xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 //===- TargetLoweringBase.cpp - Implement the TargetLoweringBase class ----===//
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 implements the TargetLoweringBase class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/BitVector.h"
14 #include "llvm/ADT/STLExtras.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/StringExtras.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/Analysis/Loads.h"
21 #include "llvm/Analysis/TargetTransformInfo.h"
22 #include "llvm/CodeGen/Analysis.h"
23 #include "llvm/CodeGen/ISDOpcodes.h"
24 #include "llvm/CodeGen/MachineBasicBlock.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstr.h"
28 #include "llvm/CodeGen/MachineInstrBuilder.h"
29 #include "llvm/CodeGen/MachineMemOperand.h"
30 #include "llvm/CodeGen/MachineOperand.h"
31 #include "llvm/CodeGen/MachineRegisterInfo.h"
32 #include "llvm/CodeGen/RuntimeLibcalls.h"
33 #include "llvm/CodeGen/StackMaps.h"
34 #include "llvm/CodeGen/TargetLowering.h"
35 #include "llvm/CodeGen/TargetOpcodes.h"
36 #include "llvm/CodeGen/TargetRegisterInfo.h"
37 #include "llvm/CodeGen/ValueTypes.h"
38 #include "llvm/IR/Attributes.h"
39 #include "llvm/IR/CallingConv.h"
40 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/DerivedTypes.h"
42 #include "llvm/IR/Function.h"
43 #include "llvm/IR/GlobalValue.h"
44 #include "llvm/IR/GlobalVariable.h"
45 #include "llvm/IR/IRBuilder.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/IR/Type.h"
48 #include "llvm/Support/BranchProbability.h"
49 #include "llvm/Support/Casting.h"
50 #include "llvm/Support/CommandLine.h"
51 #include "llvm/Support/Compiler.h"
52 #include "llvm/Support/ErrorHandling.h"
53 #include "llvm/Support/MachineValueType.h"
54 #include "llvm/Support/MathExtras.h"
55 #include "llvm/Target/TargetMachine.h"
56 #include "llvm/Transforms/Utils/SizeOpts.h"
57 #include <algorithm>
58 #include <cassert>
59 #include <cstddef>
60 #include <cstdint>
61 #include <cstring>
62 #include <iterator>
63 #include <string>
64 #include <tuple>
65 #include <utility>
66 
67 using namespace llvm;
68 
69 static cl::opt<bool> JumpIsExpensiveOverride(
70     "jump-is-expensive", cl::init(false),
71     cl::desc("Do not create extra branches to split comparison logic."),
72     cl::Hidden);
73 
74 static cl::opt<unsigned> MinimumJumpTableEntries
75   ("min-jump-table-entries", cl::init(4), cl::Hidden,
76    cl::desc("Set minimum number of entries to use a jump table."));
77 
78 static cl::opt<unsigned> MaximumJumpTableSize
79   ("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
80    cl::desc("Set maximum size of jump tables."));
81 
82 /// Minimum jump table density for normal functions.
83 static cl::opt<unsigned>
84     JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
85                      cl::desc("Minimum density for building a jump table in "
86                               "a normal function"));
87 
88 /// Minimum jump table density for -Os or -Oz functions.
89 static cl::opt<unsigned> OptsizeJumpTableDensity(
90     "optsize-jump-table-density", cl::init(40), cl::Hidden,
91     cl::desc("Minimum density for building a jump table in "
92              "an optsize function"));
93 
94 // FIXME: This option is only to test if the strict fp operation processed
95 // correctly by preventing mutating strict fp operation to normal fp operation
96 // during development. When the backend supports strict float operation, this
97 // option will be meaningless.
98 static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
99        cl::desc("Don't mutate strict-float node to a legalize node"),
100        cl::init(false), cl::Hidden);
101 
102 static bool darwinHasSinCos(const Triple &TT) {
103   assert(TT.isOSDarwin() && "should be called with darwin triple");
104   // Don't bother with 32 bit x86.
105   if (TT.getArch() == Triple::x86)
106     return false;
107   // Macos < 10.9 has no sincos_stret.
108   if (TT.isMacOSX())
109     return !TT.isMacOSXVersionLT(10, 9) && TT.isArch64Bit();
110   // iOS < 7.0 has no sincos_stret.
111   if (TT.isiOS())
112     return !TT.isOSVersionLT(7, 0);
113   // Any other darwin such as WatchOS/TvOS is new enough.
114   return true;
115 }
116 
117 // Although this default value is arbitrary, it is not random. It is assumed
118 // that a condition that evaluates the same way by a higher percentage than this
119 // is best represented as control flow. Therefore, the default value N should be
120 // set such that the win from N% correct executions is greater than the loss
121 // from (100 - N)% mispredicted executions for the majority of intended targets.
122 static cl::opt<int> MinPercentageForPredictableBranch(
123     "min-predictable-branch", cl::init(99),
124     cl::desc("Minimum percentage (0-100) that a condition must be either true "
125              "or false to assume that the condition is predictable"),
126     cl::Hidden);
127 
128 void TargetLoweringBase::InitLibcalls(const Triple &TT) {
129 #define HANDLE_LIBCALL(code, name) \
130   setLibcallName(RTLIB::code, name);
131 #include "llvm/IR/RuntimeLibcalls.def"
132 #undef HANDLE_LIBCALL
133   // Initialize calling conventions to their default.
134   for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
135     setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
136 
137   // For IEEE quad-precision libcall names, PPC uses "kf" instead of "tf".
138   if (TT.getArch() == Triple::ppc || TT.isPPC64()) {
139     setLibcallName(RTLIB::ADD_F128, "__addkf3");
140     setLibcallName(RTLIB::SUB_F128, "__subkf3");
141     setLibcallName(RTLIB::MUL_F128, "__mulkf3");
142     setLibcallName(RTLIB::DIV_F128, "__divkf3");
143     setLibcallName(RTLIB::FPEXT_F32_F128, "__extendsfkf2");
144     setLibcallName(RTLIB::FPEXT_F64_F128, "__extenddfkf2");
145     setLibcallName(RTLIB::FPROUND_F128_F32, "__trunckfsf2");
146     setLibcallName(RTLIB::FPROUND_F128_F64, "__trunckfdf2");
147     setLibcallName(RTLIB::FPTOSINT_F128_I32, "__fixkfsi");
148     setLibcallName(RTLIB::FPTOSINT_F128_I64, "__fixkfdi");
149     setLibcallName(RTLIB::FPTOUINT_F128_I32, "__fixunskfsi");
150     setLibcallName(RTLIB::FPTOUINT_F128_I64, "__fixunskfdi");
151     setLibcallName(RTLIB::SINTTOFP_I32_F128, "__floatsikf");
152     setLibcallName(RTLIB::SINTTOFP_I64_F128, "__floatdikf");
153     setLibcallName(RTLIB::UINTTOFP_I32_F128, "__floatunsikf");
154     setLibcallName(RTLIB::UINTTOFP_I64_F128, "__floatundikf");
155     setLibcallName(RTLIB::OEQ_F128, "__eqkf2");
156     setLibcallName(RTLIB::UNE_F128, "__nekf2");
157     setLibcallName(RTLIB::OGE_F128, "__gekf2");
158     setLibcallName(RTLIB::OLT_F128, "__ltkf2");
159     setLibcallName(RTLIB::OLE_F128, "__lekf2");
160     setLibcallName(RTLIB::OGT_F128, "__gtkf2");
161     setLibcallName(RTLIB::UO_F128, "__unordkf2");
162   }
163 
164   // A few names are different on particular architectures or environments.
165   if (TT.isOSDarwin()) {
166     // For f16/f32 conversions, Darwin uses the standard naming scheme, instead
167     // of the gnueabi-style __gnu_*_ieee.
168     // FIXME: What about other targets?
169     setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
170     setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
171 
172     // Some darwins have an optimized __bzero/bzero function.
173     switch (TT.getArch()) {
174     case Triple::x86:
175     case Triple::x86_64:
176       if (TT.isMacOSX() && !TT.isMacOSXVersionLT(10, 6))
177         setLibcallName(RTLIB::BZERO, "__bzero");
178       break;
179     case Triple::aarch64:
180     case Triple::aarch64_32:
181       setLibcallName(RTLIB::BZERO, "bzero");
182       break;
183     default:
184       break;
185     }
186 
187     if (darwinHasSinCos(TT)) {
188       setLibcallName(RTLIB::SINCOS_STRET_F32, "__sincosf_stret");
189       setLibcallName(RTLIB::SINCOS_STRET_F64, "__sincos_stret");
190       if (TT.isWatchABI()) {
191         setLibcallCallingConv(RTLIB::SINCOS_STRET_F32,
192                               CallingConv::ARM_AAPCS_VFP);
193         setLibcallCallingConv(RTLIB::SINCOS_STRET_F64,
194                               CallingConv::ARM_AAPCS_VFP);
195       }
196     }
197   } else {
198     setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
199     setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
200   }
201 
202   if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
203       (TT.isAndroid() && !TT.isAndroidVersionLT(9))) {
204     setLibcallName(RTLIB::SINCOS_F32, "sincosf");
205     setLibcallName(RTLIB::SINCOS_F64, "sincos");
206     setLibcallName(RTLIB::SINCOS_F80, "sincosl");
207     setLibcallName(RTLIB::SINCOS_F128, "sincosl");
208     setLibcallName(RTLIB::SINCOS_PPCF128, "sincosl");
209   }
210 
211   if (TT.isPS4CPU()) {
212     setLibcallName(RTLIB::SINCOS_F32, "sincosf");
213     setLibcallName(RTLIB::SINCOS_F64, "sincos");
214   }
215 
216   if (TT.isOSOpenBSD()) {
217     setLibcallName(RTLIB::STACKPROTECTOR_CHECK_FAIL, nullptr);
218   }
219 }
220 
221 /// getFPEXT - Return the FPEXT_*_* value for the given types, or
222 /// UNKNOWN_LIBCALL if there is none.
