xref: /llvm-project/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp (revision 4b692a95d103f3ad30d6be1ce6d5dda0bd90bc1f)
1 //===- SPIRVInstructionSelector.cpp ------------------------------*- C++ -*-==//
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 implements the targeting of the InstructionSelector class for
10 // SPIRV.
11 // TODO: This should be generated by TableGen.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "MCTargetDesc/SPIRVBaseInfo.h"
16 #include "MCTargetDesc/SPIRVMCTargetDesc.h"
17 #include "SPIRV.h"
18 #include "SPIRVGlobalRegistry.h"
19 #include "SPIRVInstrInfo.h"
20 #include "SPIRVRegisterBankInfo.h"
21 #include "SPIRVRegisterInfo.h"
22 #include "SPIRVTargetMachine.h"
23 #include "SPIRVUtils.h"
24 #include "llvm/ADT/APFloat.h"
25 #include "llvm/ADT/StringExtras.h"
26 #include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"
27 #include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
28 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
29 #include "llvm/CodeGen/MachineInstrBuilder.h"
30 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
31 #include "llvm/CodeGen/MachineRegisterInfo.h"
32 #include "llvm/CodeGen/Register.h"
33 #include "llvm/CodeGen/TargetOpcodes.h"
34 #include "llvm/IR/IntrinsicsSPIRV.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/ErrorHandling.h"
37 
38 #define DEBUG_TYPE "spirv-isel"
39 
40 using namespace llvm;
41 namespace CL = SPIRV::OpenCLExtInst;
42 namespace GL = SPIRV::GLSLExtInst;
43 
44 using ExtInstList =
45     std::vector<std::pair<SPIRV::InstructionSet::InstructionSet, uint32_t>>;
46 
47 namespace {
48 
49 llvm::SPIRV::SelectionControl::SelectionControl
50 getSelectionOperandForImm(int Imm) {
51   if (Imm == 2)
52     return SPIRV::SelectionControl::Flatten;
53   if (Imm == 1)
54     return SPIRV::SelectionControl::DontFlatten;
55   if (Imm == 0)
56     return SPIRV::SelectionControl::None;
57   llvm_unreachable("Invalid immediate");
58 }
59 
60 #define GET_GLOBALISEL_PREDICATE_BITSET
61 #include "SPIRVGenGlobalISel.inc"
62 #undef GET_GLOBALISEL_PREDICATE_BITSET
63 
64 class SPIRVInstructionSelector : public InstructionSelector {
65   const SPIRVSubtarget &STI;
66   const SPIRVInstrInfo &TII;
67   const SPIRVRegisterInfo &TRI;
68   const RegisterBankInfo &RBI;
69   SPIRVGlobalRegistry &GR;
70   MachineRegisterInfo *MRI;
71   MachineFunction *HasVRegsReset = nullptr;
72 
73   /// We need to keep track of the number we give to anonymous global values to
74   /// generate the same name every time when this is needed.
75   mutable DenseMap<const GlobalValue *, unsigned> UnnamedGlobalIDs;
76   SmallPtrSet<MachineInstr *, 8> DeadMIs;
77 
78 public:
79   SPIRVInstructionSelector(const SPIRVTargetMachine &TM,
80                            const SPIRVSubtarget &ST,
81                            const RegisterBankInfo &RBI);
82   void setupMF(MachineFunction &MF, GISelKnownBits *KB,
83                CodeGenCoverage *CoverageInfo, ProfileSummaryInfo *PSI,
84                BlockFrequencyInfo *BFI) override;
85   // Common selection code. Instruction-specific selection occurs in spvSelect.
86   bool select(MachineInstr &I) override;
87   static const char *getName() { return DEBUG_TYPE; }
88 
89 #define GET_GLOBALISEL_PREDICATES_DECL
90 #include "SPIRVGenGlobalISel.inc"
91 #undef GET_GLOBALISEL_PREDICATES_DECL
92 
93 #define GET_GLOBALISEL_TEMPORARIES_DECL
94 #include "SPIRVGenGlobalISel.inc"
95 #undef GET_GLOBALISEL_TEMPORARIES_DECL
96 
97 private:
98   void resetVRegsType(MachineFunction &MF);
99 
100   // tblgen-erated 'select' implementation, used as the initial selector for
101   // the patterns that don't require complex C++.
102   bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const;
103 
104   // All instruction-specific selection that didn't happen in "select()".
105   // Is basically a large Switch/Case delegating to all other select method.
106   bool spvSelect(Register ResVReg, const SPIRVType *ResType,
107                  MachineInstr &I) const;
108 
109   bool selectFirstBitHigh(Register ResVReg, const SPIRVType *ResType,
110                           MachineInstr &I, bool IsSigned) const;
111 
112   bool selectFirstBitLow(Register ResVReg, const SPIRVType *ResType,
113                          MachineInstr &I) const;
114 
115   bool selectFirstBitSet16(Register ResVReg, const SPIRVType *ResType,
116                            MachineInstr &I, unsigned ExtendOpcode,
117                            unsigned BitSetOpcode) const;
118 
119   bool selectFirstBitSet32(Register ResVReg, const SPIRVType *ResType,
120                            MachineInstr &I, Register SrcReg,
121                            unsigned BitSetOpcode) const;
122 
123   bool selectFirstBitSet64(Register ResVReg, const SPIRVType *ResType,
124                            MachineInstr &I, Register SrcReg,
125                            unsigned BitSetOpcode, bool SwapPrimarySide) const;
126 
127   bool selectFirstBitSet64Overflow(Register ResVReg, const SPIRVType *ResType,
128                                    MachineInstr &I, Register SrcReg,
129                                    unsigned BitSetOpcode,
130                                    bool SwapPrimarySide) const;
131 
132   bool selectGlobalValue(Register ResVReg, MachineInstr &I,
133                          const MachineInstr *Init = nullptr) const;
134 
135   bool selectOpWithSrcs(Register ResVReg, const SPIRVType *ResType,
136                         MachineInstr &I, std::vector<Register> SrcRegs,
137                         unsigned Opcode) const;
138 
139   bool selectUnOp(Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
140                   unsigned Opcode) const;
141 
142   bool selectBitcast(Register ResVReg, const SPIRVType *ResType,
143                      MachineInstr &I) const;
144 
145   bool selectLoad(Register ResVReg, const SPIRVType *ResType,
146                   MachineInstr &I) const;
147   bool selectStore(MachineInstr &I) const;
148 
149   bool selectStackSave(Register ResVReg, const SPIRVType *ResType,
150                        MachineInstr &I) const;
151   bool selectStackRestore(MachineInstr &I) const;
152 
153   bool selectMemOperation(Register ResVReg, MachineInstr &I) const;
154 
155   bool selectAtomicRMW(Register ResVReg, const SPIRVType *ResType,
156                        MachineInstr &I, unsigned NewOpcode,
157                        unsigned NegateOpcode = 0) const;
158 
159   bool selectAtomicCmpXchg(Register ResVReg, const SPIRVType *ResType,
160                            MachineInstr &I) const;
161 
162   bool selectFence(MachineInstr &I) const;
163 
164   bool selectAddrSpaceCast(Register ResVReg, const SPIRVType *ResType,
165                            MachineInstr &I) const;
166 
167   bool selectAnyOrAll(Register ResVReg, const SPIRVType *ResType,
168                       MachineInstr &I, unsigned OpType) const;
169 
170   bool selectAll(Register ResVReg, const SPIRVType *ResType,
171                  MachineInstr &I) const;
172 
173   bool selectAny(Register ResVReg, const SPIRVType *ResType,
174                  MachineInstr &I) const;
175 
176   bool selectBitreverse(Register ResVReg, const SPIRVType *ResType,
177                         MachineInstr &I) const;
178 
179   bool selectBuildVector(Register ResVReg, const SPIRVType *ResType,
180                          MachineInstr &I) const;
181   bool selectSplatVector(Register ResVReg, const SPIRVType *ResType,
182                          MachineInstr &I) const;
183 
184   bool selectCmp(Register ResVReg, const SPIRVType *ResType,
185                  unsigned comparisonOpcode, MachineInstr &I) const;
186   bool selectCross(Register ResVReg, const SPIRVType *ResType,
187                    MachineInstr &I) const;
188   bool selectDiscard(Register ResVReg, const SPIRVType *ResType,
189                      MachineInstr &I) const;
190 
191   bool selectICmp(Register ResVReg, const SPIRVType *ResType,
192                   MachineInstr &I) const;
193   bool selectFCmp(Register ResVReg, const SPIRVType *ResType,
194                   MachineInstr &I) const;
195 
196   bool selectSign(Register ResVReg, const SPIRVType *ResType,
197                   MachineInstr &I) const;
198 
199   bool selectFloatDot(Register ResVReg, const SPIRVType *ResType,
200                       MachineInstr &I) const;
201 
202   bool selectOverflowArith(Register ResVReg, const SPIRVType *ResType,
203                            MachineInstr &I, unsigned Opcode) const;
204 
205   bool selectIntegerDot(Register ResVReg, const SPIRVType *ResType,
206                         MachineInstr &I, bool Signed) const;
207 
208   bool selectIntegerDotExpansion(Register ResVReg, const SPIRVType *ResType,
209                                  MachineInstr &I) const;
210 
211   template <bool Signed>
212   bool selectDot4AddPacked(Register ResVReg, const SPIRVType *ResType,
213                            MachineInstr &I) const;
214   template <bool Signed>
215   bool selectDot4AddPackedExpansion(Register ResVReg, const SPIRVType *ResType,
216                                     MachineInstr &I) const;
217 
218   bool selectWaveReduceSum(Register ResVReg, const SPIRVType *ResType,
219                            MachineInstr &I) const;
220 
221   void renderImm32(MachineInstrBuilder &MIB, const MachineInstr &I,
222                    int OpIdx) const;
223   void renderFImm64(MachineInstrBuilder &MIB, const MachineInstr &I,
224                     int OpIdx) const;
225 
226   bool selectConst(Register ResVReg, const SPIRVType *ResType, const APInt &Imm,
227                    MachineInstr &I) const;
228 
229   bool selectSelect(Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
230                     bool IsSigned) const;
231   bool selectIToF(Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
232                   bool IsSigned, unsigned Opcode) const;
233   bool selectExt(Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
234                  bool IsSigned) const;
235 
236   bool selectTrunc(Register ResVReg, const SPIRVType *ResType,
237                    MachineInstr &I) const;
238 
239   bool selectSUCmp(Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
240                    bool IsSigned) const;
241 
242   bool selectIntToBool(Register IntReg, Register ResVReg, MachineInstr &I,
243                        const SPIRVType *intTy, const SPIRVType *boolTy) const;
244 
245   bool selectOpUndef(Register ResVReg, const SPIRVType *ResType,
246                      MachineInstr &I) const;
247   bool selectFreeze(Register ResVReg, const SPIRVType *ResType,
248                     MachineInstr &I) const;
249   bool selectIntrinsic(Register ResVReg, const SPIRVType *ResType,
250                        MachineInstr &I) const;
251   bool selectExtractVal(Register ResVReg, const SPIRVType *ResType,
252                         MachineInstr &I) const;
253   bool selectInsertVal(Register ResVReg, const SPIRVType *ResType,
254                        MachineInstr &I) const;
255   bool selectExtractElt(Register ResVReg, const SPIRVType *ResType,
256                         MachineInstr &I) const;
257   bool selectInsertElt(Register ResVReg, const SPIRVType *ResType,
258                        MachineInstr &I) const;
259   bool selectGEP(Register ResVReg, const SPIRVType *ResType,
260                  MachineInstr &I) const;
261 
262   bool selectFrameIndex(Register ResVReg, const SPIRVType *ResType,
263                         MachineInstr &I) const;
264   bool selectAllocaArray(Register ResVReg, const SPIRVType *ResType,
265                          MachineInstr &I) const;
266 
267   bool selectBranch(MachineInstr &I) const;
268   bool selectBranchCond(MachineInstr &I) const;
269 
270   bool selectPhi(Register ResVReg, const SPIRVType *ResType,
271                  MachineInstr &I) const;
272 
273   [[maybe_unused]] bool selectExtInst(Register ResVReg,
274                                       const SPIRVType *RestType,
275                                       MachineInstr &I,
276                                       GL::GLSLExtInst GLInst) const;
277   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
278                      MachineInstr &I, CL::OpenCLExtInst CLInst) const;
279   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
280                      MachineInstr &I, CL::OpenCLExtInst CLInst,
281                      GL::GLSLExtInst GLInst) const;
282   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
283                      MachineInstr &I, const ExtInstList &ExtInsts) const;
284 
285   bool selectLog10(Register ResVReg, const SPIRVType *ResType,
286                    MachineInstr &I) const;
287 
288   bool selectSaturate(Register ResVReg, const SPIRVType *ResType,
289                       MachineInstr &I) const;
290 
291   bool selectWaveOpInst(Register ResVReg, const SPIRVType *ResType,
292                         MachineInstr &I, unsigned Opcode) const;
293 
294   bool selectWaveActiveCountBits(Register ResVReg, const SPIRVType *ResType,
295                                  MachineInstr &I) const;
296 
297   bool selectUnmergeValues(MachineInstr &I) const;
298 
299   bool selectHandleFromBinding(Register &ResVReg, const SPIRVType *ResType,
300                                MachineInstr &I) const;
301 
302   bool selectReadImageIntrinsic(Register &ResVReg, const SPIRVType *ResType,
303                                 MachineInstr &I) const;
304   bool selectImageWriteIntrinsic(MachineInstr &I) const;
305   bool selectResourceGetPointer(Register &ResVReg, const SPIRVType *ResType,
306                                 MachineInstr &I) const;
307 
308   // Utilities
309   std::pair<Register, bool>
310   buildI32Constant(uint32_t Val, MachineInstr &I,
311                    const SPIRVType *ResType = nullptr) const;
312 
313   Register buildZerosVal(const SPIRVType *ResType, MachineInstr &I) const;
314   Register buildZerosValF(const SPIRVType *ResType, MachineInstr &I) const;
315   Register buildOnesVal(bool AllOnes, const SPIRVType *ResType,
316                         MachineInstr &I) const;
317   Register buildOnesValF(const SPIRVType *ResType, MachineInstr &I) const;
318 
319   bool wrapIntoSpecConstantOp(MachineInstr &I,
320                               SmallVector<Register> &CompositeArgs) const;
321 
322   Register getUcharPtrTypeReg(MachineInstr &I,
323                               SPIRV::StorageClass::StorageClass SC) const;
324   MachineInstrBuilder buildSpecConstantOp(MachineInstr &I, Register Dest,
325                                           Register Src, Register DestType,
326                                           uint32_t Opcode) const;
327   MachineInstrBuilder buildConstGenericPtr(MachineInstr &I, Register SrcPtr,
328                                            SPIRVType *SrcPtrTy) const;
329   Register buildPointerToResource(const SPIRVType *ResType, uint32_t Set,
330                                   uint32_t Binding, uint32_t ArraySize,
331                                   Register IndexReg, bool IsNonUniform,
332                                   MachineIRBuilder MIRBuilder) const;
333   SPIRVType *widenTypeToVec4(const SPIRVType *Type, MachineInstr &I) const;
334   bool extractSubvector(Register &ResVReg, const SPIRVType *ResType,
335                         Register &ReadReg, MachineInstr &InsertionPoint) const;
336   bool generateImageRead(Register &ResVReg, const SPIRVType *ResType,
337                          Register ImageReg, Register IdxReg, DebugLoc Loc,
338                          MachineInstr &Pos) const;
339   bool BuildCOPY(Register DestReg, Register SrcReg, MachineInstr &I) const;
340   bool loadVec3BuiltinInputID(SPIRV::BuiltIn::BuiltIn BuiltInValue,
341                               Register ResVReg, const SPIRVType *ResType,
342                               MachineInstr &I) const;
343   bool loadHandleBeforePosition(Register &HandleReg, const SPIRVType *ResType,
344                                 GIntrinsic &HandleDef, MachineInstr &Pos) const;
345 };
346 
347 } // end anonymous namespace
348 
349 #define GET_GLOBALISEL_IMPL
350 #include "SPIRVGenGlobalISel.inc"
351 #undef GET_GLOBALISEL_IMPL
352 
353 SPIRVInstructionSelector::SPIRVInstructionSelector(const SPIRVTargetMachine &TM,
354                                                    const SPIRVSubtarget &ST,
355                                                    const RegisterBankInfo &RBI)
356     : InstructionSelector(), STI(ST), TII(*ST.getInstrInfo()),
357       TRI(*ST.getRegisterInfo()), RBI(RBI), GR(*ST.getSPIRVGlobalRegistry()),
358 #define GET_GLOBALISEL_PREDICATES_INIT
359 #include "SPIRVGenGlobalISel.inc"
360 #undef GET_GLOBALISEL_PREDICATES_INIT
361 #define GET_GLOBALISEL_TEMPORARIES_INIT
362 #include "SPIRVGenGlobalISel.inc"
363 #undef GET_GLOBALISEL_TEMPORARIES_INIT
364 {
365 }
366 
367 void SPIRVInstructionSelector::setupMF(MachineFunction &MF, GISelKnownBits *KB,
368                                        CodeGenCoverage *CoverageInfo,
369                                        ProfileSummaryInfo *PSI,
370                                        BlockFrequencyInfo *BFI) {
371   MRI = &MF.getRegInfo();
372   GR.setCurrentFunc(MF);
373   InstructionSelector::setupMF(MF, KB, CoverageInfo, PSI, BFI);
374 }
375 
376 // Ensure that register classes correspond to pattern matching rules.
377 void SPIRVInstructionSelector::resetVRegsType(MachineFunction &MF) {
378   if (HasVRegsReset == &MF)
379     return;
380   HasVRegsReset = &MF;
381 
382   MachineRegisterInfo &MRI = MF.getRegInfo();
383   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
384     Register Reg = Register::index2VirtReg(I);
385     LLT RegType = MRI.getType(Reg);
386     if (RegType.isScalar())
387       MRI.setType(Reg, LLT::scalar(64));
388     else if (RegType.isPointer())
389       MRI.setType(Reg, LLT::pointer(0, 64));
390     else if (RegType.isVector())
391       MRI.setType(Reg, LLT::fixed_vector(2, LLT::scalar(64)));
392   }
393   for (const auto &MBB : MF) {
394     for (const auto &MI : MBB) {
395       if (MI.getOpcode() != SPIRV::ASSIGN_TYPE)
396         continue;
397       Register DstReg = MI.getOperand(0).getReg();
398       LLT DstType = MRI.getType(DstReg);
399       Register SrcReg = MI.getOperand(1).getReg();
400       LLT SrcType = MRI.getType(SrcReg);
401       if (DstType != SrcType)
402         MRI.setType(DstReg, MRI.getType(SrcReg));
403 
404       const TargetRegisterClass *DstRC = MRI.getRegClassOrNull(DstReg);
405       const TargetRegisterClass *SrcRC = MRI.getRegClassOrNull(SrcReg);
406       if (DstRC != SrcRC && SrcRC)
407         MRI.setRegClass(DstReg, SrcRC);
408     }
409   }
410 }
411 
412 static bool isImm(const MachineOperand &MO, MachineRegisterInfo *MRI);
413 
414 // Defined in SPIRVLegalizerInfo.cpp.
415 extern bool isTypeFoldingSupported(unsigned Opcode);
416 
417 bool isDead(const MachineInstr &MI, const MachineRegisterInfo &MRI) {
418   for (const auto &MO : MI.all_defs()) {
419     Register Reg = MO.getReg();
420     if (Reg.isPhysical() || !MRI.use_nodbg_empty(Reg))
421       return false;
422   }
423   if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE || MI.isFakeUse() ||
424       MI.isLifetimeMarker())
425     return false;
426   if (MI.isPHI())
427     return true;
428   if (MI.mayStore() || MI.isCall() ||
429       (MI.mayLoad() && MI.hasOrderedMemoryRef()) || MI.isPosition() ||
430       MI.isDebugInstr() || MI.isTerminator() || MI.isJumpTableDebugInfo())
431     return false;
432   return true;
433 }
434 
435 bool SPIRVInstructionSelector::select(MachineInstr &I) {
436   resetVRegsType(*I.getParent()->getParent());
437 
438   assert(I.getParent() && "Instruction should be in a basic block!");
439   assert(I.getParent()->getParent() && "Instruction should be in a function!");
440 
441   Register Opcode = I.getOpcode();
442   // If it's not a GMIR instruction, we've selected it already.
443   if (!isPreISelGenericOpcode(Opcode)) {
444     if (Opcode == SPIRV::ASSIGN_TYPE) { // These pseudos aren't needed any more.
445       Register DstReg = I.getOperand(0).getReg();
446       Register SrcReg = I.getOperand(1).getReg();
447       auto *Def = MRI->getVRegDef(SrcReg);
448       if (isTypeFoldingSupported(Def->getOpcode())) {
449         bool Res = selectImpl(I, *CoverageInfo);
450         LLVM_DEBUG({
451           if (!Res && Def->getOpcode() != TargetOpcode::G_CONSTANT) {
452             dbgs() << "Unexpected pattern in ASSIGN_TYPE.\nInstruction: ";
453             I.print(dbgs());
454           }
455         });
456         assert(Res || Def->getOpcode() == TargetOpcode::G_CONSTANT);
457         if (Res) {
458           if (!isTriviallyDead(*Def, *MRI) && isDead(*Def, *MRI))
459             DeadMIs.insert(Def);
460           return Res;
461         }
462       }
463       MRI->setRegClass(SrcReg, MRI->getRegClass(DstReg));
464       MRI->replaceRegWith(SrcReg, DstReg);
465       GR.invalidateMachineInstr(&I);
466       I.removeFromParent();
467       return true;
468     } else if (I.getNumDefs() == 1) {
469       // Make all vregs 64 bits (for SPIR-V IDs).
470       MRI->setType(I.getOperand(0).getReg(), LLT::scalar(64));
471     }
472     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
473   }
474 
475   if (DeadMIs.contains(&I)) {
476     // if the instruction has been already made dead by folding it away
477     // erase it
478     LLVM_DEBUG(dbgs() << "Instruction is folded and dead.\n");
479     salvageDebugInfo(*MRI, I);
480     GR.invalidateMachineInstr(&I);
481     I.eraseFromParent();
482     return true;
483   }
484 
485   if (I.getNumOperands() != I.getNumExplicitOperands()) {
486     LLVM_DEBUG(errs() << "Generic instr has unexpected implicit operands\n");
487     return false;
488   }
489 
490   // Common code for getting return reg+type, and removing selected instr
491   // from parent occurs here. Instr-specific selection happens in spvSelect().
492   bool HasDefs = I.getNumDefs() > 0;
493   Register ResVReg = HasDefs ? I.getOperand(0).getReg() : Register(0);
494   SPIRVType *ResType = HasDefs ? GR.getSPIRVTypeForVReg(ResVReg) : nullptr;
495   assert(!HasDefs || ResType || I.getOpcode() == TargetOpcode::G_GLOBAL_VALUE);
496   if (spvSelect(ResVReg, ResType, I)) {
497     if (HasDefs) // Make all vregs 64 bits (for SPIR-V IDs).
