xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelLowering.cpp (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 //===- MipsISelLowering.cpp - Mips DAG Lowering Implementation ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that Mips uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "MipsISelLowering.h"
15 #include "MCTargetDesc/MipsBaseInfo.h"
16 #include "MCTargetDesc/MipsInstPrinter.h"
17 #include "MCTargetDesc/MipsMCTargetDesc.h"
18 #include "MipsCCState.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsMachineFunction.h"
21 #include "MipsRegisterInfo.h"
22 #include "MipsSubtarget.h"
23 #include "MipsTargetMachine.h"
24 #include "MipsTargetObjectFile.h"
25 #include "llvm/ADT/APFloat.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringRef.h"
30 #include "llvm/ADT/StringSwitch.h"
31 #include "llvm/CodeGen/CallingConvLower.h"
32 #include "llvm/CodeGen/FunctionLoweringInfo.h"
33 #include "llvm/CodeGen/ISDOpcodes.h"
34 #include "llvm/CodeGen/MachineBasicBlock.h"
35 #include "llvm/CodeGen/MachineFrameInfo.h"
36 #include "llvm/CodeGen/MachineFunction.h"
37 #include "llvm/CodeGen/MachineInstr.h"
38 #include "llvm/CodeGen/MachineInstrBuilder.h"
39 #include "llvm/CodeGen/MachineJumpTableInfo.h"
40 #include "llvm/CodeGen/MachineMemOperand.h"
41 #include "llvm/CodeGen/MachineOperand.h"
42 #include "llvm/CodeGen/MachineRegisterInfo.h"
43 #include "llvm/CodeGen/RuntimeLibcalls.h"
44 #include "llvm/CodeGen/SelectionDAG.h"
45 #include "llvm/CodeGen/SelectionDAGNodes.h"
46 #include "llvm/CodeGen/TargetFrameLowering.h"
47 #include "llvm/CodeGen/TargetInstrInfo.h"
48 #include "llvm/CodeGen/TargetRegisterInfo.h"
49 #include "llvm/CodeGen/ValueTypes.h"
50 #include "llvm/IR/CallingConv.h"
51 #include "llvm/IR/Constants.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/DebugLoc.h"
54 #include "llvm/IR/DerivedTypes.h"
55 #include "llvm/IR/Function.h"
56 #include "llvm/IR/GlobalValue.h"
57 #include "llvm/IR/Type.h"
58 #include "llvm/IR/Value.h"
59 #include "llvm/MC/MCContext.h"
60 #include "llvm/MC/MCRegisterInfo.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CodeGen.h"
63 #include "llvm/Support/CommandLine.h"
64 #include "llvm/Support/Compiler.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/MachineValueType.h"
67 #include "llvm/Support/MathExtras.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include "llvm/Target/TargetOptions.h"
70 #include <algorithm>
71 #include <cassert>
72 #include <cctype>
73 #include <cstdint>
74 #include <deque>
75 #include <iterator>
76 #include <utility>
77 #include <vector>
78 
79 using namespace llvm;
80 
81 #define DEBUG_TYPE "mips-lower"
82 
83 STATISTIC(NumTailCalls, "Number of tail calls");
84 
85 static cl::opt<bool>
86 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
87                cl::desc("MIPS: Don't trap on integer division by zero."),
88                cl::init(false));
89 
90 extern cl::opt<bool> EmitJalrReloc;
91 
92 static const MCPhysReg Mips64DPRegs[8] = {
93   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
94   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
95 };
96 
97 // If I is a shifted mask, set the size (Size) and the first bit of the
98 // mask (Pos), and return true.
99 // For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
100 static bool isShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
101   if (!isShiftedMask_64(I))
102     return false;
103 
104   Size = countPopulation(I);
105   Pos = countTrailingZeros(I);
106   return true;
107 }
108 
109 // The MIPS MSA ABI passes vector arguments in the integer register set.
110 // The number of integer registers used is dependant on the ABI used.
111 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
112                                                       CallingConv::ID CC,
113                                                       EVT VT) const {
114   if (!VT.isVector())
115     return getRegisterType(Context, VT);
116 
117   return Subtarget.isABI_O32() || VT.getSizeInBits() == 32 ? MVT::i32
118                                                            : MVT::i64;
119 }
120 
121 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
122                                                            CallingConv::ID CC,
123                                                            EVT VT) const {
124   if (VT.isVector())
125     return std::max(((unsigned)VT.getSizeInBits() /
126                      (Subtarget.isABI_O32() ? 32 : 64)),
127                     1U);
128   return MipsTargetLowering::getNumRegisters(Context, VT);
129 }
130 
131 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
132     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
133     unsigned &NumIntermediates, MVT &RegisterVT) const {
134   // Break down vector types to either 2 i64s or 4 i32s.
135   RegisterVT = getRegisterTypeForCallingConv(Context, CC, VT);
136   IntermediateVT = RegisterVT;
137   NumIntermediates = VT.getSizeInBits() < RegisterVT.getSizeInBits()
138                          ? VT.getVectorNumElements()
139                          : VT.getSizeInBits() / RegisterVT.getSizeInBits();
140 
141   return NumIntermediates;
142 }
143 
144 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
145   MachineFunction &MF = DAG.getMachineFunction();
146   MipsFunctionInfo *FI = MF.getInfo<MipsFunctionInfo>();
147   return DAG.getRegister(FI->getGlobalBaseReg(MF), Ty);
148 }
149 
150 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
151                                           SelectionDAG &DAG,
152                                           unsigned Flag) const {
153   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
154 }
155 
156 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
157                                           SelectionDAG &DAG,
158                                           unsigned Flag) const {
159   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
160 }
161 
162 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
163                                           SelectionDAG &DAG,
164                                           unsigned Flag) const {
165   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
166 }
167 
168 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
169                                           SelectionDAG &DAG,
170                                           unsigned Flag) const {
171   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
172 }
173 
174 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
175                                           SelectionDAG &DAG,
176                                           unsigned Flag) const {
177   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
178                                    N->getOffset(), Flag);
179 }
180 
181 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
182   switch ((MipsISD::NodeType)Opcode) {
183   case MipsISD::FIRST_NUMBER:      break;
184   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
185   case MipsISD::TailCall:          return "MipsISD::TailCall";
186   case MipsISD::Highest:           return "MipsISD::Highest";
187   case MipsISD::Higher:            return "MipsISD::Higher";
188   case MipsISD::Hi:                return "MipsISD::Hi";
189   case MipsISD::Lo:                return "MipsISD::Lo";
190   case MipsISD::GotHi:             return "MipsISD::GotHi";
191   case MipsISD::TlsHi:             return "MipsISD::TlsHi";
192   case MipsISD::GPRel:             return "MipsISD::GPRel";
193   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
194   case MipsISD::Ret:               return "MipsISD::Ret";
195   case MipsISD::ERet:              return "MipsISD::ERet";
196   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
197   case MipsISD::FMS:               return "MipsISD::FMS";
198   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
199   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
200   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
201   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
202   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
203   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
204   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
205   case MipsISD::MFHI:              return "MipsISD::MFHI";
206   case MipsISD::MFLO:              return "MipsISD::MFLO";
207   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
208   case MipsISD::Mult:              return "MipsISD::Mult";
209   case MipsISD::Multu:             return "MipsISD::Multu";
210   case MipsISD::MAdd:              return "MipsISD::MAdd";
211   case MipsISD::MAddu:             return "MipsISD::MAddu";
212   case MipsISD::MSub:              return "MipsISD::MSub";
213   case MipsISD::MSubu:             return "MipsISD::MSubu";
214   case MipsISD::DivRem:            return "MipsISD::DivRem";
215   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
216   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
217   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
218   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
219   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
220   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
221   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
222   case MipsISD::Sync:              return "MipsISD::Sync";
223   case MipsISD::Ext:               return "MipsISD::Ext";
224   case MipsISD::Ins:               return "MipsISD::Ins";
225   case MipsISD::CIns:              return "MipsISD::CIns";
226   case MipsISD::LWL:               return "MipsISD::LWL";
227   case MipsISD::LWR:               return "MipsISD::LWR";
228   case MipsISD::SWL:               return "MipsISD::SWL";
229   case MipsISD::SWR:               return "MipsISD::SWR";
230   case MipsISD::LDL:               return "MipsISD::LDL";
231   case MipsISD::LDR:               return "MipsISD::LDR";
232   case MipsISD::SDL:               return "MipsISD::SDL";
233   case MipsISD::SDR:               return "MipsISD::SDR";
234   case MipsISD::EXTP:              return "MipsISD::EXTP";
235   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
236   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
237   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
238   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
239   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
240   case MipsISD::SHILO:             return "MipsISD::SHILO";
241   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
242   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
243   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
244   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
245   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
246   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
247   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
248   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
249   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
250   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
251   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
252   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
253   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
254   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
255   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
256   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
257   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
258   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
259   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
260   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
261   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
262   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
263   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
264   case MipsISD::MULT:              return "MipsISD::MULT";
265   case MipsISD::MULTU:             return "MipsISD::MULTU";
266   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
267   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
268   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
269   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
270   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
271   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
272   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
273   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
274   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
275   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
276   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
277   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
278   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
279   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
280   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
281   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
282   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
283   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
284   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
285   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
286   case MipsISD::VNOR:              return "MipsISD::VNOR";
287   case MipsISD::VSHF:              return "MipsISD::VSHF";
288   case MipsISD::SHF:               return "MipsISD::SHF";
289   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
290   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
291   case MipsISD::ILVL:              return "MipsISD::ILVL";
292   case MipsISD::ILVR:              return "MipsISD::ILVR";
293   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
294   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
295   case MipsISD::INSVE:             return "MipsISD::INSVE";
296   }
297   return nullptr;
298 }
299 
300 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
301                                        const MipsSubtarget &STI)
302     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
303   // Mips does not have i1 type, so use i32 for
304   // setcc operations results (slt, sgt, ...).
305   setBooleanContents(ZeroOrOneBooleanContent);
306   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
307   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
308   // does. Integer booleans still use 0 and 1.
309   if (Subtarget.hasMips32r6())
310     setBooleanContents(ZeroOrOneBooleanContent,
311                        ZeroOrNegativeOneBooleanContent);
312 
313   // Load extented operations for i1 types must be promoted
314   for (MVT VT : MVT::integer_valuetypes()) {
315     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
316     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
317     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
318   }
319 
320   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
321   // for f32, f16
322   for (MVT VT : MVT::fp_valuetypes()) {
323     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
324     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
325   }
326 
327   // Set LoadExtAction for f16 vectors to Expand
328   for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
329     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
330     if (F16VT.isValid())
331       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
332   }
333 
334   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
335   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
336 
337   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
338 
339   // Used by legalize types to correctly generate the setcc result.
340   // Without this, every float setcc comes with a AND/OR with the result,
341   // we don't want this, since the fpcmp result goes to a flag register,
342   // which is used implicitly by brcond and select operations.
343   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
344 
345   // Mips Custom Operations
346   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
347   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
348   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
349   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
350   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
351   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
352   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
353   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
354   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
355   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
356   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
357   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
358   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
359   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
360   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
361 
362   if (!(TM.Options.NoNaNsFPMath || Subtarget.inAbs2008Mode())) {
363     setOperationAction(ISD::FABS, MVT::f32, Custom);
364     setOperationAction(ISD::FABS, MVT::f64, Custom);
365   }
366 
367   if (Subtarget.isGP64bit()) {
368     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
369     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
370     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
371     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
372     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
373     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
374     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
375     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
376     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
377     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
378     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
379     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
380   }
381 
382   if (!Subtarget.isGP64bit()) {
383     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
384     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
385     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
386   }
387 
388   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
389   if (Subtarget.isGP64bit())
390     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
391 
392   setOperationAction(ISD::SDIV, MVT::i32, Expand);
393   setOperationAction(ISD::SREM, MVT::i32, Expand);
394   setOperationAction(ISD::UDIV, MVT::i32, Expand);
395   setOperationAction(ISD::UREM, MVT::i32, Expand);
396   setOperationAction(ISD::SDIV, MVT::i64, Expand);
397   setOperationAction(ISD::SREM, MVT::i64, Expand);
398   setOperationAction(ISD::UDIV, MVT::i64, Expand);
399   setOperationAction(ISD::UREM, MVT::i64, Expand);
400 
401   // Operations not directly supported by Mips.
402   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
403   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
404   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
405   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
406   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
407   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
408   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
409   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
410   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
411   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
412   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
413   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
414   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
415   if (Subtarget.hasCnMips()) {
416     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
417     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
418   } else {
419     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
420     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
421   }
422   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
423   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
424   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
425   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
426   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
427   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
428 
429   if (!Subtarget.hasMips32r2())
430     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
431 
432   if (!Subtarget.hasMips64r2())
433     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
434 
435   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
436   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
437   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
438   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
439   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
440   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
441   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
442   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
443   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
444   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
445   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
446   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
447   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
448   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
449   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
450   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
451 
452   // Lower f16 conversion operations into library calls
453   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
454   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
455   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
456   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
457 
458   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
459 
460   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
461   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
462   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
463   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
464 
465   // Use the default for now
466   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
467   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
468 
469   if (!Subtarget.isGP64bit()) {
470     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
471     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
472   }
473 
474   if (!Subtarget.hasMips32r2()) {
475     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
476     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
477   }
478 
479   // MIPS16 lacks MIPS32's clz and clo instructions.
480   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
481     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
482   if (!Subtarget.hasMips64())
483     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
484 
485   if (!Subtarget.hasMips32r2())
486     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
487   if (!Subtarget.hasMips64r2())
488     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
489 
490   if (Subtarget.isGP64bit()) {
491     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
492     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
493     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
494     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
495   }
496 
497   setOperationAction(ISD::TRAP, MVT::Other, Legal);
498 
499   setTargetDAGCombine(ISD::SDIVREM);
500   setTargetDAGCombine(ISD::UDIVREM);
501   setTargetDAGCombine(ISD::SELECT);
502   setTargetDAGCombine(ISD::AND);
503   setTargetDAGCombine(ISD::OR);
504   setTargetDAGCombine(ISD::ADD);
505   setTargetDAGCombine(ISD::SUB);
506   setTargetDAGCombine(ISD::AssertZext);
507   setTargetDAGCombine(ISD::SHL);
508 
509   if (ABI.IsO32()) {
510     // These libcalls are not available in 32-bit.
511     setLibcallName(RTLIB::SHL_I128, nullptr);
512     setLibcallName(RTLIB::SRL_I128, nullptr);
513     setLibcallName(RTLIB::SRA_I128, nullptr);
514   }
515 
516   setMinFunctionAlignment(Subtarget.isGP64bit() ? Align(8) : Align(4));
517 
518   // The arguments on the stack are defined in terms of 4-byte slots on O32
519   // and 8-byte slots on N32/N64.
520   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? Align(8)
521                                                             : Align(4));
522 
523   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
524 
525   MaxStoresPerMemcpy = 16;
526 
527   isMicroMips = Subtarget.inMicroMipsMode();
528 }
529 
530 const MipsTargetLowering *
531 MipsTargetLowering::create(const MipsTargetMachine &TM,
532                            const MipsSubtarget &STI) {
533   if (STI.inMips16Mode())
534     return createMips16TargetLowering(TM, STI);
535 
536   return createMipsSETargetLowering(TM, STI);
537 }
538 
539 // Create a fast isel object.
540 FastISel *
541 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
542                                   const TargetLibraryInfo *libInfo) const {
543   const MipsTargetMachine &TM =
544       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
545 
546   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
547   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
548                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
549                      !Subtarget.inMicroMipsMode();
550 
551   // Disable if either of the following is true:
552   // We do not generate PIC, the ABI is not O32, XGOT is being used.
553   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() ||
554       Subtarget.useXGOT())
555     UseFastISel = false;
556 
557   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
558 }
559 
560 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
561                                            EVT VT) const {
562   if (!VT.isVector())
563     return MVT::i32;
564   return VT.changeVectorElementTypeToInteger();
565 }
566 
567 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
568                                     TargetLowering::DAGCombinerInfo &DCI,
569                                     const MipsSubtarget &Subtarget) {
570   if (DCI.isBeforeLegalizeOps())
571     return SDValue();
572 
573   EVT Ty = N->getValueType(0);
574   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
575   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
576   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
577                                                   MipsISD::DivRemU16;
578   SDLoc DL(N);
579 
580   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
581                                N->getOperand(0), N->getOperand(1));
582   SDValue InChain = DAG.getEntryNode();
583   SDValue InGlue = DivRem;
584 
585   // insert MFLO
586   if (N->hasAnyUseOfValue(0)) {
587     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
588                                             InGlue);
589     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
590     InChain = CopyFromLo.getValue(1);
591     InGlue = CopyFromLo.getValue(2);
592   }
593 
594   // insert MFHI
595   if (N->hasAnyUseOfValue(1)) {
596     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
597                                             HI, Ty, InGlue);
598     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
599   }
600 
601   return SDValue();
602 }
603 
604 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
605   switch (CC) {
606   default: llvm_unreachable("Unknown fp condition code!");
607   case ISD::SETEQ:
608   case ISD::SETOEQ: return Mips::FCOND_OEQ;
609   case ISD::SETUNE: return Mips::FCOND_UNE;
610   case ISD::SETLT:
611   case ISD::SETOLT: return Mips::FCOND_OLT;
612   case ISD::SETGT:
613   case ISD::SETOGT: return Mips::FCOND_OGT;
614   case ISD::SETLE:
615   case ISD::SETOLE: return Mips::FCOND_OLE;
616   case ISD::SETGE:
617   case ISD::SETOGE: return Mips::FCOND_OGE;
618   case ISD::SETULT: return Mips::FCOND_ULT;
619   case ISD::SETULE: return Mips::FCOND_ULE;
620   case ISD::SETUGT: return Mips::FCOND_UGT;
621   case ISD::SETUGE: return Mips::FCOND_UGE;
622   case ISD::SETUO:  return Mips::FCOND_UN;
623   case ISD::SETO:   return Mips::FCOND_OR;
624   case ISD::SETNE:
625   case ISD::SETONE: return Mips::FCOND_ONE;
626   case ISD::SETUEQ: return Mips::FCOND_UEQ;
627   }
628 }
629 
630 /// This function returns true if the floating point conditional branches and
631 /// conditional moves which use condition code CC should be inverted.
632 static bool invertFPCondCodeUser(Mips::CondCode CC) {
633   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
634     return false;
635 
636   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
637          "Illegal Condition Code");
638 
639   return true;
640 }
641 
642 // Creates and returns an FPCmp node from a setcc node.
643 // Returns Op if setcc is not a floating point comparison.
644 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
645   // must be a SETCC node
646   if (Op.getOpcode() != ISD::SETCC)
647     return Op;
648 
649   SDValue LHS = Op.getOperand(0);
650 
651   if (!LHS.getValueType().isFloatingPoint())
652     return Op;
653 
654   SDValue RHS = Op.getOperand(1);
655   SDLoc DL(Op);
656 
657   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
658   // node if necessary.
659   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
660 
661   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
662                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
663 }
664 
665 // Creates and returns a CMovFPT/F node.
666 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
667                             SDValue False, const SDLoc &DL) {
668   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
669   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
670   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
671 
672   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
673                      True.getValueType(), True, FCC0, False, Cond);
674 }
675 
676 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
677                                     TargetLowering::DAGCombinerInfo &DCI,
678                                     const MipsSubtarget &Subtarget) {
679   if (DCI.isBeforeLegalizeOps())
680     return SDValue();
681 
682   SDValue SetCC = N->getOperand(0);
683 
684   if ((SetCC.getOpcode() != ISD::SETCC) ||
685       !SetCC.getOperand(0).getValueType().isInteger())
686     return SDValue();
687 
688   SDValue False = N->getOperand(2);
689   EVT FalseTy = False.getValueType();
690 
691   if (!FalseTy.isInteger())
692     return SDValue();
693 
694   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
695 
696   // If the RHS (False) is 0, we swap the order of the operands
697   // of ISD::SELECT (obviously also inverting the condition) so that we can
698   // take advantage of conditional moves using the $0 register.
699   // Example:
700   //   return (a != 0) ? x : 0;
701   //     load $reg, x
702   //     movz $reg, $0, a
703   if (!FalseC)
704     return SDValue();
705 
706   const SDLoc DL(N);
707 
708   if (!FalseC->getZExtValue()) {
709     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
710     SDValue True = N->getOperand(1);
711 
712     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
713                          SetCC.getOperand(1),
714                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
715 
716     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
717   }
718 
719   // If both operands are integer constants there's a possibility that we
720   // can do some interesting optimizations.
721   SDValue True = N->getOperand(1);
722   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
723 
724   if (!TrueC || !True.getValueType().isInteger())
725     return SDValue();
726 
727   // We'll also ignore MVT::i64 operands as this optimizations proves
728   // to be ineffective because of the required sign extensions as the result
729   // of a SETCC operator is always MVT::i32 for non-vector types.