223 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
224   if (OpVT == MVT::f16) {
225     if (RetVT == MVT::f32)
226       return FPEXT_F16_F32;
227   } else if (OpVT == MVT::f32) {
228     if (RetVT == MVT::f64)
229       return FPEXT_F32_F64;
230     if (RetVT == MVT::f128)
231       return FPEXT_F32_F128;
232     if (RetVT == MVT::ppcf128)
233       return FPEXT_F32_PPCF128;
234   } else if (OpVT == MVT::f64) {
235     if (RetVT == MVT::f128)
236       return FPEXT_F64_F128;
237     else if (RetVT == MVT::ppcf128)
238       return FPEXT_F64_PPCF128;
239   } else if (OpVT == MVT::f80) {
240     if (RetVT == MVT::f128)
241       return FPEXT_F80_F128;
242   }
243 
244   return UNKNOWN_LIBCALL;
245 }
246 
247 /// getFPROUND - Return the FPROUND_*_* value for the given types, or
248 /// UNKNOWN_LIBCALL if there is none.
249 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
250   if (RetVT == MVT::f16) {
251     if (OpVT == MVT::f32)
252       return FPROUND_F32_F16;
253     if (OpVT == MVT::f64)
254       return FPROUND_F64_F16;
255     if (OpVT == MVT::f80)
256       return FPROUND_F80_F16;
257     if (OpVT == MVT::f128)
258       return FPROUND_F128_F16;
259     if (OpVT == MVT::ppcf128)
260       return FPROUND_PPCF128_F16;
261   } else if (RetVT == MVT::f32) {
262     if (OpVT == MVT::f64)
263       return FPROUND_F64_F32;
264     if (OpVT == MVT::f80)
265       return FPROUND_F80_F32;
266     if (OpVT == MVT::f128)
267       return FPROUND_F128_F32;
268     if (OpVT == MVT::ppcf128)
269       return FPROUND_PPCF128_F32;
270   } else if (RetVT == MVT::f64) {
271     if (OpVT == MVT::f80)
272       return FPROUND_F80_F64;
273     if (OpVT == MVT::f128)
274       return FPROUND_F128_F64;
275     if (OpVT == MVT::ppcf128)
276       return FPROUND_PPCF128_F64;
277   } else if (RetVT == MVT::f80) {
278     if (OpVT == MVT::f128)
279       return FPROUND_F128_F80;
280   }
281 
282   return UNKNOWN_LIBCALL;
283 }
284 
285 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
286 /// UNKNOWN_LIBCALL if there is none.
287 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
288   if (OpVT == MVT::f32) {
289     if (RetVT == MVT::i32)
290       return FPTOSINT_F32_I32;
291     if (RetVT == MVT::i64)
292       return FPTOSINT_F32_I64;
293     if (RetVT == MVT::i128)
294       return FPTOSINT_F32_I128;
295   } else if (OpVT == MVT::f64) {
296     if (RetVT == MVT::i32)
297       return FPTOSINT_F64_I32;
298     if (RetVT == MVT::i64)
299       return FPTOSINT_F64_I64;
300     if (RetVT == MVT::i128)
301       return FPTOSINT_F64_I128;
302   } else if (OpVT == MVT::f80) {
303     if (RetVT == MVT::i32)
304       return FPTOSINT_F80_I32;
305     if (RetVT == MVT::i64)
306       return FPTOSINT_F80_I64;
307     if (RetVT == MVT::i128)
308       return FPTOSINT_F80_I128;
309   } else if (OpVT == MVT::f128) {
310     if (RetVT == MVT::i32)
311       return FPTOSINT_F128_I32;
312     if (RetVT == MVT::i64)
313       return FPTOSINT_F128_I64;
314     if (RetVT == MVT::i128)
315       return FPTOSINT_F128_I128;
316   } else if (OpVT == MVT::ppcf128) {
317     if (RetVT == MVT::i32)
318       return FPTOSINT_PPCF128_I32;
319     if (RetVT == MVT::i64)
320       return FPTOSINT_PPCF128_I64;
321     if (RetVT == MVT::i128)
322       return FPTOSINT_PPCF128_I128;
323   }
324   return UNKNOWN_LIBCALL;
325 }
326 
327 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
328 /// UNKNOWN_LIBCALL if there is none.
329 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
330   if (OpVT == MVT::f32) {
331     if (RetVT == MVT::i32)
332       return FPTOUINT_F32_I32;
333     if (RetVT == MVT::i64)
334       return FPTOUINT_F32_I64;
335     if (RetVT == MVT::i128)
336       return FPTOUINT_F32_I128;
337   } else if (OpVT == MVT::f64) {
338     if (RetVT == MVT::i32)
339       return FPTOUINT_F64_I32;
340     if (RetVT == MVT::i64)
341       return FPTOUINT_F64_I64;
342     if (RetVT == MVT::i128)
343       return FPTOUINT_F64_I128;
344   } else if (OpVT == MVT::f80) {
345     if (RetVT == MVT::i32)
346       return FPTOUINT_F80_I32;
347     if (RetVT == MVT::i64)
348       return FPTOUINT_F80_I64;
349     if (RetVT == MVT::i128)
350       return FPTOUINT_F80_I128;
351   } else if (OpVT == MVT::f128) {
352     if (RetVT == MVT::i32)
353       return FPTOUINT_F128_I32;
354     if (RetVT == MVT::i64)
355       return FPTOUINT_F128_I64;
356     if (RetVT == MVT::i128)
357       return FPTOUINT_F128_I128;
358   } else if (OpVT == MVT::ppcf128) {
359     if (RetVT == MVT::i32)
360       return FPTOUINT_PPCF128_I32;
361     if (RetVT == MVT::i64)
362       return FPTOUINT_PPCF128_I64;
363     if (RetVT == MVT::i128)
364       return FPTOUINT_PPCF128_I128;
365   }
366   return UNKNOWN_LIBCALL;
367 }
368 
369 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
370 /// UNKNOWN_LIBCALL if there is none.
371 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
372   if (OpVT == MVT::i32) {
373     if (RetVT == MVT::f32)
374       return SINTTOFP_I32_F32;
375     if (RetVT == MVT::f64)
376       return SINTTOFP_I32_F64;
377     if (RetVT == MVT::f80)
378       return SINTTOFP_I32_F80;
379     if (RetVT == MVT::f128)
380       return SINTTOFP_I32_F128;
381     if (RetVT == MVT::ppcf128)
382       return SINTTOFP_I32_PPCF128;
383   } else if (OpVT == MVT::i64) {
384     if (RetVT == MVT::f32)
385       return SINTTOFP_I64_F32;
386     if (RetVT == MVT::f64)
387       return SINTTOFP_I64_F64;
388     if (RetVT == MVT::f80)
389       return SINTTOFP_I64_F80;
390     if (RetVT == MVT::f128)
391       return SINTTOFP_I64_F128;
392     if (RetVT == MVT::ppcf128)
393       return SINTTOFP_I64_PPCF128;
394   } else if (OpVT == MVT::i128) {
395     if (RetVT == MVT::f32)
396       return SINTTOFP_I128_F32;
397     if (RetVT == MVT::f64)
398       return SINTTOFP_I128_F64;
399     if (RetVT == MVT::f80)
400       return SINTTOFP_I128_F80;
401     if (RetVT == MVT::f128)
402       return SINTTOFP_I128_F128;
403     if (RetVT == MVT::ppcf128)
404       return SINTTOFP_I128_PPCF128;
405   }
406   return UNKNOWN_LIBCALL;
407 }
408 
409 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
410 /// UNKNOWN_LIBCALL if there is none.
411 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
412   if (OpVT == MVT::i32) {
413     if (RetVT == MVT::f32)
414       return UINTTOFP_I32_F32;
415     if (RetVT == MVT::f64)
416       return UINTTOFP_I32_F64;
417     if (RetVT == MVT::f80)
418       return UINTTOFP_I32_F80;
419     if (RetVT == MVT::f128)
420       return UINTTOFP_I32_F128;
421     if (RetVT == MVT::ppcf128)
422       return UINTTOFP_I32_PPCF128;
423   } else if (OpVT == MVT::i64) {
424     if (RetVT == MVT::f32)
425       return UINTTOFP_I64_F32;
426     if (RetVT == MVT::f64)
427       return UINTTOFP_I64_F64;
428     if (RetVT == MVT::f80)
429       return UINTTOFP_I64_F80;
430     if (RetVT == MVT::f128)
431       return UINTTOFP_I64_F128;
432     if (RetVT == MVT::ppcf128)
433       return UINTTOFP_I64_PPCF128;
434   } else if (OpVT == MVT::i128) {
435     if (RetVT == MVT::f32)
436       return UINTTOFP_I128_F32;
437     if (RetVT == MVT::f64)
438       return UINTTOFP_I128_F64;
439     if (RetVT == MVT::f80)
440       return UINTTOFP_I128_F80;
441     if (RetVT == MVT::f128)
442       return UINTTOFP_I128_F128;
443     if (RetVT == MVT::ppcf128)
444       return UINTTOFP_I128_PPCF128;
445   }
446   return UNKNOWN_LIBCALL;
447 }
448 
449 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
450 #define OP_TO_LIBCALL(Name, Enum)                                              \
451   case Name:                                                                   \
452     switch (VT.SimpleTy) {                                                     \
453     default:                                                                   \
454       return UNKNOWN_LIBCALL;                                                  \
455     case MVT::i8:                                                              \
456       return Enum##_1;                                                         \
457     case MVT::i16:                                                             \
458       return Enum##_2;                                                         \
459     case MVT::i32:                                                             \
460       return Enum##_4;                                                         \
461     case MVT::i64:                                                             \
462       return Enum##_8;                                                         \
463     case MVT::i128:                                                            \
464       return Enum##_16;                                                        \
465     }
466 
467   switch (Opc) {
468     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
469     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
470     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
471     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
472     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
473     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
474     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
475     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
476     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
477     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
478     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
479     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
480   }
481 
482 #undef OP_TO_LIBCALL
483 
484   return UNKNOWN_LIBCALL;
485 }
486 
487 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
488   switch (ElementSize) {
489   case 1:
490     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
491   case 2:
492     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
493   case 4:
494     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
495   case 8:
496     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
497   case 16:
498     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
499   default:
500     return UNKNOWN_LIBCALL;
501   }
502 }
503 
504 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
505   switch (ElementSize) {
506   case 1:
507     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
508   case 2:
509     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
510   case 4:
511     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
512   case 8:
513     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
514   case 16:
515     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
516   default:
517     return UNKNOWN_LIBCALL;
518   }
519 }
520 
521 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
522   switch (ElementSize) {
523   case 1:
524     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
525   case 2:
526     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
527   case 4:
528     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
529   case 8:
530     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
531   case 16:
532     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
533   default:
534     return UNKNOWN_LIBCALL;
535   }
536 }
537 
538 /// InitCmpLibcallCCs - Set default comparison libcall CC.