498       for (unsigned i = 0; i < I.getNumDefs(); ++i)
499         MRI->setType(I.getOperand(i).getReg(), LLT::scalar(64));
500     GR.invalidateMachineInstr(&I);
501     I.removeFromParent();
502     return true;
503   }
504   return false;
505 }
506 
507 static bool mayApplyGenericSelection(unsigned Opcode) {
508   switch (Opcode) {
509   case TargetOpcode::G_CONSTANT:
510     return false;
511   case TargetOpcode::G_SADDO:
512   case TargetOpcode::G_SSUBO:
513     return true;
514   }
515   return isTypeFoldingSupported(Opcode);
516 }
517 
518 bool SPIRVInstructionSelector::BuildCOPY(Register DestReg, Register SrcReg,
519                                          MachineInstr &I) const {
520   const TargetRegisterClass *DstRC = MRI->getRegClassOrNull(DestReg);
521   const TargetRegisterClass *SrcRC = MRI->getRegClassOrNull(SrcReg);
522   if (DstRC != SrcRC && SrcRC)
523     MRI->setRegClass(DestReg, SrcRC);
524   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
525                  TII.get(TargetOpcode::COPY))
526       .addDef(DestReg)
527       .addUse(SrcReg)
528       .constrainAllUses(TII, TRI, RBI);
529 }
530 
531 bool SPIRVInstructionSelector::spvSelect(Register ResVReg,
532                                          const SPIRVType *ResType,
533                                          MachineInstr &I) const {
534   const unsigned Opcode = I.getOpcode();
535   if (mayApplyGenericSelection(Opcode))
536     return selectImpl(I, *CoverageInfo);
537   switch (Opcode) {
538   case TargetOpcode::G_CONSTANT:
539     return selectConst(ResVReg, ResType, I.getOperand(1).getCImm()->getValue(),
540                        I);
541   case TargetOpcode::G_GLOBAL_VALUE:
542     return selectGlobalValue(ResVReg, I);
543   case TargetOpcode::G_IMPLICIT_DEF:
544     return selectOpUndef(ResVReg, ResType, I);
545   case TargetOpcode::G_FREEZE:
546     return selectFreeze(ResVReg, ResType, I);
547 
548   case TargetOpcode::G_INTRINSIC:
549   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
550   case TargetOpcode::G_INTRINSIC_CONVERGENT:
551   case TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS:
552     return selectIntrinsic(ResVReg, ResType, I);
553   case TargetOpcode::G_BITREVERSE:
554     return selectBitreverse(ResVReg, ResType, I);
555 
556   case TargetOpcode::G_BUILD_VECTOR:
557     return selectBuildVector(ResVReg, ResType, I);
558   case TargetOpcode::G_SPLAT_VECTOR:
559     return selectSplatVector(ResVReg, ResType, I);
560 
561   case TargetOpcode::G_SHUFFLE_VECTOR: {
562     MachineBasicBlock &BB = *I.getParent();
563     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorShuffle))
564                    .addDef(ResVReg)
565                    .addUse(GR.getSPIRVTypeID(ResType))
566                    .addUse(I.getOperand(1).getReg())
567                    .addUse(I.getOperand(2).getReg());
568     for (auto V : I.getOperand(3).getShuffleMask())
569       MIB.addImm(V);
570     return MIB.constrainAllUses(TII, TRI, RBI);
571   }
572   case TargetOpcode::G_MEMMOVE:
573   case TargetOpcode::G_MEMCPY:
574   case TargetOpcode::G_MEMSET:
575     return selectMemOperation(ResVReg, I);
576 
577   case TargetOpcode::G_ICMP:
578     return selectICmp(ResVReg, ResType, I);
579   case TargetOpcode::G_FCMP:
580     return selectFCmp(ResVReg, ResType, I);
581 
582   case TargetOpcode::G_FRAME_INDEX:
583     return selectFrameIndex(ResVReg, ResType, I);
584 
585   case TargetOpcode::G_LOAD:
586     return selectLoad(ResVReg, ResType, I);
587   case TargetOpcode::G_STORE:
588     return selectStore(I);
589 
590   case TargetOpcode::G_BR:
591     return selectBranch(I);
592   case TargetOpcode::G_BRCOND:
593     return selectBranchCond(I);
594 
595   case TargetOpcode::G_PHI:
596     return selectPhi(ResVReg, ResType, I);
597 
598   case TargetOpcode::G_FPTOSI:
599     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertFToS);
600   case TargetOpcode::G_FPTOUI:
601     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertFToU);
602 
603   case TargetOpcode::G_SITOFP:
604     return selectIToF(ResVReg, ResType, I, true, SPIRV::OpConvertSToF);
605   case TargetOpcode::G_UITOFP:
606     return selectIToF(ResVReg, ResType, I, false, SPIRV::OpConvertUToF);
607 
608   case TargetOpcode::G_CTPOP:
609     return selectUnOp(ResVReg, ResType, I, SPIRV::OpBitCount);
610   case TargetOpcode::G_SMIN:
611     return selectExtInst(ResVReg, ResType, I, CL::s_min, GL::SMin);
612   case TargetOpcode::G_UMIN:
613     return selectExtInst(ResVReg, ResType, I, CL::u_min, GL::UMin);
614 
615   case TargetOpcode::G_SMAX:
616     return selectExtInst(ResVReg, ResType, I, CL::s_max, GL::SMax);
617   case TargetOpcode::G_UMAX:
618     return selectExtInst(ResVReg, ResType, I, CL::u_max, GL::UMax);
619 
620   case TargetOpcode::G_SCMP:
621     return selectSUCmp(ResVReg, ResType, I, true);
622   case TargetOpcode::G_UCMP:
623     return selectSUCmp(ResVReg, ResType, I, false);
624 
625   case TargetOpcode::G_STRICT_FMA:
626   case TargetOpcode::G_FMA:
627     return selectExtInst(ResVReg, ResType, I, CL::fma, GL::Fma);
628 
629   case TargetOpcode::G_STRICT_FLDEXP:
630     return selectExtInst(ResVReg, ResType, I, CL::ldexp);
631 
632   case TargetOpcode::G_FPOW:
633     return selectExtInst(ResVReg, ResType, I, CL::pow, GL::Pow);
634   case TargetOpcode::G_FPOWI:
635     return selectExtInst(ResVReg, ResType, I, CL::pown);
636 
637   case TargetOpcode::G_FEXP:
638     return selectExtInst(ResVReg, ResType, I, CL::exp, GL::Exp);
639   case TargetOpcode::G_FEXP2:
640     return selectExtInst(ResVReg, ResType, I, CL::exp2, GL::Exp2);
641 
642   case TargetOpcode::G_FLOG:
643     return selectExtInst(ResVReg, ResType, I, CL::log, GL::Log);
644   case TargetOpcode::G_FLOG2:
645     return selectExtInst(ResVReg, ResType, I, CL::log2, GL::Log2);
646   case TargetOpcode::G_FLOG10:
647     return selectLog10(ResVReg, ResType, I);
648 
649   case TargetOpcode::G_FABS:
650     return selectExtInst(ResVReg, ResType, I, CL::fabs, GL::FAbs);
651   case TargetOpcode::G_ABS:
652     return selectExtInst(ResVReg, ResType, I, CL::s_abs, GL::SAbs);
653 
654   case TargetOpcode::G_FMINNUM:
655   case TargetOpcode::G_FMINIMUM:
656     return selectExtInst(ResVReg, ResType, I, CL::fmin, GL::NMin);
657   case TargetOpcode::G_FMAXNUM:
658   case TargetOpcode::G_FMAXIMUM:
659     return selectExtInst(ResVReg, ResType, I, CL::fmax, GL::NMax);
660 
661   case TargetOpcode::G_FCOPYSIGN:
662     return selectExtInst(ResVReg, ResType, I, CL::copysign);
663 
664   case TargetOpcode::G_FCEIL:
665     return selectExtInst(ResVReg, ResType, I, CL::ceil, GL::Ceil);
666   case TargetOpcode::G_FFLOOR:
667     return selectExtInst(ResVReg, ResType, I, CL::floor, GL::Floor);
668 
669   case TargetOpcode::G_FCOS:
670     return selectExtInst(ResVReg, ResType, I, CL::cos, GL::Cos);
671   case TargetOpcode::G_FSIN:
672     return selectExtInst(ResVReg, ResType, I, CL::sin, GL::Sin);
673   case TargetOpcode::G_FTAN:
674     return selectExtInst(ResVReg, ResType, I, CL::tan, GL::Tan);
675   case TargetOpcode::G_FACOS:
676     return selectExtInst(ResVReg, ResType, I, CL::acos, GL::Acos);
677   case TargetOpcode::G_FASIN:
678     return selectExtInst(ResVReg, ResType, I, CL::asin, GL::Asin);
679   case TargetOpcode::G_FATAN:
680     return selectExtInst(ResVReg, ResType, I, CL::atan, GL::Atan);
681   case TargetOpcode::G_FATAN2:
682     return selectExtInst(ResVReg, ResType, I, CL::atan2, GL::Atan2);
683   case TargetOpcode::G_FCOSH:
684     return selectExtInst(ResVReg, ResType, I, CL::cosh, GL::Cosh);
685   case TargetOpcode::G_FSINH:
686     return selectExtInst(ResVReg, ResType, I, CL::sinh, GL::Sinh);
687   case TargetOpcode::G_FTANH:
688     return selectExtInst(ResVReg, ResType, I, CL::tanh, GL::Tanh);
689 
690   case TargetOpcode::G_STRICT_FSQRT:
691   case TargetOpcode::G_FSQRT:
692     return selectExtInst(ResVReg, ResType, I, CL::sqrt, GL::Sqrt);
693 
694   case TargetOpcode::G_CTTZ:
695   case TargetOpcode::G_CTTZ_ZERO_UNDEF:
696     return selectExtInst(ResVReg, ResType, I, CL::ctz);
697   case TargetOpcode::G_CTLZ:
698   case TargetOpcode::G_CTLZ_ZERO_UNDEF:
699     return selectExtInst(ResVReg, ResType, I, CL::clz);
700 
701   case TargetOpcode::G_INTRINSIC_ROUND:
702     return selectExtInst(ResVReg, ResType, I, CL::round, GL::Round);
703   case TargetOpcode::G_INTRINSIC_ROUNDEVEN:
704     return selectExtInst(ResVReg, ResType, I, CL::rint, GL::RoundEven);
705   case TargetOpcode::G_INTRINSIC_TRUNC:
706     return selectExtInst(ResVReg, ResType, I, CL::trunc, GL::Trunc);
707   case TargetOpcode::G_FRINT:
708   case TargetOpcode::G_FNEARBYINT:
709     return selectExtInst(ResVReg, ResType, I, CL::rint, GL::RoundEven);
710 
711   case TargetOpcode::G_SMULH:
712     return selectExtInst(ResVReg, ResType, I, CL::s_mul_hi);
713   case TargetOpcode::G_UMULH:
714     return selectExtInst(ResVReg, ResType, I, CL::u_mul_hi);
715 
716   case TargetOpcode::G_SADDSAT:
717     return selectExtInst(ResVReg, ResType, I, CL::s_add_sat);
718   case TargetOpcode::G_UADDSAT:
719     return selectExtInst(ResVReg, ResType, I, CL::u_add_sat);
720   case TargetOpcode::G_SSUBSAT:
721     return selectExtInst(ResVReg, ResType, I, CL::s_sub_sat);
722   case TargetOpcode::G_USUBSAT:
723     return selectExtInst(ResVReg, ResType, I, CL::u_sub_sat);
724 
725   case TargetOpcode::G_UADDO:
726     return selectOverflowArith(ResVReg, ResType, I,
727                                ResType->getOpcode() == SPIRV::OpTypeVector
728                                    ? SPIRV::OpIAddCarryV
729                                    : SPIRV::OpIAddCarryS);
730   case TargetOpcode::G_USUBO:
731     return selectOverflowArith(ResVReg, ResType, I,
732                                ResType->getOpcode() == SPIRV::OpTypeVector
733                                    ? SPIRV::OpISubBorrowV
734                                    : SPIRV::OpISubBorrowS);
735   case TargetOpcode::G_UMULO:
736     return selectOverflowArith(ResVReg, ResType, I, SPIRV::OpUMulExtended);
737   case TargetOpcode::G_SMULO:
738     return selectOverflowArith(ResVReg, ResType, I, SPIRV::OpSMulExtended);
739 
740   case TargetOpcode::G_SEXT:
741     return selectExt(ResVReg, ResType, I, true);
742   case TargetOpcode::G_ANYEXT:
743   case TargetOpcode::G_ZEXT:
744     return selectExt(ResVReg, ResType, I, false);
745   case TargetOpcode::G_TRUNC:
746     return selectTrunc(ResVReg, ResType, I);
747   case TargetOpcode::G_FPTRUNC:
748   case TargetOpcode::G_FPEXT:
749     return selectUnOp(ResVReg, ResType, I, SPIRV::OpFConvert);
750 
751   case TargetOpcode::G_PTRTOINT:
752     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertPtrToU);
753   case TargetOpcode::G_INTTOPTR:
754     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertUToPtr);
755   case TargetOpcode::G_BITCAST:
756     return selectBitcast(ResVReg, ResType, I);
757   case TargetOpcode::G_ADDRSPACE_CAST:
758     return selectAddrSpaceCast(ResVReg, ResType, I);
759   case TargetOpcode::G_PTR_ADD: {
760     // Currently, we get G_PTR_ADD only applied to global variables.
761     assert(I.getOperand(1).isReg() && I.getOperand(2).isReg());
762     Register GV = I.getOperand(1).getReg();
763     MachineRegisterInfo::def_instr_iterator II = MRI->def_instr_begin(GV);
764     (void)II;
765     assert(((*II).getOpcode() == TargetOpcode::G_GLOBAL_VALUE ||
766             (*II).getOpcode() == TargetOpcode::COPY ||
767             (*II).getOpcode() == SPIRV::OpVariable) &&
768            isImm(I.getOperand(2), MRI));
769     // It may be the initialization of a global variable.
770     bool IsGVInit = false;
771     for (MachineRegisterInfo::use_instr_iterator
772              UseIt = MRI->use_instr_begin(I.getOperand(0).getReg()),
773              UseEnd = MRI->use_instr_end();
774          UseIt != UseEnd; UseIt = std::next(UseIt)) {
775       if ((*UseIt).getOpcode() == TargetOpcode::G_GLOBAL_VALUE ||
776           (*UseIt).getOpcode() == SPIRV::OpVariable) {
777         IsGVInit = true;
778         break;
779       }
780     }
781     MachineBasicBlock &BB = *I.getParent();
782     if (!IsGVInit) {
783       SPIRVType *GVType = GR.getSPIRVTypeForVReg(GV);
784       SPIRVType *GVPointeeType = GR.getPointeeType(GVType);
785       SPIRVType *ResPointeeType = GR.getPointeeType(ResType);
786       if (GVPointeeType && ResPointeeType && GVPointeeType != ResPointeeType) {
787         // Build a new virtual register that is associated with the required
788         // data type.
789         Register NewVReg = MRI->createGenericVirtualRegister(MRI->getType(GV));
790         MRI->setRegClass(NewVReg, MRI->getRegClass(GV));
791         //  Having a correctly typed base we are ready to build the actually
792         //  required GEP. It may not be a constant though, because all Operands
793         //  of OpSpecConstantOp is to originate from other const instructions,
794         //  and only the AccessChain named opcodes accept a global OpVariable
795         //  instruction. We can't use an AccessChain opcode because of the type
796         //  mismatch between result and base types.
797         if (!GR.isBitcastCompatible(ResType, GVType))
798           report_fatal_error(
799               "incompatible result and operand types in a bitcast");
800         Register ResTypeReg = GR.getSPIRVTypeID(ResType);
801         MachineInstrBuilder MIB =
802             BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpBitcast))
803                 .addDef(NewVReg)
804                 .addUse(ResTypeReg)
805                 .addUse(GV);
806         return MIB.constrainAllUses(TII, TRI, RBI) &&
807                BuildMI(BB, I, I.getDebugLoc(),
808                        TII.get(STI.isVulkanEnv()
809                                    ? SPIRV::OpInBoundsAccessChain
810                                    : SPIRV::OpInBoundsPtrAccessChain))
811                    .addDef(ResVReg)
812                    .addUse(ResTypeReg)
813                    .addUse(NewVReg)
814                    .addUse(I.getOperand(2).getReg())
815                    .constrainAllUses(TII, TRI, RBI);
816       } else {
817         return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
818             .addDef(ResVReg)
819             .addUse(GR.getSPIRVTypeID(ResType))
820             .addImm(
821                 static_cast<uint32_t>(SPIRV::Opcode::InBoundsPtrAccessChain))
822             .addUse(GV)
823             .addUse(I.getOperand(2).getReg())
824             .constrainAllUses(TII, TRI, RBI);
825       }
826     }
827     // It's possible to translate G_PTR_ADD to OpSpecConstantOp: either to
828     // initialize a global variable with a constant expression (e.g., the test
829     // case opencl/basic/progvar_prog_scope_init.ll), or for another use case
830     Register Idx = buildZerosVal(GR.getOrCreateSPIRVIntegerType(32, I, TII), I);
831     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
832                    .addDef(ResVReg)
833                    .addUse(GR.getSPIRVTypeID(ResType))
834                    .addImm(static_cast<uint32_t>(
835                        SPIRV::Opcode::InBoundsPtrAccessChain))
836                    .addUse(GV)
837                    .addUse(Idx)
838                    .addUse(I.getOperand(2).getReg());
839     return MIB.constrainAllUses(TII, TRI, RBI);
840   }
841 
842   case TargetOpcode::G_ATOMICRMW_OR:
843     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicOr);
844   case TargetOpcode::G_ATOMICRMW_ADD:
845     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicIAdd);
846   case TargetOpcode::G_ATOMICRMW_AND:
847     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicAnd);
848   case TargetOpcode::G_ATOMICRMW_MAX:
849     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicSMax);
850   case TargetOpcode::G_ATOMICRMW_MIN:
851     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicSMin);
852   case TargetOpcode::G_ATOMICRMW_SUB:
853     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicISub);
854   case TargetOpcode::G_ATOMICRMW_XOR:
855     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicXor);
856   case TargetOpcode::G_ATOMICRMW_UMAX:
857     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicUMax);
858   case TargetOpcode::G_ATOMICRMW_UMIN:
859     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicUMin);
860   case TargetOpcode::G_ATOMICRMW_XCHG:
861     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicExchange);
862   case TargetOpcode::G_ATOMIC_CMPXCHG:
863     return selectAtomicCmpXchg(ResVReg, ResType, I);
864 
865   case TargetOpcode::G_ATOMICRMW_FADD:
866     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFAddEXT);
867   case TargetOpcode::G_ATOMICRMW_FSUB:
868     // Translate G_ATOMICRMW_FSUB to OpAtomicFAddEXT with negative value operand
869     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFAddEXT,
870                            SPIRV::OpFNegate);
871   case TargetOpcode::G_ATOMICRMW_FMIN:
872     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFMinEXT);
873   case TargetOpcode::G_ATOMICRMW_FMAX:
874     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFMaxEXT);
875 
876   case TargetOpcode::G_FENCE:
877     return selectFence(I);
878 
879   case TargetOpcode::G_STACKSAVE:
880     return selectStackSave(ResVReg, ResType, I);
881   case TargetOpcode::G_STACKRESTORE:
882     return selectStackRestore(I);
883 
884   case TargetOpcode::G_UNMERGE_VALUES:
885     return selectUnmergeValues(I);
886 
887   // Discard gen opcodes for intrinsics which we do not expect to actually
888   // represent code after lowering or intrinsics which are not implemented but
889   // should not crash when found in a customer's LLVM IR input.