730   if (True.getValueType() == MVT::i64)
731     return SDValue();
732 
733   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
734 
735   // 1)  (a < x) ? y : y-1
736   //  slti $reg1, a, x
737   //  addiu $reg2, $reg1, y-1
738   if (Diff == 1)
739     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
740 
741   // 2)  (a < x) ? y-1 : y
742   //  slti $reg1, a, x
743   //  xor $reg1, $reg1, 1
744   //  addiu $reg2, $reg1, y-1
745   if (Diff == -1) {
746     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
747     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
748                          SetCC.getOperand(1),
749                          ISD::getSetCCInverse(CC, SetCC.getValueType()));
750     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
751   }
752 
753   // Could not optimize.
754   return SDValue();
755 }
756 
757 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
758                                     TargetLowering::DAGCombinerInfo &DCI,
759                                     const MipsSubtarget &Subtarget) {
760   if (DCI.isBeforeLegalizeOps())
761     return SDValue();
762 
763   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
764 
765   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
766   if (!FalseC || FalseC->getZExtValue())
767     return SDValue();
768 
769   // Since RHS (False) is 0, we swap the order of the True/False operands
770   // (obviously also inverting the condition) so that we can
771   // take advantage of conditional moves using the $0 register.
772   // Example:
773   //   return (a != 0) ? x : 0;
774   //     load $reg, x
775   //     movz $reg, $0, a
776   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
777                                                          MipsISD::CMovFP_T;
778 
779   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
780   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
781                      ValueIfFalse, FCC, ValueIfTrue, Glue);
782 }
783 
784 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
785                                  TargetLowering::DAGCombinerInfo &DCI,
786                                  const MipsSubtarget &Subtarget) {
787   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
788     return SDValue();
789 
790   SDValue FirstOperand = N->getOperand(0);
791   unsigned FirstOperandOpc = FirstOperand.getOpcode();
792   SDValue Mask = N->getOperand(1);
793   EVT ValTy = N->getValueType(0);
794   SDLoc DL(N);
795 
796   uint64_t Pos = 0, SMPos, SMSize;
797   ConstantSDNode *CN;
798   SDValue NewOperand;
799   unsigned Opc;
800 
801   // Op's second operand must be a shifted mask.
802   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
803       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
804     return SDValue();
805 
806   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
807     // Pattern match EXT.
808     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
809     //  => ext $dst, $src, pos, size
810 
811     // The second operand of the shift must be an immediate.
812     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
813       return SDValue();
814 
815     Pos = CN->getZExtValue();
816 
817     // Return if the shifted mask does not start at bit 0 or the sum of its size
818     // and Pos exceeds the word's size.
819     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
820       return SDValue();
821 
822     Opc = MipsISD::Ext;
823     NewOperand = FirstOperand.getOperand(0);
824   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
825     // Pattern match CINS.
826     //  $dst = and (shl $src , pos), mask
827     //  => cins $dst, $src, pos, size
828     // mask is a shifted mask with consecutive 1's, pos = shift amount,
829     // size = population count.
830 
831     // The second operand of the shift must be an immediate.
832     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
833       return SDValue();
834 
835     Pos = CN->getZExtValue();
836 
837     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
838         Pos + SMSize > ValTy.getSizeInBits())
839       return SDValue();
840 
841     NewOperand = FirstOperand.getOperand(0);
842     // SMSize is 'location' (position) in this case, not size.
843     SMSize--;
844     Opc = MipsISD::CIns;
845   } else {
846     // Pattern match EXT.
847     //  $dst = and $src, (2**size - 1) , if size > 16
848     //  => ext $dst, $src, pos, size , pos = 0
849 
850     // If the mask is <= 0xffff, andi can be used instead.
851     if (CN->getZExtValue() <= 0xffff)
852       return SDValue();
853 
854     // Return if the mask doesn't start at position 0.
855     if (SMPos)
856       return SDValue();
857 
858     Opc = MipsISD::Ext;
859     NewOperand = FirstOperand;
860   }
861   return DAG.getNode(Opc, DL, ValTy, NewOperand,
862                      DAG.getConstant(Pos, DL, MVT::i32),
863                      DAG.getConstant(SMSize, DL, MVT::i32));
864 }
865 
866 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
867                                 TargetLowering::DAGCombinerInfo &DCI,
868                                 const MipsSubtarget &Subtarget) {
869   // Pattern match INS.
870   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
871   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
872   //  => ins $dst, $src, size, pos, $src1
873   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
874     return SDValue();
875 
876   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
877   uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
878   ConstantSDNode *CN, *CN1;
879 
880   // See if Op's first operand matches (and $src1 , mask0).
881   if (And0.getOpcode() != ISD::AND)
882     return SDValue();
883 
884   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
885       !isShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
886     return SDValue();
887 
888   // See if Op's second operand matches (and (shl $src, pos), mask1).
889   if (And1.getOpcode() == ISD::AND &&
890       And1.getOperand(0).getOpcode() == ISD::SHL) {
891 
892     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
893         !isShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
894       return SDValue();
895 
896     // The shift masks must have the same position and size.
897     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
898       return SDValue();
899 
900     SDValue Shl = And1.getOperand(0);
901 
902     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
903       return SDValue();
904 
905     unsigned Shamt = CN->getZExtValue();
906 
907     // Return if the shift amount and the first bit position of mask are not the
908     // same.
909     EVT ValTy = N->getValueType(0);
910     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
911       return SDValue();
912 
913     SDLoc DL(N);
914     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
915                        DAG.getConstant(SMPos0, DL, MVT::i32),
916                        DAG.getConstant(SMSize0, DL, MVT::i32),
917                        And0.getOperand(0));
918   } else {
919     // Pattern match DINS.
920     //  $dst = or (and $src, mask0), mask1
921     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
922     //  => dins $dst, $src, pos, size
923     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
924         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
925          (SMSize0 + SMPos0 <= 32))) {
926       // Check if AND instruction has constant as argument
927       bool isConstCase = And1.getOpcode() != ISD::AND;
928       if (And1.getOpcode() == ISD::AND) {
929         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
930           return SDValue();
931       } else {
932         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
933           return SDValue();
934       }
935       // Don't generate INS if constant OR operand doesn't fit into bits
936       // cleared by constant AND operand.
937       if (CN->getSExtValue() & CN1->getSExtValue())
938         return SDValue();
939 
940       SDLoc DL(N);
941       EVT ValTy = N->getOperand(0)->getValueType(0);
942       SDValue Const1;
943       SDValue SrlX;
944       if (!isConstCase) {
945         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
946         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
947       }
948       return DAG.getNode(
949           MipsISD::Ins, DL, N->getValueType(0),
950           isConstCase
951               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
952               : SrlX,
953           DAG.getConstant(SMPos0, DL, MVT::i32),
954           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
955                                                         : SMSize0,
956                           DL, MVT::i32),
957           And0->getOperand(0));
958 
959     }
960     return SDValue();
961   }
962 }
963 
964 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
965                                        const MipsSubtarget &Subtarget) {
966   // ROOTNode must have a multiplication as an operand for the match to be
967   // successful.
968   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
969       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
970     return SDValue();
971 
972   // We don't handle vector types here.
973   if (ROOTNode->getValueType(0).isVector())
974     return SDValue();
975 
976   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
977   // arithmetic. E.g.
978   // (add (mul a b) c) =>
979   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
980   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
981   //   or
982   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
983   //
984   // The overhead of setting up the Hi/Lo registers and reassembling the
985   // result makes this a dubious optimzation for MIPS64. The core of the
986   // problem is that Hi/Lo contain the upper and lower 32 bits of the
987   // operand and result.
988   //
989   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
990   // density than doing it naively, 5 for MIPS64. Additionally, using
991   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
992   // extended operands, not true 64 bit values.
993   //
994   // FIXME: For the moment, disable this completely for MIPS64.
995   if (Subtarget.hasMips64())
996     return SDValue();
997 
998   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
999                      ? ROOTNode->getOperand(0)
1000                      : ROOTNode->getOperand(1);
1001 
1002   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1003                      ? ROOTNode->getOperand(1)
1004                      : ROOTNode->getOperand(0);
1005 
1006   // Transform this to a MADD only if the user of this node is the add.
1007   // If there are other users of the mul, this function returns here.
1008   if (!Mult.hasOneUse())
1009     return SDValue();
1010 
1011   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1012   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1013   // of the multiply must have 32 or more sign bits, otherwise we cannot
1014   // perform this optimization. We have to check this here as we're performing
1015   // this optimization pre-legalization.
1016   SDValue MultLHS = Mult->getOperand(0);
1017   SDValue MultRHS = Mult->getOperand(1);
1018 
1019   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1020                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1021   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1022                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1023 
1024   if (!IsSigned && !IsUnsigned)
1025     return SDValue();
1026 
1027   // Initialize accumulator.
1028   SDLoc DL(ROOTNode);
1029   SDValue TopHalf;
1030   SDValue BottomHalf;
1031   BottomHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1032                               CurDAG.getIntPtrConstant(0, DL));
1033 
1034   TopHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1035                            CurDAG.getIntPtrConstant(1, DL));
1036   SDValue ACCIn = CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped,
1037                                   BottomHalf,
1038                                   TopHalf);
1039 
1040   // Create MipsMAdd(u) / MipsMSub(u) node.
1041   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1042   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1043                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1044   SDValue MAddOps[3] = {
1045       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1046       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1047   EVT VTs[2] = {MVT::i32, MVT::i32};
1048   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1049 
1050   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1051   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1052   SDValue Combined =
1053       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1054   return Combined;
1055 }
1056 
1057 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1058                                  TargetLowering::DAGCombinerInfo &DCI,
1059                                  const MipsSubtarget &Subtarget) {
1060   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1061   if (DCI.isBeforeLegalizeOps()) {
1062     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1063         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1064       return performMADD_MSUBCombine(N, DAG, Subtarget);
1065 
1066     return SDValue();
1067   }
1068 
1069   return SDValue();
1070 }
1071 
1072 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1073                                  TargetLowering::DAGCombinerInfo &DCI,
1074                                  const MipsSubtarget &Subtarget) {
1075   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1076   if (DCI.isBeforeLegalizeOps()) {
1077     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1078         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1079       return performMADD_MSUBCombine(N, DAG, Subtarget);
1080 
1081     return SDValue();
1082   }
1083 
1084   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1085   SDValue Add = N->getOperand(1);
1086 
1087   if (Add.getOpcode() != ISD::ADD)
1088     return SDValue();
1089 
1090   SDValue Lo = Add.getOperand(1);
1091 
1092   if ((Lo.getOpcode() != MipsISD::Lo) ||
1093       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1094     return SDValue();
1095 
1096   EVT ValTy = N->getValueType(0);
1097   SDLoc DL(N);
1098 
1099   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1100                              Add.getOperand(0));
1101   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1102 }
1103 
1104 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1105                                  TargetLowering::DAGCombinerInfo &DCI,
1106                                  const MipsSubtarget &Subtarget) {
1107   // Pattern match CINS.
1108   //  $dst = shl (and $src , imm), pos
1109   //  => cins $dst, $src, pos, size
1110 
1111   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1112     return SDValue();
1113 
1114   SDValue FirstOperand = N->getOperand(0);
1115   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1116   SDValue SecondOperand = N->getOperand(1);
1117   EVT ValTy = N->getValueType(0);
1118   SDLoc DL(N);
1119 
1120   uint64_t Pos = 0, SMPos, SMSize;
1121   ConstantSDNode *CN;
1122   SDValue NewOperand;
1123 
1124   // The second operand of the shift must be an immediate.
1125   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1126     return SDValue();
1127 
1128   Pos = CN->getZExtValue();
1129 
1130   if (Pos >= ValTy.getSizeInBits())
1131     return SDValue();
1132 
1133   if (FirstOperandOpc != ISD::AND)
1134     return SDValue();
1135 
1136   // AND's second operand must be a shifted mask.
1137   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1138       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
1139     return SDValue();
1140 
1141   // Return if the shifted mask does not start at bit 0 or the sum of its size
1142   // and Pos exceeds the word's size.
1143   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1144     return SDValue();
1145 
1146   NewOperand = FirstOperand.getOperand(0);
1147   // SMSize is 'location' (position) in this case, not size.
1148   SMSize--;
1149 
1150   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1151                      DAG.getConstant(Pos, DL, MVT::i32),
1152                      DAG.getConstant(SMSize, DL, MVT::i32));
1153 }
1154 
1155 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1156   const {
1157   SelectionDAG &DAG = DCI.DAG;
1158   unsigned Opc = N->getOpcode();
1159 
1160   switch (Opc) {
1161   default: break;
1162   case ISD::SDIVREM:
1163   case ISD::UDIVREM:
1164     return performDivRemCombine(N, DAG, DCI, Subtarget);
1165   case ISD::SELECT:
1166     return performSELECTCombine(N, DAG, DCI, Subtarget);
1167   case MipsISD::CMovFP_F:
1168   case MipsISD::CMovFP_T:
1169     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1170   case ISD::AND:
1171     return performANDCombine(N, DAG, DCI, Subtarget);
1172   case ISD::OR:
1173     return performORCombine(N, DAG, DCI, Subtarget);
1174   case ISD::ADD:
1175     return performADDCombine(N, DAG, DCI, Subtarget);
1176   case ISD::SHL:
1177     return performSHLCombine(N, DAG, DCI, Subtarget);
1178   case ISD::SUB:
1179     return performSUBCombine(N, DAG, DCI, Subtarget);
1180   }
1181 
1182   return SDValue();
1183 }
1184 
1185 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
1186   return Subtarget.hasMips32();
1187 }
1188 
1189 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
1190   return Subtarget.hasMips32();
1191 }
1192 
1193 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
1194     const SDNode *N, CombineLevel Level) const {
1195   if (N->getOperand(0).getValueType().isVector())
1196     return false;
1197   return true;
1198 }
1199 
1200 void
1201 MipsTargetLowering::LowerOperationWrapper(SDNode *N,
1202                                           SmallVectorImpl<SDValue> &Results,
1203                                           SelectionDAG &DAG) const {
1204   SDValue Res = LowerOperation(SDValue(N, 0), DAG);
1205 
1206   if (Res)
1207     for (unsigned I = 0, E = Res->getNumValues(); I != E; ++I)
1208       Results.push_back(Res.getValue(I));
1209 }
1210 
1211 void
1212 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1213                                        SmallVectorImpl<SDValue> &Results,
1214                                        SelectionDAG &DAG) const {
1215   return LowerOperationWrapper(N, Results, DAG);
1216 }
1217 
1218 SDValue MipsTargetLowering::
1219 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1220 {
1221   switch (Op.getOpcode())
1222   {
1223   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1224   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1225   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1226   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1227   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1228   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1229   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1230   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1231   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1232   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1233   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1234   case ISD::FABS:               return lowerFABS(Op, DAG);
1235   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1236   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1237   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1238   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1239   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1240   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1241   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1242   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1243   case ISD::STORE:              return lowerSTORE(Op, DAG);
1244   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1245   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1246   }
1247   return SDValue();
1248 }
1249 
1250 //===----------------------------------------------------------------------===//
1251 //  Lower helper functions
1252 //===----------------------------------------------------------------------===//
1253 
1254 // addLiveIn - This helper function adds the specified physical register to the
1255 // MachineFunction as a live in value.  It also creates a corresponding
1256 // virtual register for it.
1257 static unsigned
1258 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1259 {
1260   Register VReg = MF.getRegInfo().createVirtualRegister(RC);
1261   MF.getRegInfo().addLiveIn(PReg, VReg);
1262   return VReg;
1263 }
1264 
1265 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1266                                               MachineBasicBlock &MBB,
1267                                               const TargetInstrInfo &TII,
1268                                               bool Is64Bit, bool IsMicroMips) {
1269   if (NoZeroDivCheck)
1270     return &MBB;
1271 
1272   // Insert instruction "teq $divisor_reg, $zero, 7".
1273   MachineBasicBlock::iterator I(MI);
1274   MachineInstrBuilder MIB;
1275   MachineOperand &Divisor = MI.getOperand(2);
1276   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1277                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1278             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1279             .addReg(Mips::ZERO)
1280             .addImm(7);
1281 
1282   // Use the 32-bit sub-register if this is a 64-bit division.
1283   if (Is64Bit)
1284     MIB->getOperand(0).setSubReg(Mips::sub_32);
1285 
1286   // Clear Divisor's kill flag.
1287   Divisor.setIsKill(false);
1288 
1289   // We would normally delete the original instruction here but in this case
1290   // we only needed to inject an additional instruction rather than replace it.
