   // Make sure the RHS really is a constant.
20216   ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
20217   if (!C)
20218     return false;
20219 
20220   unsigned Mask = C->getZExtValue();
20221 
20222   unsigned Demanded = DemandedBits.getZExtValue();
20223   unsigned ShrunkMask = Mask & Demanded;
20224   unsigned ExpandedMask = Mask | ~Demanded;
20225 
20226   // If the mask is all zeros, let the target-independent code replace the
20227   // result with zero.
20228   if (ShrunkMask == 0)
20229     return false;
20230 
20231   // If the mask is all ones, erase the AND. (Currently, the target-independent
20232   // code won't do this, so we have to do it explicitly to avoid an infinite
20233   // loop in obscure cases.)
20234   if (ExpandedMask == ~0U)
20235     return TLO.CombineTo(Op, Op.getOperand(0));
20236 
20237   auto IsLegalMask = [ShrunkMask, ExpandedMask](unsigned Mask) -> bool {
20238     return (ShrunkMask & Mask) == ShrunkMask && (~ExpandedMask & Mask) == 0;
20239   };
20240   auto UseMask = [Mask, Op, VT, &TLO](unsigned NewMask) -> bool {
20241     if (NewMask == Mask)
20242       return true;
20243     SDLoc DL(Op);
20244     SDValue NewC = TLO.DAG.getConstant(NewMask, DL, VT);
20245     SDValue NewOp = TLO.DAG.getNode(ISD::AND, DL, VT, Op.getOperand(0), NewC);
20246     return TLO.CombineTo(Op, NewOp);
20247   };
20248 
20249   // Prefer uxtb mask.
20250   if (IsLegalMask(0xFF))
20251     return UseMask(0xFF);
20252 
20253   // Prefer uxth mask.
20254   if (IsLegalMask(0xFFFF))
20255     return UseMask(0xFFFF);
20256 
20257   // [1, 255] is Thumb1 movs+ands, legal immediate for ARM/Thumb2.
20258   // FIXME: Prefer a contiguous sequence of bits for other optimizations.
20259   if (ShrunkMask < 256)
20260     return UseMask(ShrunkMask);
20261 
20262   // [-256, -2] is Thumb1 movs+bics, legal immediate for ARM/Thumb2.
20263   // FIXME: Prefer a contiguous sequence of bits for other optimizations.
20264   if ((int)ExpandedMask <= -2 && (int)ExpandedMask >= -256)
20265     return UseMask(ExpandedMask);
20266 
20267   // Potential improvements:
20268   //
20269   // We could try to recognize lsls+lsrs or lsrs+lsls pairs here.
20270   // We could try to prefer Thumb1 immediates which can be lowered to a
20271   // two-instruction sequence.
20272   // We could try to recognize more legal ARM/Thumb2 immediates here.
20273 
20274   return false;
20275 }
20276 
SimplifyDemandedBitsForTargetNode(SDValue Op,const APInt & OriginalDemandedBits,const APInt & OriginalDemandedElts,KnownBits & Known,TargetLoweringOpt & TLO,unsigned Depth) const20277 bool ARMTargetLowering::SimplifyDemandedBitsForTargetNode(
20278     SDValue Op, const APInt &OriginalDemandedBits,
20279     const APInt &OriginalDemandedElts, KnownBits &Known, TargetLoweringOpt &TLO,
20280     unsigned Depth) const {
20281   unsigned Opc = Op.getOpcode();
20282 
20283   switch (Opc) {
20284   case ARMISD::ASRL:
20285   case ARMISD::LSRL: {
20286     // If this is result 0 and the other result is unused, see if the demand
20287     // bits allow us to shrink this long shift into a standard small shift in
20288     // the opposite direction.
20289     if (Op.getResNo() == 0 && !Op->hasAnyUseOfValue(1) &&
20290         isa<ConstantSDNode>(Op->getOperand(2))) {
20291       unsigned ShAmt = Op->getConstantOperandVal(2);
20292       if (ShAmt < 32 && OriginalDemandedBits.isSubsetOf(APInt::getAllOnes(32)
20293                                                         << (32 - ShAmt)))
20294         return TLO.CombineTo(
20295             Op, TLO.DAG.getNode(
20296                     ISD::SHL, SDLoc(Op), MVT::i32, Op.getOperand(1),
20297                     TLO.DAG.getConstant(32 - ShAmt, SDLoc(Op), MVT::i32)));
20298     }
20299     break;
20300   }
20301   case ARMISD::VBICIMM: {
20302     SDValue Op0 = Op.getOperand(0);
20303     unsigned ModImm = Op.getConstantOperandVal(1);
20304     unsigned EltBits = 0;
20305     uint64_t Mask = ARM_AM::decodeVMOVModImm(ModImm, EltBits);
20306     if ((OriginalDemandedBits & Mask) == 0)
20307       return TLO.CombineTo(Op, Op0);
20308   }
20309   }
20310 
20311   return TargetLowering::SimplifyDemandedBitsForTargetNode(
20312       Op, OriginalDemandedBits, OriginalDemandedElts, Known, TLO, Depth);
20313 }
20314 
20315 //===----------------------------------------------------------------------===//
20316 //                           ARM Inline Assembly Support
20317 //===----------------------------------------------------------------------===//
20318 
ExpandInlineAsm(CallInst * CI) const20319 bool ARMTargetLowering::ExpandInlineAsm(CallInst *CI) const {
20320   // Looking for "rev" which is V6+.
20321   if (!Subtarget->hasV6Ops())
20322     return false;
20323 
20324   InlineAsm *IA = cast<InlineAsm>(CI->getCalledOperand());
20325   StringRef AsmStr = IA->getAsmString();
20326   SmallVector<StringRef, 4> AsmPieces;
20327   SplitString(AsmStr, AsmPieces, ";\n");
20328 
20329   switch (AsmPieces.size()) {
20330   default: return false;
20331   case 1:
20332     AsmStr = AsmPieces[0];
20333     AsmPieces.clear();
20334     SplitString(AsmStr, AsmPieces, " \t,");
20335 
20336     // rev $0, $1
20337     if (AsmPieces.size() == 3 &&
20338         AsmPieces[0] == "rev" && AsmPieces[1] == "$0" && AsmPieces[2] == "$1" &&
20339         IA->getConstraintString().compare(0, 4, "=l,l") == 0) {
20340       IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
20341       if (Ty && Ty->getBitWidth() == 32)
20342         return IntrinsicLowering::LowerToByteSwap(CI);
20343     }
20344     break;
20345   }
20346 
20347   return false;
20348 }
20349 
LowerXConstraint(EVT ConstraintVT) const20350 const char *ARMTargetLowering::LowerXConstraint(EVT ConstraintVT) const {
20351   // At this point, we have to lower this constraint to something else, so we
20352   // lower it to an "r" or "w". However, by doing this we will force the result
20353   // to be in register, while the X constraint is much more permissive.
20354   //
20355   // Although we are correct (we are free to emit anything, without
20356   // constraints), we might break use cases that would expect us to be more
20357   // efficient and emit something else.
20358   if (!Subtarget->hasVFP2Base())
20359     return "r";
20360   if (ConstraintVT.isFloatingPoint())
20361     return "w";
20362   if (ConstraintVT.isVector() && Subtarget->hasNEON() &&
20363      (ConstraintVT.getSizeInBits() == 64 ||
20364       ConstraintVT.getSizeInBits() == 128))
20365     return "w";
20366 
20367   return "r";
20368 }
20369 
20370 /// getConstraintType - Given a constraint letter, return the type of
20371 /// constraint it is for this target.
20372 ARMTargetLowering::ConstraintType
getConstraintType(StringRef Constraint) const20373 ARMTargetLowering::getConstraintType(StringRef Constraint) const {
20374   unsigned S = Constraint.size();
20375   if (S == 1) {
20376     switch (Constraint[0]) {
20377     default:  break;
20378     case 'l': return C_RegisterClass;
20379     case 'w': return C_RegisterClass;
20380     case 'h': return C_RegisterClass;
20381     case 'x': return C_RegisterClass;
20382     case 't': return C_RegisterClass;
20383     case 'j': return C_Immediate; // Constant for movw.
20384     // An address with a single base register. Due to the way we
20385     // currently handle addresses it is the same as an 'r' memory constraint.
20386     case 'Q': return C_Memory;
20387     }
20388   } else if (S == 2) {
20389     switch (Constraint[0]) {
20390     default: break;
20391     case 'T': return C_RegisterClass;
20392     // All 'U+' constraints are addresses.
20393     case 'U': return C_Memory;
20394     }
20395   }
20396   return TargetLowering::getConstraintType(Constraint);
20397 }
20398 
20399 /// Examine constraint type and operand type and determine a weight value.
20400 /// This object must already have been set up with the operand type
20401 /// and the current alternative constraint selected.
20402 TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo & info,const char * constraint) const20403 ARMTargetLowering::getSingleConstraintMatchWeight(
20404     AsmOperandInfo &info, const char *constraint) const {
20405   ConstraintWeight weight = CW_Invalid;
20406   Value *CallOperandVal = info.CallOperandVal;
20407     // If we don't have a value, we can't do a match,
20408     // but allow it at the lowest weight.
20409   if (!CallOperandVal)
20410     return CW_Default;
20411   Type *type = CallOperandVal->getType();
20412   // Look at the constraint type.
20413   switch (*constraint) {
20414   default:
20415     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
20416     break;
20417   case 'l':
20418     if (type->isIntegerTy()) {
20419       if (Subtarget->isThumb())
20420         weight = CW_SpecificReg;
20421       else
20422         weight = CW_Register;
20423     }
20424     break;
20425   case 'w':
20426     if (type->isFloatingPointTy())
20427       weight = CW_Register;
20428     break;
20429   }
20430   return weight;
20431 }
20432 
20433 using RCPair = std::pair<unsigned, const TargetRegisterClass *>;
20434 
getRegForInlineAsmConstraint(const TargetRegisterInfo * TRI,StringRef Constraint,MVT VT) const20435 RCPair ARMTargetLowering::getRegForInlineAsmConstraint(
20436     const TargetRegisterInfo *TRI, StringRef Constraint, MVT VT) const {
20437   switch (Constraint.size()) {
20438   case 1:
20439     // GCC ARM Constraint Letters
20440     switch (Constraint[0]) {
20441     case 'l': // Low regs or general regs.
20442       if (Subtarget->isThumb())
20443         return RCPair(0U, &ARM::tGPRRegClass);
20444       return RCPair(0U, &ARM::GPRRegClass);
20445     case 'h': // High regs or no regs.
20446       if (Subtarget->isThumb())
20447         return RCPair(0U, &ARM::hGPRRegClass);
20448       break;
20449     case 'r':
20450       if (Subtarget->isThumb1Only())
20451         return RCPair(0U, &ARM::tGPRRegClass);
20452       return RCPair(0U, &ARM::GPRRegClass);
20453     case 'w':
20454       if (VT == MVT::Other)
20455         break;
20456       if (VT == MVT::f32 || VT == MVT::f16 || VT == MVT::bf16)
20457         return RCPair(0U, &ARM::SPRRegClass);
20458       if (VT.getSizeInBits() == 64)
20459         return RCPair(0U, &ARM::DPRRegClass);
20460       if (VT.getSizeInBits() == 128)
20461         return RCPair(0U, &ARM::QPRRegClass);
20462       break;
20463     case 'x':
20464       if (VT == MVT::Other)
20465         break;
20466       if (VT == MVT::f32 || VT == MVT::f16 || VT == MVT::bf16)
20467         return RCPair(0U, &ARM::SPR_8RegClass);
20468       if (VT.getSizeInBits() == 64)
20469         return RCPair(0U, &ARM::DPR_8RegClass);
20470       if (VT.getSizeInBits() == 128)
20471         return RCPair(0U, &ARM::QPR_8RegClass);
20472       break;
20473     case 't':
20474       if (VT == MVT::Other)
20475         break;
20476       if (VT == MVT::f32 || VT == MVT::i32 || VT == MVT::f16 || VT == MVT::bf16)
20477         return RCPair(0U, &ARM::SPRRegClass);
20478       if (VT.getSizeInBits() == 64)
20479         return RCPair(0U, &ARM::DPR_VFP2RegClass);
20480       if (VT.getSizeInBits() == 128)
20481         return RCPair(0U, &ARM::QPR_VFP2RegClass);
20482       break;
20483     }
20484     break;
20485 
20486   case 2:
20487     if (Constraint[0] == 'T') {
20488       switch (Constraint[1]) {
20489       default:
20490         break;
20491       case 'e':
20492         return RCPair(0U, &ARM::tGPREvenRegClass);
20493       case 'o':
20494         return RCPair(0U, &ARM::tGPROddRegClass);
20495       }
20496     }
20497     break;
20498 
20499   default:
20500     break;
20501   }
20502 
20503   if (StringRef("{cc}").equals_insensitive(Constraint))
20504     return std::make_pair(unsigned(ARM::CPSR), &ARM::CCRRegClass);
20505 
20506   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
20507 }
20508 
20509 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
20510 /// vector.  If it is invalid, don't add anything to Ops.