890   case TargetOpcode::G_TRAP:
891   case TargetOpcode::G_DEBUGTRAP:
892   case TargetOpcode::G_UBSANTRAP:
893   case TargetOpcode::DBG_LABEL:
894     return true;
895 
896   default:
897     return false;
898   }
899 }
900 
901 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
902                                              const SPIRVType *ResType,
903                                              MachineInstr &I,
904                                              GL::GLSLExtInst GLInst) const {
905   return selectExtInst(ResVReg, ResType, I,
906                        {{SPIRV::InstructionSet::GLSL_std_450, GLInst}});
907 }
908 
909 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
910                                              const SPIRVType *ResType,
911                                              MachineInstr &I,
912                                              CL::OpenCLExtInst CLInst) const {
913   return selectExtInst(ResVReg, ResType, I,
914                        {{SPIRV::InstructionSet::OpenCL_std, CLInst}});
915 }
916 
917 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
918                                              const SPIRVType *ResType,
919                                              MachineInstr &I,
920                                              CL::OpenCLExtInst CLInst,
921                                              GL::GLSLExtInst GLInst) const {
922   ExtInstList ExtInsts = {{SPIRV::InstructionSet::OpenCL_std, CLInst},
923                           {SPIRV::InstructionSet::GLSL_std_450, GLInst}};
924   return selectExtInst(ResVReg, ResType, I, ExtInsts);
925 }
926 
927 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
928                                              const SPIRVType *ResType,
929                                              MachineInstr &I,
930                                              const ExtInstList &Insts) const {
931 
932   for (const auto &Ex : Insts) {
933     SPIRV::InstructionSet::InstructionSet Set = Ex.first;
934     uint32_t Opcode = Ex.second;
935     if (STI.canUseExtInstSet(Set)) {
936       MachineBasicBlock &BB = *I.getParent();
937       auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
938                      .addDef(ResVReg)
939                      .addUse(GR.getSPIRVTypeID(ResType))
940                      .addImm(static_cast<uint32_t>(Set))
941                      .addImm(Opcode);
942       const unsigned NumOps = I.getNumOperands();
943       unsigned Index = 1;
944       if (Index < NumOps &&
945           I.getOperand(Index).getType() ==
946               MachineOperand::MachineOperandType::MO_IntrinsicID)
947         Index = 2;
948       for (; Index < NumOps; ++Index)
949         MIB.add(I.getOperand(Index));
950       return MIB.constrainAllUses(TII, TRI, RBI);
951     }
952   }
953   return false;
954 }
955 
956 bool SPIRVInstructionSelector::selectOpWithSrcs(Register ResVReg,
957                                                 const SPIRVType *ResType,
958                                                 MachineInstr &I,
959                                                 std::vector<Register> Srcs,
960                                                 unsigned Opcode) const {
961   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
962                  .addDef(ResVReg)
963                  .addUse(GR.getSPIRVTypeID(ResType));
964   for (Register SReg : Srcs) {
965     MIB.addUse(SReg);
966   }
967   return MIB.constrainAllUses(TII, TRI, RBI);
968 }
969 
970 bool SPIRVInstructionSelector::selectUnOp(Register ResVReg,
971                                           const SPIRVType *ResType,
972                                           MachineInstr &I,
973                                           unsigned Opcode) const {
974   if (STI.isOpenCLEnv() && I.getOperand(1).isReg()) {
975     Register SrcReg = I.getOperand(1).getReg();
976     bool IsGV = false;
977     for (MachineRegisterInfo::def_instr_iterator DefIt =
978              MRI->def_instr_begin(SrcReg);
979          DefIt != MRI->def_instr_end(); DefIt = std::next(DefIt)) {
980       if ((*DefIt).getOpcode() == TargetOpcode::G_GLOBAL_VALUE) {
981         IsGV = true;
982         break;
983       }
984     }
985     if (IsGV) {
986       uint32_t SpecOpcode = 0;
987       switch (Opcode) {
988       case SPIRV::OpConvertPtrToU:
989         SpecOpcode = static_cast<uint32_t>(SPIRV::Opcode::ConvertPtrToU);
990         break;
991       case SPIRV::OpConvertUToPtr:
992         SpecOpcode = static_cast<uint32_t>(SPIRV::Opcode::ConvertUToPtr);
993         break;
994       }
995       if (SpecOpcode)
996         return BuildMI(*I.getParent(), I, I.getDebugLoc(),
997                        TII.get(SPIRV::OpSpecConstantOp))
998             .addDef(ResVReg)
999             .addUse(GR.getSPIRVTypeID(ResType))
1000             .addImm(SpecOpcode)
1001             .addUse(SrcReg)
1002             .constrainAllUses(TII, TRI, RBI);
1003     }
1004   }
1005   return selectOpWithSrcs(ResVReg, ResType, I, {I.getOperand(1).getReg()},
1006                           Opcode);
1007 }
1008 
1009 bool SPIRVInstructionSelector::selectBitcast(Register ResVReg,
1010                                              const SPIRVType *ResType,
1011                                              MachineInstr &I) const {
1012   Register OpReg = I.getOperand(1).getReg();
1013   SPIRVType *OpType = OpReg.isValid() ? GR.getSPIRVTypeForVReg(OpReg) : nullptr;
1014   if (!GR.isBitcastCompatible(ResType, OpType))
1015     report_fatal_error("incompatible result and operand types in a bitcast");
1016   return selectUnOp(ResVReg, ResType, I, SPIRV::OpBitcast);
1017 }
1018 
1019 static void addMemoryOperands(MachineMemOperand *MemOp,
1020                               MachineInstrBuilder &MIB) {
1021   uint32_t SpvMemOp = static_cast<uint32_t>(SPIRV::MemoryOperand::None);
1022   if (MemOp->isVolatile())
1023     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Volatile);
1024   if (MemOp->isNonTemporal())
1025     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Nontemporal);
1026   if (MemOp->getAlign().value())
1027     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Aligned);
1028 
1029   if (SpvMemOp != static_cast<uint32_t>(SPIRV::MemoryOperand::None)) {
1030     MIB.addImm(SpvMemOp);
1031     if (SpvMemOp & static_cast<uint32_t>(SPIRV::MemoryOperand::Aligned))
1032       MIB.addImm(MemOp->getAlign().value());
1033   }
1034 }
1035 
1036 static void addMemoryOperands(uint64_t Flags, MachineInstrBuilder &MIB) {
1037   uint32_t SpvMemOp = static_cast<uint32_t>(SPIRV::MemoryOperand::None);
1038   if (Flags & MachineMemOperand::Flags::MOVolatile)
1039     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Volatile);
1040   if (Flags & MachineMemOperand::Flags::MONonTemporal)
1041     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Nontemporal);
1042 
1043   if (SpvMemOp != static_cast<uint32_t>(SPIRV::MemoryOperand::None))
1044     MIB.addImm(SpvMemOp);
1045 }
1046 
1047 bool SPIRVInstructionSelector::selectLoad(Register ResVReg,
1048                                           const SPIRVType *ResType,
1049                                           MachineInstr &I) const {
1050   unsigned OpOffset = isa<GIntrinsic>(I) ? 1 : 0;
1051   Register Ptr = I.getOperand(1 + OpOffset).getReg();
1052 
1053   auto *PtrDef = getVRegDef(*MRI, Ptr);
1054   auto *IntPtrDef = dyn_cast<GIntrinsic>(PtrDef);
1055   if (IntPtrDef &&
1056       IntPtrDef->getIntrinsicID() == Intrinsic::spv_resource_getpointer) {
1057     Register ImageReg = IntPtrDef->getOperand(2).getReg();
1058     Register NewImageReg =
1059         MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
1060     auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
1061     if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
1062                                   *ImageDef, I)) {
1063       return false;
1064     }
1065 
1066     Register IdxReg = IntPtrDef->getOperand(3).getReg();
1067     return generateImageRead(ResVReg, ResType, NewImageReg, IdxReg,
1068                              I.getDebugLoc(), I);
1069   }
1070 
1071   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpLoad))
1072                  .addDef(ResVReg)
1073                  .addUse(GR.getSPIRVTypeID(ResType))
1074                  .addUse(Ptr);
1075   if (!I.getNumMemOperands()) {
1076     assert(I.getOpcode() == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS ||
1077            I.getOpcode() ==
1078                TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS);
1079     addMemoryOperands(I.getOperand(2 + OpOffset).getImm(), MIB);
1080   } else {
1081     addMemoryOperands(*I.memoperands_begin(), MIB);
1082   }
1083   return MIB.constrainAllUses(TII, TRI, RBI);
1084 }
1085 
1086 bool SPIRVInstructionSelector::selectStore(MachineInstr &I) const {
1087   unsigned OpOffset = isa<GIntrinsic>(I) ? 1 : 0;
1088   Register StoreVal = I.getOperand(0 + OpOffset).getReg();
1089   Register Ptr = I.getOperand(1 + OpOffset).getReg();
1090 
1091   auto *PtrDef = getVRegDef(*MRI, Ptr);
1092   auto *IntPtrDef = dyn_cast<GIntrinsic>(PtrDef);
1093   if (IntPtrDef &&
1094       IntPtrDef->getIntrinsicID() == Intrinsic::spv_resource_getpointer) {
1095     Register ImageReg = IntPtrDef->getOperand(2).getReg();
1096     Register NewImageReg =
1097         MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
1098     auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
1099     if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
1100                                   *ImageDef, I)) {
1101       return false;
1102     }
1103 
1104     Register IdxReg = IntPtrDef->getOperand(3).getReg();
1105     return BuildMI(*I.getParent(), I, I.getDebugLoc(),
1106                    TII.get(SPIRV::OpImageWrite))
1107         .addUse(NewImageReg)
1108         .addUse(IdxReg)
1109         .addUse(StoreVal)
1110         .constrainAllUses(TII, TRI, RBI);
1111   }
1112 
1113   MachineBasicBlock &BB = *I.getParent();
1114   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpStore))
1115                  .addUse(Ptr)
1116                  .addUse(StoreVal);
1117   if (!I.getNumMemOperands()) {
1118     assert(I.getOpcode() == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS ||
1119            I.getOpcode() ==
1120                TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS);
1121     addMemoryOperands(I.getOperand(2 + OpOffset).getImm(), MIB);
1122   } else {
1123     addMemoryOperands(*I.memoperands_begin(), MIB);
1124   }
1125   return MIB.constrainAllUses(TII, TRI, RBI);
1126 }
1127 
1128 bool SPIRVInstructionSelector::selectStackSave(Register ResVReg,
1129                                                const SPIRVType *ResType,
1130                                                MachineInstr &I) const {
1131   if (!STI.canUseExtension(SPIRV::Extension::SPV_INTEL_variable_length_array))
1132     report_fatal_error(
1133         "llvm.stacksave intrinsic: this instruction requires the following "
1134         "SPIR-V extension: SPV_INTEL_variable_length_array",
1135         false);
1136   MachineBasicBlock &BB = *I.getParent();
1137   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSaveMemoryINTEL))
1138       .addDef(ResVReg)
1139       .addUse(GR.getSPIRVTypeID(ResType))
1140       .constrainAllUses(TII, TRI, RBI);
1141 }
1142 
1143 bool SPIRVInstructionSelector::selectStackRestore(MachineInstr &I) const {
1144   if (!STI.canUseExtension(SPIRV::Extension::SPV_INTEL_variable_length_array))
1145     report_fatal_error(
1146         "llvm.stackrestore intrinsic: this instruction requires the following "
1147         "SPIR-V extension: SPV_INTEL_variable_length_array",
1148         false);
1149   if (!I.getOperand(0).isReg())
1150     return false;
1151   MachineBasicBlock &BB = *I.getParent();
1152   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpRestoreMemoryINTEL))
1153       .addUse(I.getOperand(0).getReg())
1154       .constrainAllUses(TII, TRI, RBI);
1155 }
1156 
1157 bool SPIRVInstructionSelector::selectMemOperation(Register ResVReg,
1158                                                   MachineInstr &I) const {
1159   MachineBasicBlock &BB = *I.getParent();
1160   Register SrcReg = I.getOperand(1).getReg();
1161   bool Result = true;
1162   if (I.getOpcode() == TargetOpcode::G_MEMSET) {
1163     assert(I.getOperand(1).isReg() && I.getOperand(2).isReg());
1164     unsigned Val = getIConstVal(I.getOperand(1).getReg(), MRI);
1165     unsigned Num = getIConstVal(I.getOperand(2).getReg(), MRI);
1166     SPIRVType *ValTy = GR.getOrCreateSPIRVIntegerType(8, I, TII);
1167     SPIRVType *ArrTy = GR.getOrCreateSPIRVArrayType(ValTy, Num, I, TII);
1168     Register Const = GR.getOrCreateConstIntArray(Val, Num, I, ArrTy, TII);
1169     SPIRVType *VarTy = GR.getOrCreateSPIRVPointerType(
1170         ArrTy, I, TII, SPIRV::StorageClass::UniformConstant);
1171     // TODO: check if we have such GV, add init, use buildGlobalVariable.
1172     Function &CurFunction = GR.CurMF->getFunction();
1173     Type *LLVMArrTy =
1174         ArrayType::get(IntegerType::get(CurFunction.getContext(), 8), Num);
1175     // Module takes ownership of the global var.
1176     GlobalVariable *GV = new GlobalVariable(*CurFunction.getParent(), LLVMArrTy,
1177                                             true, GlobalValue::InternalLinkage,
1178                                             Constant::getNullValue(LLVMArrTy));
1179     Register VarReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1180     GR.add(GV, GR.CurMF, VarReg);
1181     GR.addGlobalObject(GV, GR.CurMF, VarReg);
1182 
1183     Result &=
1184         BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpVariable))
1185             .addDef(VarReg)
1186             .addUse(GR.getSPIRVTypeID(VarTy))
1187             .addImm(SPIRV::StorageClass::UniformConstant)
1188             .addUse(Const)
1189             .constrainAllUses(TII, TRI, RBI);
1190     buildOpDecorate(VarReg, I, TII, SPIRV::Decoration::Constant, {});
1191     SPIRVType *SourceTy = GR.getOrCreateSPIRVPointerType(
1192         ValTy, I, TII, SPIRV::StorageClass::UniformConstant);
1193     SrcReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1194     selectOpWithSrcs(SrcReg, SourceTy, I, {VarReg}, SPIRV::OpBitcast);
1195   }
1196   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCopyMemorySized))
1197                  .addUse(I.getOperand(0).getReg())
1198                  .addUse(SrcReg)
1199                  .addUse(I.getOperand(2).getReg());
1200   if (I.getNumMemOperands())
1201     addMemoryOperands(*I.memoperands_begin(), MIB);
1202   Result &= MIB.constrainAllUses(TII, TRI, RBI);
1203   if (ResVReg.isValid() && ResVReg != MIB->getOperand(0).getReg())
1204     Result &= BuildCOPY(ResVReg, MIB->getOperand(0).getReg(), I);
1205   return Result;
1206 }
1207 
1208 bool SPIRVInstructionSelector::selectAtomicRMW(Register ResVReg,
1209                                                const SPIRVType *ResType,
1210                                                MachineInstr &I,
1211                                                unsigned NewOpcode,
1212                                                unsigned NegateOpcode) const {
1213   bool Result = true;
1214   assert(I.hasOneMemOperand());
1215   const MachineMemOperand *MemOp = *I.memoperands_begin();
1216   uint32_t Scope = static_cast<uint32_t>(getMemScope(
1217       GR.CurMF->getFunction().getContext(), MemOp->getSyncScopeID()));
1218   auto ScopeConstant = buildI32Constant(Scope, I);
1219   Register ScopeReg = ScopeConstant.first;
1220   Result &= ScopeConstant.second;
1221 
1222   Register Ptr = I.getOperand(1).getReg();
1223   // TODO: Changed as it's implemented in the translator. See test/atomicrmw.ll
1224   // auto ScSem =
1225   // getMemSemanticsForStorageClass(GR.getPointerStorageClass(Ptr));
1226   AtomicOrdering AO = MemOp->getSuccessOrdering();
1227   uint32_t MemSem = static_cast<uint32_t>(getMemSemantics(AO));
1228   auto MemSemConstant = buildI32Constant(MemSem /*| ScSem*/, I);
1229   Register MemSemReg = MemSemConstant.first;
1230   Result &= MemSemConstant.second;
1231 
1232   Register ValueReg = I.getOperand(2).getReg();
1233   if (NegateOpcode != 0) {
1234     // Translation with negative value operand is requested
1235     Register TmpReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1236     Result &= selectOpWithSrcs(TmpReg, ResType, I, {ValueReg}, NegateOpcode);
1237     ValueReg = TmpReg;
1238   }
1239 
1240   return Result &&
1241          BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(NewOpcode))
1242              .addDef(ResVReg)
1243              .addUse(GR.getSPIRVTypeID(ResType))
1244              .addUse(Ptr)
1245              .addUse(ScopeReg)
1246              .addUse(MemSemReg)
1247              .addUse(ValueReg)
1248              .constrainAllUses(TII, TRI, RBI);
1249 }
1250 
1251 bool SPIRVInstructionSelector::selectUnmergeValues(MachineInstr &I) const {
1252   unsigned ArgI = I.getNumOperands() - 1;
1253   Register SrcReg =
1254       I.getOperand(ArgI).isReg() ? I.getOperand(ArgI).getReg() : Register(0);
1255   SPIRVType *DefType =
1256       SrcReg.isValid() ? GR.getSPIRVTypeForVReg(SrcReg) : nullptr;
1257   if (!DefType || DefType->getOpcode() != SPIRV::OpTypeVector)
1258     report_fatal_error(
1259         "cannot select G_UNMERGE_VALUES with a non-vector argument");
1260 
1261   SPIRVType *ScalarType =
1262       GR.getSPIRVTypeForVReg(DefType->getOperand(1).getReg());
1263   MachineBasicBlock &BB = *I.getParent();
1264   bool Res = false;
1265   for (unsigned i = 0; i < I.getNumDefs(); ++i) {
1266     Register ResVReg = I.getOperand(i).getReg();
1267     SPIRVType *ResType = GR.getSPIRVTypeForVReg(ResVReg);
1268     if (!ResType) {
1269       // There was no "assign type" actions, let's fix this now
1270       ResType = ScalarType;
1271       MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
1272       MRI->setType(ResVReg, LLT::scalar(GR.getScalarOrVectorBitWidth(ResType)));
1273       GR.assignSPIRVTypeToVReg(ResType, ResVReg, *GR.CurMF);
1274     }
1275     auto MIB =
1276         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1277             .addDef(ResVReg)
1278             .addUse(GR.getSPIRVTypeID(ResType))
1279             .addUse(SrcReg)
1280             .addImm(static_cast<int64_t>(i));
1281     Res |= MIB.constrainAllUses(TII, TRI, RBI);
1282   }
1283   return Res;
1284 }
1285 
1286 bool SPIRVInstructionSelector::selectFence(MachineInstr &I) const {
1287   AtomicOrdering AO = AtomicOrdering(I.getOperand(0).getImm());
1288   uint32_t MemSem = static_cast<uint32_t>(getMemSemantics(AO));
1289   auto MemSemConstant = buildI32Constant(MemSem, I);
1290   Register MemSemReg = MemSemConstant.first;
1291   bool Result = MemSemConstant.second;
1292   SyncScope::ID Ord = SyncScope::ID(I.getOperand(1).getImm());
1293   uint32_t Scope = static_cast<uint32_t>(
1294       getMemScope(GR.CurMF->getFunction().getContext(), Ord));
1295   auto ScopeConstant = buildI32Constant(Scope, I);
1296   Register ScopeReg = ScopeConstant.first;
1297   Result &= ScopeConstant.second;
1298   MachineBasicBlock &BB = *I.getParent();
1299   return Result &&
1300          BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpMemoryBarrier))
1301              .addUse(ScopeReg)
1302              .addUse(MemSemReg)
1303              .constrainAllUses(TII, TRI, RBI);
1304 }
1305 
1306 bool SPIRVInstructionSelector::selectOverflowArith(Register ResVReg,
1307                                                    const SPIRVType *ResType,
1308                                                    MachineInstr &I,
1309                                                    unsigned Opcode) const {
1310   Type *ResTy = nullptr;
1311   StringRef ResName;
1312   if (!GR.findValueAttrs(&I, ResTy, ResName))
1313     report_fatal_error(
1314         "Not enough info to select the arithmetic with overflow instruction");
1315   if (!ResTy || !ResTy->isStructTy())
1316     report_fatal_error("Expect struct type result for the arithmetic "
1317                        "with overflow instruction");
1318   // "Result Type must be from OpTypeStruct. The struct must have two members,
1319   // and the two members must be the same type."
1320   Type *ResElemTy = cast<StructType>(ResTy)->getElementType(0);
1321   ResTy = StructType::get(ResElemTy, ResElemTy);
1322   // Build SPIR-V types and constant(s) if needed.
1323   MachineIRBuilder MIRBuilder(I);
1324   SPIRVType *StructType = GR.getOrCreateSPIRVType(
1325       ResTy, MIRBuilder, SPIRV::AccessQualifier::ReadWrite, false);
1326   assert(I.getNumDefs() > 1 && "Not enought operands");
1327   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
1328   unsigned N = GR.getScalarOrVectorComponentCount(ResType);
1329   if (N > 1)
1330     BoolType = GR.getOrCreateSPIRVVectorType(BoolType, N, I, TII);
1331   Register BoolTypeReg = GR.getSPIRVTypeID(BoolType);
1332   Register ZeroReg = buildZerosVal(ResType, I);
1333   // A new virtual register to store the result struct.
1334   Register StructVReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1335   MRI->setRegClass(StructVReg, &SPIRV::IDRegClass);
1336   // Build the result name if needed.
1337   if (ResName.size() > 0)
1338     buildOpName(StructVReg, ResName, MIRBuilder);
1339   // Build the arithmetic with overflow instruction.
1340   MachineBasicBlock &BB = *I.getParent();
1341   auto MIB =
1342       BuildMI(BB, MIRBuilder.getInsertPt(), I.getDebugLoc(), TII.get(Opcode))
1343           .addDef(StructVReg)
1344           .addUse(GR.getSPIRVTypeID(StructType));
1345   for (unsigned i = I.getNumDefs(); i < I.getNumOperands(); ++i)
1346     MIB.addUse(I.getOperand(i).getReg());
1347   bool Result = MIB.constrainAllUses(TII, TRI, RBI);
1348   // Build instructions to extract fields of the instruction's result.
1349   // A new virtual register to store the higher part of the result struct.
1350   Register HigherVReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1351   MRI->setRegClass(HigherVReg, &SPIRV::iIDRegClass);
1352   for (unsigned i = 0; i < I.getNumDefs(); ++i) {
1353     auto MIB =
1354         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1355             .addDef(i == 1 ? HigherVReg : I.getOperand(i).getReg())
1356             .addUse(GR.getSPIRVTypeID(ResType))
1357             .addUse(StructVReg)
1358             .addImm(i);
1359     Result &= MIB.constrainAllUses(TII, TRI, RBI);
1360   }
1361   // Build boolean value from the higher part.
1362   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpINotEqual))
1363                        .addDef(I.getOperand(1).getReg())
1364                        .addUse(BoolTypeReg)
1365                        .addUse(HigherVReg)
1366                        .addUse(ZeroReg)
1367                        .constrainAllUses(TII, TRI, RBI);
1368 }
1369 
1370 bool SPIRVInstructionSelector::selectAtomicCmpXchg(Register ResVReg,
1371                                                    const SPIRVType *ResType,
1372                                                    MachineInstr &I) const {
1373   bool Result = true;
1374   Register ScopeReg;
1375   Register MemSemEqReg;
1376   Register MemSemNeqReg;
1377   Register Ptr = I.getOperand(2).getReg();
1378   if (!isa<GIntrinsic>(I)) {
1379     assert(I.hasOneMemOperand());
1380     const MachineMemOperand *MemOp = *I.memoperands_begin();
1381     unsigned Scope = static_cast<uint32_t>(getMemScope(
1382         GR.CurMF->getFunction().getContext(), MemOp->getSyncScopeID()));
1383     auto ScopeConstant = buildI32Constant(Scope, I);
1384     ScopeReg = ScopeConstant.first;
1385     Result &= ScopeConstant.second;
1386 
1387     unsigned ScSem = static_cast<uint32_t>(
1388         getMemSemanticsForStorageClass(GR.getPointerStorageClass(Ptr)));
1389     AtomicOrdering AO = MemOp->getSuccessOrdering();
1390     unsigned MemSemEq = static_cast<uint32_t>(getMemSemantics(AO)) | ScSem;
1391     auto MemSemEqConstant = buildI32Constant(MemSemEq, I);
1392     MemSemEqReg = MemSemEqConstant.first;
1393     Result &= MemSemEqConstant.second;
1394     AtomicOrdering FO = MemOp->getFailureOrdering();
1395     unsigned MemSemNeq = static_cast<uint32_t>(getMemSemantics(FO)) | ScSem;
1396     if (MemSemEq == MemSemNeq)
1397       MemSemNeqReg = MemSemEqReg;
1398     else {
1399       auto MemSemNeqConstant = buildI32Constant(MemSemEq, I);
1400       MemSemNeqReg = MemSemNeqConstant.first;
1401       Result &= MemSemNeqConstant.second;
1402     }
1403   } else {
1404     ScopeReg = I.getOperand(5).getReg();
1405     MemSemEqReg = I.getOperand(6).getReg();
1406     MemSemNeqReg = I.getOperand(7).getReg();
1407   }
1408 
1409   Register Cmp = I.getOperand(3).getReg();
1410   Register Val = I.getOperand(4).getReg();
1411   SPIRVType *SpvValTy = GR.getSPIRVTypeForVReg(Val);
1412   Register ACmpRes = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1413   const DebugLoc &DL = I.getDebugLoc();
1414   Result &=
1415       BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpAtomicCompareExchange))
1416           .addDef(ACmpRes)
1417           .addUse(GR.getSPIRVTypeID(SpvValTy))
1418           .addUse(Ptr)
1419           .addUse(ScopeReg)
1420           .addUse(MemSemEqReg)
1421           .addUse(MemSemNeqReg)
1422           .addUse(Val)
1423           .addUse(Cmp)
1424           .constrainAllUses(TII, TRI, RBI);
1425   Register CmpSuccReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1426   SPIRVType *BoolTy = GR.getOrCreateSPIRVBoolType(I, TII);
1427   Result &= BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpIEqual))
1428                 .addDef(CmpSuccReg)
1429                 .addUse(GR.getSPIRVTypeID(BoolTy))
1430                 .addUse(ACmpRes)
1431                 .addUse(Cmp)
1432                 .constrainAllUses(TII, TRI, RBI);
1433   Register TmpReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1434   Result &= BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpCompositeInsert))
1435                 .addDef(TmpReg)
1436                 .addUse(GR.getSPIRVTypeID(ResType))
1437                 .addUse(ACmpRes)
1438                 .addUse(GR.getOrCreateUndef(I, ResType, TII))
1439                 .addImm(0)
1440                 .constrainAllUses(TII, TRI, RBI);
1441   return Result &&
1442          BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpCompositeInsert))
1443              .addDef(ResVReg)
1444              .addUse(GR.getSPIRVTypeID(ResType))
1445              .addUse(CmpSuccReg)
1446              .addUse(TmpReg)
1447              .addImm(1)
1448              .constrainAllUses(TII, TRI, RBI);
1449 }
1450 
1451 static bool isGenericCastablePtr(SPIRV::StorageClass::StorageClass SC) {
1452   switch (SC) {
1453   case SPIRV::StorageClass::Workgroup:
1454   case SPIRV::StorageClass::CrossWorkgroup:
1455   case SPIRV::StorageClass::Function:
1456     return true;
1457   default:
1458     return false;
1459   }
1460 }
1461 
1462 static bool isUSMStorageClass(SPIRV::StorageClass::StorageClass SC) {
1463   switch (SC) {
1464   case SPIRV::StorageClass::DeviceOnlyINTEL:
1465   case SPIRV::StorageClass::HostOnlyINTEL:
1466     return true;
1467   default:
1468     return false;
1469   }
1470 }
1471 
1472 // Returns true ResVReg is referred only from global vars and OpName's.
1473 static bool isASCastInGVar(MachineRegisterInfo *MRI, Register ResVReg) {
1474   bool IsGRef = false;
1475   bool IsAllowedRefs =
1476       std::all_of(MRI->use_instr_begin(ResVReg), MRI->use_instr_end(),
1477                   [&IsGRef](auto const &It) {
1478                     unsigned Opcode = It.getOpcode();
1479                     if (Opcode == SPIRV::OpConstantComposite ||
1480                         Opcode == SPIRV::OpVariable ||
1481                         isSpvIntrinsic(It, Intrinsic::spv_init_global))
1482                       return IsGRef = true;
1483                     return Opcode == SPIRV::OpName;
1484                   });
1485   return IsAllowedRefs && IsGRef;
1486 }
1487 
1488 Register SPIRVInstructionSelector::getUcharPtrTypeReg(
1489     MachineInstr &I, SPIRV::StorageClass::StorageClass SC) const {
1490   return GR.getSPIRVTypeID(GR.getOrCreateSPIRVPointerType(
1491       GR.getOrCreateSPIRVIntegerType(8, I, TII), I, TII, SC));
1492 }
1493 
1494 MachineInstrBuilder
1495 SPIRVInstructionSelector::buildSpecConstantOp(MachineInstr &I, Register Dest,
1496                                               Register Src, Register DestType,
1497                                               uint32_t Opcode) const {
1498   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
1499                  TII.get(SPIRV::OpSpecConstantOp))
1500       .addDef(Dest)
1501       .addUse(DestType)
1502       .addImm(Opcode)
1503       .addUse(Src);
1504 }
1505 
1506 MachineInstrBuilder
1507 SPIRVInstructionSelector::buildConstGenericPtr(MachineInstr &I, Register SrcPtr,
1508                                                SPIRVType *SrcPtrTy) const {
1509   SPIRVType *GenericPtrTy = GR.getOrCreateSPIRVPointerType(
1510       GR.getPointeeType(SrcPtrTy), I, TII, SPIRV::StorageClass::Generic);
1511   Register Tmp = MRI->createVirtualRegister(&SPIRV::pIDRegClass);
1512   MRI->setType(Tmp, LLT::pointer(storageClassToAddressSpace(
1513                                      SPIRV::StorageClass::Generic),
1514                                  GR.getPointerSize()));
1515   MachineFunction *MF = I.getParent()->getParent();
1516   GR.assignSPIRVTypeToVReg(GenericPtrTy, Tmp, *MF);
1517   MachineInstrBuilder MIB = buildSpecConstantOp(
1518       I, Tmp, SrcPtr, GR.getSPIRVTypeID(GenericPtrTy),
1519       static_cast<uint32_t>(SPIRV::Opcode::PtrCastToGeneric));
1520   GR.add(MIB.getInstr(), MF, Tmp);
1521   return MIB;
1522 }
1523 
1524 // In SPIR-V address space casting can only happen to and from the Generic
1525 // storage class. We can also only cast Workgroup, CrossWorkgroup, or Function
1526 // pointers to and from Generic pointers. As such, we can convert e.g. from
1527 // Workgroup to Function by going via a Generic pointer as an intermediary. All
1528 // other combinations can only be done by a bitcast, and are probably not safe.