1291 
1292   return &MBB;
1293 }
1294 
1295 MachineBasicBlock *
1296 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1297                                                 MachineBasicBlock *BB) const {
1298   switch (MI.getOpcode()) {
1299   default:
1300     llvm_unreachable("Unexpected instr type to insert");
1301   case Mips::ATOMIC_LOAD_ADD_I8:
1302     return emitAtomicBinaryPartword(MI, BB, 1);
1303   case Mips::ATOMIC_LOAD_ADD_I16:
1304     return emitAtomicBinaryPartword(MI, BB, 2);
1305   case Mips::ATOMIC_LOAD_ADD_I32:
1306     return emitAtomicBinary(MI, BB);
1307   case Mips::ATOMIC_LOAD_ADD_I64:
1308     return emitAtomicBinary(MI, BB);
1309 
1310   case Mips::ATOMIC_LOAD_AND_I8:
1311     return emitAtomicBinaryPartword(MI, BB, 1);
1312   case Mips::ATOMIC_LOAD_AND_I16:
1313     return emitAtomicBinaryPartword(MI, BB, 2);
1314   case Mips::ATOMIC_LOAD_AND_I32:
1315     return emitAtomicBinary(MI, BB);
1316   case Mips::ATOMIC_LOAD_AND_I64:
1317     return emitAtomicBinary(MI, BB);
1318 
1319   case Mips::ATOMIC_LOAD_OR_I8:
1320     return emitAtomicBinaryPartword(MI, BB, 1);
1321   case Mips::ATOMIC_LOAD_OR_I16:
1322     return emitAtomicBinaryPartword(MI, BB, 2);
1323   case Mips::ATOMIC_LOAD_OR_I32:
1324     return emitAtomicBinary(MI, BB);
1325   case Mips::ATOMIC_LOAD_OR_I64:
1326     return emitAtomicBinary(MI, BB);
1327 
1328   case Mips::ATOMIC_LOAD_XOR_I8:
1329     return emitAtomicBinaryPartword(MI, BB, 1);
1330   case Mips::ATOMIC_LOAD_XOR_I16:
1331     return emitAtomicBinaryPartword(MI, BB, 2);
1332   case Mips::ATOMIC_LOAD_XOR_I32:
1333     return emitAtomicBinary(MI, BB);
1334   case Mips::ATOMIC_LOAD_XOR_I64:
1335     return emitAtomicBinary(MI, BB);
1336 
1337   case Mips::ATOMIC_LOAD_NAND_I8:
1338     return emitAtomicBinaryPartword(MI, BB, 1);
1339   case Mips::ATOMIC_LOAD_NAND_I16:
1340     return emitAtomicBinaryPartword(MI, BB, 2);
1341   case Mips::ATOMIC_LOAD_NAND_I32:
1342     return emitAtomicBinary(MI, BB);
1343   case Mips::ATOMIC_LOAD_NAND_I64:
1344     return emitAtomicBinary(MI, BB);
1345 
1346   case Mips::ATOMIC_LOAD_SUB_I8:
1347     return emitAtomicBinaryPartword(MI, BB, 1);
1348   case Mips::ATOMIC_LOAD_SUB_I16:
1349     return emitAtomicBinaryPartword(MI, BB, 2);
1350   case Mips::ATOMIC_LOAD_SUB_I32:
1351     return emitAtomicBinary(MI, BB);
1352   case Mips::ATOMIC_LOAD_SUB_I64:
1353     return emitAtomicBinary(MI, BB);
1354 
1355   case Mips::ATOMIC_SWAP_I8:
1356     return emitAtomicBinaryPartword(MI, BB, 1);
1357   case Mips::ATOMIC_SWAP_I16:
1358     return emitAtomicBinaryPartword(MI, BB, 2);
1359   case Mips::ATOMIC_SWAP_I32:
1360     return emitAtomicBinary(MI, BB);
1361   case Mips::ATOMIC_SWAP_I64:
1362     return emitAtomicBinary(MI, BB);
1363 
1364   case Mips::ATOMIC_CMP_SWAP_I8:
1365     return emitAtomicCmpSwapPartword(MI, BB, 1);
1366   case Mips::ATOMIC_CMP_SWAP_I16:
1367     return emitAtomicCmpSwapPartword(MI, BB, 2);
1368   case Mips::ATOMIC_CMP_SWAP_I32:
1369     return emitAtomicCmpSwap(MI, BB);
1370   case Mips::ATOMIC_CMP_SWAP_I64:
1371     return emitAtomicCmpSwap(MI, BB);
1372 
1373   case Mips::ATOMIC_LOAD_MIN_I8:
1374     return emitAtomicBinaryPartword(MI, BB, 1);
1375   case Mips::ATOMIC_LOAD_MIN_I16:
1376     return emitAtomicBinaryPartword(MI, BB, 2);
1377   case Mips::ATOMIC_LOAD_MIN_I32:
1378     return emitAtomicBinary(MI, BB);
1379   case Mips::ATOMIC_LOAD_MIN_I64:
1380     return emitAtomicBinary(MI, BB);
1381 
1382   case Mips::ATOMIC_LOAD_MAX_I8:
1383     return emitAtomicBinaryPartword(MI, BB, 1);
1384   case Mips::ATOMIC_LOAD_MAX_I16:
1385     return emitAtomicBinaryPartword(MI, BB, 2);
1386   case Mips::ATOMIC_LOAD_MAX_I32:
1387     return emitAtomicBinary(MI, BB);
1388   case Mips::ATOMIC_LOAD_MAX_I64:
1389     return emitAtomicBinary(MI, BB);
1390 
1391   case Mips::ATOMIC_LOAD_UMIN_I8:
1392     return emitAtomicBinaryPartword(MI, BB, 1);
1393   case Mips::ATOMIC_LOAD_UMIN_I16:
1394     return emitAtomicBinaryPartword(MI, BB, 2);
1395   case Mips::ATOMIC_LOAD_UMIN_I32:
1396     return emitAtomicBinary(MI, BB);
1397   case Mips::ATOMIC_LOAD_UMIN_I64:
1398     return emitAtomicBinary(MI, BB);
1399 
1400   case Mips::ATOMIC_LOAD_UMAX_I8:
1401     return emitAtomicBinaryPartword(MI, BB, 1);
1402   case Mips::ATOMIC_LOAD_UMAX_I16:
1403     return emitAtomicBinaryPartword(MI, BB, 2);
1404   case Mips::ATOMIC_LOAD_UMAX_I32:
1405     return emitAtomicBinary(MI, BB);
1406   case Mips::ATOMIC_LOAD_UMAX_I64:
1407     return emitAtomicBinary(MI, BB);
1408 
1409   case Mips::PseudoSDIV:
1410   case Mips::PseudoUDIV:
1411   case Mips::DIV:
1412   case Mips::DIVU:
1413   case Mips::MOD:
1414   case Mips::MODU:
1415     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1416                                false);
1417   case Mips::SDIV_MM_Pseudo:
1418   case Mips::UDIV_MM_Pseudo:
1419   case Mips::SDIV_MM:
1420   case Mips::UDIV_MM:
1421   case Mips::DIV_MMR6:
1422   case Mips::DIVU_MMR6:
1423   case Mips::MOD_MMR6:
1424   case Mips::MODU_MMR6:
1425     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1426   case Mips::PseudoDSDIV:
1427   case Mips::PseudoDUDIV:
1428   case Mips::DDIV:
1429   case Mips::DDIVU:
1430   case Mips::DMOD:
1431   case Mips::DMODU:
1432     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1433 
1434   case Mips::PseudoSELECT_I:
1435   case Mips::PseudoSELECT_I64:
1436   case Mips::PseudoSELECT_S:
1437   case Mips::PseudoSELECT_D32:
1438   case Mips::PseudoSELECT_D64:
1439     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1440   case Mips::PseudoSELECTFP_F_I:
1441   case Mips::PseudoSELECTFP_F_I64:
1442   case Mips::PseudoSELECTFP_F_S:
1443   case Mips::PseudoSELECTFP_F_D32:
1444   case Mips::PseudoSELECTFP_F_D64:
1445     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1446   case Mips::PseudoSELECTFP_T_I:
1447   case Mips::PseudoSELECTFP_T_I64:
1448   case Mips::PseudoSELECTFP_T_S:
1449   case Mips::PseudoSELECTFP_T_D32:
1450   case Mips::PseudoSELECTFP_T_D64:
1451     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1452   case Mips::PseudoD_SELECT_I:
1453   case Mips::PseudoD_SELECT_I64:
1454     return emitPseudoD_SELECT(MI, BB);
1455   case Mips::LDR_W:
1456     return emitLDR_W(MI, BB);
1457   case Mips::LDR_D:
1458     return emitLDR_D(MI, BB);
1459   case Mips::STR_W:
1460     return emitSTR_W(MI, BB);
1461   case Mips::STR_D:
1462     return emitSTR_D(MI, BB);
1463   }
1464 }
1465 
1466 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1467 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1468 MachineBasicBlock *
1469 MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1470                                      MachineBasicBlock *BB) const {
1471 
1472   MachineFunction *MF = BB->getParent();
1473   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1474   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1475   DebugLoc DL = MI.getDebugLoc();
1476 
1477   unsigned AtomicOp;
1478   bool NeedsAdditionalReg = false;
1479   switch (MI.getOpcode()) {
1480   case Mips::ATOMIC_LOAD_ADD_I32:
1481     AtomicOp = Mips::ATOMIC_LOAD_ADD_I32_POSTRA;
1482     break;
1483   case Mips::ATOMIC_LOAD_SUB_I32:
1484     AtomicOp = Mips::ATOMIC_LOAD_SUB_I32_POSTRA;
1485     break;
1486   case Mips::ATOMIC_LOAD_AND_I32:
1487     AtomicOp = Mips::ATOMIC_LOAD_AND_I32_POSTRA;
1488     break;
1489   case Mips::ATOMIC_LOAD_OR_I32:
1490     AtomicOp = Mips::ATOMIC_LOAD_OR_I32_POSTRA;
1491     break;
1492   case Mips::ATOMIC_LOAD_XOR_I32:
1493     AtomicOp = Mips::ATOMIC_LOAD_XOR_I32_POSTRA;
1494     break;
1495   case Mips::ATOMIC_LOAD_NAND_I32:
1496     AtomicOp = Mips::ATOMIC_LOAD_NAND_I32_POSTRA;
1497     break;
1498   case Mips::ATOMIC_SWAP_I32:
1499     AtomicOp = Mips::ATOMIC_SWAP_I32_POSTRA;
1500     break;
1501   case Mips::ATOMIC_LOAD_ADD_I64:
1502     AtomicOp = Mips::ATOMIC_LOAD_ADD_I64_POSTRA;
1503     break;
1504   case Mips::ATOMIC_LOAD_SUB_I64:
1505     AtomicOp = Mips::ATOMIC_LOAD_SUB_I64_POSTRA;
1506     break;
1507   case Mips::ATOMIC_LOAD_AND_I64:
1508     AtomicOp = Mips::ATOMIC_LOAD_AND_I64_POSTRA;
1509     break;
1510   case Mips::ATOMIC_LOAD_OR_I64:
1511     AtomicOp = Mips::ATOMIC_LOAD_OR_I64_POSTRA;
1512     break;
1513   case Mips::ATOMIC_LOAD_XOR_I64:
1514     AtomicOp = Mips::ATOMIC_LOAD_XOR_I64_POSTRA;
1515     break;
1516   case Mips::ATOMIC_LOAD_NAND_I64:
1517     AtomicOp = Mips::ATOMIC_LOAD_NAND_I64_POSTRA;
1518     break;
1519   case Mips::ATOMIC_SWAP_I64:
1520     AtomicOp = Mips::ATOMIC_SWAP_I64_POSTRA;
1521     break;
1522   case Mips::ATOMIC_LOAD_MIN_I32:
1523     AtomicOp = Mips::ATOMIC_LOAD_MIN_I32_POSTRA;
1524     NeedsAdditionalReg = true;
1525     break;
1526   case Mips::ATOMIC_LOAD_MAX_I32:
1527     AtomicOp = Mips::ATOMIC_LOAD_MAX_I32_POSTRA;
1528     NeedsAdditionalReg = true;
1529     break;
1530   case Mips::ATOMIC_LOAD_UMIN_I32:
1531     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I32_POSTRA;
1532     NeedsAdditionalReg = true;
1533     break;
1534   case Mips::ATOMIC_LOAD_UMAX_I32:
1535     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I32_POSTRA;
1536     NeedsAdditionalReg = true;
1537     break;
1538   case Mips::ATOMIC_LOAD_MIN_I64:
1539     AtomicOp = Mips::ATOMIC_LOAD_MIN_I64_POSTRA;
1540     NeedsAdditionalReg = true;
1541     break;
1542   case Mips::ATOMIC_LOAD_MAX_I64:
1543     AtomicOp = Mips::ATOMIC_LOAD_MAX_I64_POSTRA;
1544     NeedsAdditionalReg = true;
1545     break;
1546   case Mips::ATOMIC_LOAD_UMIN_I64:
1547     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I64_POSTRA;
1548     NeedsAdditionalReg = true;
1549     break;
1550   case Mips::ATOMIC_LOAD_UMAX_I64:
1551     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I64_POSTRA;
1552     NeedsAdditionalReg = true;
1553     break;
1554   default:
1555     llvm_unreachable("Unknown pseudo atomic for replacement!");
1556   }
1557 
1558   Register OldVal = MI.getOperand(0).getReg();
1559   Register Ptr = MI.getOperand(1).getReg();
1560   Register Incr = MI.getOperand(2).getReg();
1561   Register Scratch = RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1562 
1563   MachineBasicBlock::iterator II(MI);
1564 
1565   // The scratch registers here with the EarlyClobber | Define | Implicit
1566   // flags is used to persuade the register allocator and the machine
1567   // verifier to accept the usage of this register. This has to be a real
1568   // register which has an UNDEF value but is dead after the instruction which
1569   // is unique among the registers chosen for the instruction.
1570 
1571   // The EarlyClobber flag has the semantic properties that the operand it is
1572   // attached to is clobbered before the rest of the inputs are read. Hence it
1573   // must be unique among the operands to the instruction.
1574   // The Define flag is needed to coerce the machine verifier that an Undef
1575   // value isn't a problem.
1576   // The Dead flag is needed as the value in scratch isn't used by any other
1577   // instruction. Kill isn't used as Dead is more precise.
1578   // The implicit flag is here due to the interaction between the other flags
1579   // and the machine verifier.
1580 
1581   // For correctness purpose, a new pseudo is introduced here. We need this
1582   // new pseudo, so that FastRegisterAllocator does not see an ll/sc sequence
1583   // that is spread over >1 basic blocks. A register allocator which
1584   // introduces (or any codegen infact) a store, can violate the expectations
1585   // of the hardware.
1586   //
1587   // An atomic read-modify-write sequence starts with a linked load
1588   // instruction and ends with a store conditional instruction. The atomic
1589   // read-modify-write sequence fails if any of the following conditions
1590   // occur between the execution of ll and sc:
1591   //   * A coherent store is completed by another process or coherent I/O
1592   //     module into the block of synchronizable physical memory containing
1593   //     the word. The size and alignment of the block is
1594   //     implementation-dependent.
1595   //   * A coherent store is executed between an LL and SC sequence on the
1596   //     same processor to the block of synchornizable physical memory
1597   //     containing the word.
1598   //
1599 
1600   Register PtrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Ptr));
1601   Register IncrCopy = RegInfo.createVirtualRegister(RegInfo.getRegClass(Incr));
1602 
1603   BuildMI(*BB, II, DL, TII->get(Mips::COPY), IncrCopy).addReg(Incr);
1604   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1605 
1606   MachineInstrBuilder MIB =
1607       BuildMI(*BB, II, DL, TII->get(AtomicOp))
1608           .addReg(OldVal, RegState::Define | RegState::EarlyClobber)
1609           .addReg(PtrCopy)
1610           .addReg(IncrCopy)
1611           .addReg(Scratch, RegState::Define | RegState::EarlyClobber |
1612                                RegState::Implicit | RegState::Dead);
1613   if (NeedsAdditionalReg) {
1614     Register Scratch2 =
1615         RegInfo.createVirtualRegister(RegInfo.getRegClass(OldVal));
1616     MIB.addReg(Scratch2, RegState::Define | RegState::EarlyClobber |
1617                              RegState::Implicit | RegState::Dead);
1618   }
1619 
1620   MI.eraseFromParent();
1621 
1622   return BB;
1623 }
1624 
1625 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1626     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1627     unsigned SrcReg) const {
1628   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1629   const DebugLoc &DL = MI.getDebugLoc();
1630 
1631   if (Subtarget.hasMips32r2() && Size == 1) {
1632     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1633     return BB;
1634   }
1635 
1636   if (Subtarget.hasMips32r2() && Size == 2) {
1637     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1638     return BB;
1639   }
1640 
1641   MachineFunction *MF = BB->getParent();
1642   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1643   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1644   Register ScrReg = RegInfo.createVirtualRegister(RC);
1645 
1646   assert(Size < 32);
1647   int64_t ShiftImm = 32 - (Size * 8);
1648 
1649   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1650   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1651 
1652   return BB;
1653 }
1654 
1655 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1656     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1657   assert((Size == 1 || Size == 2) &&
1658          "Unsupported size for EmitAtomicBinaryPartial.");
1659 
1660   MachineFunction *MF = BB->getParent();
1661   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1662   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1663   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1664   const TargetRegisterClass *RCp =
1665     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1666   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1667   DebugLoc DL = MI.getDebugLoc();
1668 
1669   Register Dest = MI.getOperand(0).getReg();
1670   Register Ptr = MI.getOperand(1).getReg();
1671   Register Incr = MI.getOperand(2).getReg();
1672 
1673   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1674   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1675   Register Mask = RegInfo.createVirtualRegister(RC);
1676   Register Mask2 = RegInfo.createVirtualRegister(RC);
1677   Register Incr2 = RegInfo.createVirtualRegister(RC);
1678   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1679   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1680   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1681   Register Scratch = RegInfo.createVirtualRegister(RC);
1682   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1683   Register Scratch3 = RegInfo.createVirtualRegister(RC);
1684 
1685   unsigned AtomicOp = 0;
1686   bool NeedsAdditionalReg = false;
1687   switch (MI.getOpcode()) {
1688   case Mips::ATOMIC_LOAD_NAND_I8:
1689     AtomicOp = Mips::ATOMIC_LOAD_NAND_I8_POSTRA;
1690     break;
1691   case Mips::ATOMIC_LOAD_NAND_I16:
1692     AtomicOp = Mips::ATOMIC_LOAD_NAND_I16_POSTRA;
1693     break;
1694   case Mips::ATOMIC_SWAP_I8:
1695     AtomicOp = Mips::ATOMIC_SWAP_I8_POSTRA;
1696     break;
1697   case Mips::ATOMIC_SWAP_I16:
1698     AtomicOp = Mips::ATOMIC_SWAP_I16_POSTRA;
1699     break;
1700   case Mips::ATOMIC_LOAD_ADD_I8:
1701     AtomicOp = Mips::ATOMIC_LOAD_ADD_I8_POSTRA;
1702     break;
1703   case Mips::ATOMIC_LOAD_ADD_I16:
1704     AtomicOp = Mips::ATOMIC_LOAD_ADD_I16_POSTRA;
1705     break;
1706   case Mips::ATOMIC_LOAD_SUB_I8:
1707     AtomicOp = Mips::ATOMIC_LOAD_SUB_I8_POSTRA;
1708     break;
1709   case Mips::ATOMIC_LOAD_SUB_I16:
1710     AtomicOp = Mips::ATOMIC_LOAD_SUB_I16_POSTRA;
1711     break;
1712   case Mips::ATOMIC_LOAD_AND_I8:
1713     AtomicOp = Mips::ATOMIC_LOAD_AND_I8_POSTRA;
1714     break;
1715   case Mips::ATOMIC_LOAD_AND_I16:
1716     AtomicOp = Mips::ATOMIC_LOAD_AND_I16_POSTRA;
1717     break;
1718   case Mips::ATOMIC_LOAD_OR_I8:
1719     AtomicOp = Mips::ATOMIC_LOAD_OR_I8_POSTRA;
1720     break;
1721   case Mips::ATOMIC_LOAD_OR_I16:
1722     AtomicOp = Mips::ATOMIC_LOAD_OR_I16_POSTRA;
1723     break;
1724   case Mips::ATOMIC_LOAD_XOR_I8:
1725     AtomicOp = Mips::ATOMIC_LOAD_XOR_I8_POSTRA;
1726     break;
1727   case Mips::ATOMIC_LOAD_XOR_I16:
1728     AtomicOp = Mips::ATOMIC_LOAD_XOR_I16_POSTRA;
1729     break;
1730   case Mips::ATOMIC_LOAD_MIN_I8:
1731     AtomicOp = Mips::ATOMIC_LOAD_MIN_I8_POSTRA;
1732     NeedsAdditionalReg = true;
1733     break;
1734   case Mips::ATOMIC_LOAD_MIN_I16:
1735     AtomicOp = Mips::ATOMIC_LOAD_MIN_I16_POSTRA;
1736     NeedsAdditionalReg = true;
1737     break;
1738   case Mips::ATOMIC_LOAD_MAX_I8:
1739     AtomicOp = Mips::ATOMIC_LOAD_MAX_I8_POSTRA;
1740     NeedsAdditionalReg = true;
1741     break;
1742   case Mips::ATOMIC_LOAD_MAX_I16:
1743     AtomicOp = Mips::ATOMIC_LOAD_MAX_I16_POSTRA;
1744     NeedsAdditionalReg = true;
1745     break;
1746   case Mips::ATOMIC_LOAD_UMIN_I8:
1747     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I8_POSTRA;
1748     NeedsAdditionalReg = true;
1749     break;
1750   case Mips::ATOMIC_LOAD_UMIN_I16:
1751     AtomicOp = Mips::ATOMIC_LOAD_UMIN_I16_POSTRA;
1752     NeedsAdditionalReg = true;
1753     break;
1754   case Mips::ATOMIC_LOAD_UMAX_I8:
1755     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I8_POSTRA;
1756     NeedsAdditionalReg = true;
1757     break;
1758   case Mips::ATOMIC_LOAD_UMAX_I16:
1759     AtomicOp = Mips::ATOMIC_LOAD_UMAX_I16_POSTRA;
1760     NeedsAdditionalReg = true;
1761     break;
1762   default:
1763     llvm_unreachable("Unknown subword atomic pseudo for expansion!");
1764   }
1765 
1766   // insert new blocks after the current block
1767   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1768   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1769   MachineFunction::iterator It = ++BB->getIterator();
1770   MF->insert(It, exitMBB);
1771 
1772   // Transfer the remainder of BB and its successor edges to exitMBB.
1773   exitMBB->splice(exitMBB->begin(), BB,
1774                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1775   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1776 
1777   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1778 
1779   //  thisMBB:
1780   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1781   //    and     alignedaddr,ptr,masklsb2
1782   //    andi    ptrlsb2,ptr,3
1783   //    sll     shiftamt,ptrlsb2,3
1784   //    ori     maskupper,$0,255               # 0xff
1785   //    sll     mask,maskupper,shiftamt
1786   //    nor     mask2,$0,mask
1787   //    sll     incr2,incr,shiftamt
1788 
1789   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1790   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1791     .addReg(ABI.GetNullPtr()).addImm(-4);
1792   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1793     .addReg(Ptr).addReg(MaskLSB2);
1794   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1795       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1796   if (Subtarget.isLittle()) {
1797     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1798   } else {
1799     Register Off = RegInfo.createVirtualRegister(RC);
1800     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1801       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1802     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1803   }
1804   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1805     .addReg(Mips::ZERO).addImm(MaskImm);
1806   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1807     .addReg(MaskUpper).addReg(ShiftAmt);
1808   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1809   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1810 
1811 
1812   // The purposes of the flags on the scratch registers is explained in
1813   // emitAtomicBinary. In summary, we need a scratch register which is going to
1814   // be undef, that is unique among registers chosen for the instruction.
1815 
1816   MachineInstrBuilder MIB =
1817       BuildMI(BB, DL, TII->get(AtomicOp))
1818           .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1819           .addReg(AlignedAddr)
1820           .addReg(Incr2)
1821           .addReg(Mask)
1822           .addReg(Mask2)
1823           .addReg(ShiftAmt)
1824           .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1825                                RegState::Dead | RegState::Implicit)
1826           .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
1827                                 RegState::Dead | RegState::Implicit)
1828           .addReg(Scratch3, RegState::EarlyClobber | RegState::Define |
1829                                 RegState::Dead | RegState::Implicit);
1830   if (NeedsAdditionalReg) {
1831     Register Scratch4 = RegInfo.createVirtualRegister(RC);
1832     MIB.addReg(Scratch4, RegState::EarlyClobber | RegState::Define |
1833                              RegState::Dead | RegState::Implicit);
1834   }
1835 
1836   MI.eraseFromParent(); // The instruction is gone now.
1837 
1838   return exitMBB;
1839 }
1840 
1841 // Lower atomic compare and swap to a pseudo instruction, taking care to
1842 // define a scratch register for the pseudo instruction's expansion. The
1843 // instruction is expanded after the register allocator as to prevent
1844 // the insertion of stores between the linked load and the store conditional.