LowerAsmOperandForConstraint(SDValue Op,StringRef Constraint,std::vector<SDValue> & Ops,SelectionDAG & DAG) const20511 void ARMTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
20512                                                      StringRef Constraint,
20513                                                      std::vector<SDValue> &Ops,
20514                                                      SelectionDAG &DAG) const {
20515   SDValue Result;
20516 
20517   // Currently only support length 1 constraints.
20518   if (Constraint.size() != 1)
20519     return;
20520 
20521   char ConstraintLetter = Constraint[0];
20522   switch (ConstraintLetter) {
20523   default: break;
20524   case 'j':
20525   case 'I': case 'J': case 'K': case 'L':
20526   case 'M': case 'N': case 'O':
20527     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
20528     if (!C)
20529       return;
20530 
20531     int64_t CVal64 = C->getSExtValue();
20532     int CVal = (int) CVal64;
20533     // None of these constraints allow values larger than 32 bits.  Check
20534     // that the value fits in an int.
20535     if (CVal != CVal64)
20536       return;
20537 
20538     switch (ConstraintLetter) {
20539       case 'j':
20540         // Constant suitable for movw, must be between 0 and
20541         // 65535.
20542         if (Subtarget->hasV6T2Ops() || (Subtarget->hasV8MBaselineOps()))
20543           if (CVal >= 0 && CVal <= 65535)
20544             break;
20545         return;
20546       case 'I':
20547         if (Subtarget->isThumb1Only()) {
20548           // This must be a constant between 0 and 255, for ADD
20549           // immediates.
20550           if (CVal >= 0 && CVal <= 255)
20551             break;
20552         } else if (Subtarget->isThumb2()) {
20553           // A constant that can be used as an immediate value in a
20554           // data-processing instruction.
20555           if (ARM_AM::getT2SOImmVal(CVal) != -1)
20556             break;
20557         } else {
20558           // A constant that can be used as an immediate value in a
20559           // data-processing instruction.
20560           if (ARM_AM::getSOImmVal(CVal) != -1)
20561             break;
20562         }
20563         return;
20564 
20565       case 'J':
20566         if (Subtarget->isThumb1Only()) {
20567           // This must be a constant between -255 and -1, for negated ADD
20568           // immediates. This can be used in GCC with an "n" modifier that
20569           // prints the negated value, for use with SUB instructions. It is
20570           // not useful otherwise but is implemented for compatibility.
20571           if (CVal >= -255 && CVal <= -1)
20572             break;
20573         } else {
20574           // This must be a constant between -4095 and 4095. It is not clear
20575           // what this constraint is intended for. Implemented for
20576           // compatibility with GCC.
20577           if (CVal >= -4095 && CVal <= 4095)
20578             break;
20579         }
20580         return;
20581 
20582       case 'K':
20583         if (Subtarget->isThumb1Only()) {
20584           // A 32-bit value where only one byte has a nonzero value. Exclude
20585           // zero to match GCC. This constraint is used by GCC internally for
20586           // constants that can be loaded with a move/shift combination.
20587           // It is not useful otherwise but is implemented for compatibility.
20588           if (CVal != 0 && ARM_AM::isThumbImmShiftedVal(CVal))
20589             break;
20590         } else if (Subtarget->isThumb2()) {
20591           // A constant whose bitwise inverse can be used as an immediate
20592           // value in a data-processing instruction. This can be used in GCC
20593           // with a "B" modifier that prints the inverted value, for use with
20594           // BIC and MVN instructions. It is not useful otherwise but is
20595           // implemented for compatibility.
20596           if (ARM_AM::getT2SOImmVal(~CVal) != -1)
20597             break;
20598         } else {
20599           // A constant whose bitwise inverse can be used as an immediate
20600           // value in a data-processing instruction. This can be used in GCC
20601           // with a "B" modifier that prints the inverted value, for use with
20602           // BIC and MVN instructions. It is not useful otherwise but is
20603           // implemented for compatibility.
20604           if (ARM_AM::getSOImmVal(~CVal) != -1)
20605             break;
20606         }
20607         return;
20608 
20609       case 'L':
20610         if (Subtarget->isThumb1Only()) {
20611           // This must be a constant between -7 and 7,
20612           // for 3-operand ADD/SUB immediate instructions.
20613           if (CVal >= -7 && CVal < 7)
20614             break;
20615         } else if (Subtarget->isThumb2()) {
20616           // A constant whose negation can be used as an immediate value in a
20617           // data-processing instruction. This can be used in GCC with an "n"
20618           // modifier that prints the negated value, for use with SUB
20619           // instructions. It is not useful otherwise but is implemented for
20620           // compatibility.
20621           if (ARM_AM::getT2SOImmVal(-CVal) != -1)
20622             break;
20623         } else {
20624           // A constant whose negation can be used as an immediate value in a
20625           // data-processing instruction. This can be used in GCC with an "n"
20626           // modifier that prints the negated value, for use with SUB
20627           // instructions. It is not useful otherwise but is implemented for
20628           // compatibility.
20629           if (ARM_AM::getSOImmVal(-CVal) != -1)
20630             break;
20631         }
20632         return;
20633 
20634       case 'M':
20635         if (Subtarget->isThumb1Only()) {
20636           // This must be a multiple of 4 between 0 and 1020, for
20637           // ADD sp + immediate.
20638           if ((CVal >= 0 && CVal <= 1020) && ((CVal & 3) == 0))
20639             break;
20640         } else {
20641           // A power of two or a constant between 0 and 32.  This is used in
20642           // GCC for the shift amount on shifted register operands, but it is
20643           // useful in general for any shift amounts.
20644           if ((CVal >= 0 && CVal <= 32) || ((CVal & (CVal - 1)) == 0))
20645             break;
20646         }
20647         return;
20648 
20649       case 'N':
20650         if (Subtarget->isThumb1Only()) {
20651           // This must be a constant between 0 and 31, for shift amounts.
20652           if (CVal >= 0 && CVal <= 31)
20653             break;
20654         }
20655         return;
20656 
20657       case 'O':
20658         if (Subtarget->isThumb1Only()) {
20659           // This must be a multiple of 4 between -508 and 508, for
20660           // ADD/SUB sp = sp + immediate.
20661           if ((CVal >= -508 && CVal <= 508) && ((CVal & 3) == 0))
20662             break;
20663         }
20664         return;
20665     }
20666     Result = DAG.getTargetConstant(CVal, SDLoc(Op), Op.getValueType());
20667     break;
20668   }
20669 
20670   if (Result.getNode()) {
20671     Ops.push_back(Result);
20672     return;
20673   }
20674   return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
20675 }
20676 
getDivRemLibcall(const SDNode * N,MVT::SimpleValueType SVT)20677 static RTLIB::Libcall getDivRemLibcall(
20678     const SDNode *N, MVT::SimpleValueType SVT) {
20679   assert((N->getOpcode() == ISD::SDIVREM || N->getOpcode() == ISD::UDIVREM ||
20680           N->getOpcode() == ISD::SREM    || N->getOpcode() == ISD::UREM) &&
20681          "Unhandled Opcode in getDivRemLibcall");
20682   bool isSigned = N->getOpcode() == ISD::SDIVREM ||
20683                   N->getOpcode() == ISD::SREM;
20684   RTLIB::Libcall LC;
20685   switch (SVT) {
20686   default: llvm_unreachable("Unexpected request for libcall!");
20687   case MVT::i8:  LC = isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
20688   case MVT::i16: LC = isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
20689   case MVT::i32: LC = isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
20690   case MVT::i64: LC = isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
20691   }
20692   return LC;
20693 }
20694 
getDivRemArgList(const SDNode * N,LLVMContext * Context,const ARMSubtarget * Subtarget)20695 static TargetLowering::ArgListTy getDivRemArgList(
20696     const SDNode *N, LLVMContext *Context, const ARMSubtarget *Subtarget) {
20697   assert((N->getOpcode() == ISD::SDIVREM || N->getOpcode() == ISD::UDIVREM ||
20698           N->getOpcode() == ISD::SREM    || N->getOpcode() == ISD::UREM) &&
20699          "Unhandled Opcode in getDivRemArgList");
20700   bool isSigned = N->getOpcode() == ISD::SDIVREM ||
20701                   N->getOpcode() == ISD::SREM;
20702   TargetLowering::ArgListTy Args;
20703   TargetLowering::ArgListEntry Entry;
20704   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
20705     EVT ArgVT = N->getOperand(i).getValueType();
20706     Type *ArgTy = ArgVT.getTypeForEVT(*Context);
20707     Entry.Node = N->getOperand(i);
20708     Entry.Ty = ArgTy;
20709     Entry.IsSExt = isSigned;
20710     Entry.IsZExt = !isSigned;
20711     Args.push_back(Entry);
20712   }
20713   if (Subtarget->isTargetWindows() && Args.size() >= 2)
20714     std::swap(Args[0], Args[1]);
20715   return Args;
20716 }
20717 
LowerDivRem(SDValue Op,SelectionDAG & DAG) const20718 SDValue ARMTargetLowering::LowerDivRem(SDValue Op, SelectionDAG &DAG) const {
20719   assert((Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid() ||
20720           Subtarget->isTargetGNUAEABI() || Subtarget->isTargetMuslAEABI() ||
20721           Subtarget->isTargetWindows()) &&
20722          "Register-based DivRem lowering only");
20723   unsigned Opcode = Op->getOpcode();
20724   assert((Opcode == ISD::SDIVREM || Opcode == ISD::UDIVREM) &&
20725          "Invalid opcode for Div/Rem lowering");
20726   bool isSigned = (Opcode == ISD::SDIVREM);
20727   EVT VT = Op->getValueType(0);
20728   SDLoc dl(Op);
20729 
20730   if (VT == MVT::i64 && isa<ConstantSDNode>(Op.getOperand(1))) {
20731     SmallVector<SDValue> Result;
20732     if (expandDIVREMByConstant(Op.getNode(), Result, MVT::i32, DAG)) {
20733         SDValue Res0 =
20734             DAG.getNode(ISD::BUILD_PAIR, dl, VT, Result[0], Result[1]);
20735         SDValue Res1 =
20736             DAG.getNode(ISD::BUILD_PAIR, dl, VT, Result[2], Result[3]);
20737         return DAG.getNode(ISD::MERGE_VALUES, dl, Op->getVTList(),
20738                            {Res0, Res1});
20739     }
20740   }
20741 
20742   Type *Ty = VT.getTypeForEVT(*DAG.getContext());
20743 
20744   // If the target has hardware divide, use divide + multiply + subtract:
20745   //     div = a / b
20746   //     rem = a - b * div
20747   //     return {div, rem}
20748   // This should be lowered into UDIV/SDIV + MLS later on.