1529 bool SPIRVInstructionSelector::selectAddrSpaceCast(Register ResVReg,
1530                                                    const SPIRVType *ResType,
1531                                                    MachineInstr &I) const {
1532   MachineBasicBlock &BB = *I.getParent();
1533   const DebugLoc &DL = I.getDebugLoc();
1534 
1535   Register SrcPtr = I.getOperand(1).getReg();
1536   SPIRVType *SrcPtrTy = GR.getSPIRVTypeForVReg(SrcPtr);
1537 
1538   // don't generate a cast for a null that may be represented by OpTypeInt
1539   if (SrcPtrTy->getOpcode() != SPIRV::OpTypePointer ||
1540       ResType->getOpcode() != SPIRV::OpTypePointer)
1541     return BuildCOPY(ResVReg, SrcPtr, I);
1542 
1543   SPIRV::StorageClass::StorageClass SrcSC = GR.getPointerStorageClass(SrcPtrTy);
1544   SPIRV::StorageClass::StorageClass DstSC = GR.getPointerStorageClass(ResType);
1545 
1546   if (isASCastInGVar(MRI, ResVReg)) {
1547     // AddrSpaceCast uses within OpVariable and OpConstantComposite instructions
1548     // are expressed by OpSpecConstantOp with an Opcode.
1549     // TODO: maybe insert a check whether the Kernel capability was declared and
1550     // so PtrCastToGeneric/GenericCastToPtr are available.
1551     unsigned SpecOpcode =
1552         DstSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(SrcSC)
1553             ? static_cast<uint32_t>(SPIRV::Opcode::PtrCastToGeneric)
1554             : (SrcSC == SPIRV::StorageClass::Generic &&
1555                        isGenericCastablePtr(DstSC)
1556                    ? static_cast<uint32_t>(SPIRV::Opcode::GenericCastToPtr)
1557                    : 0);
1558     // TODO: OpConstantComposite expects i8*, so we are forced to forget a
1559     // correct value of ResType and use general i8* instead. Maybe this should
1560     // be addressed in the emit-intrinsic step to infer a correct
1561     // OpConstantComposite type.
1562     if (SpecOpcode) {
1563       return buildSpecConstantOp(I, ResVReg, SrcPtr,
1564                                  getUcharPtrTypeReg(I, DstSC), SpecOpcode)
1565           .constrainAllUses(TII, TRI, RBI);
1566     } else if (isGenericCastablePtr(SrcSC) && isGenericCastablePtr(DstSC)) {
1567       MachineInstrBuilder MIB = buildConstGenericPtr(I, SrcPtr, SrcPtrTy);
1568       return MIB.constrainAllUses(TII, TRI, RBI) &&
1569              buildSpecConstantOp(
1570                  I, ResVReg, MIB->getOperand(0).getReg(),
1571                  getUcharPtrTypeReg(I, DstSC),
1572                  static_cast<uint32_t>(SPIRV::Opcode::GenericCastToPtr))
1573                  .constrainAllUses(TII, TRI, RBI);
1574     }
1575   }
1576 
1577   // don't generate a cast between identical storage classes
1578   if (SrcSC == DstSC)
1579     return BuildCOPY(ResVReg, SrcPtr, I);
1580 
1581   if ((SrcSC == SPIRV::StorageClass::Function &&
1582        DstSC == SPIRV::StorageClass::Private) ||
1583       (DstSC == SPIRV::StorageClass::Function &&
1584        SrcSC == SPIRV::StorageClass::Private))
1585     return BuildCOPY(ResVReg, SrcPtr, I);
1586 
1587   // Casting from an eligible pointer to Generic.
1588   if (DstSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(SrcSC))
1589     return selectUnOp(ResVReg, ResType, I, SPIRV::OpPtrCastToGeneric);
1590   // Casting from Generic to an eligible pointer.
1591   if (SrcSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(DstSC))
1592     return selectUnOp(ResVReg, ResType, I, SPIRV::OpGenericCastToPtr);
1593   // Casting between 2 eligible pointers using Generic as an intermediary.
1594   if (isGenericCastablePtr(SrcSC) && isGenericCastablePtr(DstSC)) {
1595     Register Tmp = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1596     SPIRVType *GenericPtrTy = GR.getOrCreateSPIRVPointerType(
1597         GR.getPointeeType(SrcPtrTy), I, TII, SPIRV::StorageClass::Generic);
1598     bool Result = BuildMI(BB, I, DL, TII.get(SPIRV::OpPtrCastToGeneric))
1599                       .addDef(Tmp)
1600                       .addUse(GR.getSPIRVTypeID(GenericPtrTy))
1601                       .addUse(SrcPtr)
1602                       .constrainAllUses(TII, TRI, RBI);
1603     return Result && BuildMI(BB, I, DL, TII.get(SPIRV::OpGenericCastToPtr))
1604                          .addDef(ResVReg)
1605                          .addUse(GR.getSPIRVTypeID(ResType))
1606                          .addUse(Tmp)
1607                          .constrainAllUses(TII, TRI, RBI);
1608   }
1609 
1610   // Check if instructions from the SPV_INTEL_usm_storage_classes extension may
1611   // be applied
1612   if (isUSMStorageClass(SrcSC) && DstSC == SPIRV::StorageClass::CrossWorkgroup)
1613     return selectUnOp(ResVReg, ResType, I,
1614                       SPIRV::OpPtrCastToCrossWorkgroupINTEL);
1615   if (SrcSC == SPIRV::StorageClass::CrossWorkgroup && isUSMStorageClass(DstSC))
1616     return selectUnOp(ResVReg, ResType, I,
1617                       SPIRV::OpCrossWorkgroupCastToPtrINTEL);
1618   if (isUSMStorageClass(SrcSC) && DstSC == SPIRV::StorageClass::Generic)
1619     return selectUnOp(ResVReg, ResType, I, SPIRV::OpPtrCastToGeneric);
1620   if (SrcSC == SPIRV::StorageClass::Generic && isUSMStorageClass(DstSC))
1621     return selectUnOp(ResVReg, ResType, I, SPIRV::OpGenericCastToPtr);
1622 
1623   // Bitcast for pointers requires that the address spaces must match
1624   return false;
1625 }
1626 
1627 static unsigned getFCmpOpcode(unsigned PredNum) {
1628   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1629   switch (Pred) {
1630   case CmpInst::FCMP_OEQ:
1631     return SPIRV::OpFOrdEqual;
1632   case CmpInst::FCMP_OGE:
1633     return SPIRV::OpFOrdGreaterThanEqual;
1634   case CmpInst::FCMP_OGT:
1635     return SPIRV::OpFOrdGreaterThan;
1636   case CmpInst::FCMP_OLE:
1637     return SPIRV::OpFOrdLessThanEqual;
1638   case CmpInst::FCMP_OLT:
1639     return SPIRV::OpFOrdLessThan;
1640   case CmpInst::FCMP_ONE:
1641     return SPIRV::OpFOrdNotEqual;
1642   case CmpInst::FCMP_ORD:
1643     return SPIRV::OpOrdered;
1644   case CmpInst::FCMP_UEQ:
1645     return SPIRV::OpFUnordEqual;
1646   case CmpInst::FCMP_UGE:
1647     return SPIRV::OpFUnordGreaterThanEqual;
1648   case CmpInst::FCMP_UGT:
1649     return SPIRV::OpFUnordGreaterThan;
1650   case CmpInst::FCMP_ULE:
1651     return SPIRV::OpFUnordLessThanEqual;
1652   case CmpInst::FCMP_ULT:
1653     return SPIRV::OpFUnordLessThan;
1654   case CmpInst::FCMP_UNE:
1655     return SPIRV::OpFUnordNotEqual;
1656   case CmpInst::FCMP_UNO:
1657     return SPIRV::OpUnordered;
1658   default:
1659     llvm_unreachable("Unknown predicate type for FCmp");
1660   }
1661 }
1662 
1663 static unsigned getICmpOpcode(unsigned PredNum) {
1664   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1665   switch (Pred) {
1666   case CmpInst::ICMP_EQ:
1667     return SPIRV::OpIEqual;
1668   case CmpInst::ICMP_NE:
1669     return SPIRV::OpINotEqual;
1670   case CmpInst::ICMP_SGE:
1671     return SPIRV::OpSGreaterThanEqual;
1672   case CmpInst::ICMP_SGT:
1673     return SPIRV::OpSGreaterThan;
1674   case CmpInst::ICMP_SLE:
1675     return SPIRV::OpSLessThanEqual;
1676   case CmpInst::ICMP_SLT:
1677     return SPIRV::OpSLessThan;
1678   case CmpInst::ICMP_UGE:
1679     return SPIRV::OpUGreaterThanEqual;
1680   case CmpInst::ICMP_UGT:
1681     return SPIRV::OpUGreaterThan;
1682   case CmpInst::ICMP_ULE:
1683     return SPIRV::OpULessThanEqual;
1684   case CmpInst::ICMP_ULT:
1685     return SPIRV::OpULessThan;
1686   default:
1687     llvm_unreachable("Unknown predicate type for ICmp");
1688   }
1689 }
1690 
1691 static unsigned getPtrCmpOpcode(unsigned Pred) {
1692   switch (static_cast<CmpInst::Predicate>(Pred)) {
1693   case CmpInst::ICMP_EQ:
1694     return SPIRV::OpPtrEqual;
1695   case CmpInst::ICMP_NE:
1696     return SPIRV::OpPtrNotEqual;
1697   default:
1698     llvm_unreachable("Unknown predicate type for pointer comparison");
1699   }
1700 }
1701 
1702 // Return the logical operation, or abort if none exists.
1703 static unsigned getBoolCmpOpcode(unsigned PredNum) {
1704   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1705   switch (Pred) {
1706   case CmpInst::ICMP_EQ:
1707     return SPIRV::OpLogicalEqual;
1708   case CmpInst::ICMP_NE:
1709     return SPIRV::OpLogicalNotEqual;
1710   default:
1711     llvm_unreachable("Unknown predicate type for Bool comparison");
1712   }
1713 }
1714 
1715 static APFloat getZeroFP(const Type *LLVMFloatTy) {
1716   if (!LLVMFloatTy)
1717     return APFloat::getZero(APFloat::IEEEsingle());
1718   switch (LLVMFloatTy->getScalarType()->getTypeID()) {
1719   case Type::HalfTyID:
1720     return APFloat::getZero(APFloat::IEEEhalf());
1721   default:
1722   case Type::FloatTyID:
1723     return APFloat::getZero(APFloat::IEEEsingle());
1724   case Type::DoubleTyID:
1725     return APFloat::getZero(APFloat::IEEEdouble());
1726   }
1727 }
1728 
1729 static APFloat getOneFP(const Type *LLVMFloatTy) {
1730   if (!LLVMFloatTy)
1731     return APFloat::getOne(APFloat::IEEEsingle());
1732   switch (LLVMFloatTy->getScalarType()->getTypeID()) {
1733   case Type::HalfTyID:
1734     return APFloat::getOne(APFloat::IEEEhalf());
1735   default:
1736   case Type::FloatTyID:
1737     return APFloat::getOne(APFloat::IEEEsingle());
1738   case Type::DoubleTyID:
1739     return APFloat::getOne(APFloat::IEEEdouble());
1740   }
1741 }
1742 
1743 bool SPIRVInstructionSelector::selectAnyOrAll(Register ResVReg,
1744                                               const SPIRVType *ResType,
1745                                               MachineInstr &I,
1746                                               unsigned OpAnyOrAll) const {
1747   assert(I.getNumOperands() == 3);
1748   assert(I.getOperand(2).isReg());
1749   MachineBasicBlock &BB = *I.getParent();
1750   Register InputRegister = I.getOperand(2).getReg();
1751   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
1752 
1753   if (!InputType)
1754     report_fatal_error("Input Type could not be determined.");
1755 
1756   bool IsBoolTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeBool);
1757   bool IsVectorTy = InputType->getOpcode() == SPIRV::OpTypeVector;
1758   if (IsBoolTy && !IsVectorTy) {
1759     assert(ResVReg == I.getOperand(0).getReg());
1760     return BuildCOPY(ResVReg, InputRegister, I);
1761   }
1762 
1763   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
1764   unsigned SpirvNotEqualId =
1765       IsFloatTy ? SPIRV::OpFOrdNotEqual : SPIRV::OpINotEqual;
1766   SPIRVType *SpvBoolScalarTy = GR.getOrCreateSPIRVBoolType(I, TII);
1767   SPIRVType *SpvBoolTy = SpvBoolScalarTy;
1768   Register NotEqualReg = ResVReg;
1769 
1770   if (IsVectorTy) {
1771     NotEqualReg = IsBoolTy ? InputRegister
1772                            : MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1773     const unsigned NumElts = InputType->getOperand(2).getImm();
1774     SpvBoolTy = GR.getOrCreateSPIRVVectorType(SpvBoolTy, NumElts, I, TII);
1775   }
1776 
1777   bool Result = true;
1778   if (!IsBoolTy) {
1779     Register ConstZeroReg =
1780         IsFloatTy ? buildZerosValF(InputType, I) : buildZerosVal(InputType, I);
1781 
1782     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SpirvNotEqualId))
1783                   .addDef(NotEqualReg)
1784                   .addUse(GR.getSPIRVTypeID(SpvBoolTy))
1785                   .addUse(InputRegister)
1786                   .addUse(ConstZeroReg)
1787                   .constrainAllUses(TII, TRI, RBI);
1788   }
1789 
1790   if (!IsVectorTy)
1791     return Result;
1792 
1793   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(OpAnyOrAll))
1794                        .addDef(ResVReg)
1795                        .addUse(GR.getSPIRVTypeID(SpvBoolScalarTy))
1796                        .addUse(NotEqualReg)
1797                        .constrainAllUses(TII, TRI, RBI);
1798 }
1799 
1800 bool SPIRVInstructionSelector::selectAll(Register ResVReg,
1801                                          const SPIRVType *ResType,
1802                                          MachineInstr &I) const {
1803   return selectAnyOrAll(ResVReg, ResType, I, SPIRV::OpAll);
1804 }
1805 
1806 bool SPIRVInstructionSelector::selectAny(Register ResVReg,
1807                                          const SPIRVType *ResType,
1808                                          MachineInstr &I) const {
1809   return selectAnyOrAll(ResVReg, ResType, I, SPIRV::OpAny);
1810 }
1811 
1812 // Select the OpDot instruction for the given float dot
1813 bool SPIRVInstructionSelector::selectFloatDot(Register ResVReg,
1814                                               const SPIRVType *ResType,
1815                                               MachineInstr &I) const {
1816   assert(I.getNumOperands() == 4);
1817   assert(I.getOperand(2).isReg());
1818   assert(I.getOperand(3).isReg());
1819 
1820   [[maybe_unused]] SPIRVType *VecType =
1821       GR.getSPIRVTypeForVReg(I.getOperand(2).getReg());
1822 
1823   assert(VecType->getOpcode() == SPIRV::OpTypeVector &&
1824          GR.getScalarOrVectorComponentCount(VecType) > 1 &&
1825          "dot product requires a vector of at least 2 components");
1826 
1827   [[maybe_unused]] SPIRVType *EltType =
1828       GR.getSPIRVTypeForVReg(VecType->getOperand(1).getReg());
1829 
1830   assert(EltType->getOpcode() == SPIRV::OpTypeFloat);
1831 
1832   MachineBasicBlock &BB = *I.getParent();
1833   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpDot))
1834       .addDef(ResVReg)
1835       .addUse(GR.getSPIRVTypeID(ResType))
1836       .addUse(I.getOperand(2).getReg())
1837       .addUse(I.getOperand(3).getReg())
1838       .constrainAllUses(TII, TRI, RBI);
1839 }
1840 
1841 bool SPIRVInstructionSelector::selectIntegerDot(Register ResVReg,
1842                                                 const SPIRVType *ResType,
1843                                                 MachineInstr &I,
1844                                                 bool Signed) const {
1845   assert(I.getNumOperands() == 4);
1846   assert(I.getOperand(2).isReg());
1847   assert(I.getOperand(3).isReg());
1848   MachineBasicBlock &BB = *I.getParent();
1849 
1850   auto DotOp = Signed ? SPIRV::OpSDot : SPIRV::OpUDot;
1851   return BuildMI(BB, I, I.getDebugLoc(), TII.get(DotOp))
1852       .addDef(ResVReg)
1853       .addUse(GR.getSPIRVTypeID(ResType))
1854       .addUse(I.getOperand(2).getReg())
1855       .addUse(I.getOperand(3).getReg())
1856       .constrainAllUses(TII, TRI, RBI);
1857 }
1858 
1859 // Since pre-1.6 SPIRV has no integer dot implementation,
1860 // expand by piecewise multiplying and adding the results
1861 bool SPIRVInstructionSelector::selectIntegerDotExpansion(
1862     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
1863   assert(I.getNumOperands() == 4);
1864   assert(I.getOperand(2).isReg());
1865   assert(I.getOperand(3).isReg());
1866   MachineBasicBlock &BB = *I.getParent();
1867 
1868   // Multiply the vectors, then sum the results
1869   Register Vec0 = I.getOperand(2).getReg();
1870   Register Vec1 = I.getOperand(3).getReg();
1871   Register TmpVec = MRI->createVirtualRegister(GR.getRegClass(ResType));
1872   SPIRVType *VecType = GR.getSPIRVTypeForVReg(Vec0);
1873 
1874   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIMulV))
1875                     .addDef(TmpVec)
1876                     .addUse(GR.getSPIRVTypeID(VecType))
1877                     .addUse(Vec0)
1878                     .addUse(Vec1)
1879                     .constrainAllUses(TII, TRI, RBI);
1880 
1881   assert(VecType->getOpcode() == SPIRV::OpTypeVector &&
1882          GR.getScalarOrVectorComponentCount(VecType) > 1 &&
1883          "dot product requires a vector of at least 2 components");
1884 
1885   Register Res = MRI->createVirtualRegister(GR.getRegClass(ResType));
1886   Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1887                 .addDef(Res)
1888                 .addUse(GR.getSPIRVTypeID(ResType))
1889                 .addUse(TmpVec)
1890                 .addImm(0)
1891                 .constrainAllUses(TII, TRI, RBI);
1892 
1893   for (unsigned i = 1; i < GR.getScalarOrVectorComponentCount(VecType); i++) {
1894     Register Elt = MRI->createVirtualRegister(GR.getRegClass(ResType));
1895 
1896     Result &=
1897         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1898             .addDef(Elt)
1899             .addUse(GR.getSPIRVTypeID(ResType))
1900             .addUse(TmpVec)
1901             .addImm(i)
1902             .constrainAllUses(TII, TRI, RBI);
1903 
1904     Register Sum = i < GR.getScalarOrVectorComponentCount(VecType) - 1
1905                        ? MRI->createVirtualRegister(GR.getRegClass(ResType))
1906                        : ResVReg;
1907 
1908     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
1909                   .addDef(Sum)
1910                   .addUse(GR.getSPIRVTypeID(ResType))
1911                   .addUse(Res)
1912                   .addUse(Elt)
1913                   .constrainAllUses(TII, TRI, RBI);
1914     Res = Sum;
1915   }
1916 
1917   return Result;
1918 }
1919 
1920 template <bool Signed>
1921 bool SPIRVInstructionSelector::selectDot4AddPacked(Register ResVReg,
1922                                                    const SPIRVType *ResType,
1923                                                    MachineInstr &I) const {
1924   assert(I.getNumOperands() == 5);
1925   assert(I.getOperand(2).isReg());
1926   assert(I.getOperand(3).isReg());
1927   assert(I.getOperand(4).isReg());
1928   MachineBasicBlock &BB = *I.getParent();
1929 
1930   auto DotOp = Signed ? SPIRV::OpSDot : SPIRV::OpUDot;
1931   Register Dot = MRI->createVirtualRegister(GR.getRegClass(ResType));
1932   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(DotOp))
1933                     .addDef(Dot)
1934                     .addUse(GR.getSPIRVTypeID(ResType))
1935                     .addUse(I.getOperand(2).getReg())
1936                     .addUse(I.getOperand(3).getReg())
1937                     .constrainAllUses(TII, TRI, RBI);
1938 
1939   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
1940                        .addDef(ResVReg)
1941                        .addUse(GR.getSPIRVTypeID(ResType))
1942                        .addUse(Dot)
1943                        .addUse(I.getOperand(4).getReg())
1944                        .constrainAllUses(TII, TRI, RBI);
1945 }
1946 
1947 // Since pre-1.6 SPIRV has no DotProductInput4x8BitPacked implementation,
1948 // extract the elements of the packed inputs, multiply them and add the result
1949 // to the accumulator.
1950 template <bool Signed>
1951 bool SPIRVInstructionSelector::selectDot4AddPackedExpansion(
1952     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
1953   assert(I.getNumOperands() == 5);
1954   assert(I.getOperand(2).isReg());
1955   assert(I.getOperand(3).isReg());
1956   assert(I.getOperand(4).isReg());
1957   MachineBasicBlock &BB = *I.getParent();
1958 
1959   bool Result = true;
1960 
1961   // Acc = C
1962   Register Acc = I.getOperand(4).getReg();
1963   SPIRVType *EltType = GR.getOrCreateSPIRVIntegerType(8, I, TII);
1964   auto ExtractOp =
1965       Signed ? SPIRV::OpBitFieldSExtract : SPIRV::OpBitFieldUExtract;
1966 
1967   // Extract the i8 element, multiply and add it to the accumulator
1968   for (unsigned i = 0; i < 4; i++) {
1969     // A[i]
1970     Register AElt = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1971     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
1972                   .addDef(AElt)
1973                   .addUse(GR.getSPIRVTypeID(ResType))
1974                   .addUse(I.getOperand(2).getReg())
1975                   .addUse(GR.getOrCreateConstInt(i * 8, I, EltType, TII))
1976                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
1977                   .constrainAllUses(TII, TRI, RBI);
1978 
1979     // B[i]
1980     Register BElt = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1981     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
1982                   .addDef(BElt)
1983                   .addUse(GR.getSPIRVTypeID(ResType))
1984                   .addUse(I.getOperand(3).getReg())
1985                   .addUse(GR.getOrCreateConstInt(i * 8, I, EltType, TII))
1986                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
1987                   .constrainAllUses(TII, TRI, RBI);
1988 
1989     // A[i] * B[i]
1990     Register Mul = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1991     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIMulS))
1992                   .addDef(Mul)
1993                   .addUse(GR.getSPIRVTypeID(ResType))
1994                   .addUse(AElt)
1995                   .addUse(BElt)
1996                   .constrainAllUses(TII, TRI, RBI);
1997 
1998     // Discard 24 highest-bits so that stored i32 register is i8 equivalent
1999     Register MaskMul = MRI->createVirtualRegister(&SPIRV::IDRegClass);
2000     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
2001                   .addDef(MaskMul)
2002                   .addUse(GR.getSPIRVTypeID(ResType))
2003                   .addUse(Mul)
2004                   .addUse(GR.getOrCreateConstInt(0, I, EltType, TII))
2005                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
2006                   .constrainAllUses(TII, TRI, RBI);
2007 
2008     // Acc = Acc + A[i] * B[i]
2009     Register Sum =
2010         i < 3 ? MRI->createVirtualRegister(&SPIRV::IDRegClass) : ResVReg;
2011     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
2012                   .addDef(Sum)
2013                   .addUse(GR.getSPIRVTypeID(ResType))
2014                   .addUse(Acc)
2015                   .addUse(MaskMul)
2016                   .constrainAllUses(TII, TRI, RBI);
2017 
2018     Acc = Sum;
2019   }
2020 
2021   return Result;
2022 }
2023 
2024 /// Transform saturate(x) to clamp(x, 0.0f, 1.0f) as SPIRV
2025 /// does not have a saturate builtin.