1845 
1846 MachineBasicBlock *
1847 MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1848                                       MachineBasicBlock *BB) const {
1849 
1850   assert((MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ||
1851           MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I64) &&
1852          "Unsupported atomic pseudo for EmitAtomicCmpSwap.");
1853 
1854   const unsigned Size = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32 ? 4 : 8;
1855 
1856   MachineFunction *MF = BB->getParent();
1857   MachineRegisterInfo &MRI = MF->getRegInfo();
1858   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1859   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1860   DebugLoc DL = MI.getDebugLoc();
1861 
1862   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I32
1863                           ? Mips::ATOMIC_CMP_SWAP_I32_POSTRA
1864                           : Mips::ATOMIC_CMP_SWAP_I64_POSTRA;
1865   Register Dest = MI.getOperand(0).getReg();
1866   Register Ptr = MI.getOperand(1).getReg();
1867   Register OldVal = MI.getOperand(2).getReg();
1868   Register NewVal = MI.getOperand(3).getReg();
1869 
1870   Register Scratch = MRI.createVirtualRegister(RC);
1871   MachineBasicBlock::iterator II(MI);
1872 
1873   // We need to create copies of the various registers and kill them at the
1874   // atomic pseudo. If the copies are not made, when the atomic is expanded
1875   // after fast register allocation, the spills will end up outside of the
1876   // blocks that their values are defined in, causing livein errors.
1877 
1878   Register PtrCopy = MRI.createVirtualRegister(MRI.getRegClass(Ptr));
1879   Register OldValCopy = MRI.createVirtualRegister(MRI.getRegClass(OldVal));
1880   Register NewValCopy = MRI.createVirtualRegister(MRI.getRegClass(NewVal));
1881 
1882   BuildMI(*BB, II, DL, TII->get(Mips::COPY), PtrCopy).addReg(Ptr);
1883   BuildMI(*BB, II, DL, TII->get(Mips::COPY), OldValCopy).addReg(OldVal);
1884   BuildMI(*BB, II, DL, TII->get(Mips::COPY), NewValCopy).addReg(NewVal);
1885 
1886   // The purposes of the flags on the scratch registers is explained in
1887   // emitAtomicBinary. In summary, we need a scratch register which is going to
1888   // be undef, that is unique among registers chosen for the instruction.
1889 
1890   BuildMI(*BB, II, DL, TII->get(AtomicOp))
1891       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
1892       .addReg(PtrCopy, RegState::Kill)
1893       .addReg(OldValCopy, RegState::Kill)
1894       .addReg(NewValCopy, RegState::Kill)
1895       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
1896                            RegState::Dead | RegState::Implicit);
1897 
1898   MI.eraseFromParent(); // The instruction is gone now.
1899 
1900   return BB;
1901 }
1902 
1903 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1904     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1905   assert((Size == 1 || Size == 2) &&
1906       "Unsupported size for EmitAtomicCmpSwapPartial.");
1907 
1908   MachineFunction *MF = BB->getParent();
1909   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1910   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1911   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1912   const TargetRegisterClass *RCp =
1913     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1914   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1915   DebugLoc DL = MI.getDebugLoc();
1916 
1917   Register Dest = MI.getOperand(0).getReg();
1918   Register Ptr = MI.getOperand(1).getReg();
1919   Register CmpVal = MI.getOperand(2).getReg();
1920   Register NewVal = MI.getOperand(3).getReg();
1921 
1922   Register AlignedAddr = RegInfo.createVirtualRegister(RCp);
1923   Register ShiftAmt = RegInfo.createVirtualRegister(RC);
1924   Register Mask = RegInfo.createVirtualRegister(RC);
1925   Register Mask2 = RegInfo.createVirtualRegister(RC);
1926   Register ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1927   Register ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1928   Register MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1929   Register PtrLSB2 = RegInfo.createVirtualRegister(RC);
1930   Register MaskUpper = RegInfo.createVirtualRegister(RC);
1931   Register MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1932   Register MaskedNewVal = RegInfo.createVirtualRegister(RC);
1933   unsigned AtomicOp = MI.getOpcode() == Mips::ATOMIC_CMP_SWAP_I8
1934                           ? Mips::ATOMIC_CMP_SWAP_I8_POSTRA
1935                           : Mips::ATOMIC_CMP_SWAP_I16_POSTRA;
1936 
1937   // The scratch registers here with the EarlyClobber | Define | Dead | Implicit
1938   // flags are used to coerce the register allocator and the machine verifier to
1939   // accept the usage of these registers.
1940   // The EarlyClobber flag has the semantic properties that the operand it is
1941   // attached to is clobbered before the rest of the inputs are read. Hence it
1942   // must be unique among the operands to the instruction.
1943   // The Define flag is needed to coerce the machine verifier that an Undef
1944   // value isn't a problem.
1945   // The Dead flag is needed as the value in scratch isn't used by any other
1946   // instruction. Kill isn't used as Dead is more precise.
1947   Register Scratch = RegInfo.createVirtualRegister(RC);
1948   Register Scratch2 = RegInfo.createVirtualRegister(RC);
1949 
1950   // insert new blocks after the current block
1951   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1952   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1953   MachineFunction::iterator It = ++BB->getIterator();
1954   MF->insert(It, exitMBB);
1955 
1956   // Transfer the remainder of BB and its successor edges to exitMBB.
1957   exitMBB->splice(exitMBB->begin(), BB,
1958                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1959   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1960 
1961   BB->addSuccessor(exitMBB, BranchProbability::getOne());
1962 
1963   //  thisMBB:
1964   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1965   //    and     alignedaddr,ptr,masklsb2
1966   //    andi    ptrlsb2,ptr,3
1967   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1968   //    sll     shiftamt,ptrlsb2,3
1969   //    ori     maskupper,$0,255               # 0xff
1970   //    sll     mask,maskupper,shiftamt
1971   //    nor     mask2,$0,mask
1972   //    andi    maskedcmpval,cmpval,255
1973   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1974   //    andi    maskednewval,newval,255
1975   //    sll     shiftednewval,maskednewval,shiftamt
1976   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1977   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1978     .addReg(ABI.GetNullPtr()).addImm(-4);
1979   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1980     .addReg(Ptr).addReg(MaskLSB2);
1981   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1982       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1983   if (Subtarget.isLittle()) {
1984     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1985   } else {
1986     Register Off = RegInfo.createVirtualRegister(RC);
1987     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1988       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1989     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1990   }
1991   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1992     .addReg(Mips::ZERO).addImm(MaskImm);
1993   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1994     .addReg(MaskUpper).addReg(ShiftAmt);
1995   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1996   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1997     .addReg(CmpVal).addImm(MaskImm);
1998   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1999     .addReg(MaskedCmpVal).addReg(ShiftAmt);
2000   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
2001     .addReg(NewVal).addImm(MaskImm);
2002   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
2003     .addReg(MaskedNewVal).addReg(ShiftAmt);
2004 
2005   // The purposes of the flags on the scratch registers are explained in
2006   // emitAtomicBinary. In summary, we need a scratch register which is going to
2007   // be undef, that is unique among the register chosen for the instruction.
2008 
2009   BuildMI(BB, DL, TII->get(AtomicOp))
2010       .addReg(Dest, RegState::Define | RegState::EarlyClobber)
2011       .addReg(AlignedAddr)
2012       .addReg(Mask)
2013       .addReg(ShiftedCmpVal)
2014       .addReg(Mask2)
2015       .addReg(ShiftedNewVal)
2016       .addReg(ShiftAmt)
2017       .addReg(Scratch, RegState::EarlyClobber | RegState::Define |
2018                            RegState::Dead | RegState::Implicit)
2019       .addReg(Scratch2, RegState::EarlyClobber | RegState::Define |
2020                             RegState::Dead | RegState::Implicit);
2021 
2022   MI.eraseFromParent(); // The instruction is gone now.
2023 
2024   return exitMBB;
2025 }
2026 
2027 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
2028   // The first operand is the chain, the second is the condition, the third is
2029   // the block to branch to if the condition is true.
2030   SDValue Chain = Op.getOperand(0);
2031   SDValue Dest = Op.getOperand(2);
2032   SDLoc DL(Op);
2033 
2034   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2035   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
2036 
2037   // Return if flag is not set by a floating point comparison.
2038   if (CondRes.getOpcode() != MipsISD::FPCmp)
2039     return Op;
2040 
2041   SDValue CCNode  = CondRes.getOperand(2);
2042   Mips::CondCode CC =
2043     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
2044   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
2045   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
2046   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
2047   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
2048                      FCC0, Dest, CondRes);
2049 }
2050 
2051 SDValue MipsTargetLowering::
2052 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
2053 {
2054   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2055   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
2056 
2057   // Return if flag is not set by a floating point comparison.
2058   if (Cond.getOpcode() != MipsISD::FPCmp)
2059     return Op;
2060 
2061   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
2062                       SDLoc(Op));
2063 }
2064 
2065 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
2066   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
2067   SDValue Cond = createFPCmp(DAG, Op);
2068 
2069   assert(Cond.getOpcode() == MipsISD::FPCmp &&
2070          "Floating point operand expected.");
2071 
2072   SDLoc DL(Op);
2073   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2074   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2075 
2076   return createCMovFP(DAG, Cond, True, False, DL);
2077 }
2078 
2079 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2080                                                SelectionDAG &DAG) const {
2081   EVT Ty = Op.getValueType();
2082   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2083   const GlobalValue *GV = N->getGlobal();
2084 
2085   if (!isPositionIndependent()) {
2086     const MipsTargetObjectFile *TLOF =
2087         static_cast<const MipsTargetObjectFile *>(
2088             getTargetMachine().getObjFileLowering());
2089     const GlobalObject *GO = GV->getBaseObject();
2090     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2091       // %gp_rel relocation
2092       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2093 
2094                                 // %hi/%lo relocation
2095     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2096                                 // %highest/%higher/%hi/%lo relocation
2097                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2098   }
2099 
2100   // Every other architecture would use shouldAssumeDSOLocal in here, but
2101   // mips is special.
2102   // * In PIC code mips requires got loads even for local statics!
2103   // * To save on got entries, for local statics the got entry contains the
2104   //   page and an additional add instruction takes care of the low bits.
2105   // * It is legal to access a hidden symbol with a non hidden undefined,
2106   //   so one cannot guarantee that all access to a hidden symbol will know
2107   //   it is hidden.
2108   // * Mips linkers don't support creating a page and a full got entry for
2109   //   the same symbol.
2110   // * Given all that, we have to use a full got entry for hidden symbols :-(
2111   if (GV->hasLocalLinkage())
2112     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2113 
2114   if (Subtarget.useXGOT())
2115     return getAddrGlobalLargeGOT(
2116         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2117         DAG.getEntryNode(),
2118         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2119 
2120   return getAddrGlobal(
2121       N, SDLoc(N), Ty, DAG,
2122       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2123       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2124 }
2125 
2126 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2127                                               SelectionDAG &DAG) const {
2128   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2129   EVT Ty = Op.getValueType();
2130 
2131   if (!isPositionIndependent())
2132     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2133                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2134 
2135   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2136 }
2137 
2138 SDValue MipsTargetLowering::
2139 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2140 {
2141   // If the relocation model is PIC, use the General Dynamic TLS Model or
2142   // Local Dynamic TLS model, otherwise use the Initial Exec or
2143   // Local Exec TLS Model.
2144 
2145   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2146   if (DAG.getTarget().useEmulatedTLS())
2147     return LowerToTLSEmulatedModel(GA, DAG);
2148 
2149   SDLoc DL(GA);
2150   const GlobalValue *GV = GA->getGlobal();
2151   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2152 
2153   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2154 
2155   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2156     // General Dynamic and Local Dynamic TLS Model.
2157     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2158                                                       : MipsII::MO_TLSGD;
2159 
2160     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2161     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2162                                    getGlobalReg(DAG, PtrVT), TGA);
2163     unsigned PtrSize = PtrVT.getSizeInBits();
2164     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2165 
2166     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2167 
2168     ArgListTy Args;
2169     ArgListEntry Entry;
2170     Entry.Node = Argument;
2171     Entry.Ty = PtrTy;
2172     Args.push_back(Entry);
2173 
2174     TargetLowering::CallLoweringInfo CLI(DAG);
2175     CLI.setDebugLoc(DL)
2176         .setChain(DAG.getEntryNode())
2177         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2178     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2179 
2180     SDValue Ret = CallResult.first;
2181 
2182     if (model != TLSModel::LocalDynamic)
2183       return Ret;
2184 
2185     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2186                                                MipsII::MO_DTPREL_HI);
2187     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2188     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2189                                                MipsII::MO_DTPREL_LO);
2190     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2191     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2192     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2193   }
2194 
2195   SDValue Offset;
2196   if (model == TLSModel::InitialExec) {
2197     // Initial Exec TLS Model
2198     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2199                                              MipsII::MO_GOTTPREL);
2200     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2201                       TGA);
2202     Offset =
2203         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2204   } else {
2205     // Local Exec TLS Model
2206     assert(model == TLSModel::LocalExec);
2207     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2208                                                MipsII::MO_TPREL_HI);
2209     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2210                                                MipsII::MO_TPREL_LO);
2211     SDValue Hi = DAG.getNode(MipsISD::TlsHi, DL, PtrVT, TGAHi);
2212     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2213     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2214   }
2215 
2216   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2217   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2218 }
2219 
2220 SDValue MipsTargetLowering::
2221 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2222 {
2223   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2224   EVT Ty = Op.getValueType();
2225 
2226   if (!isPositionIndependent())
2227     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2228                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2229 
2230   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2231 }
2232 
2233 SDValue MipsTargetLowering::
2234 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2235 {
2236   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2237   EVT Ty = Op.getValueType();
2238 
2239   if (!isPositionIndependent()) {
2240     const MipsTargetObjectFile *TLOF =
2241         static_cast<const MipsTargetObjectFile *>(
2242             getTargetMachine().getObjFileLowering());
2243 
2244     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2245                                        getTargetMachine()))
2246       // %gp_rel relocation
2247       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2248 
2249     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2250                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2251   }
2252 
2253  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2254 }
2255 
2256 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2257   MachineFunction &MF = DAG.getMachineFunction();
2258   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2259 
2260   SDLoc DL(Op);
2261   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2262                                  getPointerTy(MF.getDataLayout()));
2263 
2264   // vastart just stores the address of the VarArgsFrameIndex slot into the
2265   // memory location argument.
2266   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2267   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2268                       MachinePointerInfo(SV));
2269 }
2270 
2271 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2272   SDNode *Node = Op.getNode();
2273   EVT VT = Node->getValueType(0);
2274   SDValue Chain = Node->getOperand(0);
2275   SDValue VAListPtr = Node->getOperand(1);
2276   const Align Align =
2277       llvm::MaybeAlign(Node->getConstantOperandVal(3)).valueOrOne();
2278   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2279   SDLoc DL(Node);
2280   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2281 
2282   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2283                                    VAListPtr, MachinePointerInfo(SV));
2284   SDValue VAList = VAListLoad;
2285 
2286   // Re-align the pointer if necessary.
2287   // It should only ever be necessary for 64-bit types on O32 since the minimum
2288   // argument alignment is the same as the maximum type alignment for N32/N64.
2289   //
2290   // FIXME: We currently align too often. The code generator doesn't notice
2291   //        when the pointer is still aligned from the last va_arg (or pair of
2292   //        va_args for the i64 on O32 case).
2293   if (Align > getMinStackArgumentAlignment()) {
2294     VAList = DAG.getNode(
2295         ISD::ADD, DL, VAList.getValueType(), VAList,
2296         DAG.getConstant(Align.value() - 1, DL, VAList.getValueType()));
2297 
2298     VAList = DAG.getNode(
2299         ISD::AND, DL, VAList.getValueType(), VAList,
2300         DAG.getConstant(-(int64_t)Align.value(), DL, VAList.getValueType()));
2301   }
2302 
2303   // Increment the pointer, VAList, to the next vaarg.
2304   auto &TD = DAG.getDataLayout();
2305   unsigned ArgSizeInBytes =
2306       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2307   SDValue Tmp3 =
2308       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2309                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2310                                   DL, VAList.getValueType()));
2311   // Store the incremented VAList to the legalized pointer
2312   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2313                        MachinePointerInfo(SV));
2314 
2315   // In big-endian mode we must adjust the pointer when the load size is smaller
2316   // than the argument slot size. We must also reduce the known alignment to
2317   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2318   // the correct half of the slot, and reduce the alignment from 8 (slot
2319   // alignment) down to 4 (type alignment).
2320   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2321     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2322     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2323                          DAG.getIntPtrConstant(Adjustment, DL));
2324   }
2325   // Load the actual argument out of the pointer VAList
2326   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2327 }
2328 
2329 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2330                                 bool HasExtractInsert) {
2331   EVT TyX = Op.getOperand(0).getValueType();
2332   EVT TyY = Op.getOperand(1).getValueType();
2333   SDLoc DL(Op);
2334   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2335   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2336   SDValue Res;
2337 
2338   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2339   // to i32.
2340   SDValue X = (TyX == MVT::f32) ?
2341     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2342     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2343                 Const1);
2344   SDValue Y = (TyY == MVT::f32) ?
2345     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2346     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2347                 Const1);
2348 
2349   if (HasExtractInsert) {
2350     // ext  E, Y, 31, 1  ; extract bit31 of Y
2351     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2352     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2353     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2354   } else {
2355     // sll SllX, X, 1
2356     // srl SrlX, SllX, 1
2357     // srl SrlY, Y, 31
2358     // sll SllY, SrlX, 31
2359     // or  Or, SrlX, SllY
2360     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2361     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2362     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2363     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2364     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2365   }
2366 
2367   if (TyX == MVT::f32)
2368     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2369 
2370   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2371                              Op.getOperand(0),
2372                              DAG.getConstant(0, DL, MVT::i32));
2373   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2374 }
2375 
2376 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2377                                 bool HasExtractInsert) {
2378   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2379   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2380   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2381   SDLoc DL(Op);
2382   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2383 
2384   // Bitcast to integer nodes.
2385   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2386   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2387 
2388   if (HasExtractInsert) {
2389     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2390     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2391     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2392                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2393 
2394     if (WidthX > WidthY)
2395       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2396     else if (WidthY > WidthX)
2397       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2398 
2399     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2400                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2401                             X);
2402     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2403   }
2404 
2405   // (d)sll SllX, X, 1
2406   // (d)srl SrlX, SllX, 1
2407   // (d)srl SrlY, Y, width(Y)-1
2408   // (d)sll SllY, SrlX, width(Y)-1
2409   // or     Or, SrlX, SllY
2410   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2411   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2412   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2413                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2414 
2415   if (WidthX > WidthY)
2416     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2417   else if (WidthY > WidthX)
2418     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2419 
2420   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2421                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2422   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2423   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2424 }
2425 
2426 SDValue
2427 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2428   if (Subtarget.isGP64bit())
2429     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2430 
2431   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2432 }
2433 
2434 static SDValue lowerFABS32(SDValue Op, SelectionDAG &DAG,
2435                            bool HasExtractInsert) {
2436   SDLoc DL(Op);
2437   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2438 
2439   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2440   // to i32.
2441   SDValue X = (Op.getValueType() == MVT::f32)
2442                   ? DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0))
2443                   : DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2444                                 Op.getOperand(0), Const1);
2445 
2446   // Clear MSB.
2447   if (HasExtractInsert)
2448     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32,
2449                       DAG.getRegister(Mips::ZERO, MVT::i32),
2450                       DAG.getConstant(31, DL, MVT::i32), Const1, X);
2451   else {
2452     // TODO: Provide DAG patterns which transform (and x, cst)
2453     // back to a (shl (srl x (clz cst)) (clz cst)) sequence.
2454     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2455     Res = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2456   }
2457 
2458   if (Op.getValueType() == MVT::f32)
2459     return DAG.getNode(ISD::BITCAST, DL, MVT::f32, Res);
2460 
2461   // FIXME: For mips32r2, the sequence of (BuildPairF64 (ins (ExtractElementF64
2462   // Op 1), $zero, 31 1) (ExtractElementF64 Op 0)) and the Op has one use, we
2463   // should be able to drop the usage of mfc1/mtc1 and rewrite the register in
2464   // place.
2465   SDValue LowX =
2466       DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2467                   DAG.getConstant(0, DL, MVT::i32));
2468   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2469 }
2470 
2471 static SDValue lowerFABS64(SDValue Op, SelectionDAG &DAG,
2472                            bool HasExtractInsert) {
2473   SDLoc DL(Op);
2474   SDValue Res, Const1 = DAG.getConstant(1, DL, MVT::i32);
2475 
2476   // Bitcast to integer node.
2477   SDValue X = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Op.getOperand(0));
2478 
2479   // Clear MSB.