539 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
540   memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
541   CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
542   CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
543   CCs[RTLIB::OEQ_F128] = ISD::SETEQ;
544   CCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
545   CCs[RTLIB::UNE_F32] = ISD::SETNE;
546   CCs[RTLIB::UNE_F64] = ISD::SETNE;
547   CCs[RTLIB::UNE_F128] = ISD::SETNE;
548   CCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
549   CCs[RTLIB::OGE_F32] = ISD::SETGE;
550   CCs[RTLIB::OGE_F64] = ISD::SETGE;
551   CCs[RTLIB::OGE_F128] = ISD::SETGE;
552   CCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
553   CCs[RTLIB::OLT_F32] = ISD::SETLT;
554   CCs[RTLIB::OLT_F64] = ISD::SETLT;
555   CCs[RTLIB::OLT_F128] = ISD::SETLT;
556   CCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
557   CCs[RTLIB::OLE_F32] = ISD::SETLE;
558   CCs[RTLIB::OLE_F64] = ISD::SETLE;
559   CCs[RTLIB::OLE_F128] = ISD::SETLE;
560   CCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
561   CCs[RTLIB::OGT_F32] = ISD::SETGT;
562   CCs[RTLIB::OGT_F64] = ISD::SETGT;
563   CCs[RTLIB::OGT_F128] = ISD::SETGT;
564   CCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
565   CCs[RTLIB::UO_F32] = ISD::SETNE;
566   CCs[RTLIB::UO_F64] = ISD::SETNE;
567   CCs[RTLIB::UO_F128] = ISD::SETNE;
568   CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
569 }
570 
571 /// NOTE: The TargetMachine owns TLOF.
572 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
573   initActions();
574 
575   // Perform these initializations only once.
576   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
577       MaxLoadsPerMemcmp = 8;
578   MaxGluedStoresPerMemcpy = 0;
579   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
580       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
581   HasMultipleConditionRegisters = false;
582   HasExtractBitsInsn = false;
583   JumpIsExpensive = JumpIsExpensiveOverride;
584   PredictableSelectIsExpensive = false;
585   EnableExtLdPromotion = false;
586   StackPointerRegisterToSaveRestore = 0;
587   BooleanContents = UndefinedBooleanContent;
588   BooleanFloatContents = UndefinedBooleanContent;
589   BooleanVectorContents = UndefinedBooleanContent;
590   SchedPreferenceInfo = Sched::ILP;
591   GatherAllAliasesMaxDepth = 18;
592   IsStrictFPEnabled = DisableStrictNodeMutation;
593   // TODO: the default will be switched to 0 in the next commit, along
594   // with the Target-specific changes necessary.
595   MaxAtomicSizeInBitsSupported = 1024;
596 
597   MinCmpXchgSizeInBits = 0;
598   SupportsUnalignedAtomics = false;
599 
600   std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
601 
602   InitLibcalls(TM.getTargetTriple());
603   InitCmpLibcallCCs(CmpLibcallCCs);
604 }
605 
606 void TargetLoweringBase::initActions() {
607   // All operations default to being supported.
608   memset(OpActions, 0, sizeof(OpActions));
609   memset(LoadExtActions, 0, sizeof(LoadExtActions));
610   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
611   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
612   memset(CondCodeActions, 0, sizeof(CondCodeActions));
613   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
614   std::fill(std::begin(TargetDAGCombineArray),
615             std::end(TargetDAGCombineArray), 0);
616 
617   for (MVT VT : MVT::fp_valuetypes()) {
618     MVT IntVT = MVT::getIntegerVT(VT.getSizeInBits().getFixedSize());
619     if (IntVT.isValid()) {
620       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
621       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
622     }
623   }
624 
625   // Set default actions for various operations.
626   for (MVT VT : MVT::all_valuetypes()) {
627     // Default all indexed load / store to expand.
628     for (unsigned IM = (unsigned)ISD::PRE_INC;
629          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
630       setIndexedLoadAction(IM, VT, Expand);
631       setIndexedStoreAction(IM, VT, Expand);
632       setIndexedMaskedLoadAction(IM, VT, Expand);
633       setIndexedMaskedStoreAction(IM, VT, Expand);
634     }
635 
636     // Most backends expect to see the node which just returns the value loaded.
637     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
638 
639     // These operations default to expand.
640     setOperationAction(ISD::FGETSIGN, VT, Expand);
641     setOperationAction(ISD::CONCAT_VECTORS, VT, Expand);
642     setOperationAction(ISD::FMINNUM, VT, Expand);
643     setOperationAction(ISD::FMAXNUM, VT, Expand);
644     setOperationAction(ISD::FMINNUM_IEEE, VT, Expand);
645     setOperationAction(ISD::FMAXNUM_IEEE, VT, Expand);
646     setOperationAction(ISD::FMINIMUM, VT, Expand);
647     setOperationAction(ISD::FMAXIMUM, VT, Expand);
648     setOperationAction(ISD::FMAD, VT, Expand);
649     setOperationAction(ISD::SMIN, VT, Expand);
650     setOperationAction(ISD::SMAX, VT, Expand);
651     setOperationAction(ISD::UMIN, VT, Expand);
652     setOperationAction(ISD::UMAX, VT, Expand);
653     setOperationAction(ISD::ABS, VT, Expand);
654     setOperationAction(ISD::FSHL, VT, Expand);
655     setOperationAction(ISD::FSHR, VT, Expand);
656     setOperationAction(ISD::SADDSAT, VT, Expand);
657     setOperationAction(ISD::UADDSAT, VT, Expand);
658     setOperationAction(ISD::SSUBSAT, VT, Expand);
659     setOperationAction(ISD::USUBSAT, VT, Expand);
660     setOperationAction(ISD::SMULFIX, VT, Expand);
661     setOperationAction(ISD::SMULFIXSAT, VT, Expand);
662     setOperationAction(ISD::UMULFIX, VT, Expand);
663     setOperationAction(ISD::UMULFIXSAT, VT, Expand);
664     setOperationAction(ISD::SDIVFIX, VT, Expand);
665     setOperationAction(ISD::SDIVFIXSAT, VT, Expand);
666     setOperationAction(ISD::UDIVFIX, VT, Expand);
667     setOperationAction(ISD::UDIVFIXSAT, VT, Expand);
668 
669     // Overflow operations default to expand
670     setOperationAction(ISD::SADDO, VT, Expand);
671     setOperationAction(ISD::SSUBO, VT, Expand);
672     setOperationAction(ISD::UADDO, VT, Expand);
673     setOperationAction(ISD::USUBO, VT, Expand);
674     setOperationAction(ISD::SMULO, VT, Expand);
675     setOperationAction(ISD::UMULO, VT, Expand);
676 
677     // ADDCARRY operations default to expand
678     setOperationAction(ISD::ADDCARRY, VT, Expand);
679     setOperationAction(ISD::SUBCARRY, VT, Expand);
680     setOperationAction(ISD::SETCCCARRY, VT, Expand);
681 
682     // ADDC/ADDE/SUBC/SUBE default to expand.
683     setOperationAction(ISD::ADDC, VT, Expand);
684     setOperationAction(ISD::ADDE, VT, Expand);
685     setOperationAction(ISD::SUBC, VT, Expand);
686     setOperationAction(ISD::SUBE, VT, Expand);
687 
688     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
689     setOperationAction(ISD::CTLZ_ZERO_UNDEF, VT, Expand);
690     setOperationAction(ISD::CTTZ_ZERO_UNDEF, VT, Expand);
691 
692     setOperationAction(ISD::BITREVERSE, VT, Expand);
693 
694     // These library functions default to expand.
695     setOperationAction(ISD::FROUND, VT, Expand);
696     setOperationAction(ISD::FROUNDEVEN, VT, Expand);
697     setOperationAction(ISD::FPOWI, VT, Expand);
698 
699     // These operations default to expand for vector types.
700     if (VT.isVector()) {
701       setOperationAction(ISD::FCOPYSIGN, VT, Expand);
702       setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Expand);
703       setOperationAction(ISD::ANY_EXTEND_VECTOR_INREG, VT, Expand);
704       setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Expand);
705       setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Expand);
706       setOperationAction(ISD::SPLAT_VECTOR, VT, Expand);
707     }
708 
709     // Constrained floating-point operations default to expand.
710 #define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
711     setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
712 #include "llvm/IR/ConstrainedOps.def"
713 
714     // For most targets @llvm.get.dynamic.area.offset just returns 0.
715     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
716 
717     // Vector reduction default to expand.
718     setOperationAction(ISD::VECREDUCE_FADD, VT, Expand);
719     setOperationAction(ISD::VECREDUCE_FMUL, VT, Expand);
720     setOperationAction(ISD::VECREDUCE_ADD, VT, Expand);
721     setOperationAction(ISD::VECREDUCE_MUL, VT, Expand);
722     setOperationAction(ISD::VECREDUCE_AND, VT, Expand);
723     setOperationAction(ISD::VECREDUCE_OR, VT, Expand);
724     setOperationAction(ISD::VECREDUCE_XOR, VT, Expand);
725     setOperationAction(ISD::VECREDUCE_SMAX, VT, Expand);
726     setOperationAction(ISD::VECREDUCE_SMIN, VT, Expand);
727     setOperationAction(ISD::VECREDUCE_UMAX, VT, Expand);
728     setOperationAction(ISD::VECREDUCE_UMIN, VT, Expand);
729     setOperationAction(ISD::VECREDUCE_FMAX, VT, Expand);
730     setOperationAction(ISD::VECREDUCE_FMIN, VT, Expand);
731   }
732 
733   // Most targets ignore the @llvm.prefetch intrinsic.
734   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
735 
736   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
737   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
738 
739   // ConstantFP nodes default to expand.  Targets can either change this to
740   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
741   // to optimize expansions for certain constants.
742   setOperationAction(ISD::ConstantFP, MVT::f16, Expand);
743   setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
744   setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
745   setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
746   setOperationAction(ISD::ConstantFP, MVT::f128, Expand);
747 
748   // These library functions default to expand.