2026 bool SPIRVInstructionSelector::selectSaturate(Register ResVReg,
2027                                               const SPIRVType *ResType,
2028                                               MachineInstr &I) const {
2029   assert(I.getNumOperands() == 3);
2030   assert(I.getOperand(2).isReg());
2031   MachineBasicBlock &BB = *I.getParent();
2032   Register VZero = buildZerosValF(ResType, I);
2033   Register VOne = buildOnesValF(ResType, I);
2034 
2035   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
2036       .addDef(ResVReg)
2037       .addUse(GR.getSPIRVTypeID(ResType))
2038       .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
2039       .addImm(GL::FClamp)
2040       .addUse(I.getOperand(2).getReg())
2041       .addUse(VZero)
2042       .addUse(VOne)
2043       .constrainAllUses(TII, TRI, RBI);
2044 }
2045 
2046 bool SPIRVInstructionSelector::selectSign(Register ResVReg,
2047                                           const SPIRVType *ResType,
2048                                           MachineInstr &I) const {
2049   assert(I.getNumOperands() == 3);
2050   assert(I.getOperand(2).isReg());
2051   MachineBasicBlock &BB = *I.getParent();
2052   Register InputRegister = I.getOperand(2).getReg();
2053   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
2054   auto &DL = I.getDebugLoc();
2055 
2056   if (!InputType)
2057     report_fatal_error("Input Type could not be determined.");
2058 
2059   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
2060 
2061   unsigned SignBitWidth = GR.getScalarOrVectorBitWidth(InputType);
2062   unsigned ResBitWidth = GR.getScalarOrVectorBitWidth(ResType);
2063 
2064   bool NeedsConversion = IsFloatTy || SignBitWidth != ResBitWidth;
2065 
2066   auto SignOpcode = IsFloatTy ? GL::FSign : GL::SSign;
2067   Register SignReg = NeedsConversion
2068                          ? MRI->createVirtualRegister(&SPIRV::IDRegClass)
2069                          : ResVReg;
2070 
2071   bool Result =
2072       BuildMI(BB, I, DL, TII.get(SPIRV::OpExtInst))
2073           .addDef(SignReg)
2074           .addUse(GR.getSPIRVTypeID(InputType))
2075           .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
2076           .addImm(SignOpcode)
2077           .addUse(InputRegister)
2078           .constrainAllUses(TII, TRI, RBI);
2079 
2080   if (NeedsConversion) {
2081     auto ConvertOpcode = IsFloatTy ? SPIRV::OpConvertFToS : SPIRV::OpSConvert;
2082     Result &= BuildMI(*I.getParent(), I, DL, TII.get(ConvertOpcode))
2083                   .addDef(ResVReg)
2084                   .addUse(GR.getSPIRVTypeID(ResType))
2085                   .addUse(SignReg)
2086                   .constrainAllUses(TII, TRI, RBI);
2087   }
2088 
2089   return Result;
2090 }
2091 
2092 bool SPIRVInstructionSelector::selectWaveOpInst(Register ResVReg,
2093                                                 const SPIRVType *ResType,
2094                                                 MachineInstr &I,
2095                                                 unsigned Opcode) const {
2096   MachineBasicBlock &BB = *I.getParent();
2097   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2098 
2099   auto BMI = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2100                  .addDef(ResVReg)
2101                  .addUse(GR.getSPIRVTypeID(ResType))
2102                  .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I,
2103                                                 IntTy, TII));
2104 
2105   for (unsigned J = 2; J < I.getNumOperands(); J++) {
2106     BMI.addUse(I.getOperand(J).getReg());
2107   }
2108 
2109   return BMI.constrainAllUses(TII, TRI, RBI);
2110 }
2111 
2112 bool SPIRVInstructionSelector::selectWaveActiveCountBits(
2113     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
2114 
2115   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2116   SPIRVType *BallotType = GR.getOrCreateSPIRVVectorType(IntTy, 4, I, TII);
2117   Register BallotReg = MRI->createVirtualRegister(GR.getRegClass(BallotType));
2118   bool Result = selectWaveOpInst(BallotReg, BallotType, I,
2119                                  SPIRV::OpGroupNonUniformBallot);
2120 
2121   MachineBasicBlock &BB = *I.getParent();
2122   Result &=
2123       BuildMI(BB, I, I.getDebugLoc(),
2124               TII.get(SPIRV::OpGroupNonUniformBallotBitCount))
2125           .addDef(ResVReg)
2126           .addUse(GR.getSPIRVTypeID(ResType))
2127           .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I, IntTy, TII))
2128           .addImm(SPIRV::GroupOperation::Reduce)
2129           .addUse(BallotReg)
2130           .constrainAllUses(TII, TRI, RBI);
2131 
2132   return Result;
2133 }
2134 
2135 bool SPIRVInstructionSelector::selectWaveReduceSum(Register ResVReg,
2136                                                    const SPIRVType *ResType,
2137                                                    MachineInstr &I) const {
2138   assert(I.getNumOperands() == 3);
2139   assert(I.getOperand(2).isReg());
2140   MachineBasicBlock &BB = *I.getParent();
2141   Register InputRegister = I.getOperand(2).getReg();
2142   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
2143 
2144   if (!InputType)
2145     report_fatal_error("Input Type could not be determined.");
2146 
2147   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2148   // Retreive the operation to use based on input type
2149   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
2150   auto Opcode =
2151       IsFloatTy ? SPIRV::OpGroupNonUniformFAdd : SPIRV::OpGroupNonUniformIAdd;
2152   return BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2153       .addDef(ResVReg)
2154       .addUse(GR.getSPIRVTypeID(ResType))
2155       .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I, IntTy, TII))
2156       .addImm(SPIRV::GroupOperation::Reduce)
2157       .addUse(I.getOperand(2).getReg());
2158 }
2159 
2160 bool SPIRVInstructionSelector::selectBitreverse(Register ResVReg,
2161                                                 const SPIRVType *ResType,
2162                                                 MachineInstr &I) const {
2163   MachineBasicBlock &BB = *I.getParent();
2164   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpBitReverse))
2165       .addDef(ResVReg)
2166       .addUse(GR.getSPIRVTypeID(ResType))
2167       .addUse(I.getOperand(1).getReg())
2168       .constrainAllUses(TII, TRI, RBI);
2169 }
2170 
2171 bool SPIRVInstructionSelector::selectFreeze(Register ResVReg,
2172                                             const SPIRVType *ResType,
2173                                             MachineInstr &I) const {
2174   // There is no way to implement `freeze` correctly without support on SPIR-V
2175   // standard side, but we may at least address a simple (static) case when
2176   // undef/poison value presence is obvious. The main benefit of even
2177   // incomplete `freeze` support is preventing of translation from crashing due
2178   // to lack of support on legalization and instruction selection steps.
2179   if (!I.getOperand(0).isReg() || !I.getOperand(1).isReg())
2180     return false;
2181   Register OpReg = I.getOperand(1).getReg();
2182   if (MachineInstr *Def = MRI->getVRegDef(OpReg)) {
2183     Register Reg;
2184     switch (Def->getOpcode()) {
2185     case SPIRV::ASSIGN_TYPE:
2186       if (MachineInstr *AssignToDef =
2187               MRI->getVRegDef(Def->getOperand(1).getReg())) {
2188         if (AssignToDef->getOpcode() == TargetOpcode::G_IMPLICIT_DEF)
2189           Reg = Def->getOperand(2).getReg();
2190       }
2191       break;
2192     case SPIRV::OpUndef:
2193       Reg = Def->getOperand(1).getReg();
2194       break;
2195     }
2196     unsigned DestOpCode;
2197     if (Reg.isValid()) {
2198       DestOpCode = SPIRV::OpConstantNull;
2199     } else {
2200       DestOpCode = TargetOpcode::COPY;
2201       Reg = OpReg;
2202     }
2203     return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(DestOpCode))
2204         .addDef(I.getOperand(0).getReg())
2205         .addUse(Reg)
2206         .constrainAllUses(TII, TRI, RBI);
2207   }
2208   return false;
2209 }
2210 
2211 static unsigned getArrayComponentCount(MachineRegisterInfo *MRI,
2212                                        const SPIRVType *ResType) {
2213   Register OpReg = ResType->getOperand(2).getReg();
2214   SPIRVType *OpDef = MRI->getVRegDef(OpReg);
2215   if (!OpDef)
2216     return 0;
2217   if (OpDef->getOpcode() == SPIRV::ASSIGN_TYPE &&
2218       OpDef->getOperand(1).isReg()) {
2219     if (SPIRVType *RefDef = MRI->getVRegDef(OpDef->getOperand(1).getReg()))
2220       OpDef = RefDef;
2221   }
2222   unsigned N = OpDef->getOpcode() == TargetOpcode::G_CONSTANT
2223                    ? OpDef->getOperand(1).getCImm()->getValue().getZExtValue()
2224                    : 0;
2225   return N;
2226 }
2227 
2228 // Return true if the type represents a constant register
2229 static bool isConstReg(MachineRegisterInfo *MRI, SPIRVType *OpDef,
2230                        SmallPtrSet<SPIRVType *, 4> &Visited) {
2231   if (OpDef->getOpcode() == SPIRV::ASSIGN_TYPE &&
2232       OpDef->getOperand(1).isReg()) {
2233     if (SPIRVType *RefDef = MRI->getVRegDef(OpDef->getOperand(1).getReg()))
2234       OpDef = RefDef;
2235   }
2236 
2237   if (Visited.contains(OpDef))
2238     return true;
2239   Visited.insert(OpDef);
2240 
2241   unsigned Opcode = OpDef->getOpcode();
2242   switch (Opcode) {
2243   case TargetOpcode::G_CONSTANT:
2244   case TargetOpcode::G_FCONSTANT:
2245     return true;
2246   case TargetOpcode::G_INTRINSIC:
2247   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
2248   case TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS:
2249     return cast<GIntrinsic>(*OpDef).getIntrinsicID() ==
2250            Intrinsic::spv_const_composite;
2251   case TargetOpcode::G_BUILD_VECTOR:
2252   case TargetOpcode::G_SPLAT_VECTOR: {
2253     for (unsigned i = OpDef->getNumExplicitDefs(); i < OpDef->getNumOperands();
2254          i++) {
2255       SPIRVType *OpNestedDef =
2256           OpDef->getOperand(i).isReg()
2257               ? MRI->getVRegDef(OpDef->getOperand(i).getReg())
2258               : nullptr;
2259       if (OpNestedDef && !isConstReg(MRI, OpNestedDef, Visited))
2260         return false;
2261     }
2262     return true;
2263   }
2264   }
2265   return false;
2266 }
2267 
2268 // Return true if the virtual register represents a constant
2269 static bool isConstReg(MachineRegisterInfo *MRI, Register OpReg) {
2270   SmallPtrSet<SPIRVType *, 4> Visited;
2271   if (SPIRVType *OpDef = MRI->getVRegDef(OpReg))
2272     return isConstReg(MRI, OpDef, Visited);
2273   return false;
2274 }
2275 
2276 bool SPIRVInstructionSelector::selectBuildVector(Register ResVReg,
2277                                                  const SPIRVType *ResType,
2278                                                  MachineInstr &I) const {
2279   unsigned N = 0;
2280   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2281     N = GR.getScalarOrVectorComponentCount(ResType);
2282   else if (ResType->getOpcode() == SPIRV::OpTypeArray)
2283     N = getArrayComponentCount(MRI, ResType);
2284   else
2285     report_fatal_error("Cannot select G_BUILD_VECTOR with a non-vector result");
2286   if (I.getNumExplicitOperands() - I.getNumExplicitDefs() != N)
2287     report_fatal_error("G_BUILD_VECTOR and the result type are inconsistent");
2288 
2289   // check if we may construct a constant vector
2290   bool IsConst = true;
2291   for (unsigned i = I.getNumExplicitDefs();
2292        i < I.getNumExplicitOperands() && IsConst; ++i)
2293     if (!isConstReg(MRI, I.getOperand(i).getReg()))
2294       IsConst = false;
2295 
2296   if (!IsConst && N < 2)
2297     report_fatal_error(
2298         "There must be at least two constituent operands in a vector");
2299 
2300   MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2301   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
2302                      TII.get(IsConst ? SPIRV::OpConstantComposite
2303                                      : SPIRV::OpCompositeConstruct))
2304                  .addDef(ResVReg)
2305                  .addUse(GR.getSPIRVTypeID(ResType));
2306   for (unsigned i = I.getNumExplicitDefs(); i < I.getNumExplicitOperands(); ++i)
2307     MIB.addUse(I.getOperand(i).getReg());
2308   return MIB.constrainAllUses(TII, TRI, RBI);
2309 }
2310 
2311 bool SPIRVInstructionSelector::selectSplatVector(Register ResVReg,
2312                                                  const SPIRVType *ResType,
2313                                                  MachineInstr &I) const {
2314   unsigned N = 0;
2315   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2316     N = GR.getScalarOrVectorComponentCount(ResType);
2317   else if (ResType->getOpcode() == SPIRV::OpTypeArray)
2318     N = getArrayComponentCount(MRI, ResType);
2319   else
2320     report_fatal_error("Cannot select G_SPLAT_VECTOR with a non-vector result");
2321 
2322   unsigned OpIdx = I.getNumExplicitDefs();
2323   if (!I.getOperand(OpIdx).isReg())
2324     report_fatal_error("Unexpected argument in G_SPLAT_VECTOR");
2325 
2326   // check if we may construct a constant vector
2327   Register OpReg = I.getOperand(OpIdx).getReg();
2328   bool IsConst = isConstReg(MRI, OpReg);
2329 
2330   if (!IsConst && N < 2)
2331     report_fatal_error(
2332         "There must be at least two constituent operands in a vector");
2333 
2334   MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2335   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
2336                      TII.get(IsConst ? SPIRV::OpConstantComposite
2337                                      : SPIRV::OpCompositeConstruct))
2338                  .addDef(ResVReg)
2339                  .addUse(GR.getSPIRVTypeID(ResType));
2340   for (unsigned i = 0; i < N; ++i)
2341     MIB.addUse(OpReg);
2342   return MIB.constrainAllUses(TII, TRI, RBI);
2343 }
2344 
2345 bool SPIRVInstructionSelector::selectDiscard(Register ResVReg,
2346                                              const SPIRVType *ResType,
2347                                              MachineInstr &I) const {
2348 
2349   unsigned Opcode;
2350 
2351   if (STI.canUseExtension(
2352           SPIRV::Extension::SPV_EXT_demote_to_helper_invocation) ||
2353       STI.isAtLeastSPIRVVer(llvm::VersionTuple(1, 6))) {
2354     Opcode = SPIRV::OpDemoteToHelperInvocation;
2355   } else {
2356     Opcode = SPIRV::OpKill;
2357     // OpKill must be the last operation of any basic block.
2358     if (MachineInstr *NextI = I.getNextNode()) {
2359       GR.invalidateMachineInstr(NextI);
2360       NextI->removeFromParent();
2361     }
2362   }
2363 
2364   MachineBasicBlock &BB = *I.getParent();
2365   return BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2366       .constrainAllUses(TII, TRI, RBI);
2367 }
2368 
2369 bool SPIRVInstructionSelector::selectCmp(Register ResVReg,
2370                                          const SPIRVType *ResType,
2371                                          unsigned CmpOpc,
2372                                          MachineInstr &I) const {
2373   Register Cmp0 = I.getOperand(2).getReg();
2374   Register Cmp1 = I.getOperand(3).getReg();
2375   assert(GR.getSPIRVTypeForVReg(Cmp0)->getOpcode() ==
2376              GR.getSPIRVTypeForVReg(Cmp1)->getOpcode() &&
2377          "CMP operands should have the same type");
2378   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(CmpOpc))
2379       .addDef(ResVReg)
2380       .addUse(GR.getSPIRVTypeID(ResType))
2381       .addUse(Cmp0)
2382       .addUse(Cmp1)
2383       .constrainAllUses(TII, TRI, RBI);
2384 }
2385 
2386 bool SPIRVInstructionSelector::selectICmp(Register ResVReg,
2387                                           const SPIRVType *ResType,
2388                                           MachineInstr &I) const {
2389   auto Pred = I.getOperand(1).getPredicate();
2390   unsigned CmpOpc;
2391 
2392   Register CmpOperand = I.getOperand(2).getReg();
2393   if (GR.isScalarOfType(CmpOperand, SPIRV::OpTypePointer))
2394     CmpOpc = getPtrCmpOpcode(Pred);
2395   else if (GR.isScalarOrVectorOfType(CmpOperand, SPIRV::OpTypeBool))
2396     CmpOpc = getBoolCmpOpcode(Pred);
2397   else
2398     CmpOpc = getICmpOpcode(Pred);
2399   return selectCmp(ResVReg, ResType, CmpOpc, I);
2400 }
2401 
2402 void SPIRVInstructionSelector::renderFImm64(MachineInstrBuilder &MIB,
2403                                             const MachineInstr &I,
2404                                             int OpIdx) const {
2405   assert(I.getOpcode() == TargetOpcode::G_FCONSTANT && OpIdx == -1 &&
2406          "Expected G_FCONSTANT");
2407   const ConstantFP *FPImm = I.getOperand(1).getFPImm();
2408   addNumImm(FPImm->getValueAPF().bitcastToAPInt(), MIB);
2409 }
2410 
2411 void SPIRVInstructionSelector::renderImm32(MachineInstrBuilder &MIB,
2412                                            const MachineInstr &I,
2413                                            int OpIdx) const {
2414   assert(I.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
2415          "Expected G_CONSTANT");
2416   addNumImm(I.getOperand(1).getCImm()->getValue(), MIB);
2417 }
2418 
2419 std::pair<Register, bool>
2420 SPIRVInstructionSelector::buildI32Constant(uint32_t Val, MachineInstr &I,
2421                                            const SPIRVType *ResType) const {
2422   Type *LLVMTy = IntegerType::get(GR.CurMF->getFunction().getContext(), 32);
2423   const SPIRVType *SpvI32Ty =
2424       ResType ? ResType : GR.getOrCreateSPIRVIntegerType(32, I, TII);
2425   // Find a constant in DT or build a new one.
2426   auto ConstInt = ConstantInt::get(LLVMTy, Val);
2427   Register NewReg = GR.find(ConstInt, GR.CurMF);
2428   bool Result = true;
2429   if (!NewReg.isValid()) {
2430     NewReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
2431     GR.add(ConstInt, GR.CurMF, NewReg);
2432     MachineInstr *MI;
2433     MachineBasicBlock &BB = *I.getParent();
2434     if (Val == 0) {
2435       MI = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
2436                .addDef(NewReg)
2437                .addUse(GR.getSPIRVTypeID(SpvI32Ty));
2438     } else {
2439       MI = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantI))
2440                .addDef(NewReg)
2441                .addUse(GR.getSPIRVTypeID(SpvI32Ty))
2442                .addImm(APInt(32, Val).getZExtValue());
2443     }
2444     Result &= constrainSelectedInstRegOperands(*MI, TII, TRI, RBI);
2445   }
2446   return {NewReg, Result};
2447 }
2448 
2449 bool SPIRVInstructionSelector::selectFCmp(Register ResVReg,
2450                                           const SPIRVType *ResType,
2451                                           MachineInstr &I) const {
2452   unsigned CmpOp = getFCmpOpcode(I.getOperand(1).getPredicate());
2453   return selectCmp(ResVReg, ResType, CmpOp, I);
2454 }
2455 
2456 Register SPIRVInstructionSelector::buildZerosVal(const SPIRVType *ResType,
2457                                                  MachineInstr &I) const {
2458   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2459   bool ZeroAsNull = STI.isOpenCLEnv();
2460   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2461     return GR.getOrCreateConstVector(0UL, I, ResType, TII, ZeroAsNull);
2462   return GR.getOrCreateConstInt(0, I, ResType, TII, ZeroAsNull);
2463 }
2464 
2465 Register SPIRVInstructionSelector::buildZerosValF(const SPIRVType *ResType,
2466                                                   MachineInstr &I) const {
2467   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2468   bool ZeroAsNull = STI.isOpenCLEnv();
2469   APFloat VZero = getZeroFP(GR.getTypeForSPIRVType(ResType));
2470   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2471     return GR.getOrCreateConstVector(VZero, I, ResType, TII, ZeroAsNull);
2472   return GR.getOrCreateConstFP(VZero, I, ResType, TII, ZeroAsNull);
2473 }
2474 
2475 Register SPIRVInstructionSelector::buildOnesValF(const SPIRVType *ResType,
2476                                                  MachineInstr &I) const {
2477   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2478   bool ZeroAsNull = STI.isOpenCLEnv();
2479   APFloat VOne = getOneFP(GR.getTypeForSPIRVType(ResType));
2480   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2481     return GR.getOrCreateConstVector(VOne, I, ResType, TII, ZeroAsNull);
2482   return GR.getOrCreateConstFP(VOne, I, ResType, TII, ZeroAsNull);
2483 }
2484 
2485 Register SPIRVInstructionSelector::buildOnesVal(bool AllOnes,
2486                                                 const SPIRVType *ResType,
2487                                                 MachineInstr &I) const {
2488   unsigned BitWidth = GR.getScalarOrVectorBitWidth(ResType);
2489   APInt One =
2490       AllOnes ? APInt::getAllOnes(BitWidth) : APInt::getOneBitSet(BitWidth, 0);
2491   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2492     return GR.getOrCreateConstVector(One.getZExtValue(), I, ResType, TII);
2493   return GR.getOrCreateConstInt(One.getZExtValue(), I, ResType, TII);
2494 }
2495 
2496 bool SPIRVInstructionSelector::selectSelect(Register ResVReg,
2497                                             const SPIRVType *ResType,
2498                                             MachineInstr &I,
2499                                             bool IsSigned) const {
2500   // To extend a bool, we need to use OpSelect between constants.
2501   Register ZeroReg = buildZerosVal(ResType, I);
2502   Register OneReg = buildOnesVal(IsSigned, ResType, I);
2503   bool IsScalarBool =
2504       GR.isScalarOfType(I.getOperand(1).getReg(), SPIRV::OpTypeBool);
2505   unsigned Opcode =
2506       IsScalarBool ? SPIRV::OpSelectSISCond : SPIRV::OpSelectVIVCond;
2507   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
2508       .addDef(ResVReg)
2509       .addUse(GR.getSPIRVTypeID(ResType))
2510       .addUse(I.getOperand(1).getReg())
2511       .addUse(OneReg)
2512       .addUse(ZeroReg)
2513       .constrainAllUses(TII, TRI, RBI);
2514 }
2515 
2516 bool SPIRVInstructionSelector::selectIToF(Register ResVReg,
2517                                           const SPIRVType *ResType,
2518                                           MachineInstr &I, bool IsSigned,
2519                                           unsigned Opcode) const {
2520   Register SrcReg = I.getOperand(1).getReg();
2521   // We can convert bool value directly to float type without OpConvert*ToF,
2522   // however the translator generates OpSelect+OpConvert*ToF, so we do the same.
2523   if (GR.isScalarOrVectorOfType(I.getOperand(1).getReg(), SPIRV::OpTypeBool)) {
2524     unsigned BitWidth = GR.getScalarOrVectorBitWidth(ResType);
2525     SPIRVType *TmpType = GR.getOrCreateSPIRVIntegerType(BitWidth, I, TII);
2526     if (ResType->getOpcode() == SPIRV::OpTypeVector) {
2527       const unsigned NumElts = ResType->getOperand(2).getImm();
2528       TmpType = GR.getOrCreateSPIRVVectorType(TmpType, NumElts, I, TII);
2529     }
2530     SrcReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
2531     selectSelect(SrcReg, TmpType, I, false);
2532   }
2533   return selectOpWithSrcs(ResVReg, ResType, I, {SrcReg}, Opcode);
2534 }
2535 
2536 bool SPIRVInstructionSelector::selectExt(Register ResVReg,
2537                                          const SPIRVType *ResType,
2538                                          MachineInstr &I, bool IsSigned) const {
2539   Register SrcReg = I.getOperand(1).getReg();
2540   if (GR.isScalarOrVectorOfType(SrcReg, SPIRV::OpTypeBool))
2541     return selectSelect(ResVReg, ResType, I, IsSigned);
2542 
2543   SPIRVType *SrcType = GR.getSPIRVTypeForVReg(SrcReg);
2544   if (SrcType == ResType)
2545     return BuildCOPY(ResVReg, SrcReg, I);
2546 
2547   unsigned Opcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
2548   return selectUnOp(ResVReg, ResType, I, Opcode);
2549 }
2550 
2551 bool SPIRVInstructionSelector::selectSUCmp(Register ResVReg,
2552                                            const SPIRVType *ResType,
2553                                            MachineInstr &I,
2554                                            bool IsSigned) const {
2555   MachineIRBuilder MIRBuilder(I);
2556   MachineRegisterInfo *MRI = MIRBuilder.getMRI();
2557   MachineBasicBlock &BB = *I.getParent();
2558   // Ensure we have bool.