2480   if (HasExtractInsert)
2481     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i64,
2482                       DAG.getRegister(Mips::ZERO_64, MVT::i64),
2483                       DAG.getConstant(63, DL, MVT::i32), Const1, X);
2484   else {
2485     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i64, X, Const1);
2486     Res = DAG.getNode(ISD::SRL, DL, MVT::i64, SllX, Const1);
2487   }
2488 
2489   return DAG.getNode(ISD::BITCAST, DL, MVT::f64, Res);
2490 }
2491 
2492 SDValue MipsTargetLowering::lowerFABS(SDValue Op, SelectionDAG &DAG) const {
2493   if ((ABI.IsN32() || ABI.IsN64()) && (Op.getValueType() == MVT::f64))
2494     return lowerFABS64(Op, DAG, Subtarget.hasExtractInsert());
2495 
2496   return lowerFABS32(Op, DAG, Subtarget.hasExtractInsert());
2497 }
2498 
2499 SDValue MipsTargetLowering::
2500 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2501   // check the depth
2502   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2503     DAG.getContext()->emitError(
2504         "return address can be determined only for current frame");
2505     return SDValue();
2506   }
2507 
2508   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2509   MFI.setFrameAddressIsTaken(true);
2510   EVT VT = Op.getValueType();
2511   SDLoc DL(Op);
2512   SDValue FrameAddr = DAG.getCopyFromReg(
2513       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2514   return FrameAddr;
2515 }
2516 
2517 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2518                                             SelectionDAG &DAG) const {
2519   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2520     return SDValue();
2521 
2522   // check the depth
2523   if (cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() != 0) {
2524     DAG.getContext()->emitError(
2525         "return address can be determined only for current frame");
2526     return SDValue();
2527   }
2528 
2529   MachineFunction &MF = DAG.getMachineFunction();
2530   MachineFrameInfo &MFI = MF.getFrameInfo();
2531   MVT VT = Op.getSimpleValueType();
2532   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2533   MFI.setReturnAddressIsTaken(true);
2534 
2535   // Return RA, which contains the return address. Mark it an implicit live-in.
2536   unsigned Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2537   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2538 }
2539 
2540 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2541 // generated from __builtin_eh_return (offset, handler)
2542 // The effect of this is to adjust the stack pointer by "offset"
2543 // and then branch to "handler".
2544 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2545                                                                      const {
2546   MachineFunction &MF = DAG.getMachineFunction();
2547   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2548 
2549   MipsFI->setCallsEhReturn();
2550   SDValue Chain     = Op.getOperand(0);
2551   SDValue Offset    = Op.getOperand(1);
2552   SDValue Handler   = Op.getOperand(2);
2553   SDLoc DL(Op);
2554   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2555 
2556   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2557   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2558   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2559   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2560   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2561   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2562   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2563                      DAG.getRegister(OffsetReg, Ty),
2564                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2565                      Chain.getValue(1));
2566 }
2567 
2568 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2569                                               SelectionDAG &DAG) const {
2570   // FIXME: Need pseudo-fence for 'singlethread' fences
2571   // FIXME: Set SType for weaker fences where supported/appropriate.
2572   unsigned SType = 0;
2573   SDLoc DL(Op);
2574   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2575                      DAG.getConstant(SType, DL, MVT::i32));
2576 }
2577 
2578 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2579                                                 SelectionDAG &DAG) const {
2580   SDLoc DL(Op);
2581   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2582 
2583   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2584   SDValue Shamt = Op.getOperand(2);
2585   // if shamt < (VT.bits):
2586   //  lo = (shl lo, shamt)
2587   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2588   // else:
2589   //  lo = 0
2590   //  hi = (shl lo, shamt[4:0])
2591   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2592                             DAG.getConstant(-1, DL, MVT::i32));
2593   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2594                                       DAG.getConstant(1, DL, VT));
2595   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2596   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2597   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2598   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2599   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2600                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2601   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2602                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2603   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2604 
2605   SDValue Ops[2] = {Lo, Hi};
2606   return DAG.getMergeValues(Ops, DL);
2607 }
2608 
2609 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2610                                                  bool IsSRA) const {
2611   SDLoc DL(Op);
2612   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2613   SDValue Shamt = Op.getOperand(2);
2614   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2615 
2616   // if shamt < (VT.bits):
2617   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2618   //  if isSRA:
2619   //    hi = (sra hi, shamt)
2620   //  else:
2621   //    hi = (srl hi, shamt)
2622   // else:
2623   //  if isSRA:
2624   //   lo = (sra hi, shamt[4:0])
2625   //   hi = (sra hi, 31)
2626   //  else:
2627   //   lo = (srl hi, shamt[4:0])
2628   //   hi = 0
2629   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2630                             DAG.getConstant(-1, DL, MVT::i32));
2631   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2632                                      DAG.getConstant(1, DL, VT));
2633   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2634   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2635   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2636   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2637                                      DL, VT, Hi, Shamt);
2638   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2639                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2640   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2641                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2642 
2643   if (!(Subtarget.hasMips4() || Subtarget.hasMips32())) {
2644     SDVTList VTList = DAG.getVTList(VT, VT);
2645     return DAG.getNode(Subtarget.isGP64bit() ? Mips::PseudoD_SELECT_I64
2646                                              : Mips::PseudoD_SELECT_I,
2647                        DL, VTList, Cond, ShiftRightHi,
2648                        IsSRA ? Ext : DAG.getConstant(0, DL, VT), Or,
2649                        ShiftRightHi);
2650   }
2651 
2652   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2653   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2654                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2655 
2656   SDValue Ops[2] = {Lo, Hi};
2657   return DAG.getMergeValues(Ops, DL);
2658 }
2659 
2660 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2661                             SDValue Chain, SDValue Src, unsigned Offset) {
2662   SDValue Ptr = LD->getBasePtr();
2663   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2664   EVT BasePtrVT = Ptr.getValueType();
2665   SDLoc DL(LD);
2666   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2667 
2668   if (Offset)
2669     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2670                       DAG.getConstant(Offset, DL, BasePtrVT));
2671 
2672   SDValue Ops[] = { Chain, Ptr, Src };
2673   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2674                                  LD->getMemOperand());
2675 }
2676 
2677 // Expand an unaligned 32 or 64-bit integer load node.
2678 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2679   LoadSDNode *LD = cast<LoadSDNode>(Op);
2680   EVT MemVT = LD->getMemoryVT();
2681 
2682   if (Subtarget.systemSupportsUnalignedAccess())
2683     return Op;
2684 
2685   // Return if load is aligned or if MemVT is neither i32 nor i64.
2686   if ((LD->getAlignment() >= MemVT.getSizeInBits() / 8) ||
2687       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2688     return SDValue();
2689 
2690   bool IsLittle = Subtarget.isLittle();
2691   EVT VT = Op.getValueType();
2692   ISD::LoadExtType ExtType = LD->getExtensionType();
2693   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2694 
2695   assert((VT == MVT::i32) || (VT == MVT::i64));
2696 
2697   // Expand
2698   //  (set dst, (i64 (load baseptr)))
2699   // to
2700   //  (set tmp, (ldl (add baseptr, 7), undef))
2701   //  (set dst, (ldr baseptr, tmp))
2702   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2703     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2704                                IsLittle ? 7 : 0);
2705     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2706                         IsLittle ? 0 : 7);
2707   }
2708 
2709   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2710                              IsLittle ? 3 : 0);
2711   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2712                              IsLittle ? 0 : 3);
2713 
2714   // Expand
2715   //  (set dst, (i32 (load baseptr))) or
2716   //  (set dst, (i64 (sextload baseptr))) or
2717   //  (set dst, (i64 (extload baseptr)))
2718   // to
2719   //  (set tmp, (lwl (add baseptr, 3), undef))
2720   //  (set dst, (lwr baseptr, tmp))
2721   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2722       (ExtType == ISD::EXTLOAD))
2723     return LWR;
2724 
2725   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2726 
2727   // Expand
2728   //  (set dst, (i64 (zextload baseptr)))
2729   // to
2730   //  (set tmp0, (lwl (add baseptr, 3), undef))
2731   //  (set tmp1, (lwr baseptr, tmp0))
2732   //  (set tmp2, (shl tmp1, 32))
2733   //  (set dst, (srl tmp2, 32))
2734   SDLoc DL(LD);
2735   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2736   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2737   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2738   SDValue Ops[] = { SRL, LWR.getValue(1) };
2739   return DAG.getMergeValues(Ops, DL);
2740 }
2741 
2742 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2743                              SDValue Chain, unsigned Offset) {
2744   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2745   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2746   SDLoc DL(SD);
2747   SDVTList VTList = DAG.getVTList(MVT::Other);
2748 
2749   if (Offset)
2750     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2751                       DAG.getConstant(Offset, DL, BasePtrVT));
2752 
2753   SDValue Ops[] = { Chain, Value, Ptr };
2754   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2755                                  SD->getMemOperand());
2756 }
2757 
2758 // Expand an unaligned 32 or 64-bit integer store node.
2759 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2760                                       bool IsLittle) {
2761   SDValue Value = SD->getValue(), Chain = SD->getChain();
2762   EVT VT = Value.getValueType();
2763 
2764   // Expand
2765   //  (store val, baseptr) or
2766   //  (truncstore val, baseptr)
2767   // to
2768   //  (swl val, (add baseptr, 3))
2769   //  (swr val, baseptr)
2770   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2771     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2772                                 IsLittle ? 3 : 0);
2773     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2774   }
2775 
2776   assert(VT == MVT::i64);
2777 
2778   // Expand
2779   //  (store val, baseptr)
2780   // to
2781   //  (sdl val, (add baseptr, 7))
2782   //  (sdr val, baseptr)
2783   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2784   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2785 }
2786 
2787 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2788 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG,
2789                                      bool SingleFloat) {
2790   SDValue Val = SD->getValue();
2791 
2792   if (Val.getOpcode() != ISD::FP_TO_SINT ||
2793       (Val.getValueSizeInBits() > 32 && SingleFloat))
2794     return SDValue();
2795 
2796   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2797   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2798                            Val.getOperand(0));
2799   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2800                       SD->getPointerInfo(), SD->getAlignment(),
2801                       SD->getMemOperand()->getFlags());
2802 }
2803 
2804 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2805   StoreSDNode *SD = cast<StoreSDNode>(Op);
2806   EVT MemVT = SD->getMemoryVT();
2807 
2808   // Lower unaligned integer stores.
2809   if (!Subtarget.systemSupportsUnalignedAccess() &&
2810       (SD->getAlignment() < MemVT.getSizeInBits() / 8) &&
2811       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2812     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2813 
2814   return lowerFP_TO_SINT_STORE(SD, DAG, Subtarget.isSingleFloat());
2815 }
2816 
2817 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2818                                               SelectionDAG &DAG) const {
2819 
2820   // Return a fixed StackObject with offset 0 which points to the old stack
2821   // pointer.
2822   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2823   EVT ValTy = Op->getValueType(0);
2824   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2825   return DAG.getFrameIndex(FI, ValTy);
2826 }
2827 
2828 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2829                                             SelectionDAG &DAG) const {
2830   if (Op.getValueSizeInBits() > 32 && Subtarget.isSingleFloat())
2831     return SDValue();
2832 
2833   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2834   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2835                               Op.getOperand(0));
2836   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2837 }
2838 
2839 //===----------------------------------------------------------------------===//
2840 //                      Calling Convention Implementation
2841 //===----------------------------------------------------------------------===//
2842 
2843 //===----------------------------------------------------------------------===//
2844 // TODO: Implement a generic logic using tblgen that can support this.
2845 // Mips O32 ABI rules:
2846 // ---
2847 // i32 - Passed in A0, A1, A2, A3 and stack
2848 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2849 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2850 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2851 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2852 //       not used, it must be shadowed. If only A3 is available, shadow it and
2853 //       go to stack.
2854 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2855 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2856 //         with the remainder spilled to the stack.
2857 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2858 //         spilling the remainder to the stack.
2859 //
2860 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2861 //===----------------------------------------------------------------------===//
2862 
2863 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2864                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2865                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2866   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2867       State.getMachineFunction().getSubtarget());
2868 
2869   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2870 
2871   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2872 
2873   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2874 
2875   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2876 
2877   // Do not process byval args here.
2878   if (ArgFlags.isByVal())
2879     return true;
2880 
2881   // Promote i8 and i16
2882   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2883     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2884       LocVT = MVT::i32;
2885       if (ArgFlags.isSExt())
2886         LocInfo = CCValAssign::SExtUpper;
2887       else if (ArgFlags.isZExt())
2888         LocInfo = CCValAssign::ZExtUpper;
2889       else
2890         LocInfo = CCValAssign::AExtUpper;
2891     }
2892   }
2893 
2894   // Promote i8 and i16
2895   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2896     LocVT = MVT::i32;
2897     if (ArgFlags.isSExt())
2898       LocInfo = CCValAssign::SExt;
2899     else if (ArgFlags.isZExt())
2900       LocInfo = CCValAssign::ZExt;
2901     else
2902       LocInfo = CCValAssign::AExt;
2903   }
2904 
2905   unsigned Reg;
2906 
2907   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2908   // is true: function is vararg, argument is 3rd or higher, there is previous
2909   // argument which is not f32 or f64.
2910   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2911                                 State.getFirstUnallocated(F32Regs) != ValNo;
2912   Align OrigAlign = ArgFlags.getNonZeroOrigAlign();
2913   bool isI64 = (ValVT == MVT::i32 && OrigAlign == Align(8));
2914   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2915 
2916   // The MIPS vector ABI for floats passes them in a pair of registers
2917   if (ValVT == MVT::i32 && isVectorFloat) {
2918     // This is the start of an vector that was scalarized into an unknown number
2919     // of components. It doesn't matter how many there are. Allocate one of the
2920     // notional 8 byte aligned registers which map onto the argument stack, and
2921     // shadow the register lost to alignment requirements.
2922     if (ArgFlags.isSplit()) {
2923       Reg = State.AllocateReg(FloatVectorIntRegs);
2924       if (Reg == Mips::A2)
2925         State.AllocateReg(Mips::A1);
2926       else if (Reg == 0)
2927         State.AllocateReg(Mips::A3);
2928     } else {
2929       // If we're an intermediate component of the split, we can just attempt to
2930       // allocate a register directly.
2931       Reg = State.AllocateReg(IntRegs);
2932     }
2933   } else if (ValVT == MVT::i32 ||
2934              (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2935     Reg = State.AllocateReg(IntRegs);
2936     // If this is the first part of an i64 arg,
2937     // the allocated register must be either A0 or A2.
2938     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2939       Reg = State.AllocateReg(IntRegs);
2940     LocVT = MVT::i32;
2941   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2942     // Allocate int register and shadow next int register. If first
2943     // available register is Mips::A1 or Mips::A3, shadow it too.
2944     Reg = State.AllocateReg(IntRegs);
2945     if (Reg == Mips::A1 || Reg == Mips::A3)
2946       Reg = State.AllocateReg(IntRegs);
2947     State.AllocateReg(IntRegs);
2948     LocVT = MVT::i32;
2949   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2950     // we are guaranteed to find an available float register
2951     if (ValVT == MVT::f32) {
2952       Reg = State.AllocateReg(F32Regs);
2953       // Shadow int register
2954       State.AllocateReg(IntRegs);
2955     } else {
2956       Reg = State.AllocateReg(F64Regs);
2957       // Shadow int registers
2958       unsigned Reg2 = State.AllocateReg(IntRegs);
2959       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2960         State.AllocateReg(IntRegs);
2961       State.AllocateReg(IntRegs);
2962     }
2963   } else
2964     llvm_unreachable("Cannot handle this ValVT.");
2965 
2966   if (!Reg) {
2967     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2968     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2969   } else
2970     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2971 
2972   return false;
2973 }
2974 
2975 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2976                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2977                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2978   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2979 
2980   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2981 }
2982 
2983 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2984                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2985                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2986   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2987 
2988   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2989 }
2990 
2991 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2992                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2993                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2994 
2995 #include "MipsGenCallingConv.inc"
2996 
2997  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
2998    return CC_Mips_FixedArg;
2999  }
3000 
3001  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
3002    return RetCC_Mips;
3003  }
3004 //===----------------------------------------------------------------------===//
3005 //                  Call Calling Convention Implementation
3006 //===----------------------------------------------------------------------===//
3007 
3008 // Return next O32 integer argument register.
3009 static unsigned getNextIntArgReg(unsigned Reg) {
3010   assert((Reg == Mips::A0) || (Reg == Mips::A2));
3011   return (Reg == Mips::A0) ? Mips::A1 : Mips::A3;
3012 }
3013 
3014 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
3015                                            SDValue Chain, SDValue Arg,
3016                                            const SDLoc &DL, bool IsTailCall,
3017                                            SelectionDAG &DAG) const {
3018   if (!IsTailCall) {
3019     SDValue PtrOff =
3020         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
3021                     DAG.getIntPtrConstant(Offset, DL));
3022     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
3023   }
3024 
3025   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
3026   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
3027   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3028   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(),
3029                       /* Alignment = */ 0, MachineMemOperand::MOVolatile);
3030 }
3031 
3032 void MipsTargetLowering::
3033 getOpndList(SmallVectorImpl<SDValue> &Ops,
3034             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3035             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
3036             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
3037             SDValue Chain) const {
3038   // Insert node "GP copy globalreg" before call to function.
3039   //
3040   // R_MIPS_CALL* operators (emitted when non-internal functions are called
3041   // in PIC mode) allow symbols to be resolved via lazy binding.
3042   // The lazy binding stub requires GP to point to the GOT.
3043   // Note that we don't need GP to point to the GOT for indirect calls
3044   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
3045   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
3046   // used for the function (that is, Mips linker doesn't generate lazy binding
3047   // stub for a function whose address is taken in the program).
3048   if (IsPICCall && !InternalLinkage && IsCallReloc) {
3049     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
3050     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
3051     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
3052   }
3053 
3054   // Build a sequence of copy-to-reg nodes chained together with token
3055   // chain and flag operands which copy the outgoing args into registers.
3056   // The InFlag in necessary since all emitted instructions must be
3057   // stuck together.
3058   SDValue InFlag;
3059 
3060   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
3061     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, RegsToPass[i].first,
3062                                  RegsToPass[i].second, InFlag);
3063     InFlag = Chain.getValue(1);
3064   }
3065 
3066   // Add argument registers to the end of the list so that they are
3067   // known live into the call.
3068   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
3069     Ops.push_back(CLI.DAG.getRegister(RegsToPass[i].first,
3070                                       RegsToPass[i].second.getValueType()));
3071 
3072   // Add a register mask operand representing the call-preserved registers.
3073   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
3074   const uint32_t *Mask =
3075       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
3076   assert(Mask && "Missing call preserved mask for calling convention");
3077   if (Subtarget.inMips16HardFloat()) {
3078     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
3079       StringRef Sym = G->getGlobal()->getName();
3080       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
3081       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
3082         Mask = MipsRegisterInfo::getMips16RetHelperMask();
3083       }
3084     }
3085   }
3086   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
3087 
3088   if (InFlag.getNode())
3089     Ops.push_back(InFlag);
3090 }
3091 
3092 void MipsTargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
3093                                                        SDNode *Node) const {
3094   switch (MI.getOpcode()) {
3095     default:
3096       return;
3097     case Mips::JALR:
3098     case Mips::JALRPseudo:
3099     case Mips::JALR64:
3100     case Mips::JALR64Pseudo:
3101     case Mips::JALR16_MM:
3102     case Mips::JALRC16_MMR6:
3103     case Mips::TAILCALLREG:
3104     case Mips::TAILCALLREG64:
3105     case Mips::TAILCALLR6REG:
3106     case Mips::TAILCALL64R6REG:
3107     case Mips::TAILCALLREG_MM:
3108     case Mips::TAILCALLREG_MMR6: {
3109       if (!EmitJalrReloc ||
3110           Subtarget.inMips16Mode() ||
3111           !isPositionIndependent() ||
3112           Node->getNumOperands() < 1 ||
3113           Node->getOperand(0).getNumOperands() < 2) {
3114         return;
3115       }
3116       // We are after the callee address, set by LowerCall().
3117       // If added to MI, asm printer will emit .reloc R_MIPS_JALR for the
3118       // symbol.
3119       const SDValue TargetAddr = Node->getOperand(0).getOperand(1);
3120       StringRef Sym;
3121       if (const GlobalAddressSDNode *G =
3122               dyn_cast_or_null<const GlobalAddressSDNode>(TargetAddr)) {
3123         // We must not emit the R_MIPS_JALR relocation against data symbols
3124         // since this will cause run-time crashes if the linker replaces the
3125         // call instruction with a relative branch to the data symbol.