20749   bool hasDivide = Subtarget->isThumb() ? Subtarget->hasDivideInThumbMode()
20750                                         : Subtarget->hasDivideInARMMode();
20751   if (hasDivide && Op->getValueType(0).isSimple() &&
20752       Op->getSimpleValueType(0) == MVT::i32) {
20753     unsigned DivOpcode = isSigned ? ISD::SDIV : ISD::UDIV;
20754     const SDValue Dividend = Op->getOperand(0);
20755     const SDValue Divisor = Op->getOperand(1);
20756     SDValue Div = DAG.getNode(DivOpcode, dl, VT, Dividend, Divisor);
20757     SDValue Mul = DAG.getNode(ISD::MUL, dl, VT, Div, Divisor);
20758     SDValue Rem = DAG.getNode(ISD::SUB, dl, VT, Dividend, Mul);
20759 
20760     SDValue Values[2] = {Div, Rem};
20761     return DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(VT, VT), Values);
20762   }
20763 
20764   RTLIB::Libcall LC = getDivRemLibcall(Op.getNode(),
20765                                        VT.getSimpleVT().SimpleTy);
20766   SDValue InChain = DAG.getEntryNode();
20767 
20768   TargetLowering::ArgListTy Args = getDivRemArgList(Op.getNode(),
20769                                                     DAG.getContext(),
20770                                                     Subtarget);
20771 
20772   SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC),
20773                                          getPointerTy(DAG.getDataLayout()));
20774 
20775   Type *RetTy = StructType::get(Ty, Ty);
20776 
20777   if (Subtarget->isTargetWindows())
20778     InChain = WinDBZCheckDenominator(DAG, Op.getNode(), InChain);
20779 
20780   TargetLowering::CallLoweringInfo CLI(DAG);
20781   CLI.setDebugLoc(dl).setChain(InChain)
20782     .setCallee(getLibcallCallingConv(LC), RetTy, Callee, std::move(Args))
20783     .setInRegister().setSExtResult(isSigned).setZExtResult(!isSigned);
20784 
20785   std::pair<SDValue, SDValue> CallInfo = LowerCallTo(CLI);
20786   return CallInfo.first;
20787 }
20788 
20789 // Lowers REM using divmod helpers
20790 // see RTABI section 4.2/4.3
LowerREM(SDNode * N,SelectionDAG & DAG) const20791 SDValue ARMTargetLowering::LowerREM(SDNode *N, SelectionDAG &DAG) const {
20792   EVT VT = N->getValueType(0);
20793 
20794   if (VT == MVT::i64 && isa<ConstantSDNode>(N->getOperand(1))) {
20795     SmallVector<SDValue> Result;
20796     if (expandDIVREMByConstant(N, Result, MVT::i32, DAG))
20797         return DAG.getNode(ISD::BUILD_PAIR, SDLoc(N), N->getValueType(0),
20798                            Result[0], Result[1]);
20799   }
20800 
20801   // Build return types (div and rem)
20802   std::vector<Type*> RetTyParams;
20803   Type *RetTyElement;
20804 
20805   switch (VT.getSimpleVT().SimpleTy) {
20806   default: llvm_unreachable("Unexpected request for libcall!");
20807   case MVT::i8:   RetTyElement = Type::getInt8Ty(*DAG.getContext());  break;
20808   case MVT::i16:  RetTyElement = Type::getInt16Ty(*DAG.getContext()); break;
20809   case MVT::i32:  RetTyElement = Type::getInt32Ty(*DAG.getContext()); break;
20810   case MVT::i64:  RetTyElement = Type::getInt64Ty(*DAG.getContext()); break;
20811   }
20812 
20813   RetTyParams.push_back(RetTyElement);
20814   RetTyParams.push_back(RetTyElement);
20815   ArrayRef<Type*> ret = ArrayRef<Type*>(RetTyParams);
20816   Type *RetTy = StructType::get(*DAG.getContext(), ret);
20817 
20818   RTLIB::Libcall LC = getDivRemLibcall(N, N->getValueType(0).getSimpleVT().
20819                                                              SimpleTy);
20820   SDValue InChain = DAG.getEntryNode();
20821   TargetLowering::ArgListTy Args = getDivRemArgList(N, DAG.getContext(),
20822                                                     Subtarget);
20823   bool isSigned = N->getOpcode() == ISD::SREM;
20824   SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC),
20825                                          getPointerTy(DAG.getDataLayout()));
20826 
20827   if (Subtarget->isTargetWindows())
20828     InChain = WinDBZCheckDenominator(DAG, N, InChain);
20829 
20830   // Lower call
20831   CallLoweringInfo CLI(DAG);
20832   CLI.setChain(InChain)
20833      .setCallee(CallingConv::ARM_AAPCS, RetTy, Callee, std::move(Args))
20834      .setSExtResult(isSigned).setZExtResult(!isSigned).setDebugLoc(SDLoc(N));
20835   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
20836 
20837   // Return second (rem) result operand (first contains div)
20838   SDNode *ResNode = CallResult.first.getNode();
20839   assert(ResNode->getNumOperands() == 2 && "divmod should return two operands");
20840   return ResNode->getOperand(1);
20841 }
20842 
20843 SDValue
LowerDYNAMIC_STACKALLOC(SDValue Op,SelectionDAG & DAG) const20844 ARMTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
20845   assert(Subtarget->isTargetWindows() && "unsupported target platform");
20846   SDLoc DL(Op);
20847 
20848   // Get the inputs.
20849   SDValue Chain = Op.getOperand(0);
20850   SDValue Size  = Op.getOperand(1);
20851 
20852   if (DAG.getMachineFunction().getFunction().hasFnAttribute(
20853           "no-stack-arg-probe")) {
20854     MaybeAlign Align =
20855         cast<ConstantSDNode>(Op.getOperand(2))->getMaybeAlignValue();
20856     SDValue SP = DAG.getCopyFromReg(Chain, DL, ARM::SP, MVT::i32);
20857     Chain = SP.getValue(1);
20858     SP = DAG.getNode(ISD::SUB, DL, MVT::i32, SP, Size);
20859     if (Align)
20860       SP =
20861           DAG.getNode(ISD::AND, DL, MVT::i32, SP.getValue(0),
20862                       DAG.getConstant(-(uint64_t)Align->value(), DL, MVT::i32));
20863     Chain = DAG.getCopyToReg(Chain, DL, ARM::SP, SP);
20864     SDValue Ops[2] = { SP, Chain };
20865     return DAG.getMergeValues(Ops, DL);
20866   }
20867 
20868   SDValue Words = DAG.getNode(ISD::SRL, DL, MVT::i32, Size,
20869                               DAG.getConstant(2, DL, MVT::i32));
20870 
20871   SDValue Glue;
20872   Chain = DAG.getCopyToReg(Chain, DL, ARM::R4, Words, Glue);
20873   Glue = Chain.getValue(1);
20874 
20875   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
20876   Chain = DAG.getNode(ARMISD::WIN__CHKSTK, DL, NodeTys, Chain, Glue);
20877 
20878   SDValue NewSP = DAG.getCopyFromReg(Chain, DL, ARM::SP, MVT::i32);
20879   Chain = NewSP.getValue(1);
20880 
20881   SDValue Ops[2] = { NewSP, Chain };
20882   return DAG.getMergeValues(Ops, DL);
20883 }
20884 
LowerFP_EXTEND(SDValue Op,SelectionDAG & DAG) const20885 SDValue ARMTargetLowering::LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const {
20886   bool IsStrict = Op->isStrictFPOpcode();
20887   SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
20888   const unsigned DstSz = Op.getValueType().getSizeInBits();
20889   const unsigned SrcSz = SrcVal.getValueType().getSizeInBits();
20890   assert(DstSz > SrcSz && DstSz <= 64 && SrcSz >= 16 &&
20891          "Unexpected type for custom-lowering FP_EXTEND");
20892 
20893   assert((!Subtarget->hasFP64() || !Subtarget->hasFPARMv8Base()) &&
20894          "With both FP DP and 16, any FP conversion is legal!");
20895 
20896   assert(!(DstSz == 32 && Subtarget->hasFP16()) &&
20897          "With FP16, 16 to 32 conversion is legal!");
20898 
20899   // Converting from 32 -> 64 is valid if we have FP64.
20900   if (SrcSz == 32 && DstSz == 64 && Subtarget->hasFP64()) {
20901     // FIXME: Remove this when we have strict fp instruction selection patterns
20902     if (IsStrict) {
20903       SDLoc Loc(Op);
20904       SDValue Result = DAG.getNode(ISD::FP_EXTEND,
20905                                    Loc, Op.getValueType(), SrcVal);
20906       return DAG.getMergeValues({Result, Op.getOperand(0)}, Loc);
20907     }
20908     return Op;
20909   }
20910 
20911   // Either we are converting from 16 -> 64, without FP16 and/or
20912   // FP.double-precision or without Armv8-fp. So we must do it in two
20913   // steps.
20914   // Or we are converting from 32 -> 64 without fp.double-precision or 16 -> 32
20915   // without FP16. So we must do a function call.
20916   SDLoc Loc(Op);
20917   RTLIB::Libcall LC;
20918   MakeLibCallOptions CallOptions;
20919   SDValue Chain = IsStrict ? Op.getOperand(0) : SDValue();
20920   for (unsigned Sz = SrcSz; Sz <= 32 && Sz < DstSz; Sz *= 2) {
20921     bool Supported = (Sz == 16 ? Subtarget->hasFP16() : Subtarget->hasFP64());
20922     MVT SrcVT = (Sz == 16 ? MVT::f16 : MVT::f32);
20923     MVT DstVT = (Sz == 16 ? MVT::f32 : MVT::f64);
20924     if (Supported) {
20925       if (IsStrict) {
20926         SrcVal = DAG.getNode(ISD::STRICT_FP_EXTEND, Loc,
20927                              {DstVT, MVT::Other}, {Chain, SrcVal});
20928         Chain = SrcVal.getValue(1);
20929       } else {
20930         SrcVal = DAG.getNode(ISD::FP_EXTEND, Loc, DstVT, SrcVal);
20931       }
20932     } else {
20933       LC = RTLIB::getFPEXT(SrcVT, DstVT);
20934       assert(LC != RTLIB::UNKNOWN_LIBCALL &&
20935              "Unexpected type for custom-lowering FP_EXTEND");
20936       std::tie(SrcVal, Chain) = makeLibCall(DAG, LC, DstVT, SrcVal, CallOptions,
20937                                             Loc, Chain);
20938     }
20939   }
20940 
20941   return IsStrict ? DAG.getMergeValues({SrcVal, Chain}, Loc) : SrcVal;
20942 }
20943 
LowerFP_ROUND(SDValue Op,SelectionDAG & DAG) const20944 SDValue ARMTargetLowering::LowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const {
20945   bool IsStrict = Op->isStrictFPOpcode();
20946 
20947   SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
20948   EVT SrcVT = SrcVal.getValueType();
20949   EVT DstVT = Op.getValueType();
20950   const unsigned DstSz = Op.getValueType().getSizeInBits();
20951   const unsigned SrcSz = SrcVT.getSizeInBits();
20952   (void)DstSz;
20953   assert(DstSz < SrcSz && SrcSz <= 64 && DstSz >= 16 &&
20954          "Unexpected type for custom-lowering FP_ROUND");
20955 
20956   assert((!Subtarget->hasFP64() || !Subtarget->hasFPARMv8Base()) &&
20957          "With both FP DP and 16, any FP conversion is legal!");
20958 
20959   SDLoc Loc(Op);
20960 
20961   // Instruction from 32 -> 16 if hasFP16 is valid
20962   if (SrcSz == 32 && Subtarget->hasFP16())
20963     return Op;
20964 
20965   // Lib call from 32 -> 16 / 64 -> [32, 16]
20966   RTLIB::Libcall LC = RTLIB::getFPROUND(SrcVT, DstVT);
20967   assert(LC != RTLIB::UNKNOWN_LIBCALL &&
20968          "Unexpected type for custom-lowering FP_ROUND");
20969   MakeLibCallOptions CallOptions;
20970   SDValue Chain = IsStrict ? Op.getOperand(0) : SDValue();
20971   SDValue Result;
20972   std::tie(Result, Chain) = makeLibCall(DAG, LC, DstVT, SrcVal, CallOptions,
20973                                         Loc, Chain);
20974   return IsStrict ? DAG.getMergeValues({Result, Chain}, Loc) : Result;
20975 }
20976 
20977 bool
isOffsetFoldingLegal(const GlobalAddressSDNode * GA) const20978 ARMTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
20979   // The ARM target isn't yet aware of offsets.
20980   return false;
20981 }
20982 
isBitFieldInvertedMask(unsigned v)20983 bool ARM::isBitFieldInvertedMask(unsigned v) {
20984   if (v == 0xffffffff)
20985     return false;
20986 
20987   // there can be 1's on either or both "outsides", all the "inside"
20988   // bits must be 0's
20989   return isShiftedMask_32(~v);
20990 }
20991 
20992 /// isFPImmLegal - Returns true if the target can instruction select the
20993 /// specified FP immediate natively. If false, the legalizer will
20994 /// materialize the FP immediate as a load from a constant pool.
isFPImmLegal(const APFloat & Imm,EVT VT,bool ForCodeSize) const20995 bool ARMTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
20996                                      bool ForCodeSize) const {
20997   if (!Subtarget->hasVFP3Base())
20998     return false;
20999   if (VT == MVT::f16 && Subtarget->hasFullFP16())
21000     return ARM_AM::getFP16Imm(Imm) != -1;
21001   if (VT == MVT::f32 && Subtarget->hasFullFP16() &&
21002       ARM_AM::getFP32FP16Imm(Imm) != -1)
21003     return true;
21004   if (VT == MVT::f32)
21005     return ARM_AM::getFP32Imm(Imm) != -1;
21006   if (VT == MVT::f64 && Subtarget->hasFP64())
21007     return ARM_AM::getFP64Imm(Imm) != -1;
21008   return false;
21009 }
21010 
21011 /// getTgtMemIntrinsic - Represent NEON load and store intrinsics as
21012 /// MemIntrinsicNodes.  The associated MachineMemOperands record the alignment
21013 /// specified in the intrinsic calls.
getTgtMemIntrinsic(IntrinsicInfo & Info,const CallInst & I,MachineFunction & MF,unsigned Intrinsic) const21014 bool ARMTargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
21015                                            const CallInst &I,
21016                                            MachineFunction &MF,
21017                                            unsigned Intrinsic) const {
21018   switch (Intrinsic) {
21019   case Intrinsic::arm_neon_vld1:
21020   case Intrinsic::arm_neon_vld2:
21021   case Intrinsic::arm_neon_vld3:
21022   case Intrinsic::arm_neon_vld4:
21023   case Intrinsic::arm_neon_vld2lane:
21024   case Intrinsic::arm_neon_vld3lane:
21025   case Intrinsic::arm_neon_vld4lane:
21026   case Intrinsic::arm_neon_vld2dup:
21027   case Intrinsic::arm_neon_vld3dup:
21028   case Intrinsic::arm_neon_vld4dup: {
21029     Info.opc = ISD::INTRINSIC_W_CHAIN;
21030     // Conservatively set memVT to the entire set of vectors loaded.