2559   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
2560   unsigned N = GR.getScalarOrVectorComponentCount(ResType);
2561   if (N > 1)
2562     BoolType = GR.getOrCreateSPIRVVectorType(BoolType, N, I, TII);
2563   Register BoolTypeReg = GR.getSPIRVTypeID(BoolType);
2564   // Build less-than-equal and less-than.
2565   // TODO: replace with one-liner createVirtualRegister() from
2566   // llvm/lib/Target/SPIRV/SPIRVUtils.cpp when PR #116609 is merged.
2567   Register IsLessEqReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
2568   MRI->setType(IsLessEqReg, LLT::scalar(64));
2569   GR.assignSPIRVTypeToVReg(ResType, IsLessEqReg, MIRBuilder.getMF());
2570   bool Result = BuildMI(BB, I, I.getDebugLoc(),
2571                         TII.get(IsSigned ? SPIRV::OpSLessThanEqual
2572                                          : SPIRV::OpULessThanEqual))
2573                     .addDef(IsLessEqReg)
2574                     .addUse(BoolTypeReg)
2575                     .addUse(I.getOperand(1).getReg())
2576                     .addUse(I.getOperand(2).getReg())
2577                     .constrainAllUses(TII, TRI, RBI);
2578   Register IsLessReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
2579   MRI->setType(IsLessReg, LLT::scalar(64));
2580   GR.assignSPIRVTypeToVReg(ResType, IsLessReg, MIRBuilder.getMF());
2581   Result &= BuildMI(BB, I, I.getDebugLoc(),
2582                     TII.get(IsSigned ? SPIRV::OpSLessThan : SPIRV::OpULessThan))
2583                 .addDef(IsLessReg)
2584                 .addUse(BoolTypeReg)
2585                 .addUse(I.getOperand(1).getReg())
2586                 .addUse(I.getOperand(2).getReg())
2587                 .constrainAllUses(TII, TRI, RBI);
2588   // Build selects.
2589   Register ResTypeReg = GR.getSPIRVTypeID(ResType);
2590   Register NegOneOrZeroReg =
2591       MRI->createVirtualRegister(GR.getRegClass(ResType));
2592   MRI->setType(NegOneOrZeroReg, LLT::scalar(64));
2593   GR.assignSPIRVTypeToVReg(ResType, NegOneOrZeroReg, MIRBuilder.getMF());
2594   unsigned SelectOpcode =
2595       N > 1 ? SPIRV::OpSelectVIVCond : SPIRV::OpSelectSISCond;
2596   Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SelectOpcode))
2597                 .addDef(NegOneOrZeroReg)
2598                 .addUse(ResTypeReg)
2599                 .addUse(IsLessReg)
2600                 .addUse(buildOnesVal(true, ResType, I)) // -1
2601                 .addUse(buildZerosVal(ResType, I))
2602                 .constrainAllUses(TII, TRI, RBI);
2603   return Result & BuildMI(BB, I, I.getDebugLoc(), TII.get(SelectOpcode))
2604                       .addDef(ResVReg)
2605                       .addUse(ResTypeReg)
2606                       .addUse(IsLessEqReg)
2607                       .addUse(NegOneOrZeroReg) // -1 or 0
2608                       .addUse(buildOnesVal(false, ResType, I))
2609                       .constrainAllUses(TII, TRI, RBI);
2610 }
2611 
2612 bool SPIRVInstructionSelector::selectIntToBool(Register IntReg,
2613                                                Register ResVReg,
2614                                                MachineInstr &I,
2615                                                const SPIRVType *IntTy,
2616                                                const SPIRVType *BoolTy) const {
2617   // To truncate to a bool, we use OpBitwiseAnd 1 and OpINotEqual to zero.
2618   Register BitIntReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
2619   bool IsVectorTy = IntTy->getOpcode() == SPIRV::OpTypeVector;
2620   unsigned Opcode = IsVectorTy ? SPIRV::OpBitwiseAndV : SPIRV::OpBitwiseAndS;
2621   Register Zero = buildZerosVal(IntTy, I);
2622   Register One = buildOnesVal(false, IntTy, I);
2623   MachineBasicBlock &BB = *I.getParent();
2624   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2625                     .addDef(BitIntReg)
2626                     .addUse(GR.getSPIRVTypeID(IntTy))
2627                     .addUse(IntReg)
2628                     .addUse(One)
2629                     .constrainAllUses(TII, TRI, RBI);
2630   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpINotEqual))
2631                        .addDef(ResVReg)
2632                        .addUse(GR.getSPIRVTypeID(BoolTy))
2633                        .addUse(BitIntReg)
2634                        .addUse(Zero)
2635                        .constrainAllUses(TII, TRI, RBI);
2636 }
2637 
2638 bool SPIRVInstructionSelector::selectTrunc(Register ResVReg,
2639                                            const SPIRVType *ResType,
2640                                            MachineInstr &I) const {
2641   Register IntReg = I.getOperand(1).getReg();
2642   const SPIRVType *ArgType = GR.getSPIRVTypeForVReg(IntReg);
2643   if (GR.isScalarOrVectorOfType(ResVReg, SPIRV::OpTypeBool))
2644     return selectIntToBool(IntReg, ResVReg, I, ArgType, ResType);
2645   if (ArgType == ResType)
2646     return BuildCOPY(ResVReg, IntReg, I);
2647   bool IsSigned = GR.isScalarOrVectorSigned(ResType);
2648   unsigned Opcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
2649   return selectUnOp(ResVReg, ResType, I, Opcode);
2650 }
2651 
2652 bool SPIRVInstructionSelector::selectConst(Register ResVReg,
2653                                            const SPIRVType *ResType,
2654                                            const APInt &Imm,
2655                                            MachineInstr &I) const {
2656   unsigned TyOpcode = ResType->getOpcode();
2657   assert(TyOpcode != SPIRV::OpTypePointer || Imm.isZero());
2658   MachineBasicBlock &BB = *I.getParent();
2659   if ((TyOpcode == SPIRV::OpTypePointer || TyOpcode == SPIRV::OpTypeEvent) &&
2660       Imm.isZero())
2661     return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
2662         .addDef(ResVReg)
2663         .addUse(GR.getSPIRVTypeID(ResType))
2664         .constrainAllUses(TII, TRI, RBI);
2665   if (TyOpcode == SPIRV::OpTypeInt) {
2666     assert(Imm.getBitWidth() <= 64 && "Unsupported integer width!");
2667     Register Reg = GR.getOrCreateConstInt(Imm.getZExtValue(), I, ResType, TII);
2668     return Reg == ResVReg ? true : BuildCOPY(ResVReg, Reg, I);
2669   }
2670   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantI))
2671                  .addDef(ResVReg)
2672                  .addUse(GR.getSPIRVTypeID(ResType));
2673   // <=32-bit integers should be caught by the sdag pattern.
2674   assert(Imm.getBitWidth() > 32);
2675   addNumImm(Imm, MIB);
2676   return MIB.constrainAllUses(TII, TRI, RBI);
2677 }
2678 
2679 bool SPIRVInstructionSelector::selectOpUndef(Register ResVReg,
2680                                              const SPIRVType *ResType,
2681                                              MachineInstr &I) const {
2682   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
2683       .addDef(ResVReg)
2684       .addUse(GR.getSPIRVTypeID(ResType))
2685       .constrainAllUses(TII, TRI, RBI);
2686 }
2687 
2688 static bool isImm(const MachineOperand &MO, MachineRegisterInfo *MRI) {
2689   assert(MO.isReg());
2690   const SPIRVType *TypeInst = MRI->getVRegDef(MO.getReg());
2691   if (TypeInst->getOpcode() == SPIRV::ASSIGN_TYPE) {
2692     assert(TypeInst->getOperand(1).isReg());
2693     MachineInstr *ImmInst = MRI->getVRegDef(TypeInst->getOperand(1).getReg());
2694     return ImmInst->getOpcode() == TargetOpcode::G_CONSTANT;
2695   }
2696   return TypeInst->getOpcode() == SPIRV::OpConstantI;
2697 }
2698 
2699 static int64_t foldImm(const MachineOperand &MO, MachineRegisterInfo *MRI) {
2700   const SPIRVType *TypeInst = MRI->getVRegDef(MO.getReg());
2701   if (TypeInst->getOpcode() == SPIRV::OpConstantI)
2702     return TypeInst->getOperand(2).getImm();
2703   MachineInstr *ImmInst = MRI->getVRegDef(TypeInst->getOperand(1).getReg());
2704   assert(ImmInst->getOpcode() == TargetOpcode::G_CONSTANT);
2705   return ImmInst->getOperand(1).getCImm()->getZExtValue();
2706 }
2707 
2708 bool SPIRVInstructionSelector::selectInsertVal(Register ResVReg,
2709                                                const SPIRVType *ResType,
2710                                                MachineInstr &I) const {
2711   MachineBasicBlock &BB = *I.getParent();
2712   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeInsert))
2713                  .addDef(ResVReg)
2714                  .addUse(GR.getSPIRVTypeID(ResType))
2715                  // object to insert
2716                  .addUse(I.getOperand(3).getReg())
2717                  // composite to insert into
2718                  .addUse(I.getOperand(2).getReg());
2719   for (unsigned i = 4; i < I.getNumOperands(); i++)
2720     MIB.addImm(foldImm(I.getOperand(i), MRI));
2721   return MIB.constrainAllUses(TII, TRI, RBI);
2722 }
2723 
2724 bool SPIRVInstructionSelector::selectExtractVal(Register ResVReg,
2725                                                 const SPIRVType *ResType,
2726                                                 MachineInstr &I) const {
2727   MachineBasicBlock &BB = *I.getParent();
2728   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
2729                  .addDef(ResVReg)
2730                  .addUse(GR.getSPIRVTypeID(ResType))
2731                  .addUse(I.getOperand(2).getReg());
2732   for (unsigned i = 3; i < I.getNumOperands(); i++)
2733     MIB.addImm(foldImm(I.getOperand(i), MRI));
2734   return MIB.constrainAllUses(TII, TRI, RBI);
2735 }
2736 
2737 bool SPIRVInstructionSelector::selectInsertElt(Register ResVReg,
2738                                                const SPIRVType *ResType,
2739                                                MachineInstr &I) const {
2740   if (isImm(I.getOperand(4), MRI))
2741     return selectInsertVal(ResVReg, ResType, I);
2742   MachineBasicBlock &BB = *I.getParent();
2743   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorInsertDynamic))
2744       .addDef(ResVReg)
2745       .addUse(GR.getSPIRVTypeID(ResType))
2746       .addUse(I.getOperand(2).getReg())
2747       .addUse(I.getOperand(3).getReg())
2748       .addUse(I.getOperand(4).getReg())
2749       .constrainAllUses(TII, TRI, RBI);
2750 }
2751 
2752 bool SPIRVInstructionSelector::selectExtractElt(Register ResVReg,
2753                                                 const SPIRVType *ResType,
2754                                                 MachineInstr &I) const {
2755   if (isImm(I.getOperand(3), MRI))
2756     return selectExtractVal(ResVReg, ResType, I);
2757   MachineBasicBlock &BB = *I.getParent();
2758   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorExtractDynamic))
2759       .addDef(ResVReg)
2760       .addUse(GR.getSPIRVTypeID(ResType))
2761       .addUse(I.getOperand(2).getReg())
2762       .addUse(I.getOperand(3).getReg())
2763       .constrainAllUses(TII, TRI, RBI);
2764 }
2765 
2766 bool SPIRVInstructionSelector::selectGEP(Register ResVReg,
2767                                          const SPIRVType *ResType,
2768                                          MachineInstr &I) const {
2769   const bool IsGEPInBounds = I.getOperand(2).getImm();
2770 
2771   // OpAccessChain could be used for OpenCL, but the SPIRV-LLVM Translator only
2772   // relies on PtrAccessChain, so we'll try not to deviate. For Vulkan however,
2773   // we have to use Op[InBounds]AccessChain.
2774   const unsigned Opcode = STI.isVulkanEnv()
2775                               ? (IsGEPInBounds ? SPIRV::OpInBoundsAccessChain
2776                                                : SPIRV::OpAccessChain)
2777                               : (IsGEPInBounds ? SPIRV::OpInBoundsPtrAccessChain
2778                                                : SPIRV::OpPtrAccessChain);
2779 
2780   auto Res = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
2781                  .addDef(ResVReg)
2782                  .addUse(GR.getSPIRVTypeID(ResType))
2783                  // Object to get a pointer to.
2784                  .addUse(I.getOperand(3).getReg());
2785   // Adding indices.
2786   const unsigned StartingIndex =
2787       (Opcode == SPIRV::OpAccessChain || Opcode == SPIRV::OpInBoundsAccessChain)
2788           ? 5
2789           : 4;
2790   for (unsigned i = StartingIndex; i < I.getNumExplicitOperands(); ++i)
2791     Res.addUse(I.getOperand(i).getReg());
2792   return Res.constrainAllUses(TII, TRI, RBI);
2793 }
2794 
2795 // Maybe wrap a value into OpSpecConstantOp
2796 bool SPIRVInstructionSelector::wrapIntoSpecConstantOp(
2797     MachineInstr &I, SmallVector<Register> &CompositeArgs) const {
2798   bool Result = true;
2799   unsigned Lim = I.getNumExplicitOperands();
2800   for (unsigned i = I.getNumExplicitDefs() + 1; i < Lim; ++i) {
2801     Register OpReg = I.getOperand(i).getReg();
2802     SPIRVType *OpDefine = MRI->getVRegDef(OpReg);
2803     SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
2804     SmallPtrSet<SPIRVType *, 4> Visited;
2805     if (!OpDefine || !OpType || isConstReg(MRI, OpDefine, Visited) ||
2806         OpDefine->getOpcode() == TargetOpcode::G_ADDRSPACE_CAST ||
2807         GR.isAggregateType(OpType)) {
2808       // The case of G_ADDRSPACE_CAST inside spv_const_composite() is processed
2809       // by selectAddrSpaceCast()
2810       CompositeArgs.push_back(OpReg);
2811       continue;
2812     }
2813     MachineFunction *MF = I.getMF();
2814     Register WrapReg = GR.find(OpDefine, MF);
2815     if (WrapReg.isValid()) {
2816       CompositeArgs.push_back(WrapReg);
2817       continue;
2818     }
2819     // Create a new register for the wrapper
2820     WrapReg = MRI->createVirtualRegister(GR.getRegClass(OpType));
2821     GR.add(OpDefine, MF, WrapReg);
2822     CompositeArgs.push_back(WrapReg);
2823     // Decorate the wrapper register and generate a new instruction
2824     MRI->setType(WrapReg, LLT::pointer(0, 64));
2825     GR.assignSPIRVTypeToVReg(OpType, WrapReg, *MF);
2826     MachineBasicBlock &BB = *I.getParent();
2827     Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
2828                  .addDef(WrapReg)
2829                  .addUse(GR.getSPIRVTypeID(OpType))
2830                  .addImm(static_cast<uint32_t>(SPIRV::Opcode::Bitcast))
2831                  .addUse(OpReg)
2832                  .constrainAllUses(TII, TRI, RBI);
2833     if (!Result)
2834       break;
2835   }
2836   return Result;
2837 }
2838 
2839 bool SPIRVInstructionSelector::selectIntrinsic(Register ResVReg,
2840                                                const SPIRVType *ResType,
2841                                                MachineInstr &I) const {
2842   MachineBasicBlock &BB = *I.getParent();
2843   Intrinsic::ID IID = cast<GIntrinsic>(I).getIntrinsicID();
2844   switch (IID) {
2845   case Intrinsic::spv_load:
2846     return selectLoad(ResVReg, ResType, I);
2847   case Intrinsic::spv_store:
2848     return selectStore(I);
2849   case Intrinsic::spv_extractv:
2850     return selectExtractVal(ResVReg, ResType, I);
2851   case Intrinsic::spv_insertv:
2852     return selectInsertVal(ResVReg, ResType, I);
2853   case Intrinsic::spv_extractelt:
2854     return selectExtractElt(ResVReg, ResType, I);
2855   case Intrinsic::spv_insertelt:
2856     return selectInsertElt(ResVReg, ResType, I);
2857   case Intrinsic::spv_gep:
2858     return selectGEP(ResVReg, ResType, I);
2859   case Intrinsic::spv_unref_global:
2860   case Intrinsic::spv_init_global: {
2861     MachineInstr *MI = MRI->getVRegDef(I.getOperand(1).getReg());
2862     MachineInstr *Init = I.getNumExplicitOperands() > 2
2863                              ? MRI->getVRegDef(I.getOperand(2).getReg())
2864                              : nullptr;
2865     assert(MI);
2866     return selectGlobalValue(MI->getOperand(0).getReg(), *MI, Init);
2867   }
2868   case Intrinsic::spv_undef: {
2869     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
2870                    .addDef(ResVReg)
2871                    .addUse(GR.getSPIRVTypeID(ResType));
2872     return MIB.constrainAllUses(TII, TRI, RBI);
2873   }
2874   case Intrinsic::spv_const_composite: {
2875     // If no values are attached, the composite is null constant.
2876     bool IsNull = I.getNumExplicitDefs() + 1 == I.getNumExplicitOperands();
2877     // Select a proper instruction.
2878     unsigned Opcode = SPIRV::OpConstantNull;
2879     SmallVector<Register> CompositeArgs;
2880     if (!IsNull) {
2881       Opcode = SPIRV::OpConstantComposite;
2882       if (!wrapIntoSpecConstantOp(I, CompositeArgs))
2883         return false;
2884     }
2885     MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2886     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2887                    .addDef(ResVReg)
2888                    .addUse(GR.getSPIRVTypeID(ResType));
2889     // skip type MD node we already used when generated assign.type for this
2890     if (!IsNull) {
2891       for (Register OpReg : CompositeArgs)
2892         MIB.addUse(OpReg);
2893     }
2894     return MIB.constrainAllUses(TII, TRI, RBI);
2895   }
2896   case Intrinsic::spv_assign_name: {
2897     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpName));
2898     MIB.addUse(I.getOperand(I.getNumExplicitDefs() + 1).getReg());
2899     for (unsigned i = I.getNumExplicitDefs() + 2;
2900          i < I.getNumExplicitOperands(); ++i) {
2901       MIB.addImm(I.getOperand(i).getImm());
2902     }
2903     return MIB.constrainAllUses(TII, TRI, RBI);
2904   }
2905   case Intrinsic::spv_switch: {
2906     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSwitch));
2907     for (unsigned i = 1; i < I.getNumExplicitOperands(); ++i) {
2908       if (I.getOperand(i).isReg())
2909         MIB.addReg(I.getOperand(i).getReg());
2910       else if (I.getOperand(i).isCImm())
2911         addNumImm(I.getOperand(i).getCImm()->getValue(), MIB);
2912       else if (I.getOperand(i).isMBB())
2913         MIB.addMBB(I.getOperand(i).getMBB());
2914       else
2915         llvm_unreachable("Unexpected OpSwitch operand");
2916     }
2917     return MIB.constrainAllUses(TII, TRI, RBI);
2918   }
2919   case Intrinsic::spv_loop_merge: {
2920     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpLoopMerge));
2921     for (unsigned i = 1; i < I.getNumExplicitOperands(); ++i) {
2922       assert(I.getOperand(i).isMBB());
2923       MIB.addMBB(I.getOperand(i).getMBB());
2924     }
2925     MIB.addImm(SPIRV::SelectionControl::None);
2926     return MIB.constrainAllUses(TII, TRI, RBI);
2927   }
2928   case Intrinsic::spv_selection_merge: {
2929     auto MIB =
2930         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSelectionMerge));
2931     assert(I.getOperand(1).isMBB() &&
2932            "operand 1 to spv_selection_merge must be a basic block");
2933     MIB.addMBB(I.getOperand(1).getMBB());
2934     MIB.addImm(getSelectionOperandForImm(I.getOperand(2).getImm()));
2935     return MIB.constrainAllUses(TII, TRI, RBI);
2936   }
2937   case Intrinsic::spv_cmpxchg:
2938     return selectAtomicCmpXchg(ResVReg, ResType, I);
2939   case Intrinsic::spv_unreachable:
2940     return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUnreachable))
2941         .constrainAllUses(TII, TRI, RBI);
2942   case Intrinsic::spv_alloca:
2943     return selectFrameIndex(ResVReg, ResType, I);
2944   case Intrinsic::spv_alloca_array:
2945     return selectAllocaArray(ResVReg, ResType, I);
2946   case Intrinsic::spv_assume:
2947     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_expect_assume))
2948       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpAssumeTrueKHR))
2949           .addUse(I.getOperand(1).getReg())
2950           .constrainAllUses(TII, TRI, RBI);
2951     break;
2952   case Intrinsic::spv_expect:
2953     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_expect_assume))
2954       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExpectKHR))
2955           .addDef(ResVReg)
2956           .addUse(GR.getSPIRVTypeID(ResType))
2957           .addUse(I.getOperand(2).getReg())
2958           .addUse(I.getOperand(3).getReg())
2959           .constrainAllUses(TII, TRI, RBI);
2960     break;
2961   case Intrinsic::arithmetic_fence:
2962     if (STI.canUseExtension(SPIRV::Extension::SPV_EXT_arithmetic_fence))
2963       return BuildMI(BB, I, I.getDebugLoc(),
2964                      TII.get(SPIRV::OpArithmeticFenceEXT))
2965           .addDef(ResVReg)
2966           .addUse(GR.getSPIRVTypeID(ResType))
2967           .addUse(I.getOperand(2).getReg())
2968           .constrainAllUses(TII, TRI, RBI);
2969     else
2970       return BuildCOPY(ResVReg, I.getOperand(2).getReg(), I);
2971     break;
2972   case Intrinsic::spv_thread_id:
2973     // The HLSL SV_DispatchThreadID semantic is lowered to llvm.spv.thread.id
2974     // intrinsic in LLVM IR for SPIR-V backend.
2975     //
2976     // In SPIR-V backend, llvm.spv.thread.id is now correctly translated to a
2977     // `GlobalInvocationId` builtin variable
2978     return loadVec3BuiltinInputID(SPIRV::BuiltIn::GlobalInvocationId, ResVReg,
2979                                   ResType, I);
2980   case Intrinsic::spv_thread_id_in_group:
2981     // The HLSL SV_GroupThreadId semantic is lowered to
2982     // llvm.spv.thread.id.in.group intrinsic in LLVM IR for SPIR-V backend.
2983     //
2984     // In SPIR-V backend, llvm.spv.thread.id.in.group is now correctly
2985     // translated to a `LocalInvocationId` builtin variable
2986     return loadVec3BuiltinInputID(SPIRV::BuiltIn::LocalInvocationId, ResVReg,
2987                                   ResType, I);
2988   case Intrinsic::spv_group_id:
2989     // The HLSL SV_GroupId semantic is lowered to
2990     // llvm.spv.group.id intrinsic in LLVM IR for SPIR-V backend.