749   for (MVT VT : {MVT::f32, MVT::f64, MVT::f128}) {
750     setOperationAction(ISD::FCBRT,      VT, Expand);
751     setOperationAction(ISD::FLOG ,      VT, Expand);
752     setOperationAction(ISD::FLOG2,      VT, Expand);
753     setOperationAction(ISD::FLOG10,     VT, Expand);
754     setOperationAction(ISD::FEXP ,      VT, Expand);
755     setOperationAction(ISD::FEXP2,      VT, Expand);
756     setOperationAction(ISD::FFLOOR,     VT, Expand);
757     setOperationAction(ISD::FNEARBYINT, VT, Expand);
758     setOperationAction(ISD::FCEIL,      VT, Expand);
759     setOperationAction(ISD::FRINT,      VT, Expand);
760     setOperationAction(ISD::FTRUNC,     VT, Expand);
761     setOperationAction(ISD::FROUND,     VT, Expand);
762     setOperationAction(ISD::FROUNDEVEN, VT, Expand);
763     setOperationAction(ISD::LROUND,     VT, Expand);
764     setOperationAction(ISD::LLROUND,    VT, Expand);
765     setOperationAction(ISD::LRINT,      VT, Expand);
766     setOperationAction(ISD::LLRINT,     VT, Expand);
767   }
768 
769   // Default ISD::TRAP to expand (which turns it into abort).
770   setOperationAction(ISD::TRAP, MVT::Other, Expand);
771 
772   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
773   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
774   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
775 }
776 
777 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
778                                                EVT) const {
779   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
780 }
781 
782 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
783                                          bool LegalTypes) const {
784   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
785   if (LHSTy.isVector())
786     return LHSTy;
787   return LegalTypes ? getScalarShiftAmountTy(DL, LHSTy)
788                     : getPointerTy(DL);
789 }
790 
791 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
792   assert(isTypeLegal(VT));
793   switch (Op) {
794   default:
795     return false;
796   case ISD::SDIV:
797   case ISD::UDIV:
798   case ISD::SREM:
799   case ISD::UREM:
800     return true;
801   }
802 }
803 
804 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
805   // If the command-line option was specified, ignore this request.
806   if (!JumpIsExpensiveOverride.getNumOccurrences())
807     JumpIsExpensive = isExpensive;
808 }
809 
810 TargetLoweringBase::LegalizeKind
811 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
812   // If this is a simple type, use the ComputeRegisterProp mechanism.
813   if (VT.isSimple()) {
814     MVT SVT = VT.getSimpleVT();
815     assert((unsigned)SVT.SimpleTy < array_lengthof(TransformToType));
816     MVT NVT = TransformToType[SVT.SimpleTy];
817     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
818 
819     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
820             LA == TypeSoftPromoteHalf ||
821             (NVT.isVector() ||
822              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
823            "Promote may not follow Expand or Promote");
824 
825     if (LA == TypeSplitVector)
826       return LegalizeKind(LA,
827                           EVT::getVectorVT(Context, SVT.getVectorElementType(),
828                                            SVT.getVectorElementCount() / 2));
829     if (LA == TypeScalarizeVector)
830       return LegalizeKind(LA, SVT.getVectorElementType());
831     return LegalizeKind(LA, NVT);
832   }
833 
834   // Handle Extended Scalar Types.
835   if (!VT.isVector()) {
836     assert(VT.isInteger() && "Float types must be simple");
837     unsigned BitSize = VT.getSizeInBits();
838     // First promote to a power-of-two size, then expand if necessary.
839     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
840       EVT NVT = VT.getRoundIntegerType(Context);
841       assert(NVT != VT && "Unable to round integer VT");
842       LegalizeKind NextStep = getTypeConversion(Context, NVT);
843       // Avoid multi-step promotion.
844       if (NextStep.first == TypePromoteInteger)
845         return NextStep;
846       // Return rounded integer type.
847       return LegalizeKind(TypePromoteInteger, NVT);
848     }
849 
850     return LegalizeKind(TypeExpandInteger,
851                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
852   }
853 
854   // Handle vector types.
855   ElementCount NumElts = VT.getVectorElementCount();
856   EVT EltVT = VT.getVectorElementType();
857 
858   // Vectors with only one element are always scalarized.
859   if (NumElts == 1)
860     return LegalizeKind(TypeScalarizeVector, EltVT);
861 
862   if (VT.getVectorElementCount() == ElementCount(1, true))
863     report_fatal_error("Cannot legalize this vector");
864 
865   // Try to widen vector elements until the element type is a power of two and
866   // promote it to a legal type later on, for example:
867   // <3 x i8> -> <4 x i8> -> <4 x i32>
868   if (EltVT.isInteger()) {
869     // Vectors with a number of elements that is not a power of two are always
870     // widened, for example <3 x i8> -> <4 x i8>.
871     if (!VT.isPow2VectorType()) {
872       NumElts = NumElts.NextPowerOf2();
873       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
874       return LegalizeKind(TypeWidenVector, NVT);
875     }
876 
877     // Examine the element type.
878     LegalizeKind LK = getTypeConversion(Context, EltVT);
879 
880     // If type is to be expanded, split the vector.
881     //  <4 x i140> -> <2 x i140>
882     if (LK.first == TypeExpandInteger)
883       return LegalizeKind(TypeSplitVector,
884                           EVT::getVectorVT(Context, EltVT, NumElts / 2));
885 
886     // Promote the integer element types until a legal vector type is found
887     // or until the element integer type is too big. If a legal type was not
888     // found, fallback to the usual mechanism of widening/splitting the
889     // vector.
890     EVT OldEltVT = EltVT;
891     while (true) {
892       // Increase the bitwidth of the element to the next pow-of-two
893       // (which is greater than 8 bits).
894       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
895                   .getRoundIntegerType(Context);
896 
897       // Stop trying when getting a non-simple element type.
898       // Note that vector elements may be greater than legal vector element
899       // types. Example: X86 XMM registers hold 64bit element on 32bit
900       // systems.
901       if (!EltVT.isSimple())
902         break;
903 
904       // Build a new vector type and check if it is legal.
905       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
906       // Found a legal promoted vector type.
907       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
908         return LegalizeKind(TypePromoteInteger,
909                             EVT::getVectorVT(Context, EltVT, NumElts));
910     }
911 
912     // Reset the type to the unexpanded type if we did not find a legal vector
913     // type with a promoted vector element type.
914     EltVT = OldEltVT;
915   }
916 
917   // Try to widen the vector until a legal type is found.
918   // If there is no wider legal type, split the vector.
919   while (true) {
920     // Round up to the next power of 2.
921     NumElts = NumElts.NextPowerOf2();
922 
923     // If there is no simple vector type with this many elements then there
924     // cannot be a larger legal vector type.  Note that this assumes that
925     // there are no skipped intermediate vector types in the simple types.
926     if (!EltVT.isSimple())
927       break;
928     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
929     if (LargerVector == MVT())
930       break;
931 
932     // If this type is legal then widen the vector.
933     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
934       return LegalizeKind(TypeWidenVector, LargerVector);
935   }
936 
937   // Widen odd vectors to next power of two.
938   if (!VT.isPow2VectorType()) {
939     EVT NVT = VT.getPow2VectorType(Context);
940     return LegalizeKind(TypeWidenVector, NVT);
941   }
942 
943   // Vectors with illegal element types are expanded.
944   EVT NVT = EVT::getVectorVT(Context, EltVT, VT.getVectorElementCount() / 2);
945   return LegalizeKind(TypeSplitVector, NVT);
946 }
947 
948 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
949                                           unsigned &NumIntermediates,
950                                           MVT &RegisterVT,
951                                           TargetLoweringBase *TLI) {
952   // Figure out the right, legal destination reg to copy into.
953   ElementCount EC = VT.getVectorElementCount();
954   MVT EltTy = VT.getVectorElementType();
955 
956   unsigned NumVectorRegs = 1;
957 
958   // Scalable vectors cannot be scalarized, so splitting or widening is
959   // required.
960   if (VT.isScalableVector() && !isPowerOf2_32(EC.Min))
961     llvm_unreachable(
962         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
963 
964   // FIXME: We don't support non-power-of-2-sized vectors for now.
965   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
966   if (!isPowerOf2_32(EC.Min)) {
967     // Split EC to unit size (scalable property is preserved).
968     NumVectorRegs = EC.Min;
969     EC = EC / NumVectorRegs;
970   }
971 
972   // Divide the input until we get to a supported size. This will
973   // always end up with an EC that represent a scalar or a scalable
974   // scalar.
975   while (EC.Min > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
976     EC.Min >>= 1;
977     NumVectorRegs <<= 1;
978   }
979 
980   NumIntermediates = NumVectorRegs;
981 
982   MVT NewVT = MVT::getVectorVT(EltTy, EC);
983   if (!TLI->isTypeLegal(NewVT))
984     NewVT = EltTy;
985   IntermediateVT = NewVT;
986 
987   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits().getFixedSize();
988 
989   // Convert sizes such as i33 to i64.
990   if (!isPowerOf2_32(LaneSizeInBits))
991     LaneSizeInBits = NextPowerOf2(LaneSizeInBits);
992 
993   MVT DestVT = TLI->getRegisterType(NewVT);
994   RegisterVT = DestVT;
995   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
996     return NumVectorRegs *
997            (LaneSizeInBits / DestVT.getScalarSizeInBits().getFixedSize());
998 
999   // Otherwise, promotion or legal types use the same number of registers as
1000   // the vector decimated to the appropriate level.
1001   return NumVectorRegs;
1002 }
1003 
1004 /// isLegalRC - Return true if the value types that can be represented by the
1005 /// specified register class are all legal.
1006 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1007                                    const TargetRegisterClass &RC) const {
1008   for (auto I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1009     if (isTypeLegal(*I))
1010       return true;
1011   return false;
1012 }
1013 
1014 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1015 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1016 MachineBasicBlock *
1017 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1018                                    MachineBasicBlock *MBB) const {
1019   MachineInstr *MI = &InitialMI;
1020   MachineFunction &MF = *MI->getMF();
1021   MachineFrameInfo &MFI = MF.getFrameInfo();
1022 
1023   // We're handling multiple types of operands here:
1024   // PATCHPOINT MetaArgs - live-in, read only, direct
1025   // STATEPOINT Deopt Spill - live-through, read only, indirect
1026   // STATEPOINT Deopt Alloca - live-through, read only, direct
1027   // (We're currently conservative and mark the deopt slots read/write in
1028   // practice.)