3126         if (!isa<Function>(G->getGlobal())) {
3127           LLVM_DEBUG(dbgs() << "Not adding R_MIPS_JALR against data symbol "
3128                             << G->getGlobal()->getName() << "\n");
3129           return;
3130         }
3131         Sym = G->getGlobal()->getName();
3132       }
3133       else if (const ExternalSymbolSDNode *ES =
3134                    dyn_cast_or_null<const ExternalSymbolSDNode>(TargetAddr)) {
3135         Sym = ES->getSymbol();
3136       }
3137 
3138       if (Sym.empty())
3139         return;
3140 
3141       MachineFunction *MF = MI.getParent()->getParent();
3142       MCSymbol *S = MF->getContext().getOrCreateSymbol(Sym);
3143       LLVM_DEBUG(dbgs() << "Adding R_MIPS_JALR against " << Sym << "\n");
3144       MI.addOperand(MachineOperand::CreateMCSymbol(S, MipsII::MO_JALR));
3145     }
3146   }
3147 }
3148 
3149 /// LowerCall - functions arguments are copied from virtual regs to
3150 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
3151 SDValue
3152 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
3153                               SmallVectorImpl<SDValue> &InVals) const {
3154   SelectionDAG &DAG                     = CLI.DAG;
3155   SDLoc DL                              = CLI.DL;
3156   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
3157   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
3158   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
3159   SDValue Chain                         = CLI.Chain;
3160   SDValue Callee                        = CLI.Callee;
3161   bool &IsTailCall                      = CLI.IsTailCall;
3162   CallingConv::ID CallConv              = CLI.CallConv;
3163   bool IsVarArg                         = CLI.IsVarArg;
3164 
3165   MachineFunction &MF = DAG.getMachineFunction();
3166   MachineFrameInfo &MFI = MF.getFrameInfo();
3167   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3168   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
3169   bool IsPIC = isPositionIndependent();
3170 
3171   // Analyze operands of the call, assigning locations to each operand.
3172   SmallVector<CCValAssign, 16> ArgLocs;
3173   MipsCCState CCInfo(
3174       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
3175       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
3176 
3177   const ExternalSymbolSDNode *ES =
3178       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
3179 
3180   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
3181   // is during the lowering of a call with a byval argument which produces
3182   // a call to memcpy. For the O32 case, this causes the caller to allocate
3183   // stack space for the reserved argument area for the callee, then recursively
3184   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
3185   // ABIs mandate that the callee allocates the reserved argument area. We do
3186   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
3187   //
3188   // If the callee has a byval argument and memcpy is used, we are mandated
3189   // to already have produced a reserved argument area for the callee for O32.
3190   // Therefore, the reserved argument area can be reused for both calls.
3191   //
3192   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
3193   // present, as we have yet to hook that node onto the chain.
3194   //
3195   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
3196   // case. GCC does a similar trick, in that wherever possible, it calculates
3197   // the maximum out going argument area (including the reserved area), and
3198   // preallocates the stack space on entrance to the caller.
3199   //
3200   // FIXME: We should do the same for efficiency and space.
3201 
3202   // Note: The check on the calling convention below must match
3203   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
3204   bool MemcpyInByVal = ES &&
3205                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
3206                        CallConv != CallingConv::Fast &&
3207                        Chain.getOpcode() == ISD::CALLSEQ_START;
3208 
3209   // Allocate the reserved argument area. It seems strange to do this from the
3210   // caller side but removing it breaks the frame size calculation.
3211   unsigned ReservedArgArea =
3212       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
3213   CCInfo.AllocateStack(ReservedArgArea, Align(1));
3214 
3215   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
3216                              ES ? ES->getSymbol() : nullptr);
3217 
3218   // Get a count of how many bytes are to be pushed on the stack.
3219   unsigned NextStackOffset = CCInfo.getNextStackOffset();
3220 
3221   // Call site info for function parameters tracking.
3222   MachineFunction::CallSiteInfo CSInfo;
3223 
3224   // Check if it's really possible to do a tail call. Restrict it to functions
3225   // that are part of this compilation unit.
3226   bool InternalLinkage = false;
3227   if (IsTailCall) {
3228     IsTailCall = isEligibleForTailCallOptimization(
3229         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
3230      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3231       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3232       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3233                      G->getGlobal()->hasPrivateLinkage() ||
3234                      G->getGlobal()->hasHiddenVisibility() ||
3235                      G->getGlobal()->hasProtectedVisibility());
3236      }
3237   }
3238   if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
3239     report_fatal_error("failed to perform tail call elimination on a call "
3240                        "site marked musttail");
3241 
3242   if (IsTailCall)
3243     ++NumTailCalls;
3244 
3245   // Chain is the output chain of the last Load/Store or CopyToReg node.
3246   // ByValChain is the output chain of the last Memcpy node created for copying
3247   // byval arguments to the stack.
3248   unsigned StackAlignment = TFL->getStackAlignment();
3249   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
3250   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
3251 
3252   if (!(IsTailCall || MemcpyInByVal))
3253     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffset, 0, DL);
3254 
3255   SDValue StackPtr =
3256       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3257                          getPointerTy(DAG.getDataLayout()));
3258 
3259   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3260   SmallVector<SDValue, 8> MemOpChains;
3261 
3262   CCInfo.rewindByValRegsInfo();
3263 
3264   // Walk the register/memloc assignments, inserting copies/loads.
3265   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3266     SDValue Arg = OutVals[i];
3267     CCValAssign &VA = ArgLocs[i];
3268     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3269     ISD::ArgFlagsTy Flags = Outs[i].Flags;
3270     bool UseUpperBits = false;
3271 
3272     // ByVal Arg.
3273     if (Flags.isByVal()) {
3274       unsigned FirstByValReg, LastByValReg;
3275       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3276       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3277 
3278       assert(Flags.getByValSize() &&
3279              "ByVal args of size 0 should have been ignored by front-end.");
3280       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3281       assert(!IsTailCall &&
3282              "Do not tail-call optimize if there is a byval argument.");
3283       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3284                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3285                    VA);
3286       CCInfo.nextInRegsParam();
3287       continue;
3288     }
3289 
3290     // Promote the value if needed.
3291     switch (VA.getLocInfo()) {
3292     default:
3293       llvm_unreachable("Unknown loc info!");
3294     case CCValAssign::Full:
3295       if (VA.isRegLoc()) {
3296         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3297             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3298             (ValVT == MVT::i64 && LocVT == MVT::f64))
3299           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3300         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3301           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3302                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3303           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3304                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3305           if (!Subtarget.isLittle())
3306             std::swap(Lo, Hi);
3307           Register LocRegLo = VA.getLocReg();
3308           unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
3309           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3310           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3311           continue;
3312         }
3313       }
3314       break;
3315     case CCValAssign::BCvt:
3316       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3317       break;
3318     case CCValAssign::SExtUpper:
3319       UseUpperBits = true;
3320       LLVM_FALLTHROUGH;
3321     case CCValAssign::SExt:
3322       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3323       break;
3324     case CCValAssign::ZExtUpper:
3325       UseUpperBits = true;
3326       LLVM_FALLTHROUGH;
3327     case CCValAssign::ZExt:
3328       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3329       break;
3330     case CCValAssign::AExtUpper:
3331       UseUpperBits = true;
3332       LLVM_FALLTHROUGH;
3333     case CCValAssign::AExt:
3334       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3335       break;
3336     }
3337 
3338     if (UseUpperBits) {
3339       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3340       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3341       Arg = DAG.getNode(
3342           ISD::SHL, DL, VA.getLocVT(), Arg,
3343           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3344     }
3345 
3346     // Arguments that can be passed on register must be kept at
3347     // RegsToPass vector
3348     if (VA.isRegLoc()) {
3349       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3350 
3351       // If the parameter is passed through reg $D, which splits into
3352       // two physical registers, avoid creating call site info.
3353       if (Mips::AFGR64RegClass.contains(VA.getLocReg()))
3354         continue;
3355 
3356       // Collect CSInfo about which register passes which parameter.
3357       const TargetOptions &Options = DAG.getTarget().Options;
3358       if (Options.SupportsDebugEntryValues)
3359         CSInfo.emplace_back(VA.getLocReg(), i);
3360 
3361       continue;
3362     }
3363 
3364     // Register can't get to this point...
3365     assert(VA.isMemLoc());
3366 
3367     // emit ISD::STORE whichs stores the
3368     // parameter value to a stack Location
3369     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3370                                          Chain, Arg, DL, IsTailCall, DAG));
3371   }
3372 
3373   // Transform all store nodes into one single node because all store
3374   // nodes are independent of each other.
3375   if (!MemOpChains.empty())
3376     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3377 
3378   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3379   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3380   // node so that legalize doesn't hack it.
3381 
3382   EVT Ty = Callee.getValueType();
3383   bool GlobalOrExternal = false, IsCallReloc = false;
3384 
3385   // The long-calls feature is ignored in case of PIC.
3386   // While we do not support -mshared / -mno-shared properly,
3387   // ignore long-calls in case of -mabicalls too.
3388   if (!Subtarget.isABICalls() && !IsPIC) {
3389     // If the function should be called using "long call",
3390     // get its address into a register to prevent using
3391     // of the `jal` instruction for the direct call.
3392     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3393       if (Subtarget.useLongCalls())
3394         Callee = Subtarget.hasSym32()
3395                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3396                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3397     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3398       bool UseLongCalls = Subtarget.useLongCalls();
3399       // If the function has long-call/far/near attribute
3400       // it overrides command line switch pased to the backend.
3401       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3402         if (F->hasFnAttribute("long-call"))
3403           UseLongCalls = true;
3404         else if (F->hasFnAttribute("short-call"))
3405           UseLongCalls = false;
3406       }
3407       if (UseLongCalls)
3408         Callee = Subtarget.hasSym32()
3409                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3410                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3411     }
3412   }
3413 
3414   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3415     if (IsPIC) {
3416       const GlobalValue *Val = G->getGlobal();
3417       InternalLinkage = Val->hasInternalLinkage();
3418 
3419       if (InternalLinkage)
3420         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3421       else if (Subtarget.useXGOT()) {
3422         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3423                                        MipsII::MO_CALL_LO16, Chain,
3424                                        FuncInfo->callPtrInfo(MF, Val));
3425         IsCallReloc = true;
3426       } else {
3427         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3428                                FuncInfo->callPtrInfo(MF, Val));
3429         IsCallReloc = true;
3430       }
3431     } else
3432       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3433                                           getPointerTy(DAG.getDataLayout()), 0,
3434                                           MipsII::MO_NO_FLAG);
3435     GlobalOrExternal = true;
3436   }
3437   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3438     const char *Sym = S->getSymbol();
3439 
3440     if (!IsPIC) // static
3441       Callee = DAG.getTargetExternalSymbol(
3442           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3443     else if (Subtarget.useXGOT()) {
3444       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3445                                      MipsII::MO_CALL_LO16, Chain,
3446                                      FuncInfo->callPtrInfo(MF, Sym));
3447       IsCallReloc = true;
3448     } else { // PIC
3449       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3450                              FuncInfo->callPtrInfo(MF, Sym));
3451       IsCallReloc = true;
3452     }
3453 
3454     GlobalOrExternal = true;
3455   }
3456 
3457   SmallVector<SDValue, 8> Ops(1, Chain);
3458   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3459 
3460   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3461               IsCallReloc, CLI, Callee, Chain);
3462 
3463   if (IsTailCall) {
3464     MF.getFrameInfo().setHasTailCall();
3465     SDValue Ret = DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3466     DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
3467     return Ret;
3468   }
3469 
3470   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3471   SDValue InFlag = Chain.getValue(1);
3472 
3473   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
3474 
3475   // Create the CALLSEQ_END node in the case of where it is not a call to
3476   // memcpy.
3477   if (!(MemcpyInByVal)) {
3478     Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
3479                                DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
3480     InFlag = Chain.getValue(1);
3481   }
3482 
3483   // Handle result values, copying them out of physregs into vregs that we
3484   // return.
3485   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
3486                          InVals, CLI);
3487 }
3488 
3489 /// LowerCallResult - Lower the result values of a call into the
3490 /// appropriate copies out of appropriate physical registers.
3491 SDValue MipsTargetLowering::LowerCallResult(
3492     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
3493     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3494     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3495     TargetLowering::CallLoweringInfo &CLI) const {
3496   // Assign locations to each value returned by this call.
3497   SmallVector<CCValAssign, 16> RVLocs;
3498   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3499                      *DAG.getContext());
3500 
3501   const ExternalSymbolSDNode *ES =
3502       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3503   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3504                            ES ? ES->getSymbol() : nullptr);
3505 
3506   // Copy all of the result registers out of their specified physreg.
3507   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3508     CCValAssign &VA = RVLocs[i];
3509     assert(VA.isRegLoc() && "Can only return in registers!");
3510 
3511     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3512                                      RVLocs[i].getLocVT(), InFlag);
3513     Chain = Val.getValue(1);
3514     InFlag = Val.getValue(2);
3515 
3516     if (VA.isUpperBitsInLoc()) {
3517       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3518       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3519       unsigned Shift =
3520           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3521       Val = DAG.getNode(
3522           Shift, DL, VA.getLocVT(), Val,
3523           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3524     }
3525 
3526     switch (VA.getLocInfo()) {
3527     default:
3528       llvm_unreachable("Unknown loc info!");
3529     case CCValAssign::Full:
3530       break;
3531     case CCValAssign::BCvt:
3532       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3533       break;
3534     case CCValAssign::AExt:
3535     case CCValAssign::AExtUpper:
3536       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3537       break;
3538     case CCValAssign::ZExt:
3539     case CCValAssign::ZExtUpper:
3540       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3541                         DAG.getValueType(VA.getValVT()));
3542       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3543       break;
3544     case CCValAssign::SExt:
3545     case CCValAssign::SExtUpper:
3546       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3547                         DAG.getValueType(VA.getValVT()));
3548       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3549       break;
3550     }
3551 
3552     InVals.push_back(Val);
3553   }
3554 
3555   return Chain;
3556 }
3557 
3558 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3559                                       EVT ArgVT, const SDLoc &DL,
3560                                       SelectionDAG &DAG) {
3561   MVT LocVT = VA.getLocVT();
3562   EVT ValVT = VA.getValVT();
3563 
3564   // Shift into the upper bits if necessary.
3565   switch (VA.getLocInfo()) {
3566   default:
3567     break;
3568   case CCValAssign::AExtUpper:
3569   case CCValAssign::SExtUpper:
3570   case CCValAssign::ZExtUpper: {
3571     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3572     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3573     unsigned Opcode =
3574         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3575     Val = DAG.getNode(
3576         Opcode, DL, VA.getLocVT(), Val,
3577         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3578     break;
3579   }
3580   }
3581 
3582   // If this is an value smaller than the argument slot size (32-bit for O32,
3583   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3584   // size. Extract the value and insert any appropriate assertions regarding
3585   // sign/zero extension.
3586   switch (VA.getLocInfo()) {
3587   default:
3588     llvm_unreachable("Unknown loc info!");
3589   case CCValAssign::Full:
3590     break;
3591   case CCValAssign::AExtUpper:
3592   case CCValAssign::AExt:
3593     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3594     break;
3595   case CCValAssign::SExtUpper:
3596   case CCValAssign::SExt:
3597     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3598     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3599     break;
3600   case CCValAssign::ZExtUpper:
3601   case CCValAssign::ZExt:
3602     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3603     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3604     break;
3605   case CCValAssign::BCvt:
3606     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3607     break;
3608   }
3609 
3610   return Val;
3611 }
3612 
3613 //===----------------------------------------------------------------------===//
3614 //             Formal Arguments Calling Convention Implementation
3615 //===----------------------------------------------------------------------===//
3616 /// LowerFormalArguments - transform physical registers into virtual registers
3617 /// and generate load operations for arguments places on the stack.
3618 SDValue MipsTargetLowering::LowerFormalArguments(
3619     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3620     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3621     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3622   MachineFunction &MF = DAG.getMachineFunction();
3623   MachineFrameInfo &MFI = MF.getFrameInfo();
3624   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3625 
3626   MipsFI->setVarArgsFrameIndex(0);
3627 
3628   // Used with vargs to acumulate store chains.
3629   std::vector<SDValue> OutChains;
3630 
3631   // Assign locations to all of the incoming arguments.
3632   SmallVector<CCValAssign, 16> ArgLocs;
3633   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3634                      *DAG.getContext());
3635   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), Align(1));
3636   const Function &Func = DAG.getMachineFunction().getFunction();
3637   Function::const_arg_iterator FuncArg = Func.arg_begin();
3638 
3639   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3640     report_fatal_error(
3641         "Functions with the interrupt attribute cannot have arguments!");
3642 
3643   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3644   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3645                            CCInfo.getInRegsParamsCount() > 0);
3646 
3647   unsigned CurArgIdx = 0;
3648   CCInfo.rewindByValRegsInfo();
3649 
3650   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3651     CCValAssign &VA = ArgLocs[i];
3652     if (Ins[i].isOrigArg()) {
3653       std::advance(FuncArg, Ins[i].getOrigArgIndex() - CurArgIdx);
3654       CurArgIdx = Ins[i].getOrigArgIndex();
3655     }
3656     EVT ValVT = VA.getValVT();
3657     ISD::ArgFlagsTy Flags = Ins[i].Flags;
3658     bool IsRegLoc = VA.isRegLoc();
3659 
3660     if (Flags.isByVal()) {
3661       assert(Ins[i].isOrigArg() && "Byval arguments cannot be implicit");
3662       unsigned FirstByValReg, LastByValReg;
3663       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3664       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3665 
3666       assert(Flags.getByValSize() &&
3667              "ByVal args of size 0 should have been ignored by front-end.");
3668       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3669       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3670                     FirstByValReg, LastByValReg, VA, CCInfo);
3671       CCInfo.nextInRegsParam();
3672       continue;
3673     }
3674 
3675     // Arguments stored on registers
3676     if (IsRegLoc) {
3677       MVT RegVT = VA.getLocVT();
3678       Register ArgReg = VA.getLocReg();
3679       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3680 
3681       // Transform the arguments stored on
3682       // physical registers into virtual ones
3683       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3684       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3685 
3686       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3687 
3688       // Handle floating point arguments passed in integer registers and
3689       // long double arguments passed in floating point registers.
3690       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3691           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3692           (RegVT == MVT::f64 && ValVT == MVT::i64))
3693         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3694       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3695                ValVT == MVT::f64) {
3696         unsigned Reg2 = addLiveIn(DAG.getMachineFunction(),
3697                                   getNextIntArgReg(ArgReg), RC);
3698         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3699         if (!Subtarget.isLittle())
3700           std::swap(ArgValue, ArgValue2);
3701         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3702                                ArgValue, ArgValue2);
3703       }
3704 
3705       InVals.push_back(ArgValue);
3706     } else { // VA.isRegLoc()
3707       MVT LocVT = VA.getLocVT();
3708 
3709       if (ABI.IsO32()) {
3710         // We ought to be able to use LocVT directly but O32 sets it to i32
3711         // when allocating floating point values to integer registers.
3712         // This shouldn't influence how we load the value into registers unless
3713         // we are targeting softfloat.
3714         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3715           LocVT = VA.getValVT();
3716       }
3717 
3718       // sanity check
3719       assert(VA.isMemLoc());
3720 
3721       // The stack pointer offset is relative to the caller stack frame.
3722       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3723                                      VA.getLocMemOffset(), true);
3724 
3725       // Create load nodes to retrieve arguments from the stack
3726       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3727       SDValue ArgValue = DAG.getLoad(
3728           LocVT, DL, Chain, FIN,
3729           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3730       OutChains.push_back(ArgValue.getValue(1));
3731 
3732       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3733 
3734       InVals.push_back(ArgValue);
3735     }
3736   }
3737 
3738   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3739     // The mips ABIs for returning structs by value requires that we copy
3740     // the sret argument into $v0 for the return. Save the argument into
3741     // a virtual register so that we can access it from the return points.
3742     if (Ins[i].Flags.isSRet()) {
3743       unsigned Reg = MipsFI->getSRetReturnReg();
3744       if (!Reg) {
3745         Reg = MF.getRegInfo().createVirtualRegister(
3746             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3747         MipsFI->setSRetReturnReg(Reg);
3748       }
3749       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3750       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3751       break;
3752     }
3753   }
3754 
3755   if (IsVarArg)
3756     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3757 
3758   // All stores are grouped in one node to allow the matching between
3759   // the size of Ins and InVals. This only happens when on varg functions
3760   if (!OutChains.empty()) {
3761     OutChains.push_back(Chain);
3762     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3763   }
3764 
3765   return Chain;
3766 }
3767 
3768 //===----------------------------------------------------------------------===//
3769 //               Return Value Calling Convention Implementation
3770 //===----------------------------------------------------------------------===//
3771 
3772 bool
3773 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3774                                    MachineFunction &MF, bool IsVarArg,
3775                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3776                                    LLVMContext &Context) const {
3777   SmallVector<CCValAssign, 16> RVLocs;
3778   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3779   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3780 }
3781 
3782 bool MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type,
3783                                                        bool IsSigned) const {
3784   if ((ABI.IsN32() || ABI.IsN64()) && Type == MVT::i32)
3785       return true;
3786 
3787   return IsSigned;
3788 }
3789 
3790 SDValue
3791 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3792                                          const SDLoc &DL,
3793                                          SelectionDAG &DAG) const {
3794   MachineFunction &MF = DAG.getMachineFunction();
3795   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3796 
3797   MipsFI->setISR();
3798 
3799   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3800 }
3801 
3802 SDValue
3803 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3804                                 bool IsVarArg,
3805                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3806                                 const SmallVectorImpl<SDValue> &OutVals,
3807                                 const SDLoc &DL, SelectionDAG &DAG) const {
3808   // CCValAssign - represent the assignment of
3809   // the return value to a location
3810   SmallVector<CCValAssign, 16> RVLocs;
3811   MachineFunction &MF = DAG.getMachineFunction();
3812 
3813   // CCState - Info about the registers and stack slot.