2991     //
2992     // In SPIR-V backend, llvm.spv.group.id is now translated to a `WorkgroupId`
2993     // builtin variable
2994     return loadVec3BuiltinInputID(SPIRV::BuiltIn::WorkgroupId, ResVReg, ResType,
2995                                   I);
2996   case Intrinsic::spv_fdot:
2997     return selectFloatDot(ResVReg, ResType, I);
2998   case Intrinsic::spv_udot:
2999   case Intrinsic::spv_sdot:
3000     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3001         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3002       return selectIntegerDot(ResVReg, ResType, I,
3003                               /*Signed=*/IID == Intrinsic::spv_sdot);
3004     return selectIntegerDotExpansion(ResVReg, ResType, I);
3005   case Intrinsic::spv_dot4add_i8packed:
3006     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3007         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3008       return selectDot4AddPacked<true>(ResVReg, ResType, I);
3009     return selectDot4AddPackedExpansion<true>(ResVReg, ResType, I);
3010   case Intrinsic::spv_dot4add_u8packed:
3011     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3012         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3013       return selectDot4AddPacked<false>(ResVReg, ResType, I);
3014     return selectDot4AddPackedExpansion<false>(ResVReg, ResType, I);
3015   case Intrinsic::spv_all:
3016     return selectAll(ResVReg, ResType, I);
3017   case Intrinsic::spv_any:
3018     return selectAny(ResVReg, ResType, I);
3019   case Intrinsic::spv_cross:
3020     return selectExtInst(ResVReg, ResType, I, CL::cross, GL::Cross);
3021   case Intrinsic::spv_distance:
3022     return selectExtInst(ResVReg, ResType, I, CL::distance, GL::Distance);
3023   case Intrinsic::spv_lerp:
3024     return selectExtInst(ResVReg, ResType, I, CL::mix, GL::FMix);
3025   case Intrinsic::spv_length:
3026     return selectExtInst(ResVReg, ResType, I, CL::length, GL::Length);
3027   case Intrinsic::spv_degrees:
3028     return selectExtInst(ResVReg, ResType, I, CL::degrees, GL::Degrees);
3029   case Intrinsic::spv_frac:
3030     return selectExtInst(ResVReg, ResType, I, CL::fract, GL::Fract);
3031   case Intrinsic::spv_normalize:
3032     return selectExtInst(ResVReg, ResType, I, CL::normalize, GL::Normalize);
3033   case Intrinsic::spv_rsqrt:
3034     return selectExtInst(ResVReg, ResType, I, CL::rsqrt, GL::InverseSqrt);
3035   case Intrinsic::spv_sign:
3036     return selectSign(ResVReg, ResType, I);
3037   case Intrinsic::spv_firstbituhigh: // There is no CL equivalent of FindUMsb
3038     return selectFirstBitHigh(ResVReg, ResType, I, /*IsSigned=*/false);
3039   case Intrinsic::spv_firstbitshigh: // There is no CL equivalent of FindSMsb
3040     return selectFirstBitHigh(ResVReg, ResType, I, /*IsSigned=*/true);
3041   case Intrinsic::spv_firstbitlow: // There is no CL equivlent of FindILsb
3042     return selectFirstBitLow(ResVReg, ResType, I);
3043   case Intrinsic::spv_group_memory_barrier_with_group_sync: {
3044     bool Result = true;
3045     auto MemSemConstant =
3046         buildI32Constant(SPIRV::MemorySemantics::SequentiallyConsistent, I);
3047     Register MemSemReg = MemSemConstant.first;
3048     Result &= MemSemConstant.second;
3049     auto ScopeConstant = buildI32Constant(SPIRV::Scope::Workgroup, I);
3050     Register ScopeReg = ScopeConstant.first;
3051     Result &= ScopeConstant.second;
3052     MachineBasicBlock &BB = *I.getParent();
3053     return Result &&
3054            BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpControlBarrier))
3055                .addUse(ScopeReg)
3056                .addUse(ScopeReg)
3057                .addUse(MemSemReg)
3058                .constrainAllUses(TII, TRI, RBI);
3059   }
3060   case Intrinsic::spv_lifetime_start:
3061   case Intrinsic::spv_lifetime_end: {
3062     unsigned Op = IID == Intrinsic::spv_lifetime_start ? SPIRV::OpLifetimeStart
3063                                                        : SPIRV::OpLifetimeStop;
3064     int64_t Size = I.getOperand(I.getNumExplicitDefs() + 1).getImm();
3065     Register PtrReg = I.getOperand(I.getNumExplicitDefs() + 2).getReg();
3066     if (Size == -1)
3067       Size = 0;
3068     return BuildMI(BB, I, I.getDebugLoc(), TII.get(Op))
3069         .addUse(PtrReg)
3070         .addImm(Size)
3071         .constrainAllUses(TII, TRI, RBI);
3072   }
3073   case Intrinsic::spv_saturate:
3074     return selectSaturate(ResVReg, ResType, I);
3075   case Intrinsic::spv_nclamp:
3076     return selectExtInst(ResVReg, ResType, I, CL::fclamp, GL::NClamp);
3077   case Intrinsic::spv_uclamp:
3078     return selectExtInst(ResVReg, ResType, I, CL::u_clamp, GL::UClamp);
3079   case Intrinsic::spv_sclamp:
3080     return selectExtInst(ResVReg, ResType, I, CL::s_clamp, GL::SClamp);
3081   case Intrinsic::spv_wave_active_countbits:
3082     return selectWaveActiveCountBits(ResVReg, ResType, I);
3083   case Intrinsic::spv_wave_all:
3084     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformAll);
3085   case Intrinsic::spv_wave_any:
3086     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformAny);
3087   case Intrinsic::spv_wave_is_first_lane:
3088     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformElect);
3089   case Intrinsic::spv_wave_reduce_sum:
3090     return selectWaveReduceSum(ResVReg, ResType, I);
3091   case Intrinsic::spv_wave_readlane:
3092     return selectWaveOpInst(ResVReg, ResType, I,
3093                             SPIRV::OpGroupNonUniformShuffle);
3094   case Intrinsic::spv_step:
3095     return selectExtInst(ResVReg, ResType, I, CL::step, GL::Step);
3096   case Intrinsic::spv_radians:
3097     return selectExtInst(ResVReg, ResType, I, CL::radians, GL::Radians);
3098   // Discard intrinsics which we do not expect to actually represent code after
3099   // lowering or intrinsics which are not implemented but should not crash when
3100   // found in a customer's LLVM IR input.
3101   case Intrinsic::instrprof_increment:
3102   case Intrinsic::instrprof_increment_step:
3103   case Intrinsic::instrprof_value_profile:
3104     break;
3105   // Discard internal intrinsics.
3106   case Intrinsic::spv_value_md:
3107     break;
3108   case Intrinsic::spv_resource_handlefrombinding: {
3109     return selectHandleFromBinding(ResVReg, ResType, I);
3110   }
3111   case Intrinsic::spv_resource_store_typedbuffer: {
3112     return selectImageWriteIntrinsic(I);
3113   }
3114   case Intrinsic::spv_resource_load_typedbuffer: {
3115     return selectReadImageIntrinsic(ResVReg, ResType, I);
3116   }
3117   case Intrinsic::spv_resource_getpointer: {
3118     return selectResourceGetPointer(ResVReg, ResType, I);
3119   }
3120   case Intrinsic::spv_discard: {
3121     return selectDiscard(ResVReg, ResType, I);
3122   }
3123   default: {
3124     std::string DiagMsg;
3125     raw_string_ostream OS(DiagMsg);
3126     I.print(OS);
3127     DiagMsg = "Intrinsic selection not implemented: " + DiagMsg;
3128     report_fatal_error(DiagMsg.c_str(), false);
3129   }
3130   }
3131   return true;
3132 }
3133 
3134 bool SPIRVInstructionSelector::selectHandleFromBinding(Register &ResVReg,
3135                                                        const SPIRVType *ResType,
3136                                                        MachineInstr &I) const {
3137   return true;
3138 }
3139 
3140 bool SPIRVInstructionSelector::selectReadImageIntrinsic(
3141     Register &ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
3142 
3143   // If the load of the image is in a different basic block, then
3144   // this will generate invalid code. A proper solution is to move
3145   // the OpLoad from selectHandleFromBinding here. However, to do
3146   // that we will need to change the return type of the intrinsic.
3147   // We will do that when we can, but for now trying to move forward with other
3148   // issues.
3149   Register ImageReg = I.getOperand(2).getReg();
3150   auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
3151   Register NewImageReg = MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
3152   if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
3153                                 *ImageDef, I)) {
3154     return false;
3155   }
3156 
3157   Register IdxReg = I.getOperand(3).getReg();
3158   DebugLoc Loc = I.getDebugLoc();
3159   MachineInstr &Pos = I;
3160 
3161   return generateImageRead(ResVReg, ResType, NewImageReg, IdxReg, Loc, Pos);
3162 }
3163 
3164 bool SPIRVInstructionSelector::generateImageRead(Register &ResVReg,
3165                                                  const SPIRVType *ResType,
3166                                                  Register ImageReg,
3167                                                  Register IdxReg, DebugLoc Loc,
3168                                                  MachineInstr &Pos) const {
3169   uint64_t ResultSize = GR.getScalarOrVectorComponentCount(ResType);
3170   if (ResultSize == 4) {
3171     return BuildMI(*Pos.getParent(), Pos, Loc, TII.get(SPIRV::OpImageRead))
3172         .addDef(ResVReg)
3173         .addUse(GR.getSPIRVTypeID(ResType))
3174         .addUse(ImageReg)
3175         .addUse(IdxReg)
3176         .constrainAllUses(TII, TRI, RBI);
3177   }
3178 
3179   SPIRVType *ReadType = widenTypeToVec4(ResType, Pos);
3180   Register ReadReg = MRI->createVirtualRegister(GR.getRegClass(ReadType));
3181   bool Succeed =
3182       BuildMI(*Pos.getParent(), Pos, Loc, TII.get(SPIRV::OpImageRead))
3183           .addDef(ReadReg)
3184           .addUse(GR.getSPIRVTypeID(ReadType))
3185           .addUse(ImageReg)
3186           .addUse(IdxReg)
3187           .constrainAllUses(TII, TRI, RBI);
3188   if (!Succeed)
3189     return false;
3190 
3191   if (ResultSize == 1) {
3192     return BuildMI(*Pos.getParent(), Pos, Loc,
3193                    TII.get(SPIRV::OpCompositeExtract))
3194         .addDef(ResVReg)
3195         .addUse(GR.getSPIRVTypeID(ResType))
3196         .addUse(ReadReg)
3197         .addImm(0)
3198         .constrainAllUses(TII, TRI, RBI);
3199   }
3200   return extractSubvector(ResVReg, ResType, ReadReg, Pos);
3201 }
3202 
3203 bool SPIRVInstructionSelector::selectResourceGetPointer(
3204     Register &ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
3205 #ifdef ASSERT
3206   // For now, the operand is an image. This will change once we start handling
3207   // more resource types.
3208   Register ResourcePtr = I.getOperand(2).getReg();
3209   SPIRVType *RegType = GR.getResultType(ResourcePtr);
3210   assert(RegType->getOpcode() == SPIRV::OpTypeImage &&
3211          "Can only handle texel buffers for now.");
3212 #endif
3213 
3214   // For texel buffers, the index into the image is part of the OpImageRead or
3215   // OpImageWrite instructions. So we will do nothing in this case. This
3216   // intrinsic will be combined with the load or store when selecting the load
3217   // or store.
3218   return true;
3219 }
3220 
3221 bool SPIRVInstructionSelector::extractSubvector(
3222     Register &ResVReg, const SPIRVType *ResType, Register &ReadReg,
3223     MachineInstr &InsertionPoint) const {
3224   SPIRVType *InputType = GR.getResultType(ReadReg);
3225   [[maybe_unused]] uint64_t InputSize =
3226       GR.getScalarOrVectorComponentCount(InputType);
3227   uint64_t ResultSize = GR.getScalarOrVectorComponentCount(ResType);
3228   assert(InputSize > 1 && "The input must be a vector.");
3229   assert(ResultSize > 1 && "The result must be a vector.");
3230   assert(ResultSize < InputSize &&
3231          "Cannot extract more element than there are in the input.");
3232   SmallVector<Register> ComponentRegisters;
3233   SPIRVType *ScalarType = GR.getScalarOrVectorComponentType(ResType);
3234   const TargetRegisterClass *ScalarRegClass = GR.getRegClass(ScalarType);
3235   for (uint64_t I = 0; I < ResultSize; I++) {
3236     Register ComponentReg = MRI->createVirtualRegister(ScalarRegClass);
3237     bool Succeed = BuildMI(*InsertionPoint.getParent(), InsertionPoint,
3238                            InsertionPoint.getDebugLoc(),
3239                            TII.get(SPIRV::OpCompositeExtract))
3240                        .addDef(ComponentReg)
3241                        .addUse(ScalarType->getOperand(0).getReg())
3242                        .addUse(ReadReg)
3243                        .addImm(I)
3244                        .constrainAllUses(TII, TRI, RBI);
3245     if (!Succeed)
3246       return false;
3247     ComponentRegisters.emplace_back(ComponentReg);
3248   }
3249 
3250   MachineInstrBuilder MIB = BuildMI(*InsertionPoint.getParent(), InsertionPoint,
3251                                     InsertionPoint.getDebugLoc(),
3252                                     TII.get(SPIRV::OpCompositeConstruct))
3253                                 .addDef(ResVReg)
3254                                 .addUse(GR.getSPIRVTypeID(ResType));
3255 
3256   for (Register ComponentReg : ComponentRegisters)
3257     MIB.addUse(ComponentReg);
3258   return MIB.constrainAllUses(TII, TRI, RBI);
3259 }
3260 
3261 bool SPIRVInstructionSelector::selectImageWriteIntrinsic(
3262     MachineInstr &I) const {
3263   // If the load of the image is in a different basic block, then
3264   // this will generate invalid code. A proper solution is to move
3265   // the OpLoad from selectHandleFromBinding here. However, to do
3266   // that we will need to change the return type of the intrinsic.
3267   // We will do that when we can, but for now trying to move forward with other
3268   // issues.
3269   Register ImageReg = I.getOperand(1).getReg();
3270   auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
3271   Register NewImageReg = MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
3272   if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
3273                                 *ImageDef, I)) {
3274     return false;
3275   }
3276 
3277   Register CoordinateReg = I.getOperand(2).getReg();
3278   Register DataReg = I.getOperand(3).getReg();
3279   assert(GR.getResultType(DataReg)->getOpcode() == SPIRV::OpTypeVector);
3280   assert(GR.getScalarOrVectorComponentCount(GR.getResultType(DataReg)) == 4);
3281   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
3282                  TII.get(SPIRV::OpImageWrite))
3283       .addUse(NewImageReg)
3284       .addUse(CoordinateReg)
3285       .addUse(DataReg)
3286       .constrainAllUses(TII, TRI, RBI);
3287 }
3288 
3289 Register SPIRVInstructionSelector::buildPointerToResource(
3290     const SPIRVType *ResType, uint32_t Set, uint32_t Binding,
3291     uint32_t ArraySize, Register IndexReg, bool IsNonUniform,
3292     MachineIRBuilder MIRBuilder) const {
3293   if (ArraySize == 1)
3294     return GR.getOrCreateGlobalVariableWithBinding(ResType, Set, Binding,
3295                                                    MIRBuilder);
3296 
3297   const SPIRVType *VarType = GR.getOrCreateSPIRVArrayType(
3298       ResType, ArraySize, *MIRBuilder.getInsertPt(), TII);
3299   Register VarReg = GR.getOrCreateGlobalVariableWithBinding(
3300       VarType, Set, Binding, MIRBuilder);
3301 
3302   SPIRVType *ResPointerType = GR.getOrCreateSPIRVPointerType(
3303       ResType, MIRBuilder, SPIRV::StorageClass::UniformConstant);
3304 
3305   Register AcReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
3306   if (IsNonUniform) {
3307     // It is unclear which value needs to be marked an non-uniform, so both
3308     // the index and the access changed are decorated as non-uniform.
3309     buildOpDecorate(IndexReg, MIRBuilder, SPIRV::Decoration::NonUniformEXT, {});
3310     buildOpDecorate(AcReg, MIRBuilder, SPIRV::Decoration::NonUniformEXT, {});
3311   }
3312 
3313   MIRBuilder.buildInstr(SPIRV::OpAccessChain)
3314       .addDef(AcReg)
3315       .addUse(GR.getSPIRVTypeID(ResPointerType))
3316       .addUse(VarReg)
3317       .addUse(IndexReg);
3318 
3319   return AcReg;
3320 }
3321 
3322 bool SPIRVInstructionSelector::selectFirstBitSet16(
3323     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3324     unsigned ExtendOpcode, unsigned BitSetOpcode) const {
3325   Register ExtReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3326   bool Result = selectOpWithSrcs(ExtReg, ResType, I, {I.getOperand(2).getReg()},
3327                                  ExtendOpcode);
3328 
3329   return Result &&
3330          selectFirstBitSet32(ResVReg, ResType, I, ExtReg, BitSetOpcode);
3331 }
3332 
3333 bool SPIRVInstructionSelector::selectFirstBitSet32(
3334     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3335     Register SrcReg, unsigned BitSetOpcode) const {
3336   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
3337       .addDef(ResVReg)
3338       .addUse(GR.getSPIRVTypeID(ResType))
3339       .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
3340       .addImm(BitSetOpcode)
3341       .addUse(SrcReg)
3342       .constrainAllUses(TII, TRI, RBI);
3343 }
3344 
3345 bool SPIRVInstructionSelector::selectFirstBitSet64Overflow(
3346     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3347     Register SrcReg, unsigned BitSetOpcode, bool SwapPrimarySide) const {
3348 
3349   // SPIR-V allow vectors of size 2,3,4 only. Calling with a larger vectors
3350   // requires creating a param register and return register with an invalid
3351   // vector size. If that is resolved, then this function can be used for
3352   // vectors of any component size.
3353   unsigned ComponentCount = GR.getScalarOrVectorComponentCount(ResType);
3354   assert(ComponentCount < 5 && "Vec 5+ will generate invalid SPIR-V ops");
3355 
3356   MachineIRBuilder MIRBuilder(I);
3357   SPIRVType *BaseType = GR.retrieveScalarOrVectorIntType(ResType);
3358   SPIRVType *I64Type = GR.getOrCreateSPIRVIntegerType(64, MIRBuilder);
3359   SPIRVType *I64x2Type = GR.getOrCreateSPIRVVectorType(I64Type, 2, MIRBuilder);
3360   SPIRVType *Vec2ResType =
3361       GR.getOrCreateSPIRVVectorType(BaseType, 2, MIRBuilder);
3362 
3363   std::vector<Register> PartialRegs;
3364 
3365   // Loops 0, 2, 4, ... but stops one loop early when ComponentCount is odd
3366   unsigned CurrentComponent = 0;
3367   for (; CurrentComponent + 1 < ComponentCount; CurrentComponent += 2) {
3368     // This register holds the firstbitX result for each of the i64x2 vectors
3369     // extracted from SrcReg
3370     Register BitSetResult =
3371         MRI->createVirtualRegister(GR.getRegClass(I64x2Type));
3372 
3373     auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3374                        TII.get(SPIRV::OpVectorShuffle))
3375                    .addDef(BitSetResult)
3376                    .addUse(GR.getSPIRVTypeID(I64x2Type))
3377                    .addUse(SrcReg)
3378                    .addUse(SrcReg)
3379                    .addImm(CurrentComponent)
3380                    .addImm(CurrentComponent + 1);
3381 
3382     if (!MIB.constrainAllUses(TII, TRI, RBI))
3383       return false;
3384 
3385     Register SubVecBitSetReg =
3386         MRI->createVirtualRegister(GR.getRegClass(Vec2ResType));
3387 
3388     if (!selectFirstBitSet64(SubVecBitSetReg, Vec2ResType, I, BitSetResult,
3389                              BitSetOpcode, SwapPrimarySide))
3390       return false;
3391 
3392     PartialRegs.push_back(SubVecBitSetReg);
3393   }
3394 
3395   // On odd component counts we need to handle one more component
3396   if (CurrentComponent != ComponentCount) {
3397     bool ZeroAsNull = STI.isOpenCLEnv();
3398     Register FinalElemReg = MRI->createVirtualRegister(GR.getRegClass(I64Type));
3399     Register ConstIntLastIdx = GR.getOrCreateConstInt(
3400         ComponentCount - 1, I, BaseType, TII, ZeroAsNull);
3401 
3402     if (!selectOpWithSrcs(FinalElemReg, I64Type, I, {SrcReg, ConstIntLastIdx},
3403                           SPIRV::OpVectorExtractDynamic))
3404       return false;
3405 
3406     Register FinalElemBitSetReg =
3407         MRI->createVirtualRegister(GR.getRegClass(BaseType));
3408 
3409     if (!selectFirstBitSet64(FinalElemBitSetReg, BaseType, I, FinalElemReg,
3410                              BitSetOpcode, SwapPrimarySide))
3411       return false;
3412 
3413     PartialRegs.push_back(FinalElemBitSetReg);
3414   }
3415 
3416   // Join all the resulting registers back into the return type in order
3417   // (ie i32x2, i32x2, i32x1 -> i32x5)
3418   return selectOpWithSrcs(ResVReg, ResType, I, PartialRegs,
3419                           SPIRV::OpCompositeConstruct);
3420 }
3421 
3422 bool SPIRVInstructionSelector::selectFirstBitSet64(
3423     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3424     Register SrcReg, unsigned BitSetOpcode, bool SwapPrimarySide) const {
3425   unsigned ComponentCount = GR.getScalarOrVectorComponentCount(ResType);
3426   SPIRVType *BaseType = GR.retrieveScalarOrVectorIntType(ResType);
3427   bool ZeroAsNull = STI.isOpenCLEnv();
3428   Register ConstIntZero =
3429       GR.getOrCreateConstInt(0, I, BaseType, TII, ZeroAsNull);
3430   Register ConstIntOne =
3431       GR.getOrCreateConstInt(1, I, BaseType, TII, ZeroAsNull);
3432 
3433   // SPIRV doesn't support vectors with more than 4 components. Since the
3434   // algoritm below converts i64 -> i32x2 and i64x4 -> i32x8 it can only
3435   // operate on vectors with 2 or less components. When largers vectors are
3436   // seen. Split them, recurse, then recombine them.
3437   if (ComponentCount > 2) {
3438     return selectFirstBitSet64Overflow(ResVReg, ResType, I, SrcReg,
3439                                        BitSetOpcode, SwapPrimarySide);
3440   }
3441 
3442   // 1. Split int64 into 2 pieces using a bitcast
3443   MachineIRBuilder MIRBuilder(I);
3444   SPIRVType *PostCastType =
3445       GR.getOrCreateSPIRVVectorType(BaseType, 2 * ComponentCount, MIRBuilder);
3446   Register BitcastReg =
3447       MRI->createVirtualRegister(GR.getRegClass(PostCastType));
3448 
3449   if (!selectOpWithSrcs(BitcastReg, PostCastType, I, {SrcReg},
3450                         SPIRV::OpBitcast))
3451     return false;
3452 
3453   // 2. Find the first set bit from the primary side for all the pieces in #1
3454   Register FBSReg = MRI->createVirtualRegister(GR.getRegClass(PostCastType));
3455   if (!selectFirstBitSet32(FBSReg, PostCastType, I, BitcastReg, BitSetOpcode))
3456     return false;
3457 
3458   // 3. Split result vector into high bits and low bits
3459   Register HighReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3460   Register LowReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3461 
3462   bool IsScalarRes = ResType->getOpcode() != SPIRV::OpTypeVector;
3463   if (IsScalarRes) {
3464     // if scalar do a vector extract
3465     if (!selectOpWithSrcs(HighReg, ResType, I, {FBSReg, ConstIntZero},
3466                           SPIRV::OpVectorExtractDynamic))
3467       return false;
3468     if (!selectOpWithSrcs(LowReg, ResType, I, {FBSReg, ConstIntOne},
3469                           SPIRV::OpVectorExtractDynamic))
3470       return false;
3471   } else {
3472     // if vector do a shufflevector
3473     auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3474                        TII.get(SPIRV::OpVectorShuffle))
3475                    .addDef(HighReg)
3476                    .addUse(GR.getSPIRVTypeID(ResType))
3477                    .addUse(FBSReg)
3478                    // Per the spec, repeat the vector if only one vec is needed
3479                    .addUse(FBSReg);
3480 
3481     // high bits are stored in even indexes. Extract them from FBSReg
3482     for (unsigned J = 0; J < ComponentCount * 2; J += 2) {
3483       MIB.addImm(J);
3484     }
3485 
3486     if (!MIB.constrainAllUses(TII, TRI, RBI))
3487       return false;
3488 
3489     MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3490                   TII.get(SPIRV::OpVectorShuffle))
3491               .addDef(LowReg)
3492               .addUse(GR.getSPIRVTypeID(ResType))
3493               .addUse(FBSReg)
3494               // Per the spec, repeat the vector if only one vec is needed
3495               .addUse(FBSReg);
3496 
3497     // low bits are stored in odd indexes. Extract them from FBSReg
3498     for (unsigned J = 1; J < ComponentCount * 2; J += 2) {
3499       MIB.addImm(J);
3500     }
3501     if (!MIB.constrainAllUses(TII, TRI, RBI))
3502       return false;
3503   }
3504 
3505   // 4. Check the result. When primary bits == -1 use secondary, otherwise use
3506   // primary
3507   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
3508   Register NegOneReg;
3509   Register Reg0;
3510   Register Reg32;
3511   unsigned SelectOp;
3512   unsigned AddOp;
3513 
3514   if (IsScalarRes) {
3515     NegOneReg =
3516         GR.getOrCreateConstInt((unsigned)-1, I, ResType, TII, ZeroAsNull);
3517     Reg0 = GR.getOrCreateConstInt(0, I, ResType, TII, ZeroAsNull);
3518     Reg32 = GR.getOrCreateConstInt(32, I, ResType, TII, ZeroAsNull);
3519     SelectOp = SPIRV::OpSelectSISCond;
3520     AddOp = SPIRV::OpIAddS;
3521   } else {
3522     BoolType =
3523         GR.getOrCreateSPIRVVectorType(BoolType, ComponentCount, MIRBuilder);
3524     NegOneReg =
3525         GR.getOrCreateConstVector((unsigned)-1, I, ResType, TII, ZeroAsNull);
3526     Reg0 = GR.getOrCreateConstVector(0, I, ResType, TII, ZeroAsNull);
3527     Reg32 = GR.getOrCreateConstVector(32, I, ResType, TII, ZeroAsNull);
3528     SelectOp = SPIRV::OpSelectVIVCond;
3529     AddOp = SPIRV::OpIAddV;
3530   }
3531 
3532   Register PrimaryReg = HighReg;
3533   Register SecondaryReg = LowReg;
3534   Register PrimaryShiftReg = Reg32;
3535   Register SecondaryShiftReg = Reg0;
3536 
3537   // By default the emitted opcodes check for the set bit from the MSB side.