1029   // STATEPOINT GC Spill - live-through, read/write, indirect
1030   // STATEPOINT GC Alloca - live-through, read/write, direct
1031   // The live-in vs live-through is handled already (the live through ones are
1032   // all stack slots), but we need to handle the different type of stackmap
1033   // operands and memory effects here.
1034 
1035   if (!llvm::any_of(MI->operands(),
1036                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1037     return MBB;
1038 
1039   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1040 
1041   // Inherit previous memory operands.
1042   MIB.cloneMemRefs(*MI);
1043 
1044   for (auto &MO : MI->operands()) {
1045     if (!MO.isFI()) {
1046       MIB.add(MO);
1047       continue;
1048     }
1049 
1050     // foldMemoryOperand builds a new MI after replacing a single FI operand
1051     // with the canonical set of five x86 addressing-mode operands.
1052     int FI = MO.getIndex();
1053 
1054     // Add frame index operands recognized by stackmaps.cpp
1055     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1056       // indirect-mem-ref tag, size, #FI, offset.
1057       // Used for spills inserted by StatepointLowering.  This codepath is not
1058       // used for patchpoints/stackmaps at all, for these spilling is done via
1059       // foldMemoryOperand callback only.
1060       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1061       MIB.addImm(StackMaps::IndirectMemRefOp);
1062       MIB.addImm(MFI.getObjectSize(FI));
1063       MIB.add(MO);
1064       MIB.addImm(0);
1065     } else {
1066       // direct-mem-ref tag, #FI, offset.
1067       // Used by patchpoint, and direct alloca arguments to statepoints
1068       MIB.addImm(StackMaps::DirectMemRefOp);
1069       MIB.add(MO);
1070       MIB.addImm(0);
1071     }
1072 
1073     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1074 
1075     // Add a new memory operand for this FI.
1076     assert(MFI.getObjectOffset(FI) != -1);
1077 
1078     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1079     // PATCHPOINT should be updated to do the same. (TODO)
1080     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1081       auto Flags = MachineMemOperand::MOLoad;
1082       MachineMemOperand *MMO = MF.getMachineMemOperand(
1083           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1084           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1085       MIB->addMemOperand(MF, MMO);
1086     }
1087   }
1088   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1089   MI->eraseFromParent();
1090   return MBB;
1091 }
1092 
1093 MachineBasicBlock *
1094 TargetLoweringBase::emitXRayCustomEvent(MachineInstr &MI,
1095                                         MachineBasicBlock *MBB) const {
1096   assert(MI.getOpcode() == TargetOpcode::PATCHABLE_EVENT_CALL &&
1097          "Called emitXRayCustomEvent on the wrong MI!");
1098   auto &MF = *MI.getMF();
1099   auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1100   for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1101     MIB.add(MI.getOperand(OpIdx));
1102 
1103   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1104   MI.eraseFromParent();
1105   return MBB;
1106 }
1107 
1108 MachineBasicBlock *
1109 TargetLoweringBase::emitXRayTypedEvent(MachineInstr &MI,
1110                                        MachineBasicBlock *MBB) const {
1111   assert(MI.getOpcode() == TargetOpcode::PATCHABLE_TYPED_EVENT_CALL &&
1112          "Called emitXRayTypedEvent on the wrong MI!");
1113   auto &MF = *MI.getMF();
1114   auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1115   for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1116     MIB.add(MI.getOperand(OpIdx));
1117 
1118   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1119   MI.eraseFromParent();
1120   return MBB;
1121 }
1122 
1123 /// findRepresentativeClass - Return the largest legal super-reg register class
1124 /// of the register class for the specified type and its associated "cost".
1125 // This function is in TargetLowering because it uses RegClassForVT which would
1126 // need to be moved to TargetRegisterInfo and would necessitate moving
1127 // isTypeLegal over as well - a massive change that would just require
1128 // TargetLowering having a TargetRegisterInfo class member that it would use.
1129 std::pair<const TargetRegisterClass *, uint8_t>
1130 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1131                                             MVT VT) const {
1132   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1133   if (!RC)
1134     return std::make_pair(RC, 0);
1135 
1136   // Compute the set of all super-register classes.
1137   BitVector SuperRegRC(TRI->getNumRegClasses());
1138   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1139     SuperRegRC.setBitsInMask(RCI.getMask());
1140 
1141   // Find the first legal register class with the largest spill size.
1142   const TargetRegisterClass *BestRC = RC;
1143   for (unsigned i : SuperRegRC.set_bits()) {
1144     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1145     // We want the largest possible spill size.
1146     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1147       continue;
1148     if (!isLegalRC(*TRI, *SuperRC))
1149       continue;
1150     BestRC = SuperRC;
1151   }
1152   return std::make_pair(BestRC, 1);
1153 }
1154 
1155 /// computeRegisterProperties - Once all of the register classes are added,
1156 /// this allows us to compute derived properties we expose.
1157 void TargetLoweringBase::computeRegisterProperties(
1158     const TargetRegisterInfo *TRI) {
1159   static_assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE,
1160                 "Too many value types for ValueTypeActions to hold!");
1161 
1162   // Everything defaults to needing one register.
1163   for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1164     NumRegistersForVT[i] = 1;
1165     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1166   }
1167   // ...except isVoid, which doesn't need any registers.
1168   NumRegistersForVT[MVT::isVoid] = 0;
1169 
1170   // Find the largest integer register class.
1171   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1172   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1173     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1174 
1175   // Every integer value type larger than this largest register takes twice as
1176   // many registers to represent as the previous ValueType.
1177   for (unsigned ExpandedReg = LargestIntReg + 1;
1178        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1179     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1180     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1181     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1182     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1183                                    TypeExpandInteger);
1184   }
1185 
1186   // Inspect all of the ValueType's smaller than the largest integer
1187   // register to see which ones need promotion.
1188   unsigned LegalIntReg = LargestIntReg;
1189   for (unsigned IntReg = LargestIntReg - 1;
1190        IntReg >= (unsigned)MVT::i1; --IntReg) {
1191     MVT IVT = (MVT::SimpleValueType)IntReg;
1192     if (isTypeLegal(IVT)) {
1193       LegalIntReg = IntReg;
1194     } else {
1195       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1196         (MVT::SimpleValueType)LegalIntReg;
1197       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1198     }
1199   }
1200 
1201   // ppcf128 type is really two f64's.
1202   if (!isTypeLegal(MVT::ppcf128)) {
1203     if (isTypeLegal(MVT::f64)) {
1204       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1205       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1206       TransformToType[MVT::ppcf128] = MVT::f64;
1207       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1208     } else {
1209       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1210       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1211       TransformToType[MVT::ppcf128] = MVT::i128;
1212       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1213     }
1214   }
1215 
1216   // Decide how to handle f128. If the target does not have native f128 support,
1217   // expand it to i128 and we will be generating soft float library calls.
1218   if (!isTypeLegal(MVT::f128)) {
1219     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1220     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1221     TransformToType[MVT::f128] = MVT::i128;
1222     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1223   }
1224 
1225   // Decide how to handle f64. If the target does not have native f64 support,
1226   // expand it to i64 and we will be generating soft float library calls.
1227   if (!isTypeLegal(MVT::f64)) {
1228     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1229     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1230     TransformToType[MVT::f64] = MVT::i64;
1231     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1232   }
1233 
1234   // Decide how to handle f32. If the target does not have native f32 support,
1235   // expand it to i32 and we will be generating soft float library calls.
1236   if (!isTypeLegal(MVT::f32)) {
1237     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1238     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1239     TransformToType[MVT::f32] = MVT::i32;
1240     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1241   }
1242 
1243   // Decide how to handle f16. If the target does not have native f16 support,
1244   // promote it to f32, because there are no f16 library calls (except for
1245   // conversions).
1246   if (!isTypeLegal(MVT::f16)) {
1247     // Allow targets to control how we legalize half.
1248     if (softPromoteHalfType()) {
1249       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1250       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1251       TransformToType[MVT::f16] = MVT::f32;
1252       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1253     } else {
1254       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1255       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1256       TransformToType[MVT::f16] = MVT::f32;
1257       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1258     }
1259   }
1260 
1261   // Loop over all of the vector value types to see which need transformations.
1262   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1263        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1264     MVT VT = (MVT::SimpleValueType) i;
1265     if (isTypeLegal(VT))
1266       continue;
1267 
1268     MVT EltVT = VT.getVectorElementType();
1269     ElementCount EC = VT.getVectorElementCount();
1270     bool IsLegalWiderType = false;
1271     bool IsScalable = VT.isScalableVector();
1272     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1273     switch (PreferredAction) {
1274     case TypePromoteInteger: {
1275       MVT::SimpleValueType EndVT = IsScalable ?
1276                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1277                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1278       // Try to promote the elements of integer vectors. If no legal
1279       // promotion was found, fall through to the widen-vector method.
1280       for (unsigned nVT = i + 1;
1281            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1282         MVT SVT = (MVT::SimpleValueType) nVT;
1283         // Promote vectors of integers to vectors with the same number
1284         // of elements, with a wider element type.
1285         if (SVT.getScalarSizeInBits() > EltVT.getSizeInBits() &&
1286             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1287           TransformToType[i] = SVT;
1288           RegisterTypeForVT[i] = SVT;
1289           NumRegistersForVT[i] = 1;
1290           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1291           IsLegalWiderType = true;
1292           break;
1293         }
1294       }
1295       if (IsLegalWiderType)
1296         break;
1297       LLVM_FALLTHROUGH;
1298     }
1299 
1300     case TypeWidenVector:
1301       if (isPowerOf2_32(EC.Min)) {
1302         // Try to widen the vector.
1303         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1304           MVT SVT = (MVT::SimpleValueType) nVT;
1305           if (SVT.getVectorElementType() == EltVT &&
1306               SVT.isScalableVector() == IsScalable &&
1307               SVT.getVectorElementCount().Min > EC.Min && isTypeLegal(SVT)) {
1308             TransformToType[i] = SVT;
1309             RegisterTypeForVT[i] = SVT;
1310             NumRegistersForVT[i] = 1;
1311             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1312             IsLegalWiderType = true;
1313             break;
1314           }
1315         }
1316         if (IsLegalWiderType)
1317           break;
1318       } else {
1319         // Only widen to the next power of 2 to keep consistency with EVT.