3814   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3815 
3816   // Analyze return values.
3817   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3818 
3819   SDValue Flag;
3820   SmallVector<SDValue, 4> RetOps(1, Chain);
3821 
3822   // Copy the result values into the output registers.
3823   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3824     SDValue Val = OutVals[i];
3825     CCValAssign &VA = RVLocs[i];
3826     assert(VA.isRegLoc() && "Can only return in registers!");
3827     bool UseUpperBits = false;
3828 
3829     switch (VA.getLocInfo()) {
3830     default:
3831       llvm_unreachable("Unknown loc info!");
3832     case CCValAssign::Full:
3833       break;
3834     case CCValAssign::BCvt:
3835       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3836       break;
3837     case CCValAssign::AExtUpper:
3838       UseUpperBits = true;
3839       LLVM_FALLTHROUGH;
3840     case CCValAssign::AExt:
3841       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3842       break;
3843     case CCValAssign::ZExtUpper:
3844       UseUpperBits = true;
3845       LLVM_FALLTHROUGH;
3846     case CCValAssign::ZExt:
3847       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3848       break;
3849     case CCValAssign::SExtUpper:
3850       UseUpperBits = true;
3851       LLVM_FALLTHROUGH;
3852     case CCValAssign::SExt:
3853       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3854       break;
3855     }
3856 
3857     if (UseUpperBits) {
3858       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3859       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3860       Val = DAG.getNode(
3861           ISD::SHL, DL, VA.getLocVT(), Val,
3862           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3863     }
3864 
3865     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3866 
3867     // Guarantee that all emitted copies are stuck together with flags.
3868     Flag = Chain.getValue(1);
3869     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3870   }
3871 
3872   // The mips ABIs for returning structs by value requires that we copy
3873   // the sret argument into $v0 for the return. We saved the argument into
3874   // a virtual register in the entry block, so now we copy the value out
3875   // and into $v0.
3876   if (MF.getFunction().hasStructRetAttr()) {
3877     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3878     unsigned Reg = MipsFI->getSRetReturnReg();
3879 
3880     if (!Reg)
3881       llvm_unreachable("sret virtual register not created in the entry block");
3882     SDValue Val =
3883         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3884     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3885 
3886     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3887     Flag = Chain.getValue(1);
3888     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3889   }
3890 
3891   RetOps[0] = Chain;  // Update chain.
3892 
3893   // Add the flag if we have it.
3894   if (Flag.getNode())
3895     RetOps.push_back(Flag);
3896 
3897   // ISRs must use "eret".
3898   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
3899     return LowerInterruptReturn(RetOps, DL, DAG);
3900 
3901   // Standard return on Mips is a "jr $ra"
3902   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3903 }
3904 
3905 //===----------------------------------------------------------------------===//
3906 //                           Mips Inline Assembly Support
3907 //===----------------------------------------------------------------------===//
3908 
3909 /// getConstraintType - Given a constraint letter, return the type of
3910 /// constraint it is for this target.
3911 MipsTargetLowering::ConstraintType
3912 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3913   // Mips specific constraints
3914   // GCC config/mips/constraints.md
3915   //
3916   // 'd' : An address register. Equivalent to r
3917   //       unless generating MIPS16 code.
3918   // 'y' : Equivalent to r; retained for
3919   //       backwards compatibility.
3920   // 'c' : A register suitable for use in an indirect
3921   //       jump. This will always be $25 for -mabicalls.
3922   // 'l' : The lo register. 1 word storage.
3923   // 'x' : The hilo register pair. Double word storage.
3924   if (Constraint.size() == 1) {
3925     switch (Constraint[0]) {
3926       default : break;
3927       case 'd':
3928       case 'y':
3929       case 'f':
3930       case 'c':
3931       case 'l':
3932       case 'x':
3933         return C_RegisterClass;
3934       case 'R':
3935         return C_Memory;
3936     }
3937   }
3938 
3939   if (Constraint == "ZC")
3940     return C_Memory;
3941 
3942   return TargetLowering::getConstraintType(Constraint);
3943 }
3944 
3945 /// Examine constraint type and operand type and determine a weight value.
3946 /// This object must already have been set up with the operand type
3947 /// and the current alternative constraint selected.
3948 TargetLowering::ConstraintWeight
3949 MipsTargetLowering::getSingleConstraintMatchWeight(
3950     AsmOperandInfo &info, const char *constraint) const {
3951   ConstraintWeight weight = CW_Invalid;
3952   Value *CallOperandVal = info.CallOperandVal;
3953     // If we don't have a value, we can't do a match,
3954     // but allow it at the lowest weight.
3955   if (!CallOperandVal)
3956     return CW_Default;
3957   Type *type = CallOperandVal->getType();
3958   // Look at the constraint type.
3959   switch (*constraint) {
3960   default:
3961     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3962     break;
3963   case 'd':
3964   case 'y':
3965     if (type->isIntegerTy())
3966       weight = CW_Register;
3967     break;
3968   case 'f': // FPU or MSA register
3969     if (Subtarget.hasMSA() && type->isVectorTy() &&
3970         type->getPrimitiveSizeInBits().getFixedSize() == 128)
3971       weight = CW_Register;
3972     else if (type->isFloatTy())
3973       weight = CW_Register;
3974     break;
3975   case 'c': // $25 for indirect jumps
3976   case 'l': // lo register
3977   case 'x': // hilo register pair
3978     if (type->isIntegerTy())
3979       weight = CW_SpecificReg;
3980     break;
3981   case 'I': // signed 16 bit immediate
3982   case 'J': // integer zero
3983   case 'K': // unsigned 16 bit immediate
3984   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3985   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3986   case 'O': // signed 15 bit immediate (+- 16383)
3987   case 'P': // immediate in the range of 65535 to 1 (inclusive)
3988     if (isa<ConstantInt>(CallOperandVal))
3989       weight = CW_Constant;
3990     break;
3991   case 'R':
3992     weight = CW_Memory;
3993     break;
3994   }
3995   return weight;
3996 }
3997 
3998 /// This is a helper function to parse a physical register string and split it
3999 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
4000 /// that is returned indicates whether parsing was successful. The second flag
4001 /// is true if the numeric part exists.
4002 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
4003                                               unsigned long long &Reg) {
4004   if (C.front() != '{' || C.back() != '}')
4005     return std::make_pair(false, false);
4006 
4007   // Search for the first numeric character.
4008   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
4009   I = std::find_if(B, E, isdigit);
4010 
4011   Prefix = StringRef(B, I - B);
4012 
4013   // The second flag is set to false if no numeric characters were found.
4014   if (I == E)
4015     return std::make_pair(true, false);
4016 
4017   // Parse the numeric characters.
4018   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
4019                         true);
4020 }
4021 
4022 EVT MipsTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
4023                                             ISD::NodeType) const {
4024   bool Cond = !Subtarget.isABI_O32() && VT.getSizeInBits() == 32;
4025   EVT MinVT = getRegisterType(Context, Cond ? MVT::i64 : MVT::i32);
4026   return VT.bitsLT(MinVT) ? MinVT : VT;
4027 }
4028 
4029 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
4030 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
4031   const TargetRegisterInfo *TRI =
4032       Subtarget.getRegisterInfo();
4033   const TargetRegisterClass *RC;
4034   StringRef Prefix;
4035   unsigned long long Reg;
4036 
4037   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
4038 
4039   if (!R.first)
4040     return std::make_pair(0U, nullptr);
4041 
4042   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
4043     // No numeric characters follow "hi" or "lo".
4044     if (R.second)
4045       return std::make_pair(0U, nullptr);
4046 
4047     RC = TRI->getRegClass(Prefix == "hi" ?
4048                           Mips::HI32RegClassID : Mips::LO32RegClassID);
4049     return std::make_pair(*(RC->begin()), RC);
4050   } else if (Prefix.startswith("$msa")) {
4051     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
4052 
4053     // No numeric characters follow the name.
4054     if (R.second)
4055       return std::make_pair(0U, nullptr);
4056 
4057     Reg = StringSwitch<unsigned long long>(Prefix)
4058               .Case("$msair", Mips::MSAIR)
4059               .Case("$msacsr", Mips::MSACSR)
4060               .Case("$msaaccess", Mips::MSAAccess)
4061               .Case("$msasave", Mips::MSASave)
4062               .Case("$msamodify", Mips::MSAModify)
4063               .Case("$msarequest", Mips::MSARequest)
4064               .Case("$msamap", Mips::MSAMap)
4065               .Case("$msaunmap", Mips::MSAUnmap)
4066               .Default(0);
4067 
4068     if (!Reg)
4069       return std::make_pair(0U, nullptr);
4070 
4071     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
4072     return std::make_pair(Reg, RC);
4073   }
4074 
4075   if (!R.second)
4076     return std::make_pair(0U, nullptr);
4077 
4078   if (Prefix == "$f") { // Parse $f0-$f31.
4079     // If the size of FP registers is 64-bit or Reg is an even number, select
4080     // the 64-bit register class. Otherwise, select the 32-bit register class.
4081     if (VT == MVT::Other)
4082       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
4083 
4084     RC = getRegClassFor(VT);
4085 
4086     if (RC == &Mips::AFGR64RegClass) {
4087       assert(Reg % 2 == 0);
4088       Reg >>= 1;
4089     }
4090   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
4091     RC = TRI->getRegClass(Mips::FCCRegClassID);
4092   else if (Prefix == "$w") { // Parse $w0-$w31.
4093     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
4094   } else { // Parse $0-$31.
4095     assert(Prefix == "$");
4096     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
4097   }
4098 
4099   assert(Reg < RC->getNumRegs());
4100   return std::make_pair(*(RC->begin() + Reg), RC);
4101 }
4102 
4103 /// Given a register class constraint, like 'r', if this corresponds directly
4104 /// to an LLVM register class, return a register of 0 and the register class
4105 /// pointer.
4106 std::pair<unsigned, const TargetRegisterClass *>
4107 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
4108                                                  StringRef Constraint,
4109                                                  MVT VT) const {
4110   if (Constraint.size() == 1) {
4111     switch (Constraint[0]) {
4112     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
4113     case 'y': // Same as 'r'. Exists for compatibility.
4114     case 'r':
4115       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) {
4116         if (Subtarget.inMips16Mode())
4117           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
4118         return std::make_pair(0U, &Mips::GPR32RegClass);
4119       }
4120       if (VT == MVT::i64 && !Subtarget.isGP64bit())
4121         return std::make_pair(0U, &Mips::GPR32RegClass);
4122       if (VT == MVT::i64 && Subtarget.isGP64bit())
4123         return std::make_pair(0U, &Mips::GPR64RegClass);
4124       // This will generate an error message
4125       return std::make_pair(0U, nullptr);
4126     case 'f': // FPU or MSA register
4127       if (VT == MVT::v16i8)
4128         return std::make_pair(0U, &Mips::MSA128BRegClass);
4129       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
4130         return std::make_pair(0U, &Mips::MSA128HRegClass);
4131       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
4132         return std::make_pair(0U, &Mips::MSA128WRegClass);
4133       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
4134         return std::make_pair(0U, &Mips::MSA128DRegClass);
4135       else if (VT == MVT::f32)
4136         return std::make_pair(0U, &Mips::FGR32RegClass);
4137       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
4138         if (Subtarget.isFP64bit())
4139           return std::make_pair(0U, &Mips::FGR64RegClass);
4140         return std::make_pair(0U, &Mips::AFGR64RegClass);
4141       }
4142       break;
4143     case 'c': // register suitable for indirect jump
4144       if (VT == MVT::i32)
4145         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
4146       if (VT == MVT::i64)
4147         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
4148       // This will generate an error message
4149       return std::make_pair(0U, nullptr);
4150     case 'l': // use the `lo` register to store values
4151               // that are no bigger than a word
4152       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
4153         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
4154       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
4155     case 'x': // use the concatenated `hi` and `lo` registers
4156               // to store doubleword values
4157       // Fixme: Not triggering the use of both hi and low
4158       // This will generate an error message
4159       return std::make_pair(0U, nullptr);
4160     }
4161   }
4162 
4163   if (!Constraint.empty()) {
4164     std::pair<unsigned, const TargetRegisterClass *> R;
4165     R = parseRegForInlineAsmConstraint(Constraint, VT);
4166 
4167     if (R.second)
4168       return R;
4169   }
4170 
4171   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
4172 }
4173 
4174 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
4175 /// vector.  If it is invalid, don't add anything to Ops.
4176 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
4177                                                      std::string &Constraint,
4178                                                      std::vector<SDValue>&Ops,
4179                                                      SelectionDAG &DAG) const {
4180   SDLoc DL(Op);
4181   SDValue Result;
4182 
4183   // Only support length 1 constraints for now.
4184   if (Constraint.length() > 1) return;
4185 
4186   char ConstraintLetter = Constraint[0];
4187   switch (ConstraintLetter) {
4188   default: break; // This will fall through to the generic implementation
4189   case 'I': // Signed 16 bit constant
4190     // If this fails, the parent routine will give an error
4191     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4192       EVT Type = Op.getValueType();
4193       int64_t Val = C->getSExtValue();
4194       if (isInt<16>(Val)) {
4195         Result = DAG.getTargetConstant(Val, DL, Type);
4196         break;
4197       }
4198     }
4199     return;
4200   case 'J': // integer zero
4201     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4202       EVT Type = Op.getValueType();
4203       int64_t Val = C->getZExtValue();
4204       if (Val == 0) {
4205         Result = DAG.getTargetConstant(0, DL, Type);
4206         break;
4207       }
4208     }
4209     return;
4210   case 'K': // unsigned 16 bit immediate
4211     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4212       EVT Type = Op.getValueType();
4213       uint64_t Val = (uint64_t)C->getZExtValue();
4214       if (isUInt<16>(Val)) {
4215         Result = DAG.getTargetConstant(Val, DL, Type);
4216         break;
4217       }
4218     }
4219     return;
4220   case 'L': // signed 32 bit immediate where lower 16 bits are 0
4221     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4222       EVT Type = Op.getValueType();
4223       int64_t Val = C->getSExtValue();
4224       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
4225         Result = DAG.getTargetConstant(Val, DL, Type);
4226         break;
4227       }
4228     }
4229     return;
4230   case 'N': // immediate in the range of -65535 to -1 (inclusive)
4231     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4232       EVT Type = Op.getValueType();
4233       int64_t Val = C->getSExtValue();
4234       if ((Val >= -65535) && (Val <= -1)) {
4235         Result = DAG.getTargetConstant(Val, DL, Type);
4236         break;
4237       }
4238     }
4239     return;
4240   case 'O': // signed 15 bit immediate
4241     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4242       EVT Type = Op.getValueType();
4243       int64_t Val = C->getSExtValue();
4244       if ((isInt<15>(Val))) {
4245         Result = DAG.getTargetConstant(Val, DL, Type);
4246         break;
4247       }
4248     }
4249     return;
4250   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4251     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4252       EVT Type = Op.getValueType();
4253       int64_t Val = C->getSExtValue();
4254       if ((Val <= 65535) && (Val >= 1)) {
4255         Result = DAG.getTargetConstant(Val, DL, Type);
4256         break;
4257       }
4258     }
4259     return;
4260   }
4261 
4262   if (Result.getNode()) {
4263     Ops.push_back(Result);
4264     return;
4265   }
4266 
4267   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4268 }
4269 
4270 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4271                                                const AddrMode &AM, Type *Ty,
4272                                                unsigned AS,
4273                                                Instruction *I) const {
4274   // No global is ever allowed as a base.
4275   if (AM.BaseGV)
4276     return false;
4277 
4278   switch (AM.Scale) {
4279   case 0: // "r+i" or just "i", depending on HasBaseReg.
4280     break;
4281   case 1:
4282     if (!AM.HasBaseReg) // allow "r+i".
4283       break;
4284     return false; // disallow "r+r" or "r+r+i".
4285   default:
4286     return false;
4287   }
4288 
4289   return true;
4290 }
4291 
4292 bool
4293 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4294   // The Mips target isn't yet aware of offsets.
4295   return false;
4296 }
4297 
4298 EVT MipsTargetLowering::getOptimalMemOpType(
4299     const MemOp &Op, const AttributeList &FuncAttributes) const {
4300   if (Subtarget.hasMips64())
4301     return MVT::i64;
4302 
4303   return MVT::i32;
4304 }
4305 
4306 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
4307                                       bool ForCodeSize) const {
4308   if (VT != MVT::f32 && VT != MVT::f64)
4309     return false;
4310   if (Imm.isNegZero())
4311     return false;
4312   return Imm.isZero();
4313 }
4314 
4315 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4316 
4317   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4318   if (ABI.IsN64() && isPositionIndependent())
4319     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4320 
4321   return TargetLowering::getJumpTableEncoding();
4322 }
4323 
4324 bool MipsTargetLowering::useSoftFloat() const {
4325   return Subtarget.useSoftFloat();
4326 }
4327 
4328 void MipsTargetLowering::copyByValRegs(
4329     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4330     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4331     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4332     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4333     MipsCCState &State) const {
4334   MachineFunction &MF = DAG.getMachineFunction();
4335   MachineFrameInfo &MFI = MF.getFrameInfo();
4336   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4337   unsigned NumRegs = LastReg - FirstReg;
4338   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4339   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4340   int FrameObjOffset;
4341   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4342 
4343   if (RegAreaSize)
4344     FrameObjOffset =
4345         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4346         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4347   else
4348     FrameObjOffset = VA.getLocMemOffset();
4349 
4350   // Create frame object.
4351   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4352   // Make the fixed object stored to mutable so that the load instructions
4353   // referencing it have their memory dependencies added.
4354   // Set the frame object as isAliased which clears the underlying objects
4355   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4356   // stores as dependencies for loads referencing this fixed object.
4357   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4358   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4359   InVals.push_back(FIN);
4360 
4361   if (!NumRegs)
4362     return;
4363 
4364   // Copy arg registers.
4365   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4366   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4367 
4368   for (unsigned I = 0; I < NumRegs; ++I) {
4369     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4370     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4371     unsigned Offset = I * GPRSizeInBytes;
4372     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4373                                    DAG.getConstant(Offset, DL, PtrTy));
4374     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4375                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4376     OutChains.push_back(Store);
4377   }
4378 }
4379 
4380 // Copy byVal arg to registers and stack.
4381 void MipsTargetLowering::passByValArg(
4382     SDValue Chain, const SDLoc &DL,
4383     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4384     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4385     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4386     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4387     const CCValAssign &VA) const {
4388   unsigned ByValSizeInBytes = Flags.getByValSize();
4389   unsigned OffsetInBytes = 0; // From beginning of struct
4390   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4391   Align Alignment =
4392       std::min(Flags.getNonZeroByValAlign(), Align(RegSizeInBytes));
4393   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4394       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4395   unsigned NumRegs = LastReg - FirstReg;
4396 
4397   if (NumRegs) {
4398     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4399     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4400     unsigned I = 0;
4401 
4402     // Copy words to registers.
4403     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4404       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4405                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4406       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4407                                     MachinePointerInfo(), Alignment.value());
4408       MemOpChains.push_back(LoadVal.getValue(1));
4409       unsigned ArgReg = ArgRegs[FirstReg + I];
4410       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4411     }
4412 
4413     // Return if the struct has been fully copied.
4414     if (ByValSizeInBytes == OffsetInBytes)
4415       return;
4416 
4417     // Copy the remainder of the byval argument with sub-word loads and shifts.
4418     if (LeftoverBytes) {
4419       SDValue Val;
4420 
4421       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4422            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4423         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4424 
4425         if (RemainingSizeInBytes < LoadSizeInBytes)
4426           continue;
4427 
4428         // Load subword.
4429         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4430                                       DAG.getConstant(OffsetInBytes, DL,
4431                                                       PtrTy));
4432         SDValue LoadVal = DAG.getExtLoad(
4433             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4434             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment.value());
4435         MemOpChains.push_back(LoadVal.getValue(1));
4436 
4437         // Shift the loaded value.