21031     auto &DL = I.getDataLayout();
21032     uint64_t NumElts = DL.getTypeSizeInBits(I.getType()) / 64;
21033     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
21034     Info.ptrVal = I.getArgOperand(0);
21035     Info.offset = 0;
21036     Value *AlignArg = I.getArgOperand(I.arg_size() - 1);
21037     Info.align = cast<ConstantInt>(AlignArg)->getMaybeAlignValue();
21038     // volatile loads with NEON intrinsics not supported
21039     Info.flags = MachineMemOperand::MOLoad;
21040     return true;
21041   }
21042   case Intrinsic::arm_neon_vld1x2:
21043   case Intrinsic::arm_neon_vld1x3:
21044   case Intrinsic::arm_neon_vld1x4: {
21045     Info.opc = ISD::INTRINSIC_W_CHAIN;
21046     // Conservatively set memVT to the entire set of vectors loaded.
21047     auto &DL = I.getDataLayout();
21048     uint64_t NumElts = DL.getTypeSizeInBits(I.getType()) / 64;
21049     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
21050     Info.ptrVal = I.getArgOperand(I.arg_size() - 1);
21051     Info.offset = 0;
21052     Info.align.reset();
21053     // volatile loads with NEON intrinsics not supported
21054     Info.flags = MachineMemOperand::MOLoad;
21055     return true;
21056   }
21057   case Intrinsic::arm_neon_vst1:
21058   case Intrinsic::arm_neon_vst2:
21059   case Intrinsic::arm_neon_vst3:
21060   case Intrinsic::arm_neon_vst4:
21061   case Intrinsic::arm_neon_vst2lane:
21062   case Intrinsic::arm_neon_vst3lane:
21063   case Intrinsic::arm_neon_vst4lane: {
21064     Info.opc = ISD::INTRINSIC_VOID;
21065     // Conservatively set memVT to the entire set of vectors stored.
21066     auto &DL = I.getDataLayout();
21067     unsigned NumElts = 0;
21068     for (unsigned ArgI = 1, ArgE = I.arg_size(); ArgI < ArgE; ++ArgI) {
21069       Type *ArgTy = I.getArgOperand(ArgI)->getType();
21070       if (!ArgTy->isVectorTy())
21071         break;
21072       NumElts += DL.getTypeSizeInBits(ArgTy) / 64;
21073     }
21074     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
21075     Info.ptrVal = I.getArgOperand(0);
21076     Info.offset = 0;
21077     Value *AlignArg = I.getArgOperand(I.arg_size() - 1);
21078     Info.align = cast<ConstantInt>(AlignArg)->getMaybeAlignValue();
21079     // volatile stores with NEON intrinsics not supported
21080     Info.flags = MachineMemOperand::MOStore;
21081     return true;
21082   }
21083   case Intrinsic::arm_neon_vst1x2:
21084   case Intrinsic::arm_neon_vst1x3:
21085   case Intrinsic::arm_neon_vst1x4: {
21086     Info.opc = ISD::INTRINSIC_VOID;
21087     // Conservatively set memVT to the entire set of vectors stored.
21088     auto &DL = I.getDataLayout();
21089     unsigned NumElts = 0;
21090     for (unsigned ArgI = 1, ArgE = I.arg_size(); ArgI < ArgE; ++ArgI) {
21091       Type *ArgTy = I.getArgOperand(ArgI)->getType();
21092       if (!ArgTy->isVectorTy())
21093         break;
21094       NumElts += DL.getTypeSizeInBits(ArgTy) / 64;
21095     }
21096     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
21097     Info.ptrVal = I.getArgOperand(0);
21098     Info.offset = 0;
21099     Info.align.reset();
21100     // volatile stores with NEON intrinsics not supported
21101     Info.flags = MachineMemOperand::MOStore;
21102     return true;
21103   }
21104   case Intrinsic::arm_mve_vld2q:
21105   case Intrinsic::arm_mve_vld4q: {
21106     Info.opc = ISD::INTRINSIC_W_CHAIN;
21107     // Conservatively set memVT to the entire set of vectors loaded.
21108     Type *VecTy = cast<StructType>(I.getType())->getElementType(1);
21109     unsigned Factor = Intrinsic == Intrinsic::arm_mve_vld2q ? 2 : 4;
21110     Info.memVT = EVT::getVectorVT(VecTy->getContext(), MVT::i64, Factor * 2);
21111     Info.ptrVal = I.getArgOperand(0);
21112     Info.offset = 0;
21113     Info.align = Align(VecTy->getScalarSizeInBits() / 8);
21114     // volatile loads with MVE intrinsics not supported
21115     Info.flags = MachineMemOperand::MOLoad;
21116     return true;
21117   }
21118   case Intrinsic::arm_mve_vst2q:
21119   case Intrinsic::arm_mve_vst4q: {
21120     Info.opc = ISD::INTRINSIC_VOID;
21121     // Conservatively set memVT to the entire set of vectors stored.
21122     Type *VecTy = I.getArgOperand(1)->getType();
21123     unsigned Factor = Intrinsic == Intrinsic::arm_mve_vst2q ? 2 : 4;
21124     Info.memVT = EVT::getVectorVT(VecTy->getContext(), MVT::i64, Factor * 2);
21125     Info.ptrVal = I.getArgOperand(0);
21126     Info.offset = 0;
21127     Info.align = Align(VecTy->getScalarSizeInBits() / 8);
21128     // volatile stores with MVE intrinsics not supported
21129     Info.flags = MachineMemOperand::MOStore;
21130     return true;
21131   }
21132   case Intrinsic::arm_mve_vldr_gather_base:
21133   case Intrinsic::arm_mve_vldr_gather_base_predicated: {
21134     Info.opc = ISD::INTRINSIC_W_CHAIN;
21135     Info.ptrVal = nullptr;
21136     Info.memVT = MVT::getVT(I.getType());
21137     Info.align = Align(1);
21138     Info.flags |= MachineMemOperand::MOLoad;
21139     return true;
21140   }
21141   case Intrinsic::arm_mve_vldr_gather_base_wb:
21142   case Intrinsic::arm_mve_vldr_gather_base_wb_predicated: {
21143     Info.opc = ISD::INTRINSIC_W_CHAIN;
21144     Info.ptrVal = nullptr;
21145     Info.memVT = MVT::getVT(I.getType()->getContainedType(0));
21146     Info.align = Align(1);
21147     Info.flags |= MachineMemOperand::MOLoad;
21148     return true;
21149   }
21150   case Intrinsic::arm_mve_vldr_gather_offset:
21151   case Intrinsic::arm_mve_vldr_gather_offset_predicated: {
21152     Info.opc = ISD::INTRINSIC_W_CHAIN;
21153     Info.ptrVal = nullptr;
21154     MVT DataVT = MVT::getVT(I.getType());
21155     unsigned MemSize = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue();
21156     Info.memVT = MVT::getVectorVT(MVT::getIntegerVT(MemSize),
21157                                   DataVT.getVectorNumElements());
21158     Info.align = Align(1);
21159     Info.flags |= MachineMemOperand::MOLoad;
21160     return true;
21161   }
21162   case Intrinsic::arm_mve_vstr_scatter_base:
21163   case Intrinsic::arm_mve_vstr_scatter_base_predicated: {
21164     Info.opc = ISD::INTRINSIC_VOID;
21165     Info.ptrVal = nullptr;
21166     Info.memVT = MVT::getVT(I.getArgOperand(2)->getType());
21167     Info.align = Align(1);
21168     Info.flags |= MachineMemOperand::MOStore;
21169     return true;
21170   }
21171   case Intrinsic::arm_mve_vstr_scatter_base_wb:
21172   case Intrinsic::arm_mve_vstr_scatter_base_wb_predicated: {
21173     Info.opc = ISD::INTRINSIC_W_CHAIN;
21174     Info.ptrVal = nullptr;
21175     Info.memVT = MVT::getVT(I.getArgOperand(2)->getType());
21176     Info.align = Align(1);
21177     Info.flags |= MachineMemOperand::MOStore;
21178     return true;
21179   }
21180   case Intrinsic::arm_mve_vstr_scatter_offset:
21181   case Intrinsic::arm_mve_vstr_scatter_offset_predicated: {
21182     Info.opc = ISD::INTRINSIC_VOID;
21183     Info.ptrVal = nullptr;
21184     MVT DataVT = MVT::getVT(I.getArgOperand(2)->getType());
21185     unsigned MemSize = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
21186     Info.memVT = MVT::getVectorVT(MVT::getIntegerVT(MemSize),
21187                                   DataVT.getVectorNumElements());
21188     Info.align = Align(1);
21189     Info.flags |= MachineMemOperand::MOStore;
21190     return true;
21191   }
21192   case Intrinsic::arm_ldaex:
21193   case Intrinsic::arm_ldrex: {
21194     auto &DL = I.getDataLayout();
21195     Type *ValTy = I.getParamElementType(0);
21196     Info.opc = ISD::INTRINSIC_W_CHAIN;
21197     Info.memVT = MVT::getVT(ValTy);
21198     Info.ptrVal = I.getArgOperand(0);
21199     Info.offset = 0;
21200     Info.align = DL.getABITypeAlign(ValTy);
21201     Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MOVolatile;
21202     return true;
21203   }
21204   case Intrinsic::arm_stlex:
21205   case Intrinsic::arm_strex: {
21206     auto &DL = I.getDataLayout();
21207     Type *ValTy = I.getParamElementType(1);
21208     Info.opc = ISD::INTRINSIC_W_CHAIN;
21209     Info.memVT = MVT::getVT(ValTy);
21210     Info.ptrVal = I.getArgOperand(1);
21211     Info.offset = 0;
21212     Info.align = DL.getABITypeAlign(ValTy);
21213     Info.flags = MachineMemOperand::MOStore | MachineMemOperand::MOVolatile;
21214     return true;
21215   }
21216   case Intrinsic::arm_stlexd:
21217   case Intrinsic::arm_strexd:
21218     Info.opc = ISD::INTRINSIC_W_CHAIN;
21219     Info.memVT = MVT::i64;
21220     Info.ptrVal = I.getArgOperand(2);
21221     Info.offset = 0;
21222     Info.align = Align(8);
21223     Info.flags = MachineMemOperand::MOStore | MachineMemOperand::MOVolatile;
21224     return true;
21225 
21226   case Intrinsic::arm_ldaexd:
21227   case Intrinsic::arm_ldrexd:
21228     Info.opc = ISD::INTRINSIC_W_CHAIN;
21229     Info.memVT = MVT::i64;
21230     Info.ptrVal = I.getArgOperand(0);
21231     Info.offset = 0;
21232     Info.align = Align(8);
21233     Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MOVolatile;
21234     return true;
21235 
21236   default:
21237     break;
21238   }
21239 
21240   return false;
21241 }
21242 
21243 /// Returns true if it is beneficial to convert a load of a constant
21244 /// to just the constant itself.
shouldConvertConstantLoadToIntImm(const APInt & Imm,Type * Ty) const21245 bool ARMTargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
21246                                                           Type *Ty) const {
21247   assert(Ty->isIntegerTy());
21248 
21249   unsigned Bits = Ty->getPrimitiveSizeInBits();
21250   if (Bits == 0 || Bits > 32)
21251     return false;
21252   return true;
21253 }
21254 
isExtractSubvectorCheap(EVT ResVT,EVT SrcVT,unsigned Index) const21255 bool ARMTargetLowering::isExtractSubvectorCheap(EVT ResVT, EVT SrcVT,
21256                                                 unsigned Index) const {
21257   if (!isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, ResVT))
21258     return false;
21259 
21260   return (Index == 0 || Index == ResVT.getVectorNumElements());
21261 }
21262 
makeDMB(IRBuilderBase & Builder,ARM_MB::MemBOpt Domain) const21263 Instruction *ARMTargetLowering::makeDMB(IRBuilderBase &Builder,
21264                                         ARM_MB::MemBOpt Domain) const {
21265   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
21266 
21267   // First, if the target has no DMB, see what fallback we can use.