1320         MVT NVT = VT.getPow2VectorType();
1321         if (isTypeLegal(NVT)) {
1322           TransformToType[i] = NVT;
1323           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1324           RegisterTypeForVT[i] = NVT;
1325           NumRegistersForVT[i] = 1;
1326           break;
1327         }
1328       }
1329       LLVM_FALLTHROUGH;
1330 
1331     case TypeSplitVector:
1332     case TypeScalarizeVector: {
1333       MVT IntermediateVT;
1334       MVT RegisterVT;
1335       unsigned NumIntermediates;
1336       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1337           NumIntermediates, RegisterVT, this);
1338       NumRegistersForVT[i] = NumRegisters;
1339       assert(NumRegistersForVT[i] == NumRegisters &&
1340              "NumRegistersForVT size cannot represent NumRegisters!");
1341       RegisterTypeForVT[i] = RegisterVT;
1342 
1343       MVT NVT = VT.getPow2VectorType();
1344       if (NVT == VT) {
1345         // Type is already a power of 2.  The default action is to split.
1346         TransformToType[i] = MVT::Other;
1347         if (PreferredAction == TypeScalarizeVector)
1348           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1349         else if (PreferredAction == TypeSplitVector)
1350           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1351         else if (EC.Min > 1)
1352           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1353         else
1354           ValueTypeActions.setTypeAction(VT, EC.Scalable
1355                                                  ? TypeScalarizeScalableVector
1356                                                  : TypeScalarizeVector);
1357       } else {
1358         TransformToType[i] = NVT;
1359         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1360       }
1361       break;
1362     }
1363     default:
1364       llvm_unreachable("Unknown vector legalization action!");
1365     }
1366   }
1367 
1368   // Determine the 'representative' register class for each value type.
1369   // An representative register class is the largest (meaning one which is
1370   // not a sub-register class / subreg register class) legal register class for
1371   // a group of value types. For example, on i386, i8, i16, and i32
1372   // representative would be GR32; while on x86_64 it's GR64.
1373   for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1374     const TargetRegisterClass* RRC;
1375     uint8_t Cost;
1376     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1377     RepRegClassForVT[i] = RRC;
1378     RepRegClassCostForVT[i] = Cost;
1379   }
1380 }
1381 
1382 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1383                                            EVT VT) const {
1384   assert(!VT.isVector() && "No default SetCC type for vectors!");
1385   return getPointerTy(DL).SimpleTy;
1386 }
1387 
1388 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1389   return MVT::i32; // return the default value
1390 }
1391 
1392 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1393 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1394 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1395 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1396 ///
1397 /// This method returns the number of registers needed, and the VT for each
1398 /// register.  It also returns the VT and quantity of the intermediate values
1399 /// before they are promoted/expanded.
1400 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
1401                                                 EVT &IntermediateVT,
1402                                                 unsigned &NumIntermediates,
1403                                                 MVT &RegisterVT) const {
1404   ElementCount EltCnt = VT.getVectorElementCount();
1405 
1406   // If there is a wider vector type with the same element type as this one,
1407   // or a promoted vector type that has the same number of elements which
1408   // are wider, then we should convert to that legal vector type.
1409   // This handles things like <2 x float> -> <4 x float> and
1410   // <4 x i1> -> <4 x i32>.
1411   LegalizeTypeAction TA = getTypeAction(Context, VT);
1412   if (EltCnt.Min != 1 && (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1413     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1414     if (isTypeLegal(RegisterEVT)) {
1415       IntermediateVT = RegisterEVT;
1416       RegisterVT = RegisterEVT.getSimpleVT();
1417       NumIntermediates = 1;
1418       return 1;
1419     }
1420   }
1421 
1422   // Figure out the right, legal destination reg to copy into.
1423   EVT EltTy = VT.getVectorElementType();
1424 
1425   unsigned NumVectorRegs = 1;
1426 
1427   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1428   // types like done elsewhere in SelectionDAG.
1429   if (VT.isScalableVector() && !isPowerOf2_32(EltCnt.Min)) {
1430     LegalizeKind LK;
1431     EVT PartVT = VT;
1432     do {
1433       // Iterate until we've found a legal (part) type to hold VT.
1434       LK = getTypeConversion(Context, PartVT);
1435       PartVT = LK.second;
1436     } while (LK.first != TypeLegal);
1437 
1438     NumIntermediates =
1439         VT.getVectorElementCount().Min / PartVT.getVectorElementCount().Min;
1440 
1441     // FIXME: This code needs to be extended to handle more complex vector
1442     // breakdowns, like nxv7i64 -> nxv8i64 -> 4 x nxv2i64. Currently the only
1443     // supported cases are vectors that are broken down into equal parts
1444     // such as nxv6i64 -> 3 x nxv2i64.
1445     assert(NumIntermediates * PartVT.getVectorElementCount().Min ==
1446                VT.getVectorElementCount().Min &&
1447            "Expected an integer multiple of PartVT");
1448     IntermediateVT = PartVT;
1449     RegisterVT = getRegisterType(Context, IntermediateVT);
1450     return NumIntermediates;
1451   }
1452 
1453   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1454   // we could break down into LHS/RHS like LegalizeDAG does.
1455   if (!isPowerOf2_32(EltCnt.Min)) {
1456     NumVectorRegs = EltCnt.Min;
1457     EltCnt.Min = 1;
1458   }
1459 
1460   // Divide the input until we get to a supported size.  This will always
1461   // end with a scalar if the target doesn't support vectors.
1462   while (EltCnt.Min > 1 &&
1463          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1464     EltCnt.Min >>= 1;
1465     NumVectorRegs <<= 1;
1466   }
1467 
1468   NumIntermediates = NumVectorRegs;
1469 
1470   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1471   if (!isTypeLegal(NewVT))
1472     NewVT = EltTy;
1473   IntermediateVT = NewVT;
1474 
1475   MVT DestVT = getRegisterType(Context, NewVT);
1476   RegisterVT = DestVT;
1477 
1478   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1479     TypeSize NewVTSize = NewVT.getSizeInBits();
1480     // Convert sizes such as i33 to i64.
1481     if (!isPowerOf2_32(NewVTSize.getKnownMinSize()))
1482       NewVTSize = NewVTSize.NextPowerOf2();
1483     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1484   }
1485 
1486   // Otherwise, promotion or legal types use the same number of registers as
1487   // the vector decimated to the appropriate level.
1488   return NumVectorRegs;
1489 }
1490 
1491 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1492                                                 uint64_t NumCases,
1493                                                 uint64_t Range,
1494                                                 ProfileSummaryInfo *PSI,
1495                                                 BlockFrequencyInfo *BFI) const {
1496   // FIXME: This function check the maximum table size and density, but the
1497   // minimum size is not checked. It would be nice if the minimum size is
1498   // also combined within this function. Currently, the minimum size check is
1499   // performed in findJumpTable() in SelectionDAGBuiler and
1500   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1501   const bool OptForSize =
1502       SI->getParent()->getParent()->hasOptSize() ||
1503       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1504   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1505   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1506 
1507   // Check whether the number of cases is small enough and
1508   // the range is dense enough for a jump table.
1509   return (OptForSize || Range <= MaxJumpTableSize) &&
1510          (NumCases * 100 >= Range * MinDensity);
1511 }
1512 
1513 /// Get the EVTs and ArgFlags collections that represent the legalized return
1514 /// type of the given function.  This does not require a DAG or a return value,
1515 /// and is suitable for use before any DAGs for the function are constructed.
1516 /// TODO: Move this out of TargetLowering.cpp.
1517 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1518                          AttributeList attr,
1519                          SmallVectorImpl<ISD::OutputArg> &Outs,
1520                          const TargetLowering &TLI, const DataLayout &DL) {
1521   SmallVector<EVT, 4> ValueVTs;
1522   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1523   unsigned NumValues = ValueVTs.size();
1524   if (NumValues == 0) return;
1525 
1526   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1527     EVT VT = ValueVTs[j];
1528     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1529 
1530     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1531       ExtendKind = ISD::SIGN_EXTEND;
1532     else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1533       ExtendKind = ISD::ZERO_EXTEND;
1534 
1535     // FIXME: C calling convention requires the return type to be promoted to
1536     // at least 32-bit. But this is not necessary for non-C calling
1537     // conventions. The frontend should mark functions whose return values
1538     // require promoting with signext or zeroext attributes.
1539     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
1540       MVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
1541       if (VT.bitsLT(MinVT))
1542         VT = MinVT;
1543     }
1544 
1545     unsigned NumParts =
1546         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1547     MVT PartVT =
1548         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1549 
1550     // 'inreg' on function refers to return value
1551     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1552     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::InReg))
1553       Flags.setInReg();
1554 
1555     // Propagate extension type if any
1556     if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1557       Flags.setSExt();
1558     else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1559       Flags.setZExt();
1560 
1561     for (unsigned i = 0; i < NumParts; ++i)
1562       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1563   }
1564 }
1565 
1566 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1567 /// function arguments in the caller parameter area.  This is the actual
1568 /// alignment, not its logarithm.
1569 unsigned TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1570                                                    const DataLayout &DL) const {
1571   return DL.getABITypeAlign(Ty).value();
1572 }
1573 
1574 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1575     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1576     Align Alignment, MachineMemOperand::Flags Flags, bool *Fast) const {
1577   // Check if the specified alignment is sufficient based on the data layout.
1578   // TODO: While using the data layout works in practice, a better solution
1579   // would be to implement this check directly (make this a virtual function).
1580   // For example, the ABI alignment may change based on software platform while
1581   // this function should only be affected by hardware implementation.
1582   Type *Ty = VT.getTypeForEVT(Context);
1583   if (Alignment >= DL.getABITypeAlign(Ty)) {
1584     // Assume that an access that meets the ABI-specified alignment is fast.
1585     if (Fast != nullptr)
1586       *Fast = true;
1587     return true;
1588   }
1589 
1590   // This is a misaligned access.