4438         unsigned Shamt;
4439 
4440         if (isLittle)
4441           Shamt = TotalBytesLoaded * 8;
4442         else
4443           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4444 
4445         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4446                                     DAG.getConstant(Shamt, DL, MVT::i32));
4447 
4448         if (Val.getNode())
4449           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4450         else
4451           Val = Shift;
4452 
4453         OffsetInBytes += LoadSizeInBytes;
4454         TotalBytesLoaded += LoadSizeInBytes;
4455         Alignment = std::min(Alignment, Align(LoadSizeInBytes));
4456       }
4457 
4458       unsigned ArgReg = ArgRegs[FirstReg + I];
4459       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4460       return;
4461     }
4462   }
4463 
4464   // Copy remainder of byval arg to it with memcpy.
4465   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4466   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4467                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4468   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4469                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4470   Chain = DAG.getMemcpy(
4471       Chain, DL, Dst, Src, DAG.getConstant(MemCpySize, DL, PtrTy),
4472       Align(Alignment), /*isVolatile=*/false, /*AlwaysInline=*/false,
4473       /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
4474   MemOpChains.push_back(Chain);
4475 }
4476 
4477 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4478                                          SDValue Chain, const SDLoc &DL,
4479                                          SelectionDAG &DAG,
4480                                          CCState &State) const {
4481   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4482   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4483   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4484   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4485   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4486   MachineFunction &MF = DAG.getMachineFunction();
4487   MachineFrameInfo &MFI = MF.getFrameInfo();
4488   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4489 
4490   // Offset of the first variable argument from stack pointer.
4491   int VaArgOffset;
4492 
4493   if (ArgRegs.size() == Idx)
4494     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
4495   else {
4496     VaArgOffset =
4497         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4498         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4499   }
4500 
4501   // Record the frame index of the first variable argument
4502   // which is a value necessary to VASTART.
4503   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4504   MipsFI->setVarArgsFrameIndex(FI);
4505 
4506   // Copy the integer registers that have not been used for argument passing
4507   // to the argument register save area. For O32, the save area is allocated
4508   // in the caller's stack frame, while for N32/64, it is allocated in the
4509   // callee's stack frame.
4510   for (unsigned I = Idx; I < ArgRegs.size();
4511        ++I, VaArgOffset += RegSizeInBytes) {
4512     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4513     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4514     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4515     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4516     SDValue Store =
4517         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4518     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4519         (Value *)nullptr);
4520     OutChains.push_back(Store);
4521   }
4522 }
4523 
4524 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4525                                      Align Alignment) const {
4526   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4527 
4528   assert(Size && "Byval argument's size shouldn't be 0.");
4529 
4530   Alignment = std::min(Alignment, TFL->getStackAlign());
4531 
4532   unsigned FirstReg = 0;
4533   unsigned NumRegs = 0;
4534 
4535   if (State->getCallingConv() != CallingConv::Fast) {
4536     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4537     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4538     // FIXME: The O32 case actually describes no shadow registers.
4539     const MCPhysReg *ShadowRegs =
4540         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4541 
4542     // We used to check the size as well but we can't do that anymore since
4543     // CCState::HandleByVal() rounds up the size after calling this function.
4544     assert(
4545         Alignment >= Align(RegSizeInBytes) &&
4546         "Byval argument's alignment should be a multiple of RegSizeInBytes.");
4547 
4548     FirstReg = State->getFirstUnallocated(IntArgRegs);
4549 
4550     // If Alignment > RegSizeInBytes, the first arg register must be even.
4551     // FIXME: This condition happens to do the right thing but it's not the
4552     //        right way to test it. We want to check that the stack frame offset
4553     //        of the register is aligned.
4554     if ((Alignment > RegSizeInBytes) && (FirstReg % 2)) {
4555       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4556       ++FirstReg;
4557     }
4558 
4559     // Mark the registers allocated.
4560     Size = alignTo(Size, RegSizeInBytes);
4561     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4562          Size -= RegSizeInBytes, ++I, ++NumRegs)
4563       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4564   }
4565 
4566   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4567 }
4568 
4569 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4570                                                         MachineBasicBlock *BB,
4571                                                         bool isFPCmp,
4572                                                         unsigned Opc) const {
4573   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4574          "Subtarget already supports SELECT nodes with the use of"
4575          "conditional-move instructions.");
4576 
4577   const TargetInstrInfo *TII =
4578       Subtarget.getInstrInfo();
4579   DebugLoc DL = MI.getDebugLoc();
4580 
4581   // To "insert" a SELECT instruction, we actually have to insert the
4582   // diamond control-flow pattern.  The incoming instruction knows the
4583   // destination vreg to set, the condition code register to branch on, the
4584   // true/false values to select between, and a branch opcode to use.
4585   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4586   MachineFunction::iterator It = ++BB->getIterator();
4587 
4588   //  thisMBB:
4589   //  ...
4590   //   TrueVal = ...
4591   //   setcc r1, r2, r3
4592   //   bNE   r1, r0, copy1MBB
4593   //   fallthrough --> copy0MBB
4594   MachineBasicBlock *thisMBB  = BB;
4595   MachineFunction *F = BB->getParent();
4596   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4597   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4598   F->insert(It, copy0MBB);
4599   F->insert(It, sinkMBB);
4600 
4601   // Transfer the remainder of BB and its successor edges to sinkMBB.
4602   sinkMBB->splice(sinkMBB->begin(), BB,
4603                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4604   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4605 
4606   // Next, add the true and fallthrough blocks as its successors.
4607   BB->addSuccessor(copy0MBB);
4608   BB->addSuccessor(sinkMBB);
4609 
4610   if (isFPCmp) {
4611     // bc1[tf] cc, sinkMBB
4612     BuildMI(BB, DL, TII->get(Opc))
4613         .addReg(MI.getOperand(1).getReg())
4614         .addMBB(sinkMBB);
4615   } else {
4616     // bne rs, $0, sinkMBB
4617     BuildMI(BB, DL, TII->get(Opc))
4618         .addReg(MI.getOperand(1).getReg())
4619         .addReg(Mips::ZERO)
4620         .addMBB(sinkMBB);
4621   }
4622 
4623   //  copy0MBB:
4624   //   %FalseValue = ...
4625   //   # fallthrough to sinkMBB
4626   BB = copy0MBB;
4627 
4628   // Update machine-CFG edges
4629   BB->addSuccessor(sinkMBB);
4630 
4631   //  sinkMBB:
4632   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4633   //  ...
4634   BB = sinkMBB;
4635 
4636   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4637       .addReg(MI.getOperand(2).getReg())
4638       .addMBB(thisMBB)
4639       .addReg(MI.getOperand(3).getReg())
4640       .addMBB(copy0MBB);
4641 
4642   MI.eraseFromParent(); // The pseudo instruction is gone now.
4643 
4644   return BB;
4645 }
4646 
4647 MachineBasicBlock *
4648 MipsTargetLowering::emitPseudoD_SELECT(MachineInstr &MI,
4649                                        MachineBasicBlock *BB) const {
4650   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4651          "Subtarget already supports SELECT nodes with the use of"
4652          "conditional-move instructions.");
4653 
4654   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4655   DebugLoc DL = MI.getDebugLoc();
4656 
4657   // D_SELECT substitutes two SELECT nodes that goes one after another and
4658   // have the same condition operand. On machines which don't have
4659   // conditional-move instruction, it reduces unnecessary branch instructions
4660   // which are result of using two diamond patterns that are result of two
4661   // SELECT pseudo instructions.
4662   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4663   MachineFunction::iterator It = ++BB->getIterator();
4664 
4665   //  thisMBB:
4666   //  ...
4667   //   TrueVal = ...
4668   //   setcc r1, r2, r3
4669   //   bNE   r1, r0, copy1MBB
4670   //   fallthrough --> copy0MBB
4671   MachineBasicBlock *thisMBB = BB;
4672   MachineFunction *F = BB->getParent();
4673   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4674   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
4675   F->insert(It, copy0MBB);
4676   F->insert(It, sinkMBB);
4677 
4678   // Transfer the remainder of BB and its successor edges to sinkMBB.
4679   sinkMBB->splice(sinkMBB->begin(), BB,
4680                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4681   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4682 
4683   // Next, add the true and fallthrough blocks as its successors.
4684   BB->addSuccessor(copy0MBB);
4685   BB->addSuccessor(sinkMBB);
4686 
4687   // bne rs, $0, sinkMBB
4688   BuildMI(BB, DL, TII->get(Mips::BNE))
4689       .addReg(MI.getOperand(2).getReg())
4690       .addReg(Mips::ZERO)
4691       .addMBB(sinkMBB);
4692 
4693   //  copy0MBB:
4694   //   %FalseValue = ...
4695   //   # fallthrough to sinkMBB
4696   BB = copy0MBB;
4697 
4698   // Update machine-CFG edges
4699   BB->addSuccessor(sinkMBB);
4700 
4701   //  sinkMBB:
4702   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4703   //  ...
4704   BB = sinkMBB;
4705 
4706   // Use two PHI nodes to select two reults
4707   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4708       .addReg(MI.getOperand(3).getReg())
4709       .addMBB(thisMBB)
4710       .addReg(MI.getOperand(5).getReg())
4711       .addMBB(copy0MBB);
4712   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(1).getReg())
4713       .addReg(MI.getOperand(4).getReg())
4714       .addMBB(thisMBB)
4715       .addReg(MI.getOperand(6).getReg())
4716       .addMBB(copy0MBB);
4717 
4718   MI.eraseFromParent(); // The pseudo instruction is gone now.
4719 
4720   return BB;
4721 }
4722 
4723 // FIXME? Maybe this could be a TableGen attribute on some registers and
4724 // this table could be generated automatically from RegInfo.
4725 Register
4726 MipsTargetLowering::getRegisterByName(const char *RegName, LLT VT,
4727                                       const MachineFunction &MF) const {
4728   // Named registers is expected to be fairly rare. For now, just support $28
4729   // since the linux kernel uses it.
4730   if (Subtarget.isGP64bit()) {
4731     Register Reg = StringSwitch<Register>(RegName)
4732                          .Case("$28", Mips::GP_64)
4733                          .Default(Register());
4734     if (Reg)
4735       return Reg;
4736   } else {
4737     Register Reg = StringSwitch<Register>(RegName)
4738                          .Case("$28", Mips::GP)
4739                          .Default(Register());
4740     if (Reg)
4741       return Reg;
4742   }
4743   report_fatal_error("Invalid register name global variable");
4744 }
4745 
4746 MachineBasicBlock *MipsTargetLowering::emitLDR_W(MachineInstr &MI,
4747                                                  MachineBasicBlock *BB) const {
4748   MachineFunction *MF = BB->getParent();
4749   MachineRegisterInfo &MRI = MF->getRegInfo();
4750   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4751   const bool IsLittle = Subtarget.isLittle();
4752   DebugLoc DL = MI.getDebugLoc();
4753 
4754   Register Dest = MI.getOperand(0).getReg();
4755   Register Address = MI.getOperand(1).getReg();
4756   unsigned Imm = MI.getOperand(2).getImm();
4757 
4758   MachineBasicBlock::iterator I(MI);
4759 
4760   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4761     // Mips release 6 can load from adress that is not naturally-aligned.
4762     Register Temp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4763     BuildMI(*BB, I, DL, TII->get(Mips::LW))
4764         .addDef(Temp)
4765         .addUse(Address)
4766         .addImm(Imm);
4767     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(Temp);
4768   } else {
4769     // Mips release 5 needs to use instructions that can load from an unaligned
4770     // memory address.
4771     Register LoadHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4772     Register LoadFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4773     Register Undef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4774     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(Undef);
4775     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4776         .addDef(LoadHalf)
4777         .addUse(Address)
4778         .addImm(Imm + (IsLittle ? 0 : 3))
4779         .addUse(Undef);
4780     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4781         .addDef(LoadFull)
4782         .addUse(Address)
4783         .addImm(Imm + (IsLittle ? 3 : 0))
4784         .addUse(LoadHalf);
4785     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Dest).addUse(LoadFull);
4786   }
4787 
4788   MI.eraseFromParent();
4789   return BB;
4790 }
4791 
4792 MachineBasicBlock *MipsTargetLowering::emitLDR_D(MachineInstr &MI,
4793                                                  MachineBasicBlock *BB) const {
4794   MachineFunction *MF = BB->getParent();
4795   MachineRegisterInfo &MRI = MF->getRegInfo();
4796   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4797   const bool IsLittle = Subtarget.isLittle();
4798   DebugLoc DL = MI.getDebugLoc();
4799 
4800   Register Dest = MI.getOperand(0).getReg();
4801   Register Address = MI.getOperand(1).getReg();
4802   unsigned Imm = MI.getOperand(2).getImm();
4803 
4804   MachineBasicBlock::iterator I(MI);
4805 
4806   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4807     // Mips release 6 can load from adress that is not naturally-aligned.
4808     if (Subtarget.isGP64bit()) {
4809       Register Temp = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4810       BuildMI(*BB, I, DL, TII->get(Mips::LD))
4811           .addDef(Temp)
4812           .addUse(Address)
4813           .addImm(Imm);
4814       BuildMI(*BB, I, DL, TII->get(Mips::FILL_D)).addDef(Dest).addUse(Temp);
4815     } else {
4816       Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4817       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4818       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4819       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4820           .addDef(Lo)
4821           .addUse(Address)
4822           .addImm(Imm + (IsLittle ? 0 : 4));
4823       BuildMI(*BB, I, DL, TII->get(Mips::LW))
4824           .addDef(Hi)
4825           .addUse(Address)
4826           .addImm(Imm + (IsLittle ? 4 : 0));
4827       BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(Lo);
4828       BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4829           .addUse(Wtemp)
4830           .addUse(Hi)
4831           .addImm(1);
4832     }
4833   } else {
4834     // Mips release 5 needs to use instructions that can load from an unaligned
4835     // memory address.
4836     Register LoHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4837     Register LoFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4838     Register LoUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4839     Register HiHalf = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4840     Register HiFull = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4841     Register HiUndef = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4842     Register Wtemp = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4843     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(LoUndef);
4844     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4845         .addDef(LoHalf)
4846         .addUse(Address)
4847         .addImm(Imm + (IsLittle ? 0 : 7))
4848         .addUse(LoUndef);
4849     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4850         .addDef(LoFull)
4851         .addUse(Address)
4852         .addImm(Imm + (IsLittle ? 3 : 4))
4853         .addUse(LoHalf);
4854     BuildMI(*BB, I, DL, TII->get(Mips::IMPLICIT_DEF)).addDef(HiUndef);
4855     BuildMI(*BB, I, DL, TII->get(Mips::LWR))
4856         .addDef(HiHalf)
4857         .addUse(Address)
4858         .addImm(Imm + (IsLittle ? 4 : 3))
4859         .addUse(HiUndef);
4860     BuildMI(*BB, I, DL, TII->get(Mips::LWL))
4861         .addDef(HiFull)
4862         .addUse(Address)
4863         .addImm(Imm + (IsLittle ? 7 : 0))
4864         .addUse(HiHalf);
4865     BuildMI(*BB, I, DL, TII->get(Mips::FILL_W)).addDef(Wtemp).addUse(LoFull);
4866     BuildMI(*BB, I, DL, TII->get(Mips::INSERT_W), Dest)
4867         .addUse(Wtemp)
4868         .addUse(HiFull)
4869         .addImm(1);
4870   }
4871 
4872   MI.eraseFromParent();
4873   return BB;
4874 }
4875 
4876 MachineBasicBlock *MipsTargetLowering::emitSTR_W(MachineInstr &MI,
4877                                                  MachineBasicBlock *BB) const {
4878   MachineFunction *MF = BB->getParent();
4879   MachineRegisterInfo &MRI = MF->getRegInfo();
4880   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4881   const bool IsLittle = Subtarget.isLittle();
4882   DebugLoc DL = MI.getDebugLoc();
4883 
4884   Register StoreVal = MI.getOperand(0).getReg();
4885   Register Address = MI.getOperand(1).getReg();
4886   unsigned Imm = MI.getOperand(2).getImm();
4887 
4888   MachineBasicBlock::iterator I(MI);
4889 
4890   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4891     // Mips release 6 can store to adress that is not naturally-aligned.
4892     Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4893     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4894     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(BitcastW).addUse(StoreVal);
4895     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4896         .addDef(Tmp)
4897         .addUse(BitcastW)
4898         .addImm(0);
4899     BuildMI(*BB, I, DL, TII->get(Mips::SW))
4900         .addUse(Tmp)
4901         .addUse(Address)
4902         .addImm(Imm);
4903   } else {
4904     // Mips release 5 needs to use instructions that can store to an unaligned
4905     // memory address.
4906     Register Tmp = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4907     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4908         .addDef(Tmp)
4909         .addUse(StoreVal)
4910         .addImm(0);
4911     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4912         .addUse(Tmp)
4913         .addUse(Address)
4914         .addImm(Imm + (IsLittle ? 0 : 3));
4915     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
4916         .addUse(Tmp)
4917         .addUse(Address)
4918         .addImm(Imm + (IsLittle ? 3 : 0));
4919   }
4920 
4921   MI.eraseFromParent();
4922 
4923   return BB;
4924 }
4925 
4926 MachineBasicBlock *MipsTargetLowering::emitSTR_D(MachineInstr &MI,
4927                                                  MachineBasicBlock *BB) const {
4928   MachineFunction *MF = BB->getParent();
4929   MachineRegisterInfo &MRI = MF->getRegInfo();
4930   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
4931   const bool IsLittle = Subtarget.isLittle();
4932   DebugLoc DL = MI.getDebugLoc();
4933 
4934   Register StoreVal = MI.getOperand(0).getReg();
4935   Register Address = MI.getOperand(1).getReg();
4936   unsigned Imm = MI.getOperand(2).getImm();
4937 
4938   MachineBasicBlock::iterator I(MI);
4939 
4940   if (Subtarget.hasMips32r6() || Subtarget.hasMips64r6()) {
4941     // Mips release 6 can store to adress that is not naturally-aligned.
4942     if (Subtarget.isGP64bit()) {
4943       Register BitcastD = MRI.createVirtualRegister(&Mips::MSA128DRegClass);
4944       Register Lo = MRI.createVirtualRegister(&Mips::GPR64RegClass);
4945       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4946           .addDef(BitcastD)
4947           .addUse(StoreVal);
4948       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_D))
4949           .addDef(Lo)
4950           .addUse(BitcastD)
4951           .addImm(0);
4952       BuildMI(*BB, I, DL, TII->get(Mips::SD))
4953           .addUse(Lo)
4954           .addUse(Address)
4955           .addImm(Imm);
4956     } else {
4957       Register BitcastW = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4958       Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4959       Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4960       BuildMI(*BB, I, DL, TII->get(Mips::COPY))
4961           .addDef(BitcastW)
4962           .addUse(StoreVal);
4963       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4964           .addDef(Lo)
4965           .addUse(BitcastW)
4966           .addImm(0);
4967       BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4968           .addDef(Hi)
4969           .addUse(BitcastW)
4970           .addImm(1);
4971       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4972           .addUse(Lo)
4973           .addUse(Address)
4974           .addImm(Imm + (IsLittle ? 0 : 4));
4975       BuildMI(*BB, I, DL, TII->get(Mips::SW))
4976           .addUse(Hi)
4977           .addUse(Address)
4978           .addImm(Imm + (IsLittle ? 4 : 0));
4979     }
4980   } else {
4981     // Mips release 5 needs to use instructions that can store to an unaligned
4982     // memory address.
4983     Register Bitcast = MRI.createVirtualRegister(&Mips::MSA128WRegClass);
4984     Register Lo = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4985     Register Hi = MRI.createVirtualRegister(&Mips::GPR32RegClass);
4986     BuildMI(*BB, I, DL, TII->get(Mips::COPY)).addDef(Bitcast).addUse(StoreVal);
4987     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4988         .addDef(Lo)
4989         .addUse(Bitcast)
4990         .addImm(0);
4991     BuildMI(*BB, I, DL, TII->get(Mips::COPY_S_W))
4992         .addDef(Hi)
4993         .addUse(Bitcast)
4994         .addImm(1);
4995     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
4996         .addUse(Lo)
4997         .addUse(Address)
4998         .addImm(Imm + (IsLittle ? 0 : 3));
4999     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5000         .addUse(Lo)
5001         .addUse(Address)
5002         .addImm(Imm + (IsLittle ? 3 : 0));
5003     BuildMI(*BB, I, DL, TII->get(Mips::SWR))
5004         .addUse(Hi)
5005         .addUse(Address)
5006         .addImm(Imm + (IsLittle ? 4 : 7));
5007     BuildMI(*BB, I, DL, TII->get(Mips::SWL))
5008         .addUse(Hi)
5009         .addUse(Address)
5010         .addImm(Imm + (IsLittle ? 7 : 4));
5011   }
5012 
5013   MI.eraseFromParent();
5014   return BB;
5015 }
5016