21268   if (!Subtarget->hasDataBarrier()) {
21269     // Some ARMv6 cpus can support data barriers with an mcr instruction.
21270     // Thumb1 and pre-v6 ARM mode use a libcall instead and should never get
21271     // here.
21272     if (Subtarget->hasV6Ops() && !Subtarget->isThumb()) {
21273       Function *MCR = Intrinsic::getDeclaration(M, Intrinsic::arm_mcr);
21274       Value* args[6] = {Builder.getInt32(15), Builder.getInt32(0),
21275                         Builder.getInt32(0), Builder.getInt32(7),
21276                         Builder.getInt32(10), Builder.getInt32(5)};
21277       return Builder.CreateCall(MCR, args);
21278     } else {
21279       // Instead of using barriers, atomic accesses on these subtargets use
21280       // libcalls.
21281       llvm_unreachable("makeDMB on a target so old that it has no barriers");
21282     }
21283   } else {
21284     Function *DMB = Intrinsic::getDeclaration(M, Intrinsic::arm_dmb);
21285     // Only a full system barrier exists in the M-class architectures.
21286     Domain = Subtarget->isMClass() ? ARM_MB::SY : Domain;
21287     Constant *CDomain = Builder.getInt32(Domain);
21288     return Builder.CreateCall(DMB, CDomain);
21289   }
21290 }
21291 
21292 // Based on http://www.cl.cam.ac.uk/~pes20/cpp/cpp0xmappings.html
emitLeadingFence(IRBuilderBase & Builder,Instruction * Inst,AtomicOrdering Ord) const21293 Instruction *ARMTargetLowering::emitLeadingFence(IRBuilderBase &Builder,
21294                                                  Instruction *Inst,
21295                                                  AtomicOrdering Ord) const {
21296   switch (Ord) {
21297   case AtomicOrdering::NotAtomic:
21298   case AtomicOrdering::Unordered:
21299     llvm_unreachable("Invalid fence: unordered/non-atomic");
21300   case AtomicOrdering::Monotonic:
21301   case AtomicOrdering::Acquire:
21302     return nullptr; // Nothing to do
21303   case AtomicOrdering::SequentiallyConsistent:
21304     if (!Inst->hasAtomicStore())
21305       return nullptr; // Nothing to do
21306     [[fallthrough]];
21307   case AtomicOrdering::Release:
21308   case AtomicOrdering::AcquireRelease:
21309     if (Subtarget->preferISHSTBarriers())
21310       return makeDMB(Builder, ARM_MB::ISHST);
21311     // FIXME: add a comment with a link to documentation justifying this.
21312     else
21313       return makeDMB(Builder, ARM_MB::ISH);
21314   }
21315   llvm_unreachable("Unknown fence ordering in emitLeadingFence");
21316 }
21317 
emitTrailingFence(IRBuilderBase & Builder,Instruction * Inst,AtomicOrdering Ord) const21318 Instruction *ARMTargetLowering::emitTrailingFence(IRBuilderBase &Builder,
21319                                                   Instruction *Inst,
21320                                                   AtomicOrdering Ord) const {
21321   switch (Ord) {
21322   case AtomicOrdering::NotAtomic:
21323   case AtomicOrdering::Unordered:
21324     llvm_unreachable("Invalid fence: unordered/not-atomic");
21325   case AtomicOrdering::Monotonic:
21326   case AtomicOrdering::Release:
21327     return nullptr; // Nothing to do
21328   case AtomicOrdering::Acquire:
21329   case AtomicOrdering::AcquireRelease:
21330   case AtomicOrdering::SequentiallyConsistent:
21331     return makeDMB(Builder, ARM_MB::ISH);
21332   }
21333   llvm_unreachable("Unknown fence ordering in emitTrailingFence");
21334 }
21335 
21336 // Loads and stores less than 64-bits are already atomic; ones above that
21337 // are doomed anyway, so defer to the default libcall and blame the OS when
21338 // things go wrong. Cortex M doesn't have ldrexd/strexd though, so don't emit
21339 // anything for those.
21340 TargetLoweringBase::AtomicExpansionKind
shouldExpandAtomicStoreInIR(StoreInst * SI) const21341 ARMTargetLowering::shouldExpandAtomicStoreInIR(StoreInst *SI) const {
21342   bool has64BitAtomicStore;
21343   if (Subtarget->isMClass())
21344     has64BitAtomicStore = false;
21345   else if (Subtarget->isThumb())
21346     has64BitAtomicStore = Subtarget->hasV7Ops();
21347   else
21348     has64BitAtomicStore = Subtarget->hasV6Ops();
21349 
21350   unsigned Size = SI->getValueOperand()->getType()->getPrimitiveSizeInBits();
21351   return Size == 64 && has64BitAtomicStore ? AtomicExpansionKind::Expand
21352                                            : AtomicExpansionKind::None;
21353 }
21354 
21355 // Loads and stores less than 64-bits are already atomic; ones above that
21356 // are doomed anyway, so defer to the default libcall and blame the OS when
21357 // things go wrong. Cortex M doesn't have ldrexd/strexd though, so don't emit
21358 // anything for those.
21359 // FIXME: ldrd and strd are atomic if the CPU has LPAE (e.g. A15 has that
21360 // guarantee, see DDI0406C ARM architecture reference manual,
21361 // sections A8.8.72-74 LDRD)
21362 TargetLowering::AtomicExpansionKind
shouldExpandAtomicLoadInIR(LoadInst * LI) const21363 ARMTargetLowering::shouldExpandAtomicLoadInIR(LoadInst *LI) const {
21364   bool has64BitAtomicLoad;
21365   if (Subtarget->isMClass())
21366     has64BitAtomicLoad = false;
21367   else if (Subtarget->isThumb())
21368     has64BitAtomicLoad = Subtarget->hasV7Ops();
21369   else
21370     has64BitAtomicLoad = Subtarget->hasV6Ops();
21371 
21372   unsigned Size = LI->getType()->getPrimitiveSizeInBits();
21373   return (Size == 64 && has64BitAtomicLoad) ? AtomicExpansionKind::LLOnly
21374                                             : AtomicExpansionKind::None;
21375 }
21376 
21377 // For the real atomic operations, we have ldrex/strex up to 32 bits,
21378 // and up to 64 bits on the non-M profiles
21379 TargetLowering::AtomicExpansionKind
shouldExpandAtomicRMWInIR(AtomicRMWInst * AI) const21380 ARMTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const {
21381   if (AI->isFloatingPointOperation())
21382     return AtomicExpansionKind::CmpXChg;
21383 
21384   unsigned Size = AI->getType()->getPrimitiveSizeInBits();
21385   bool hasAtomicRMW;
21386   if (Subtarget->isMClass())
21387     hasAtomicRMW = Subtarget->hasV8MBaselineOps();
21388   else if (Subtarget->isThumb())
21389     hasAtomicRMW = Subtarget->hasV7Ops();
21390   else
21391     hasAtomicRMW = Subtarget->hasV6Ops();
21392   if (Size <= (Subtarget->isMClass() ? 32U : 64U) && hasAtomicRMW) {
21393     // At -O0, fast-regalloc cannot cope with the live vregs necessary to
21394     // implement atomicrmw without spilling. If the target address is also on
21395     // the stack and close enough to the spill slot, this can lead to a
21396     // situation where the monitor always gets cleared and the atomic operation
21397     // can never succeed. So at -O0 lower this operation to a CAS loop.
21398     if (getTargetMachine().getOptLevel() == CodeGenOptLevel::None)
21399       return AtomicExpansionKind::CmpXChg;
21400     return AtomicExpansionKind::LLSC;
21401   }
21402   return AtomicExpansionKind::None;
21403 }
21404 
21405 // Similar to shouldExpandAtomicRMWInIR, ldrex/strex can be used  up to 32
21406 // bits, and up to 64 bits on the non-M profiles.
21407 TargetLowering::AtomicExpansionKind
shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst * AI) const21408 ARMTargetLowering::shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *AI) const {
21409   // At -O0, fast-regalloc cannot cope with the live vregs necessary to
21410   // implement cmpxchg without spilling. If the address being exchanged is also
21411   // on the stack and close enough to the spill slot, this can lead to a
21412   // situation where the monitor always gets cleared and the atomic operation
21413   // can never succeed. So at -O0 we need a late-expanded pseudo-inst instead.
21414   unsigned Size = AI->getOperand(1)->getType()->getPrimitiveSizeInBits();
21415   bool HasAtomicCmpXchg;
21416   if (Subtarget->isMClass())
21417     HasAtomicCmpXchg = Subtarget->hasV8MBaselineOps();
21418   else if (Subtarget->isThumb())
21419     HasAtomicCmpXchg = Subtarget->hasV7Ops();
21420   else
21421     HasAtomicCmpXchg = Subtarget->hasV6Ops();
21422   if (getTargetMachine().getOptLevel() != CodeGenOptLevel::None &&
21423       HasAtomicCmpXchg && Size <= (Subtarget->isMClass() ? 32U : 64U))
21424     return AtomicExpansionKind::LLSC;
21425   return AtomicExpansionKind::None;
21426 }
21427 
shouldInsertFencesForAtomic(const Instruction * I) const21428 bool ARMTargetLowering::shouldInsertFencesForAtomic(
21429     const Instruction *I) const {
21430   return InsertFencesForAtomic;
21431 }
21432 
useLoadStackGuardNode() const21433 bool ARMTargetLowering::useLoadStackGuardNode() const {
21434   // ROPI/RWPI are not supported currently.
21435   return !Subtarget->isROPI() && !Subtarget->isRWPI();
21436 }
21437 
insertSSPDeclarations(Module & M) const21438 void ARMTargetLowering::insertSSPDeclarations(Module &M) const {
21439   if (!Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
21440     return TargetLowering::insertSSPDeclarations(M);
21441 
21442   // MSVC CRT has a global variable holding security cookie.
21443   M.getOrInsertGlobal("__security_cookie",
21444                       PointerType::getUnqual(M.getContext()));
21445 
21446   // MSVC CRT has a function to validate security cookie.
21447   FunctionCallee SecurityCheckCookie = M.getOrInsertFunction(
21448       "__security_check_cookie", Type::getVoidTy(M.getContext()),
21449       PointerType::getUnqual(M.getContext()));
21450   if (Function *F = dyn_cast<Function>(SecurityCheckCookie.getCallee()))
21451     F->addParamAttr(0, Attribute::AttrKind::InReg);
21452 }
21453 
getSDagStackGuard(const Module & M) const21454 Value *ARMTargetLowering::getSDagStackGuard(const Module &M) const {
21455   // MSVC CRT has a global variable holding security cookie.
21456   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
21457     return M.getGlobalVariable("__security_cookie");
21458   return TargetLowering::getSDagStackGuard(M);
21459 }
21460 
getSSPStackGuardCheck(const Module & M) const21461 Function *ARMTargetLowering::getSSPStackGuardCheck(const Module &M) const {
21462   // MSVC CRT has a function to validate security cookie.
21463   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())
21464     return M.getFunction("__security_check_cookie");
21465   return TargetLowering::getSSPStackGuardCheck(M);
21466 }
21467 
canCombineStoreAndExtract(Type * VectorTy,Value * Idx,unsigned & Cost) const21468 bool ARMTargetLowering::canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
21469                                                   unsigned &Cost) const {
21470   // If we do not have NEON, vector types are not natively supported.
21471   if (!Subtarget->hasNEON())
21472     return false;
21473 
21474   // Floating point values and vector values map to the same register file.
21475   // Therefore, although we could do a store extract of a vector type, this is
21476   // better to leave at float as we have more freedom in the addressing mode for
21477   // those.
21478   if (VectorTy->isFPOrFPVectorTy())
21479     return false;
21480 
21481   // If the index is unknown at compile time, this is very expensive to lower
21482   // and it is not possible to combine the store with the extract.
21483   if (!isa<ConstantInt>(Idx))
21484     return false;
21485 
21486   assert(VectorTy->isVectorTy() && "VectorTy is not a vector type");
21487   unsigned BitWidth = VectorTy->getPrimitiveSizeInBits().getFixedValue();
21488   // We can do a store + vector extract on any vector that fits perfectly in a D
21489   // or Q register.
21490   if (BitWidth == 64 || BitWidth == 128) {
21491     Cost = 0;
21492     return true;
21493   }
21494   return false;
21495 }
21496 
isCheapToSpeculateCttz(Type * Ty) const21497 bool ARMTargetLowering::isCheapToSpeculateCttz(Type *Ty) const {
21498   return Subtarget->hasV6T2Ops();
21499 }
21500 
isCheapToSpeculateCtlz(Type * Ty) const21501 bool ARMTargetLowering::isCheapToSpeculateCtlz(Type *Ty) const {
21502   return Subtarget->hasV6T2Ops();
21503 }
21504 
isMaskAndCmp0FoldingBeneficial(const Instruction & AndI) const21505 bool ARMTargetLowering::isMaskAndCmp0FoldingBeneficial(
21506     const Instruction &AndI) const {
21507   if (!Subtarget->hasV7Ops())
21508     return false;
21509 
21510   // Sink the `and` instruction only if the mask would fit into a modified
21511   // immediate operand.