1591   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment.value(), Flags,
1592                                         Fast);
1593 }
1594 
1595 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1596     LLVMContext &Context, const DataLayout &DL, EVT VT,
1597     const MachineMemOperand &MMO, bool *Fast) const {
1598   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1599                                         MMO.getAlign(), MMO.getFlags(), Fast);
1600 }
1601 
1602 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1603                                             const DataLayout &DL, EVT VT,
1604                                             unsigned AddrSpace, Align Alignment,
1605                                             MachineMemOperand::Flags Flags,
1606                                             bool *Fast) const {
1607   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1608                                         Flags, Fast);
1609 }
1610 
1611 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1612                                             const DataLayout &DL, EVT VT,
1613                                             const MachineMemOperand &MMO,
1614                                             bool *Fast) const {
1615   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1616                             MMO.getFlags(), Fast);
1617 }
1618 
1619 BranchProbability TargetLoweringBase::getPredictableBranchThreshold() const {
1620   return BranchProbability(MinPercentageForPredictableBranch, 100);
1621 }
1622 
1623 //===----------------------------------------------------------------------===//
1624 //  TargetTransformInfo Helpers
1625 //===----------------------------------------------------------------------===//
1626 
1627 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1628   enum InstructionOpcodes {
1629 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1630 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1631 #include "llvm/IR/Instruction.def"
1632   };
1633   switch (static_cast<InstructionOpcodes>(Opcode)) {
1634   case Ret:            return 0;
1635   case Br:             return 0;
1636   case Switch:         return 0;
1637   case IndirectBr:     return 0;
1638   case Invoke:         return 0;
1639   case CallBr:         return 0;
1640   case Resume:         return 0;
1641   case Unreachable:    return 0;
1642   case CleanupRet:     return 0;
1643   case CatchRet:       return 0;
1644   case CatchPad:       return 0;
1645   case CatchSwitch:    return 0;
1646   case CleanupPad:     return 0;
1647   case FNeg:           return ISD::FNEG;
1648   case Add:            return ISD::ADD;
1649   case FAdd:           return ISD::FADD;
1650   case Sub:            return ISD::SUB;
1651   case FSub:           return ISD::FSUB;
1652   case Mul:            return ISD::MUL;
1653   case FMul:           return ISD::FMUL;
1654   case UDiv:           return ISD::UDIV;
1655   case SDiv:           return ISD::SDIV;
1656   case FDiv:           return ISD::FDIV;
1657   case URem:           return ISD::UREM;
1658   case SRem:           return ISD::SREM;
1659   case FRem:           return ISD::FREM;
1660   case Shl:            return ISD::SHL;
1661   case LShr:           return ISD::SRL;
1662   case AShr:           return ISD::SRA;
1663   case And:            return ISD::AND;
1664   case Or:             return ISD::OR;
1665   case Xor:            return ISD::XOR;
1666   case Alloca:         return 0;
1667   case Load:           return ISD::LOAD;
1668   case Store:          return ISD::STORE;
1669   case GetElementPtr:  return 0;
1670   case Fence:          return 0;
1671   case AtomicCmpXchg:  return 0;
1672   case AtomicRMW:      return 0;
1673   case Trunc:          return ISD::TRUNCATE;
1674   case ZExt:           return ISD::ZERO_EXTEND;
1675   case SExt:           return ISD::SIGN_EXTEND;
1676   case FPToUI:         return ISD::FP_TO_UINT;
1677   case FPToSI:         return ISD::FP_TO_SINT;
1678   case UIToFP:         return ISD::UINT_TO_FP;
1679   case SIToFP:         return ISD::SINT_TO_FP;
1680   case FPTrunc:        return ISD::FP_ROUND;
1681   case FPExt:          return ISD::FP_EXTEND;
1682   case PtrToInt:       return ISD::BITCAST;
1683   case IntToPtr:       return ISD::BITCAST;
1684   case BitCast:        return ISD::BITCAST;
1685   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1686   case ICmp:           return ISD::SETCC;
1687   case FCmp:           return ISD::SETCC;
1688   case PHI:            return 0;
1689   case Call:           return 0;
1690   case Select:         return ISD::SELECT;
1691   case UserOp1:        return 0;
1692   case UserOp2:        return 0;
1693   case VAArg:          return 0;
1694   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1695   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1696   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1697   case ExtractValue:   return ISD::MERGE_VALUES;
1698   case InsertValue:    return ISD::MERGE_VALUES;
1699   case LandingPad:     return 0;
1700   case Freeze:         return ISD::FREEZE;
1701   }
1702 
1703   llvm_unreachable("Unknown instruction type encountered!");
1704 }
1705 
1706 std::pair<int, MVT>
1707 TargetLoweringBase::getTypeLegalizationCost(const DataLayout &DL,
1708                                             Type *Ty) const {
1709   LLVMContext &C = Ty->getContext();
1710   EVT MTy = getValueType(DL, Ty);
1711 
1712   int Cost = 1;
1713   // We keep legalizing the type until we find a legal kind. We assume that
1714   // the only operation that costs anything is the split. After splitting
1715   // we need to handle two types.
1716   while (true) {
1717     LegalizeKind LK = getTypeConversion(C, MTy);
1718 
1719     if (LK.first == TypeLegal)
1720       return std::make_pair(Cost, MTy.getSimpleVT());
1721 
1722     if (LK.first == TypeSplitVector || LK.first == TypeExpandInteger)
1723       Cost *= 2;
1724 
1725     // Do not loop with f128 type.
1726     if (MTy == LK.second)
1727       return std::make_pair(Cost, MTy.getSimpleVT());
1728 
1729     // Keep legalizing the type.
1730     MTy = LK.second;
1731   }
1732 }
1733 
1734 Value *TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilder<> &IRB,
1735                                                               bool UseTLS) const {
1736   // compiler-rt provides a variable with a magic name.  Targets that do not
1737   // link with compiler-rt may also provide such a variable.
1738   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1739   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1740   auto UnsafeStackPtr =
1741       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1742 
1743   Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1744 
1745   if (!UnsafeStackPtr) {
1746     auto TLSModel = UseTLS ?
1747         GlobalValue::InitialExecTLSModel :
1748         GlobalValue::NotThreadLocal;
1749     // The global variable is not defined yet, define it ourselves.
1750     // We use the initial-exec TLS model because we do not support the
1751     // variable living anywhere other than in the main executable.
1752     UnsafeStackPtr = new GlobalVariable(
1753         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1754         UnsafeStackPtrVar, nullptr, TLSModel);
1755   } else {
1756     // The variable exists, check its type and attributes.
1757     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1758       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1759     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1760       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1761                          (UseTLS ? "" : "not ") + "be thread-local");
1762   }
1763   return UnsafeStackPtr;
1764 }
1765 
1766 Value *TargetLoweringBase::getSafeStackPointerLocation(IRBuilder<> &IRB) const {
1767   if (!TM.getTargetTriple().isAndroid())
1768     return getDefaultSafeStackPointerLocation(IRB, true);
1769 
1770   // Android provides a libc function to retrieve the address of the current
1771   // thread's unsafe stack pointer.
1772   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1773   Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1774   FunctionCallee Fn = M->getOrInsertFunction("__safestack_pointer_address",
1775                                              StackPtrTy->getPointerTo(0));
1776   return IRB.CreateCall(Fn);
1777 }
1778 
1779 //===----------------------------------------------------------------------===//
1780 //  Loop Strength Reduction hooks
1781 //===----------------------------------------------------------------------===//
1782 
1783 /// isLegalAddressingMode - Return true if the addressing mode represented
1784 /// by AM is legal for this target, for a load/store of the specified type.
1785 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1786                                                const AddrMode &AM, Type *Ty,
1787                                                unsigned AS, Instruction *I) const {
1788   // The default implementation of this implements a conservative RISCy, r+r and
1789   // r+i addr mode.
1790 
1791   // Allows a sign-extended 16-bit immediate field.
1792   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1793     return false;
1794 
1795   // No global is ever allowed as a base.
1796   if (AM.BaseGV)
1797     return false;
1798 
1799   // Only support r+r,
1800   switch (AM.Scale) {
1801   case 0:  // "r+i" or just "i", depending on HasBaseReg.
1802     break;
1803   case 1:
1804     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1805       return false;
1806     // Otherwise we have r+r or r+i.
1807     break;
1808   case 2:
1809     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1810       return false;
1811     // Allow 2*r as r+r.
1812     break;
1813   default: // Don't allow n * r
1814     return false;
1815   }
1816 
1817   return true;
1818 }
1819 
1820 //===----------------------------------------------------------------------===//
1821 //  Stack Protector
1822 //===----------------------------------------------------------------------===//
1823 
1824 // For OpenBSD return its special guard variable. Otherwise return nullptr,
1825 // so that SelectionDAG handle SSP.
1826 Value *TargetLoweringBase::getIRStackGuard(IRBuilder<> &IRB) const {
1827   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1828     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1829     PointerType *PtrTy = Type::getInt8PtrTy(M.getContext());
1830     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
1831     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
1832       G->setVisibility(GlobalValue::HiddenVisibility);
1833     return C;
1834   }
1835   return nullptr;
1836 }
1837 
1838 // Currently only support "standard" __stack_chk_guard.
1839 // TODO: add LOAD_STACK_GUARD support.
1840 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1841   if (!M.getNamedValue("__stack_chk_guard"))
1842     new GlobalVariable(M, Type::getInt8PtrTy(M.getContext()), false,
1843                        GlobalVariable::ExternalLinkage,
1844                        nullptr, "__stack_chk_guard");
1845 }
1846 
1847 // Currently only support "standard" __stack_chk_guard.
1848 // TODO: add LOAD_STACK_GUARD support.
1849 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1850   return M.getNamedValue("__stack_chk_guard");
1851 }
1852 
1853 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1854   return nullptr;
1855 }
1856 
1857 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1858   return MinimumJumpTableEntries;
1859 }
1860 
1861 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
1862   MinimumJumpTableEntries = Val;
1863 }
1864 
1865 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
1866   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
1867 }
1868 
1869 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
1870   return MaximumJumpTableSize;
1871 }
1872 
1873 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
1874   MaximumJumpTableSize = Val;
1875 }
1876 
1877 bool TargetLoweringBase::isJumpTableRelative() const {
1878   return getTargetMachine().isPositionIndependent();
1879 }
1880 
1881 //===----------------------------------------------------------------------===//
1882 //  Reciprocal Estimates
1883 //===----------------------------------------------------------------------===//
1884 
1885 /// Get the reciprocal estimate attribute string for a function that will
1886 /// override the target defaults.
1887 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
1888   const Function &F = MF.getFunction();
1889   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
1890 }
1891 
1892 /// Construct a string for the given reciprocal operation of the given type.
1893 /// This string should match the corresponding option to the front-end's
1894 /// "-mrecip" flag assuming those strings have been passed through in an
1895 /// attribute string. For example, "vec-divf" for a division of a vXf32.
1896 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
1897   std::string Name = VT.isVector() ? "vec-" : "";
1898 
1899   Name += IsSqrt ? "sqrt" : "div";
1900 
1901   // TODO: Handle "half" or other float types?
1902   if (VT.getScalarType() == MVT::f64) {
1903     Name += "d";
1904   } else {
1905     assert(VT.getScalarType() == MVT::f32 &&
1906            "Unexpected FP type for reciprocal estimate");
1907     Name += "f";
1908   }
1909 
1910   return Name;
1911 }
1912 
1913 /// Return the character position and value (a single numeric character) of a
1914 /// customized refinement operation in the input string if it exists. Return
1915 /// false if there is no customized refinement step count.
1916 static bool parseRefinementStep(StringRef In, size_t &Position,
1917                                 uint8_t &Value) {
1918   const char RefStepToken = ':';
1919   Position = In.find(RefStepToken);
1920   if (Position == StringRef::npos)
1921     return false;
1922 
1923   StringRef RefStepString = In.substr(Position + 1);
1924   // Allow exactly one numeric character for the additional refinement
1925   // step parameter.
1926   if (RefStepString.size() == 1) {
1927     char RefStepChar = RefStepString[0];
1928     if (RefStepChar >= '0' && RefStepChar <= '9') {
1929       Value = RefStepChar - '0';
1930       return true;
1931     }
1932   }
1933   report_fatal_error("Invalid refinement step for -recip.");
1934 }
1935 
1936 /// For the input attribute string, return one of the ReciprocalEstimate enum
1937 /// status values (enabled, disabled, or not specified) for this operation on
1938 /// the specified data type.
1939 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
1940   if (Override.empty())
1941     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1942 
1943   SmallVector<StringRef, 4> OverrideVector;
1944   Override.split(OverrideVector, ',');
1945   unsigned NumArgs = OverrideVector.size();
1946 
1947   // Check if "all", "none", or "default" was specified.
1948   if (NumArgs == 1) {
1949     // Look for an optional setting of the number of refinement steps needed
1950     // for this type of reciprocal operation.
1951     size_t RefPos;
1952     uint8_t RefSteps;
1953     if (parseRefinementStep(Override, RefPos, RefSteps)) {
1954       // Split the string for further processing.
1955       Override = Override.substr(0, RefPos);
1956     }
1957 
1958     // All reciprocal types are enabled.
1959     if (Override == "all")
1960       return TargetLoweringBase::ReciprocalEstimate::Enabled;
1961 
1962     // All reciprocal types are disabled.
1963     if (Override == "none")
1964       return TargetLoweringBase::ReciprocalEstimate::Disabled;
1965 
1966     // Target defaults for enablement are used.
1967     if (Override == "default")
1968       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1969   }
1970 
1971   // The attribute string may omit the size suffix ('f'/'d').
1972   std::string VTName = getReciprocalOpName(IsSqrt, VT);
1973   std::string VTNameNoSize = VTName;
1974   VTNameNoSize.pop_back();
1975   static const char DisabledPrefix = '!';
1976 
1977   for (StringRef RecipType : OverrideVector) {
1978     size_t RefPos;
1979     uint8_t RefSteps;
1980     if (parseRefinementStep(RecipType, RefPos, RefSteps))
1981       RecipType = RecipType.substr(0, RefPos);
1982 
1983     // Ignore the disablement token for string matching.
1984     bool IsDisabled = RecipType[0] == DisabledPrefix;
1985     if (IsDisabled)
1986       RecipType = RecipType.substr(1);
1987 
1988     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
1989       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
1990                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
1991   }
1992 
1993   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1994 }
1995 
1996 /// For the input attribute string, return the customized refinement step count
1997 /// for this operation on the specified data type. If the step count does not
1998 /// exist, return the ReciprocalEstimate enum value for unspecified.
1999 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2000   if (Override.empty())
2001     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2002 
2003   SmallVector<StringRef, 4> OverrideVector;
2004   Override.split(OverrideVector, ',');
2005   unsigned NumArgs = OverrideVector.size();
2006 
2007   // Check if "all", "default", or "none" was specified.
2008   if (NumArgs == 1) {
2009     // Look for an optional setting of the number of refinement steps needed
2010     // for this type of reciprocal operation.
2011     size_t RefPos;
2012     uint8_t RefSteps;
2013     if (!parseRefinementStep(Override, RefPos, RefSteps))
2014       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2015 
2016     // Split the string for further processing.
2017     Override = Override.substr(0, RefPos);
2018     assert(Override != "none" &&
2019            "Disabled reciprocals, but specifed refinement steps?");
2020 
2021     // If this is a general override, return the specified number of steps.
2022     if (Override == "all" || Override == "default")
2023       return RefSteps;
2024   }
2025 
2026   // The attribute string may omit the size suffix ('f'/'d').
2027   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2028   std::string VTNameNoSize = VTName;
2029   VTNameNoSize.pop_back();
2030 
2031   for (StringRef RecipType : OverrideVector) {
2032     size_t RefPos;
2033     uint8_t RefSteps;
2034     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2035       continue;
2036 
2037     RecipType = RecipType.substr(0, RefPos);
2038     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2039       return RefSteps;
2040   }
2041 
2042   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2043 }
2044 
2045 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2046                                                     MachineFunction &MF) const {
2047   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2048 }
2049 
2050 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2051                                                    MachineFunction &MF) const {
2052   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2053 }
2054 
2055 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2056                                                MachineFunction &MF) const {
2057   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2058 }
2059 
2060 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2061                                               MachineFunction &MF) const {
2062   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2063 }
2064 
2065 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2066   MF.getRegInfo().freezeReservedRegs(MF);
2067 }
2068 
2069 MachineMemOperand::Flags
2070 TargetLoweringBase::getLoadMemOperandFlags(const LoadInst &LI,
2071                                            const DataLayout &DL) const {
2072   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2073   if (LI.isVolatile())
2074     Flags |= MachineMemOperand::MOVolatile;
2075 
2076   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2077     Flags |= MachineMemOperand::MONonTemporal;
2078 
2079   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2080     Flags |= MachineMemOperand::MOInvariant;
2081 
2082   if (isDereferenceablePointer(LI.getPointerOperand(), LI.getType(), DL))
2083     Flags |= MachineMemOperand::MODereferenceable;
2084 
2085   Flags |= getTargetMMOFlags(LI);
2086   return Flags;
2087 }
2088 
2089 MachineMemOperand::Flags
2090 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2091                                             const DataLayout &DL) const {
2092   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2093 
2094   if (SI.isVolatile())
2095     Flags |= MachineMemOperand::MOVolatile;
2096 
2097   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2098     Flags |= MachineMemOperand::MONonTemporal;
2099 
2100   // FIXME: Not preserving dereferenceable
2101   Flags |= getTargetMMOFlags(SI);
2102   return Flags;
2103 }
2104 
2105 MachineMemOperand::Flags
2106 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2107                                              const DataLayout &DL) const {
2108   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2109 
2110   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2111     if (RMW->isVolatile())
2112       Flags |= MachineMemOperand::MOVolatile;
2113   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2114     if (CmpX->isVolatile())
2115       Flags |= MachineMemOperand::MOVolatile;
2116   } else
2117     llvm_unreachable("not an atomic instruction");
2118 
2119   // FIXME: Not preserving dereferenceable
2120   Flags |= getTargetMMOFlags(AI);
2121   return Flags;
2122 }
2123 
2124 //===----------------------------------------------------------------------===//
2125 //  GlobalISel Hooks
2126 //===----------------------------------------------------------------------===//
2127 
2128 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2129                                         const TargetTransformInfo *TTI) const {
2130   auto &MF = *MI.getMF();
2131   auto &MRI = MF.getRegInfo();
2132   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2133   // this helper function computes the maximum number of uses we should consider
2134   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2135   // break even in terms of code size when the original MI has 2 users vs
2136   // choosing to potentially spill. Any more than 2 users we we have a net code
2137   // size increase. This doesn't take into account register pressure though.
2138   auto maxUses = [](unsigned RematCost) {
2139     // A cost of 1 means remats are basically free.
2140     if (RematCost == 1)
2141       return UINT_MAX;
2142     if (RematCost == 2)
2143       return 2U;
2144 
2145     // Remat is too expensive, only sink if there's one user.
2146     if (RematCost > 2)
2147       return 1U;
2148     llvm_unreachable("Unexpected remat cost");
2149   };
2150 
2151   // Helper to walk through uses and terminate if we've reached a limit. Saves
2152   // us spending time traversing uses if all we want to know is if it's >= min.
2153   auto isUsesAtMost = [&](unsigned Reg, unsigned MaxUses) {
2154     unsigned NumUses = 0;
2155     auto UI = MRI.use_instr_nodbg_begin(Reg), UE = MRI.use_instr_nodbg_end();
2156     for (; UI != UE && NumUses < MaxUses; ++UI) {
2157       NumUses++;
2158     }
2159     // If we haven't reached the end yet then there are more than MaxUses users.
2160     return UI == UE;
2161   };
2162 
2163   switch (MI.getOpcode()) {
2164   default:
2165     return false;
2166   // Constants-like instructions should be close to their users.
2167   // We don't want long live-ranges for them.
2168   case TargetOpcode::G_CONSTANT:
2169   case TargetOpcode::G_FCONSTANT:
2170   case TargetOpcode::G_FRAME_INDEX:
2171   case TargetOpcode::G_INTTOPTR:
2172     return true;
2173   case TargetOpcode::G_GLOBAL_VALUE: {
2174     unsigned RematCost = TTI->getGISelRematGlobalCost();
2175     Register Reg = MI.getOperand(0).getReg();
2176     unsigned MaxUses = maxUses(RematCost);
2177     if (MaxUses == UINT_MAX)
2178       return true; // Remats are "free" so always localize.
2179     bool B = isUsesAtMost(Reg, MaxUses);
2180     return B;
2181   }
2182   }
2183 }
2184