21512   ConstantInt *Mask = dyn_cast<ConstantInt>(AndI.getOperand(1));
21513   if (!Mask || Mask->getValue().getBitWidth() > 32u)
21514     return false;
21515   auto MaskVal = unsigned(Mask->getValue().getZExtValue());
21516   return (Subtarget->isThumb2() ? ARM_AM::getT2SOImmVal(MaskVal)
21517                                 : ARM_AM::getSOImmVal(MaskVal)) != -1;
21518 }
21519 
21520 TargetLowering::ShiftLegalizationStrategy
preferredShiftLegalizationStrategy(SelectionDAG & DAG,SDNode * N,unsigned ExpansionFactor) const21521 ARMTargetLowering::preferredShiftLegalizationStrategy(
21522     SelectionDAG &DAG, SDNode *N, unsigned ExpansionFactor) const {
21523   if (Subtarget->hasMinSize() && !Subtarget->isTargetWindows())
21524     return ShiftLegalizationStrategy::LowerToLibcall;
21525   return TargetLowering::preferredShiftLegalizationStrategy(DAG, N,
21526                                                             ExpansionFactor);
21527 }
21528 
emitLoadLinked(IRBuilderBase & Builder,Type * ValueTy,Value * Addr,AtomicOrdering Ord) const21529 Value *ARMTargetLowering::emitLoadLinked(IRBuilderBase &Builder, Type *ValueTy,
21530                                          Value *Addr,
21531                                          AtomicOrdering Ord) const {
21532   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
21533   bool IsAcquire = isAcquireOrStronger(Ord);
21534 
21535   // Since i64 isn't legal and intrinsics don't get type-lowered, the ldrexd
21536   // intrinsic must return {i32, i32} and we have to recombine them into a
21537   // single i64 here.
21538   if (ValueTy->getPrimitiveSizeInBits() == 64) {
21539     Intrinsic::ID Int =
21540         IsAcquire ? Intrinsic::arm_ldaexd : Intrinsic::arm_ldrexd;
21541     Function *Ldrex = Intrinsic::getDeclaration(M, Int);
21542 
21543     Value *LoHi = Builder.CreateCall(Ldrex, Addr, "lohi");
21544 
21545     Value *Lo = Builder.CreateExtractValue(LoHi, 0, "lo");
21546     Value *Hi = Builder.CreateExtractValue(LoHi, 1, "hi");
21547     if (!Subtarget->isLittle())
21548       std::swap (Lo, Hi);
21549     Lo = Builder.CreateZExt(Lo, ValueTy, "lo64");
21550     Hi = Builder.CreateZExt(Hi, ValueTy, "hi64");
21551     return Builder.CreateOr(
21552         Lo, Builder.CreateShl(Hi, ConstantInt::get(ValueTy, 32)), "val64");
21553   }
21554 
21555   Type *Tys[] = { Addr->getType() };
21556   Intrinsic::ID Int = IsAcquire ? Intrinsic::arm_ldaex : Intrinsic::arm_ldrex;
21557   Function *Ldrex = Intrinsic::getDeclaration(M, Int, Tys);
21558   CallInst *CI = Builder.CreateCall(Ldrex, Addr);
21559 
21560   CI->addParamAttr(
21561       0, Attribute::get(M->getContext(), Attribute::ElementType, ValueTy));
21562   return Builder.CreateTruncOrBitCast(CI, ValueTy);
21563 }
21564 
emitAtomicCmpXchgNoStoreLLBalance(IRBuilderBase & Builder) const21565 void ARMTargetLowering::emitAtomicCmpXchgNoStoreLLBalance(
21566     IRBuilderBase &Builder) const {
21567   if (!Subtarget->hasV7Ops())
21568     return;
21569   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
21570   Builder.CreateCall(Intrinsic::getDeclaration(M, Intrinsic::arm_clrex));
21571 }
21572 
emitStoreConditional(IRBuilderBase & Builder,Value * Val,Value * Addr,AtomicOrdering Ord) const21573 Value *ARMTargetLowering::emitStoreConditional(IRBuilderBase &Builder,
21574                                                Value *Val, Value *Addr,
21575                                                AtomicOrdering Ord) const {
21576   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
21577   bool IsRelease = isReleaseOrStronger(Ord);
21578 
21579   // Since the intrinsics must have legal type, the i64 intrinsics take two
21580   // parameters: "i32, i32". We must marshal Val into the appropriate form
21581   // before the call.
21582   if (Val->getType()->getPrimitiveSizeInBits() == 64) {
21583     Intrinsic::ID Int =
21584         IsRelease ? Intrinsic::arm_stlexd : Intrinsic::arm_strexd;
21585     Function *Strex = Intrinsic::getDeclaration(M, Int);
21586     Type *Int32Ty = Type::getInt32Ty(M->getContext());
21587 
21588     Value *Lo = Builder.CreateTrunc(Val, Int32Ty, "lo");
21589     Value *Hi = Builder.CreateTrunc(Builder.CreateLShr(Val, 32), Int32Ty, "hi");
21590     if (!Subtarget->isLittle())
21591       std::swap(Lo, Hi);
21592     return Builder.CreateCall(Strex, {Lo, Hi, Addr});
21593   }
21594 
21595   Intrinsic::ID Int = IsRelease ? Intrinsic::arm_stlex : Intrinsic::arm_strex;
21596   Type *Tys[] = { Addr->getType() };
21597   Function *Strex = Intrinsic::getDeclaration(M, Int, Tys);
21598 
21599   CallInst *CI = Builder.CreateCall(
21600       Strex, {Builder.CreateZExtOrBitCast(
21601                   Val, Strex->getFunctionType()->getParamType(0)),
21602               Addr});
21603   CI->addParamAttr(1, Attribute::get(M->getContext(), Attribute::ElementType,
21604                                      Val->getType()));
21605   return CI;
21606 }
21607 
21608 
alignLoopsWithOptSize() const21609 bool ARMTargetLowering::alignLoopsWithOptSize() const {
21610   return Subtarget->isMClass();
21611 }
21612 
21613 /// A helper function for determining the number of interleaved accesses we
21614 /// will generate when lowering accesses of the given type.
21615 unsigned
getNumInterleavedAccesses(VectorType * VecTy,const DataLayout & DL) const21616 ARMTargetLowering::getNumInterleavedAccesses(VectorType *VecTy,
21617                                              const DataLayout &DL) const {
21618   return (DL.getTypeSizeInBits(VecTy) + 127) / 128;
21619 }
21620 
isLegalInterleavedAccessType(unsigned Factor,FixedVectorType * VecTy,Align Alignment,const DataLayout & DL) const21621 bool ARMTargetLowering::isLegalInterleavedAccessType(
21622     unsigned Factor, FixedVectorType *VecTy, Align Alignment,
21623     const DataLayout &DL) const {
21624 
21625   unsigned VecSize = DL.getTypeSizeInBits(VecTy);
21626   unsigned ElSize = DL.getTypeSizeInBits(VecTy->getElementType());
21627 
21628   if (!Subtarget->hasNEON() && !Subtarget->hasMVEIntegerOps())
21629     return false;
21630 
21631   // Ensure the vector doesn't have f16 elements. Even though we could do an
21632   // i16 vldN, we can't hold the f16 vectors and will end up converting via
21633   // f32.
21634   if (Subtarget->hasNEON() && VecTy->getElementType()->isHalfTy())
21635     return false;
21636   if (Subtarget->hasMVEIntegerOps() && Factor == 3)
21637     return false;
21638 
21639   // Ensure the number of vector elements is greater than 1.
21640   if (VecTy->getNumElements() < 2)
21641     return false;
21642 
21643   // Ensure the element type is legal.
21644   if (ElSize != 8 && ElSize != 16 && ElSize != 32)
21645     return false;
21646   // And the alignment if high enough under MVE.
21647   if (Subtarget->hasMVEIntegerOps() && Alignment < ElSize / 8)
21648     return false;
21649 
21650   // Ensure the total vector size is 64 or a multiple of 128. Types larger than
21651   // 128 will be split into multiple interleaved accesses.
21652   if (Subtarget->hasNEON() && VecSize == 64)
21653     return true;
21654   return VecSize % 128 == 0;
21655 }
21656 
getMaxSupportedInterleaveFactor() const21657 unsigned ARMTargetLowering::getMaxSupportedInterleaveFactor() const {
21658   if (Subtarget->hasNEON())
21659     return 4;
21660   if (Subtarget->hasMVEIntegerOps())
21661     return MVEMaxSupportedInterleaveFactor;
21662   return TargetLoweringBase::getMaxSupportedInterleaveFactor();
21663 }
21664 
21665 /// Lower an interleaved load into a vldN intrinsic.
21666 ///
21667 /// E.g. Lower an interleaved load (Factor = 2):
21668 ///        %wide.vec = load <8 x i32>, <8 x i32>* %ptr, align 4
21669 ///        %v0 = shuffle %wide.vec, undef, <0, 2, 4, 6>  ; Extract even elements
21670 ///        %v1 = shuffle %wide.vec, undef, <1, 3, 5, 7>  ; Extract odd elements
21671 ///
21672 ///      Into:
21673 ///        %vld2 = { <4 x i32>, <4 x i32> } call llvm.arm.neon.vld2(%ptr, 4)
21674 ///        %vec0 = extractelement { <4 x i32>, <4 x i32> } %vld2, i32 0
21675 ///        %vec1 = extractelement { <4 x i32>, <4 x i32> } %vld2, i32 1
lowerInterleavedLoad(LoadInst * LI,ArrayRef<ShuffleVectorInst * > Shuffles,ArrayRef<unsigned> Indices,unsigned Factor) const21676 bool ARMTargetLowering::lowerInterleavedLoad(
21677     LoadInst *LI, ArrayRef<ShuffleVectorInst *> Shuffles,
21678     ArrayRef<unsigned> Indices, unsigned Factor) const {
21679   assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
21680          "Invalid interleave factor");
21681   assert(!Shuffles.empty() && "Empty shufflevector input");
21682   assert(Shuffles.size() == Indices.size() &&
21683          "Unmatched number of shufflevectors and indices");
21684 
21685   auto *VecTy = cast<FixedVectorType>(Shuffles[0]->getType());
21686   Type *EltTy = VecTy->getElementType();
21687 
21688   const DataLayout &DL = LI->getDataLayout();
21689   Align Alignment = LI->getAlign();
21690 
21691   // Skip if we do not have NEON and skip illegal vector types. We can
21692   // "legalize" wide vector types into multiple interleaved accesses as long as
21693   // the vector types are divisible by 128.
21694   if (!isLegalInterleavedAccessType(Factor, VecTy, Alignment, DL))
21695     return false;
21696 
21697   unsigned NumLoads = getNumInterleavedAccesses(VecTy, DL);
21698 
21699   // A pointer vector can not be the return type of the ldN intrinsics. Need to
21700   // load integer vectors first and then convert to pointer vectors.
21701   if (EltTy->isPointerTy())
21702     VecTy = FixedVectorType::get(DL.getIntPtrType(EltTy), VecTy);
21703 
21704   IRBuilder<> Builder(LI);
21705 
21706   // The base address of the load.
21707   Value *BaseAddr = LI->getPointerOperand();
21708 
21709   if (NumLoads > 1) {
21710     // If we're going to generate more than one load, reset the sub-vector type
21711     // to something legal.
21712     VecTy = FixedVectorType::get(VecTy->getElementType(),
21713                                  VecTy->getNumElements() / NumLoads);
21714   }
21715 
21716   assert(isTypeLegal(EVT::getEVT(VecTy)) && "Illegal vldN vector type!");
21717 
21718   auto createLoadIntrinsic = [&](Value *BaseAddr) {
21719     if (Subtarget->hasNEON()) {
21720       Type *PtrTy = Builder.getPtrTy(LI->getPointerAddressSpace());
21721       Type *Tys[] = {VecTy, PtrTy};
21722       static const Intrinsic::ID LoadInts[3] = {Intrinsic::arm_neon_vld2,
21723                                                 Intrinsic::arm_neon_vld3,
21724                                                 Intrinsic::arm_neon_vld4};
21725       Function *VldnFunc =
21726           Intrinsic::getDeclaration(LI->getModule(), LoadInts[Factor - 2], Tys);
21727 
21728       SmallVector<Value *, 2> Ops;
21729       Ops.push_back(BaseAddr);
21730       Ops.push_back(Builder.getInt32(LI->getAlign().value()));
21731 
21732       return Builder.CreateCall(VldnFunc, Ops, "vldN");
21733     } else {
21734       assert((Factor == 2 || Factor == 4) &&
21735              "expected interleave factor of 2 or 4 for MVE");
21736       Intrinsic::ID LoadInts =
21737           Factor == 2 ? Intrinsic::arm_mve_vld2q : Intrinsic::arm_mve_vld4q;
21738       Type *PtrTy = Builder.getPtrTy(LI->getPointerAddressSpace());
21739       Type *Tys[] = {VecTy, PtrTy};
21740       Function *VldnFunc =
21741           Intrinsic::getDeclaration(LI->getModule(), LoadInts, Tys);
21742 
21743       SmallVector<Value *, 2> Ops;
21744       Ops.push_back(BaseAddr);
21745       return Builder.CreateCall(VldnFunc, Ops, "vldN");
21746     }
21747   };
21748 
21749   // Holds sub-vectors extracted from the load intrinsic return values. The
21750   // sub-vectors are associated with the shufflevector instructions they will
21751   // replace.
21752   DenseMap<ShuffleVectorInst *, SmallVector<Value *, 4>> SubVecs;
21753 
21754   for (unsigned LoadCount = 0; LoadCount < NumLoads; ++LoadCount) {
21755     // If we're generating more than one load, compute the base address of
21756     // subsequent loads as an offset from the previous.
21757     if (LoadCount > 0)
21758       BaseAddr = Builder.CreateConstGEP1_32(VecTy->getElementType(), BaseAddr,
21759                                             VecTy->getNumElements() * Factor);
21760 
21761     CallInst *VldN = createLoadIntrinsic(BaseAddr);
21762 
21763     // Replace uses of each shufflevector with the corresponding vector loaded
21764     // by ldN.
21765     for (unsigned i = 0; i < Shuffles.size(); i++) {
21766       ShuffleVectorInst *SV = Shuffles[i];
21767       unsigned Index = Indices[i];
21768 
21769       Value *SubVec = Builder.CreateExtractValue(VldN, Index);
21770 
21771       // Convert the integer vector to pointer vector if the element is pointer.
21772       if (EltTy->isPointerTy())
21773         SubVec = Builder.CreateIntToPtr(
21774             SubVec,
21775             FixedVectorType::get(SV->getType()->getElementType(), VecTy));
21776 
21777       SubVecs[SV].push_back(SubVec);
21778     }
21779   }
21780 
21781   // Replace uses of the shufflevector instructions with the sub-vectors
21782   // returned by the load intrinsic. If a shufflevector instruction is
21783   // associated with more than one sub-vector, those sub-vectors will be
21784   // concatenated into a single wide vector.
21785   for (ShuffleVectorInst *SVI : Shuffles) {
21786     auto &SubVec = SubVecs[SVI];
21787     auto *WideVec =
21788         SubVec.size() > 1 ? concatenateVectors(Builder, SubVec) : SubVec[0];
21789     SVI->replaceAllUsesWith(WideVec);
21790   }
21791 
21792   return true;
21793 }
21794 
21795 /// Lower an interleaved store into a vstN intrinsic.
21796 ///
21797 /// E.g. Lower an interleaved store (Factor = 3):
21798 ///        %i.vec = shuffle <8 x i32> %v0, <8 x i32> %v1,
21799 ///                                  <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11>
21800 ///        store <12 x i32> %i.vec, <12 x i32>* %ptr, align 4
21801 ///
21802 ///      Into:
21803 ///        %sub.v0 = shuffle <8 x i32> %v0, <8 x i32> v1, <0, 1, 2, 3>
21804 ///        %sub.v1 = shuffle <8 x i32> %v0, <8 x i32> v1, <4, 5, 6, 7>
21805 ///        %sub.v2 = shuffle <8 x i32> %v0, <8 x i32> v1, <8, 9, 10, 11>
21806 ///        call void llvm.arm.neon.vst3(%ptr, %sub.v0, %sub.v1, %sub.v2, 4)
21807 ///
21808 /// Note that the new shufflevectors will be removed and we'll only generate one
21809 /// vst3 instruction in CodeGen.
21810 ///
21811 /// Example for a more general valid mask (Factor 3). Lower:
21812 ///        %i.vec = shuffle <32 x i32> %v0, <32 x i32> %v1,
21813 ///                 <4, 32, 16, 5, 33, 17, 6, 34, 18, 7, 35, 19>
21814 ///        store <12 x i32> %i.vec, <12 x i32>* %ptr
21815 ///
21816 ///      Into:
21817 ///        %sub.v0 = shuffle <32 x i32> %v0, <32 x i32> v1, <4, 5, 6, 7>
21818 ///        %sub.v1 = shuffle <32 x i32> %v0, <32 x i32> v1, <32, 33, 34, 35>
21819 ///        %sub.v2 = shuffle <32 x i32> %v0, <32 x i32> v1, <16, 17, 18, 19>
21820 ///        call void llvm.arm.neon.vst3(%ptr, %sub.v0, %sub.v1, %sub.v2, 4)
lowerInterleavedStore(StoreInst * SI,ShuffleVectorInst * SVI,unsigned Factor) const21821 bool ARMTargetLowering::lowerInterleavedStore(StoreInst *SI,
21822                                               ShuffleVectorInst *SVI,
21823                                               unsigned Factor) const {
21824   assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
21825          "Invalid interleave factor");
21826 
21827   auto *VecTy = cast<FixedVectorType>(SVI->getType());
21828   assert(VecTy->getNumElements() % Factor == 0 && "Invalid interleaved store");
21829 
21830   unsigned LaneLen = VecTy->getNumElements() / Factor;
21831   Type *EltTy = VecTy->getElementType();
21832   auto *SubVecTy = FixedVectorType::get(EltTy, LaneLen);
21833 
21834   const DataLayout &DL = SI->getDataLayout();
21835   Align Alignment = SI->getAlign();
21836 
21837   // Skip if we do not have NEON and skip illegal vector types. We can
21838   // "legalize" wide vector types into multiple interleaved accesses as long as
21839   // the vector types are divisible by 128.
21840   if (!isLegalInterleavedAccessType(Factor, SubVecTy, Alignment, DL))
21841     return false;
21842 
21843   unsigned NumStores = getNumInterleavedAccesses(SubVecTy, DL);
21844 
21845   Value *Op0 = SVI->getOperand(0);
21846   Value *Op1 = SVI->getOperand(1);
21847   IRBuilder<> Builder(SI);
21848 
21849   // StN intrinsics don't support pointer vectors as arguments. Convert pointer
21850   // vectors to integer vectors.
21851   if (EltTy->isPointerTy()) {
21852     Type *IntTy = DL.getIntPtrType(EltTy);
21853 
21854     // Convert to the corresponding integer vector.
21855     auto *IntVecTy =
21856         FixedVectorType::get(IntTy, cast<FixedVectorType>(Op0->getType()));
21857     Op0 = Builder.CreatePtrToInt(Op0, IntVecTy);
21858     Op1 = Builder.CreatePtrToInt(Op1, IntVecTy);
21859 
21860     SubVecTy = FixedVectorType::get(IntTy, LaneLen);
21861   }
21862 
21863   // The base address of the store.
21864   Value *BaseAddr = SI->getPointerOperand();
21865 
21866   if (NumStores > 1) {
21867     // If we're going to generate more than one store, reset the lane length
21868     // and sub-vector type to something legal.
21869     LaneLen /= NumStores;
21870     SubVecTy = FixedVectorType::get(SubVecTy->getElementType(), LaneLen);
21871   }
21872 
21873   assert(isTypeLegal(EVT::getEVT(SubVecTy)) && "Illegal vstN vector type!");
21874 
21875   auto Mask = SVI->getShuffleMask();
21876 
21877   auto createStoreIntrinsic = [&](Value *BaseAddr,
21878                                   SmallVectorImpl<Value *> &Shuffles) {
21879     if (Subtarget->hasNEON()) {
21880       static const Intrinsic::ID StoreInts[3] = {Intrinsic::arm_neon_vst2,
21881                                                  Intrinsic::arm_neon_vst3,
21882                                                  Intrinsic::arm_neon_vst4};
21883       Type *PtrTy = Builder.getPtrTy(SI->getPointerAddressSpace());
21884       Type *Tys[] = {PtrTy, SubVecTy};
21885 
21886       Function *VstNFunc = Intrinsic::getDeclaration(
21887           SI->getModule(), StoreInts[Factor - 2], Tys);
21888 
21889       SmallVector<Value *, 6> Ops;
21890       Ops.push_back(BaseAddr);
21891       append_range(Ops, Shuffles);
21892       Ops.push_back(Builder.getInt32(SI->getAlign().value()));
21893       Builder.CreateCall(VstNFunc, Ops);
21894     } else {
21895       assert((Factor == 2 || Factor == 4) &&
21896              "expected interleave factor of 2 or 4 for MVE");
21897       Intrinsic::ID StoreInts =
21898           Factor == 2 ? Intrinsic::arm_mve_vst2q : Intrinsic::arm_mve_vst4q;
21899       Type *PtrTy = Builder.getPtrTy(SI->getPointerAddressSpace());
21900       Type *Tys[] = {PtrTy, SubVecTy};
21901       Function *VstNFunc =
21902           Intrinsic::getDeclaration(SI->getModule(), StoreInts, Tys);
21903 
21904       SmallVector<Value *, 6> Ops;
21905       Ops.push_back(BaseAddr);
21906       append_range(Ops, Shuffles);
21907       for (unsigned F = 0; F < Factor; F++) {
21908         Ops.push_back(Builder.getInt32(F));
21909         Builder.CreateCall(VstNFunc, Ops);
21910         Ops.pop_back();
21911       }
21912     }
21913   };
21914 
21915   for (unsigned StoreCount = 0; StoreCount < NumStores; ++StoreCount) {
21916     // If we generating more than one store, we compute the base address of
21917     // subsequent stores as an offset from the previous.
21918     if (StoreCount > 0)
21919       BaseAddr = Builder.CreateConstGEP1_32(SubVecTy->getElementType(),
21920                                             BaseAddr, LaneLen * Factor);
21921 
21922     SmallVector<Value *, 4> Shuffles;
21923 
21924     // Split the shufflevector operands into sub vectors for the new vstN call.
21925     for (unsigned i = 0; i < Factor; i++) {
21926       unsigned IdxI = StoreCount * LaneLen * Factor + i;
21927       if (Mask[IdxI] >= 0) {
21928         Shuffles.push_back(Builder.CreateShuffleVector(
21929             Op0, Op1, createSequentialMask(Mask[IdxI], LaneLen, 0)));
21930       } else {
21931         unsigned StartMask = 0;
21932         for (unsigned j = 1; j < LaneLen; j++) {
21933           unsigned IdxJ = StoreCount * LaneLen * Factor + j;
21934           if (Mask[IdxJ * Factor + IdxI] >= 0) {
21935             StartMask = Mask[IdxJ * Factor + IdxI] - IdxJ;
21936             break;
21937           }
21938         }
21939         // Note: If all elements in a chunk are undefs, StartMask=0!
21940         // Note: Filling undef gaps with random elements is ok, since
21941         // those elements were being written anyway (with undefs).
21942         // In the case of all undefs we're defaulting to using elems from 0
21943         // Note: StartMask cannot be negative, it's checked in
21944         // isReInterleaveMask
21945         Shuffles.push_back(Builder.CreateShuffleVector(
21946             Op0, Op1, createSequentialMask(StartMask, LaneLen, 0)));
21947       }
21948     }
21949 
21950     createStoreIntrinsic(BaseAddr, Shuffles);
21951   }
21952   return true;
21953 }
21954 
21955 enum HABaseType {
21956   HA_UNKNOWN = 0,
21957   HA_FLOAT,
21958   HA_DOUBLE,
21959   HA_VECT64,
21960   HA_VECT128
21961 };
21962 
isHomogeneousAggregate(Type * Ty,HABaseType & Base,uint64_t & Members)21963 static bool isHomogeneousAggregate(Type *Ty, HABaseType &Base,
21964                                    uint64_t &Members) {
21965   if (auto *ST = dyn_cast<StructType>(Ty)) {
21966     for (unsigned i = 0; i < ST->getNumElements(); ++i) {
21967       uint64_t SubMembers = 0;
21968       if (!isHomogeneousAggregate(ST->getElementType(i), Base, SubMembers))
21969         return false;
21970       Members += SubMembers;
21971     }
21972   } else if (auto *AT = dyn_cast<ArrayType>(Ty)) {
21973     uint64_t SubMembers = 0;
21974     if (!isHomogeneousAggregate(AT->getElementType(), Base, SubMembers))
21975       return false;
21976     Members += SubMembers * AT->getNumElements();
21977   } else if (Ty->isFloatTy()) {
21978     if (Base != HA_UNKNOWN && Base != HA_FLOAT)
21979       return false;
21980     Members = 1;
21981     Base = HA_FLOAT;
21982   } else if (Ty->isDoubleTy()) {
21983     if (Base != HA_UNKNOWN && Base != HA_DOUBLE)
21984       return false;
21985     Members = 1;
21986     Base = HA_DOUBLE;
21987   } else if (auto *VT = dyn_cast<VectorType>(Ty)) {
21988     Members = 1;
21989     switch (Base) {
21990     case HA_FLOAT:
21991     case HA_DOUBLE:
21992       return false;
21993     case HA_VECT64:
21994       return VT->getPrimitiveSizeInBits().getFixedValue() == 64;
21995     case HA_VECT128:
21996       return VT->getPrimitiveSizeInBits().getFixedValue() == 128;
21997     case HA_UNKNOWN:
21998       switch (VT->getPrimitiveSizeInBits().getFixedValue()) {
21999       case 64:
22000         Base = HA_VECT64;
22001         return true;
22002       case 128:
22003         Base = HA_VECT128;
22004         return true;
22005       default:
22006         return false;
22007       }
22008     }
22009   }
22010 
22011   return (Members > 0 && Members <= 4);
22012 }
22013 
22014 /// Return the correct alignment for the current calling convention.
getABIAlignmentForCallingConv(Type * ArgTy,const DataLayout & DL) const22015 Align ARMTargetLowering::getABIAlignmentForCallingConv(
22016     Type *ArgTy, const DataLayout &DL) const {
22017   const Align ABITypeAlign = DL.getABITypeAlign(ArgTy);
22018   if (!ArgTy->isVectorTy())
22019     return ABITypeAlign;
22020 
22021   // Avoid over-aligning vector parameters. It would require realigning the
22022   // stack and waste space for no real benefit.
22023   return std::min(ABITypeAlign, DL.getStackAlignment());
22024 }
22025 
22026 /// Return true if a type is an AAPCS-VFP homogeneous aggregate or one of
22027 /// [N x i32] or [N x i64]. This allows front-ends to skip emitting padding when
22028 /// passing according to AAPCS rules.
functionArgumentNeedsConsecutiveRegisters(Type * Ty,CallingConv::ID CallConv,bool isVarArg,const DataLayout & DL) const22029 bool ARMTargetLowering::functionArgumentNeedsConsecutiveRegisters(
22030     Type *Ty, CallingConv::ID CallConv, bool isVarArg,
22031     const DataLayout &DL) const {
22032   if (getEffectiveCallingConv(CallConv, isVarArg) !=
22033       CallingConv::ARM_AAPCS_VFP)
22034     return false;
22035 
22036   HABaseType Base = HA_UNKNOWN;
22037   uint64_t Members = 0;
22038   bool IsHA = isHomogeneousAggregate(Ty, Base, Members);
22039   LLVM_DEBUG(dbgs() << "isHA: " << IsHA << " "; Ty->dump());
22040 
22041   bool IsIntArray = Ty->isArrayTy() && Ty->getArrayElementType()->isIntegerTy();
22042   return IsHA || IsIntArray;
22043 }
22044 
getExceptionPointerRegister(const Constant * PersonalityFn) const22045 Register ARMTargetLowering::getExceptionPointerRegister(
22046     const Constant *PersonalityFn) const {
22047   // Platforms which do not use SjLj EH may return values in these registers
22048   // via the personality function.
22049   return Subtarget->useSjLjEH() ? Register() : ARM::R0;
22050 }
22051 
getExceptionSelectorRegister(const Constant * PersonalityFn) const22052 Register ARMTargetLowering::getExceptionSelectorRegister(
22053     const Constant *PersonalityFn) const {
22054   // Platforms which do not use SjLj EH may return values in these registers
22055   // via the personality function.
22056   return Subtarget->useSjLjEH() ? Register() : ARM::R1;
22057 }
22058 
initializeSplitCSR(MachineBasicBlock * Entry) const22059 void ARMTargetLowering::initializeSplitCSR(MachineBasicBlock *Entry) const {
22060   // Update IsSplitCSR in ARMFunctionInfo.
22061   ARMFunctionInfo *AFI = Entry->getParent()->getInfo<ARMFunctionInfo>();
22062   AFI->setIsSplitCSR(true);
22063 }
22064 
insertCopiesSplitCSR(MachineBasicBlock * Entry,const SmallVectorImpl<MachineBasicBlock * > & Exits) const22065 void ARMTargetLowering::insertCopiesSplitCSR(
22066     MachineBasicBlock *Entry,
22067     const SmallVectorImpl<MachineBasicBlock *> &Exits) const {
22068   const ARMBaseRegisterInfo *TRI = Subtarget->getRegisterInfo();
22069   const MCPhysReg *IStart = TRI->getCalleeSavedRegsViaCopy(Entry->getParent());
22070   if (!IStart)
22071     return;
22072 
22073   const TargetInstrInfo *TII = Subtarget->getInstrInfo();
22074   MachineRegisterInfo *MRI = &Entry->getParent()->getRegInfo();
22075   MachineBasicBlock::iterator MBBI = Entry->begin();
22076   for (const MCPhysReg *I = IStart; *I; ++I) {
22077     const TargetRegisterClass *RC = nullptr;
22078     if (ARM::GPRRegClass.contains(*I))
22079       RC = &ARM::GPRRegClass;
22080     else if (ARM::DPRRegClass.contains(*I))
22081       RC = &ARM::DPRRegClass;
22082     else
22083       llvm_unreachable("Unexpected register class in CSRsViaCopy!");
22084 
22085     Register NewVR = MRI->createVirtualRegister(RC);
22086     // Create copy from CSR to a virtual register.
22087     // FIXME: this currently does not emit CFI pseudo-instructions, it works
22088     // fine for CXX_FAST_TLS since the C++-style TLS access functions should be
22089     // nounwind. If we want to generalize this later, we may need to emit
22090     // CFI pseudo-instructions.
22091     assert(Entry->getParent()->getFunction().hasFnAttribute(
22092                Attribute::NoUnwind) &&
22093            "Function should be nounwind in insertCopiesSplitCSR!");
22094     Entry->addLiveIn(*I);
22095     BuildMI(*Entry, MBBI, DebugLoc(), TII->get(TargetOpcode::COPY), NewVR)
22096         .addReg(*I);
22097 
22098     // Insert the copy-back instructions right before the terminator.
22099     for (auto *Exit : Exits)
22100       BuildMI(*Exit, Exit->getFirstTerminator(), DebugLoc(),
22101               TII->get(TargetOpcode::COPY), *I)
22102           .addReg(NewVR);
22103   }
22104 }
22105 
finalizeLowering(MachineFunction & MF) const22106 void ARMTargetLowering::finalizeLowering(MachineFunction &MF) const {
22107   MF.getFrameInfo().computeMaxCallFrameSize(MF);
22108   TargetLoweringBase::finalizeLowering(MF);
22109 }
22110 
isComplexDeinterleavingSupported() const22111 bool ARMTargetLowering::isComplexDeinterleavingSupported() const {
22112   return Subtarget->hasMVEIntegerOps();
22113 }
22114 
isComplexDeinterleavingOperationSupported(ComplexDeinterleavingOperation Operation,Type * Ty) const22115 bool ARMTargetLowering::isComplexDeinterleavingOperationSupported(
22116     ComplexDeinterleavingOperation Operation, Type *Ty) const {
22117   auto *VTy = dyn_cast<FixedVectorType>(Ty);
22118   if (!VTy)
22119     return false;
22120 
22121   auto *ScalarTy = VTy->getScalarType();
22122   unsigned NumElements = VTy->getNumElements();
22123 
22124   unsigned VTyWidth = VTy->getScalarSizeInBits() * NumElements;
22125   if (VTyWidth < 128 || !llvm::isPowerOf2_32(VTyWidth))
22126     return false;
22127 
22128   // Both VCADD and VCMUL/VCMLA support the same types, F16 and F32
22129   if (ScalarTy->isHalfTy() || ScalarTy->isFloatTy())
22130     return Subtarget->hasMVEFloatOps();
22131 
22132   if (Operation != ComplexDeinterleavingOperation::CAdd)
22133     return false;
22134 
22135   return Subtarget->hasMVEIntegerOps() &&
22136          (ScalarTy->isIntegerTy(8) || ScalarTy->isIntegerTy(16) ||
22137           ScalarTy->isIntegerTy(32));
22138 }
22139 
createComplexDeinterleavingIR(IRBuilderBase & B,ComplexDeinterleavingOperation OperationType,ComplexDeinterleavingRotation Rotation,Value * InputA,Value * InputB,Value * Accumulator) const22140 Value *ARMTargetLowering::createComplexDeinterleavingIR(
22141     IRBuilderBase &B, ComplexDeinterleavingOperation OperationType,
22142     ComplexDeinterleavingRotation Rotation, Value *InputA, Value *InputB,
22143     Value *Accumulator) const {
22144 
22145   FixedVectorType *Ty = cast<FixedVectorType>(InputA->getType());
22146 
22147   unsigned TyWidth = Ty->getScalarSizeInBits() * Ty->getNumElements();
22148 
22149   assert(TyWidth >= 128 && "Width of vector type must be at least 128 bits");
22150 
22151   if (TyWidth > 128) {
22152     int Stride = Ty->getNumElements() / 2;
22153     auto SplitSeq = llvm::seq<int>(0, Ty->getNumElements());
22154     auto SplitSeqVec = llvm::to_vector(SplitSeq);
22155     ArrayRef<int> LowerSplitMask(&SplitSeqVec[0], Stride);
22156     ArrayRef<int> UpperSplitMask(&SplitSeqVec[Stride], Stride);
22157 
22158     auto *LowerSplitA = B.CreateShuffleVector(InputA, LowerSplitMask);
22159     auto *LowerSplitB = B.CreateShuffleVector(InputB, LowerSplitMask);
22160     auto *UpperSplitA = B.CreateShuffleVector(InputA, UpperSplitMask);
22161     auto *UpperSplitB = B.CreateShuffleVector(InputB, UpperSplitMask);
22162     Value *LowerSplitAcc = nullptr;
22163     Value *UpperSplitAcc = nullptr;
22164 
22165     if (Accumulator) {
22166       LowerSplitAcc = B.CreateShuffleVector(Accumulator, LowerSplitMask);
22167       UpperSplitAcc = B.CreateShuffleVector(Accumulator, UpperSplitMask);
22168     }
22169 
22170     auto *LowerSplitInt = createComplexDeinterleavingIR(
22171         B, OperationType, Rotation, LowerSplitA, LowerSplitB, LowerSplitAcc);
22172     auto *UpperSplitInt = createComplexDeinterleavingIR(
22173         B, OperationType, Rotation, UpperSplitA, UpperSplitB, UpperSplitAcc);
22174 
22175     ArrayRef<int> JoinMask(&SplitSeqVec[0], Ty->getNumElements());
22176     return B.CreateShuffleVector(LowerSplitInt, UpperSplitInt, JoinMask);
22177   }
22178 
22179   auto *IntTy = Type::getInt32Ty(B.getContext());
22180 
22181   ConstantInt *ConstRotation = nullptr;
22182   if (OperationType == ComplexDeinterleavingOperation::CMulPartial) {
22183     ConstRotation = ConstantInt::get(IntTy, (int)Rotation);
22184 
22185     if (Accumulator)
22186       return B.CreateIntrinsic(Intrinsic::arm_mve_vcmlaq, Ty,
22187                                {ConstRotation, Accumulator, InputB, InputA});
22188     return B.CreateIntrinsic(Intrinsic::arm_mve_vcmulq, Ty,
22189                              {ConstRotation, InputB, InputA});
22190   }
22191 
22192   if (OperationType == ComplexDeinterleavingOperation::CAdd) {
22193     // 1 means the value is not halved.
22194     auto *ConstHalving = ConstantInt::get(IntTy, 1);
22195 
22196     if (Rotation == ComplexDeinterleavingRotation::Rotation_90)
22197       ConstRotation = ConstantInt::get(IntTy, 0);
22198     else if (Rotation == ComplexDeinterleavingRotation::Rotation_270)
22199       ConstRotation = ConstantInt::get(IntTy, 1);
22200 
22201     if (!ConstRotation)
22202       return nullptr; // Invalid rotation for arm_mve_vcaddq
22203 
22204     return B.CreateIntrinsic(Intrinsic::arm_mve_vcaddq, Ty,
22205                              {ConstHalving, ConstRotation, InputA, InputB});
22206   }
22207 
22208   return nullptr;
22209 }
22210