3538   // Setting SwapPrimarySide checks the set bit from the LSB side
3539   if (SwapPrimarySide) {
3540     PrimaryReg = LowReg;
3541     SecondaryReg = HighReg;
3542     PrimaryShiftReg = Reg0;
3543     SecondaryShiftReg = Reg32;
3544   }
3545 
3546   // Check if the primary bits are == -1
3547   Register BReg = MRI->createVirtualRegister(GR.getRegClass(BoolType));
3548   if (!selectOpWithSrcs(BReg, BoolType, I, {PrimaryReg, NegOneReg},
3549                         SPIRV::OpIEqual))
3550     return false;
3551 
3552   // Select secondary bits if true in BReg, otherwise primary bits
3553   Register TmpReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3554   if (!selectOpWithSrcs(TmpReg, ResType, I, {BReg, SecondaryReg, PrimaryReg},
3555                         SelectOp))
3556     return false;
3557 
3558   // 5. Add 32 when high bits are used, otherwise 0 for low bits
3559   Register ValReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3560   if (!selectOpWithSrcs(ValReg, ResType, I,
3561                         {BReg, SecondaryShiftReg, PrimaryShiftReg}, SelectOp))
3562     return false;
3563 
3564   return selectOpWithSrcs(ResVReg, ResType, I, {ValReg, TmpReg}, AddOp);
3565 }
3566 
3567 bool SPIRVInstructionSelector::selectFirstBitHigh(Register ResVReg,
3568                                                   const SPIRVType *ResType,
3569                                                   MachineInstr &I,
3570                                                   bool IsSigned) const {
3571   // FindUMsb and FindSMsb intrinsics only support 32 bit integers
3572   Register OpReg = I.getOperand(2).getReg();
3573   SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
3574   // zero or sign extend
3575   unsigned ExtendOpcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
3576   unsigned BitSetOpcode = IsSigned ? GL::FindSMsb : GL::FindUMsb;
3577 
3578   switch (GR.getScalarOrVectorBitWidth(OpType)) {
3579   case 16:
3580     return selectFirstBitSet16(ResVReg, ResType, I, ExtendOpcode, BitSetOpcode);
3581   case 32:
3582     return selectFirstBitSet32(ResVReg, ResType, I, OpReg, BitSetOpcode);
3583   case 64:
3584     return selectFirstBitSet64(ResVReg, ResType, I, OpReg, BitSetOpcode,
3585                                /*SwapPrimarySide=*/false);
3586   default:
3587     report_fatal_error(
3588         "spv_firstbituhigh and spv_firstbitshigh only support 16,32,64 bits.");
3589   }
3590 }
3591 
3592 bool SPIRVInstructionSelector::selectFirstBitLow(Register ResVReg,
3593                                                  const SPIRVType *ResType,
3594                                                  MachineInstr &I) const {
3595   // FindILsb intrinsic only supports 32 bit integers
3596   Register OpReg = I.getOperand(2).getReg();
3597   SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
3598   // OpUConvert treats the operand bits as an unsigned i16 and zero extends it
3599   // to an unsigned i32. As this leaves all the least significant bits unchanged
3600   // so the first set bit from the LSB side doesn't change.
3601   unsigned ExtendOpcode = SPIRV::OpUConvert;
3602   unsigned BitSetOpcode = GL::FindILsb;
3603 
3604   switch (GR.getScalarOrVectorBitWidth(OpType)) {
3605   case 16:
3606     return selectFirstBitSet16(ResVReg, ResType, I, ExtendOpcode, BitSetOpcode);
3607   case 32:
3608     return selectFirstBitSet32(ResVReg, ResType, I, OpReg, BitSetOpcode);
3609   case 64:
3610     return selectFirstBitSet64(ResVReg, ResType, I, OpReg, BitSetOpcode,
3611                                /*SwapPrimarySide=*/true);
3612   default:
3613     report_fatal_error("spv_firstbitlow only supports 16,32,64 bits.");
3614   }
3615 }
3616 
3617 bool SPIRVInstructionSelector::selectAllocaArray(Register ResVReg,
3618                                                  const SPIRVType *ResType,
3619                                                  MachineInstr &I) const {
3620   // there was an allocation size parameter to the allocation instruction
3621   // that is not 1
3622   MachineBasicBlock &BB = *I.getParent();
3623   bool Res = BuildMI(BB, I, I.getDebugLoc(),
3624                      TII.get(SPIRV::OpVariableLengthArrayINTEL))
3625                  .addDef(ResVReg)
3626                  .addUse(GR.getSPIRVTypeID(ResType))
3627                  .addUse(I.getOperand(2).getReg())
3628                  .constrainAllUses(TII, TRI, RBI);
3629   if (!STI.isVulkanEnv()) {
3630     unsigned Alignment = I.getOperand(3).getImm();
3631     buildOpDecorate(ResVReg, I, TII, SPIRV::Decoration::Alignment, {Alignment});
3632   }
3633   return Res;
3634 }
3635 
3636 bool SPIRVInstructionSelector::selectFrameIndex(Register ResVReg,
3637                                                 const SPIRVType *ResType,
3638                                                 MachineInstr &I) const {
3639   // Change order of instructions if needed: all OpVariable instructions in a
3640   // function must be the first instructions in the first block
3641   auto It = getOpVariableMBBIt(I);
3642   bool Res = BuildMI(*It->getParent(), It, It->getDebugLoc(),
3643                      TII.get(SPIRV::OpVariable))
3644                  .addDef(ResVReg)
3645                  .addUse(GR.getSPIRVTypeID(ResType))
3646                  .addImm(static_cast<uint32_t>(SPIRV::StorageClass::Function))
3647                  .constrainAllUses(TII, TRI, RBI);
3648   if (!STI.isVulkanEnv()) {
3649     unsigned Alignment = I.getOperand(2).getImm();
3650     buildOpDecorate(ResVReg, *It, TII, SPIRV::Decoration::Alignment,
3651                     {Alignment});
3652   }
3653   return Res;
3654 }
3655 
3656 bool SPIRVInstructionSelector::selectBranch(MachineInstr &I) const {
3657   // InstructionSelector walks backwards through the instructions. We can use
3658   // both a G_BR and a G_BRCOND to create an OpBranchConditional. We hit G_BR
3659   // first, so can generate an OpBranchConditional here. If there is no
3660   // G_BRCOND, we just use OpBranch for a regular unconditional branch.
3661   const MachineInstr *PrevI = I.getPrevNode();
3662   MachineBasicBlock &MBB = *I.getParent();
3663   if (PrevI != nullptr && PrevI->getOpcode() == TargetOpcode::G_BRCOND) {
3664     return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranchConditional))
3665         .addUse(PrevI->getOperand(0).getReg())
3666         .addMBB(PrevI->getOperand(1).getMBB())
3667         .addMBB(I.getOperand(0).getMBB())
3668         .constrainAllUses(TII, TRI, RBI);
3669   }
3670   return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranch))
3671       .addMBB(I.getOperand(0).getMBB())
3672       .constrainAllUses(TII, TRI, RBI);
3673 }
3674 
3675 bool SPIRVInstructionSelector::selectBranchCond(MachineInstr &I) const {
3676   // InstructionSelector walks backwards through the instructions. For an
3677   // explicit conditional branch with no fallthrough, we use both a G_BR and a
3678   // G_BRCOND to create an OpBranchConditional. We should hit G_BR first, and
3679   // generate the OpBranchConditional in selectBranch above.
3680   //
3681   // If an OpBranchConditional has been generated, we simply return, as the work
3682   // is alread done. If there is no OpBranchConditional, LLVM must be relying on
3683   // implicit fallthrough to the next basic block, so we need to create an
3684   // OpBranchConditional with an explicit "false" argument pointing to the next
3685   // basic block that LLVM would fall through to.
3686   const MachineInstr *NextI = I.getNextNode();
3687   // Check if this has already been successfully selected.
3688   if (NextI != nullptr && NextI->getOpcode() == SPIRV::OpBranchConditional)
3689     return true;
3690   // Must be relying on implicit block fallthrough, so generate an
3691   // OpBranchConditional with the "next" basic block as the "false" target.
3692   MachineBasicBlock &MBB = *I.getParent();
3693   unsigned NextMBBNum = MBB.getNextNode()->getNumber();
3694   MachineBasicBlock *NextMBB = I.getMF()->getBlockNumbered(NextMBBNum);
3695   return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranchConditional))
3696       .addUse(I.getOperand(0).getReg())
3697       .addMBB(I.getOperand(1).getMBB())
3698       .addMBB(NextMBB)
3699       .constrainAllUses(TII, TRI, RBI);
3700 }
3701 
3702 bool SPIRVInstructionSelector::selectPhi(Register ResVReg,
3703                                          const SPIRVType *ResType,
3704                                          MachineInstr &I) const {
3705   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpPhi))
3706                  .addDef(ResVReg)
3707                  .addUse(GR.getSPIRVTypeID(ResType));
3708   const unsigned NumOps = I.getNumOperands();
3709   for (unsigned i = 1; i < NumOps; i += 2) {
3710     MIB.addUse(I.getOperand(i + 0).getReg());
3711     MIB.addMBB(I.getOperand(i + 1).getMBB());
3712   }
3713   bool Res = MIB.constrainAllUses(TII, TRI, RBI);
3714   MIB->setDesc(TII.get(TargetOpcode::PHI));
3715   MIB->removeOperand(1);
3716   return Res;
3717 }
3718 
3719 bool SPIRVInstructionSelector::selectGlobalValue(
3720     Register ResVReg, MachineInstr &I, const MachineInstr *Init) const {
3721   // FIXME: don't use MachineIRBuilder here, replace it with BuildMI.
3722   MachineIRBuilder MIRBuilder(I);
3723   const GlobalValue *GV = I.getOperand(1).getGlobal();
3724   Type *GVType = toTypedPointer(GR.getDeducedGlobalValueType(GV));
3725   SPIRVType *PointerBaseType;
3726   if (GVType->isArrayTy()) {
3727     SPIRVType *ArrayElementType =
3728         GR.getOrCreateSPIRVType(GVType->getArrayElementType(), MIRBuilder,
3729                                 SPIRV::AccessQualifier::ReadWrite, false);
3730     PointerBaseType = GR.getOrCreateSPIRVArrayType(
3731         ArrayElementType, GVType->getArrayNumElements(), I, TII);
3732   } else {
3733     PointerBaseType = GR.getOrCreateSPIRVType(
3734         GVType, MIRBuilder, SPIRV::AccessQualifier::ReadWrite, false);
3735   }
3736 
3737   std::string GlobalIdent;
3738   if (!GV->hasName()) {
3739     unsigned &ID = UnnamedGlobalIDs[GV];
3740     if (ID == 0)
3741       ID = UnnamedGlobalIDs.size();
3742     GlobalIdent = "__unnamed_" + Twine(ID).str();
3743   } else {
3744     GlobalIdent = GV->getName();
3745   }
3746 
3747   // Behaviour of functions as operands depends on availability of the
3748   // corresponding extension (SPV_INTEL_function_pointers):
3749   // - If there is an extension to operate with functions as operands:
3750   // We create a proper constant operand and evaluate a correct type for a
3751   // function pointer.
3752   // - Without the required extension:
3753   // We have functions as operands in tests with blocks of instruction e.g. in
3754   // transcoding/global_block.ll. These operands are not used and should be
3755   // substituted by zero constants. Their type is expected to be always
3756   // OpTypePointer Function %uchar.
3757   if (isa<Function>(GV)) {
3758     const Constant *ConstVal = GV;
3759     MachineBasicBlock &BB = *I.getParent();
3760     Register NewReg = GR.find(ConstVal, GR.CurMF);
3761     if (!NewReg.isValid()) {
3762       Register NewReg = ResVReg;
3763       GR.add(ConstVal, GR.CurMF, NewReg);
3764       const Function *GVFun =
3765           STI.canUseExtension(SPIRV::Extension::SPV_INTEL_function_pointers)
3766               ? dyn_cast<Function>(GV)
3767               : nullptr;
3768       SPIRVType *ResType = GR.getOrCreateSPIRVPointerType(
3769           PointerBaseType, I, TII,
3770           GVFun ? SPIRV::StorageClass::CodeSectionINTEL
3771                 : addressSpaceToStorageClass(GV->getAddressSpace(), STI));
3772       if (GVFun) {
3773         // References to a function via function pointers generate virtual
3774         // registers without a definition. We will resolve it later, during
3775         // module analysis stage.
3776         Register ResTypeReg = GR.getSPIRVTypeID(ResType);
3777         MachineRegisterInfo *MRI = MIRBuilder.getMRI();
3778         Register FuncVReg =
3779             MRI->createGenericVirtualRegister(GR.getRegType(ResType));
3780         MRI->setRegClass(FuncVReg, &SPIRV::pIDRegClass);
3781         MachineInstrBuilder MIB1 =
3782             BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
3783                 .addDef(FuncVReg)
3784                 .addUse(ResTypeReg);
3785         MachineInstrBuilder MIB2 =
3786             BuildMI(BB, I, I.getDebugLoc(),
3787                     TII.get(SPIRV::OpConstantFunctionPointerINTEL))
3788                 .addDef(NewReg)
3789                 .addUse(ResTypeReg)
3790                 .addUse(FuncVReg);
3791         // mapping the function pointer to the used Function
3792         GR.recordFunctionPointer(&MIB2.getInstr()->getOperand(2), GVFun);
3793         return MIB1.constrainAllUses(TII, TRI, RBI) &&
3794                MIB2.constrainAllUses(TII, TRI, RBI);
3795       }
3796       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
3797           .addDef(NewReg)
3798           .addUse(GR.getSPIRVTypeID(ResType))
3799           .constrainAllUses(TII, TRI, RBI);
3800     }
3801     assert(NewReg != ResVReg);
3802     return BuildCOPY(ResVReg, NewReg, I);
3803   }
3804   auto GlobalVar = cast<GlobalVariable>(GV);
3805   assert(GlobalVar->getName() != "llvm.global.annotations");
3806 
3807   // Skip empty declaration for GVs with initializers till we get the decl with
3808   // passed initializer.
3809   if (hasInitializer(GlobalVar) && !Init)
3810     return true;
3811 
3812   bool HasLnkTy = !GV->hasInternalLinkage() && !GV->hasPrivateLinkage();
3813   SPIRV::LinkageType::LinkageType LnkType =
3814       GV->isDeclarationForLinker()
3815           ? SPIRV::LinkageType::Import
3816           : (GV->hasLinkOnceODRLinkage() &&
3817                      STI.canUseExtension(SPIRV::Extension::SPV_KHR_linkonce_odr)
3818                  ? SPIRV::LinkageType::LinkOnceODR
3819                  : SPIRV::LinkageType::Export);
3820 
3821   const unsigned AddrSpace = GV->getAddressSpace();
3822   SPIRV::StorageClass::StorageClass StorageClass =
3823       addressSpaceToStorageClass(AddrSpace, STI);
3824   SPIRVType *ResType =
3825       GR.getOrCreateSPIRVPointerType(PointerBaseType, I, TII, StorageClass);
3826   Register Reg = GR.buildGlobalVariable(
3827       ResVReg, ResType, GlobalIdent, GV, StorageClass, Init,
3828       GlobalVar->isConstant(), HasLnkTy, LnkType, MIRBuilder, true);
3829   return Reg.isValid();
3830 }
3831 
3832 bool SPIRVInstructionSelector::selectLog10(Register ResVReg,
3833                                            const SPIRVType *ResType,
3834                                            MachineInstr &I) const {
3835   if (STI.canUseExtInstSet(SPIRV::InstructionSet::OpenCL_std)) {
3836     return selectExtInst(ResVReg, ResType, I, CL::log10);
3837   }
3838 
3839   // There is no log10 instruction in the GLSL Extended Instruction set, so it
3840   // is implemented as:
3841   // log10(x) = log2(x) * (1 / log2(10))
3842   //          = log2(x) * 0.30103
3843 
3844   MachineIRBuilder MIRBuilder(I);
3845   MachineBasicBlock &BB = *I.getParent();
3846 
3847   // Build log2(x).
3848   Register VarReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3849   bool Result =
3850       BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
3851           .addDef(VarReg)
3852           .addUse(GR.getSPIRVTypeID(ResType))
3853           .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
3854           .addImm(GL::Log2)
3855           .add(I.getOperand(1))
3856           .constrainAllUses(TII, TRI, RBI);
3857 
3858   // Build 0.30103.
3859   assert(ResType->getOpcode() == SPIRV::OpTypeVector ||
3860          ResType->getOpcode() == SPIRV::OpTypeFloat);
3861   // TODO: Add matrix implementation once supported by the HLSL frontend.
3862   const SPIRVType *SpirvScalarType =
3863       ResType->getOpcode() == SPIRV::OpTypeVector
3864           ? GR.getSPIRVTypeForVReg(ResType->getOperand(1).getReg())
3865           : ResType;
3866   Register ScaleReg =
3867       GR.buildConstantFP(APFloat(0.30103f), MIRBuilder, SpirvScalarType);
3868 
3869   // Multiply log2(x) by 0.30103 to get log10(x) result.
3870   auto Opcode = ResType->getOpcode() == SPIRV::OpTypeVector
3871                     ? SPIRV::OpVectorTimesScalar
3872                     : SPIRV::OpFMulS;
3873   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
3874                        .addDef(ResVReg)
3875                        .addUse(GR.getSPIRVTypeID(ResType))
3876                        .addUse(VarReg)
3877                        .addUse(ScaleReg)
3878                        .constrainAllUses(TII, TRI, RBI);
3879 }
3880 
3881 // Generate the instructions to load 3-element vector builtin input
3882 // IDs/Indices.
3883 // Like: GlobalInvocationId, LocalInvocationId, etc....
3884 bool SPIRVInstructionSelector::loadVec3BuiltinInputID(
3885     SPIRV::BuiltIn::BuiltIn BuiltInValue, Register ResVReg,
3886     const SPIRVType *ResType, MachineInstr &I) const {
3887   MachineIRBuilder MIRBuilder(I);
3888   const SPIRVType *U32Type = GR.getOrCreateSPIRVIntegerType(32, MIRBuilder);
3889   const SPIRVType *Vec3Ty =
3890       GR.getOrCreateSPIRVVectorType(U32Type, 3, MIRBuilder);
3891   const SPIRVType *PtrType = GR.getOrCreateSPIRVPointerType(
3892       Vec3Ty, MIRBuilder, SPIRV::StorageClass::Input);
3893 
3894   // Create new register for the input ID builtin variable.
3895   Register NewRegister =
3896       MIRBuilder.getMRI()->createVirtualRegister(&SPIRV::iIDRegClass);
3897   MIRBuilder.getMRI()->setType(NewRegister, LLT::pointer(0, 64));
3898   GR.assignSPIRVTypeToVReg(PtrType, NewRegister, MIRBuilder.getMF());
3899 
3900   // Build global variable with the necessary decorations for the input ID
3901   // builtin variable.
3902   Register Variable = GR.buildGlobalVariable(
3903       NewRegister, PtrType, getLinkStringForBuiltIn(BuiltInValue), nullptr,
3904       SPIRV::StorageClass::Input, nullptr, true, true,
3905       SPIRV::LinkageType::Import, MIRBuilder, false);
3906 
3907   // Create new register for loading value.
3908   MachineRegisterInfo *MRI = MIRBuilder.getMRI();
3909   Register LoadedRegister = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
3910   MIRBuilder.getMRI()->setType(LoadedRegister, LLT::pointer(0, 64));
3911   GR.assignSPIRVTypeToVReg(Vec3Ty, LoadedRegister, MIRBuilder.getMF());
3912 
3913   // Load v3uint value from the global variable.
3914   bool Result =
3915       BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpLoad))
3916           .addDef(LoadedRegister)
3917           .addUse(GR.getSPIRVTypeID(Vec3Ty))
3918           .addUse(Variable);
3919 
3920   // Get the input ID index. Expecting operand is a constant immediate value,
3921   // wrapped in a type assignment.
3922   assert(I.getOperand(2).isReg());
3923   const uint32_t ThreadId = foldImm(I.getOperand(2), MRI);
3924 
3925   // Extract the input ID from the loaded vector value.
3926   MachineBasicBlock &BB = *I.getParent();
3927   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
3928                  .addDef(ResVReg)
3929                  .addUse(GR.getSPIRVTypeID(ResType))
3930                  .addUse(LoadedRegister)
3931                  .addImm(ThreadId);
3932   return Result && MIB.constrainAllUses(TII, TRI, RBI);
3933 }
3934 
3935 SPIRVType *SPIRVInstructionSelector::widenTypeToVec4(const SPIRVType *Type,
3936                                                      MachineInstr &I) const {
3937   MachineIRBuilder MIRBuilder(I);
3938   if (Type->getOpcode() != SPIRV::OpTypeVector)
3939     return GR.getOrCreateSPIRVVectorType(Type, 4, MIRBuilder);
3940 
3941   uint64_t VectorSize = Type->getOperand(2).getImm();
3942   if (VectorSize == 4)
3943     return Type;
3944 
3945   Register ScalarTypeReg = Type->getOperand(1).getReg();
3946   const SPIRVType *ScalarType = GR.getSPIRVTypeForVReg(ScalarTypeReg);
3947   return GR.getOrCreateSPIRVVectorType(ScalarType, 4, MIRBuilder);
3948 }
3949 
3950 bool SPIRVInstructionSelector::loadHandleBeforePosition(
3951     Register &HandleReg, const SPIRVType *ResType, GIntrinsic &HandleDef,
3952     MachineInstr &Pos) const {
3953 
3954   assert(HandleDef.getIntrinsicID() ==
3955          Intrinsic::spv_resource_handlefrombinding);
3956   uint32_t Set = foldImm(HandleDef.getOperand(2), MRI);
3957   uint32_t Binding = foldImm(HandleDef.getOperand(3), MRI);
3958   uint32_t ArraySize = foldImm(HandleDef.getOperand(4), MRI);
3959   Register IndexReg = HandleDef.getOperand(5).getReg();
3960   bool IsNonUniform = ArraySize > 1 && foldImm(HandleDef.getOperand(6), MRI);
3961 
3962   MachineIRBuilder MIRBuilder(HandleDef);
3963   Register VarReg = buildPointerToResource(ResType, Set, Binding, ArraySize,
3964                                            IndexReg, IsNonUniform, MIRBuilder);
3965 
3966   if (IsNonUniform)
3967     buildOpDecorate(HandleReg, HandleDef, TII, SPIRV::Decoration::NonUniformEXT,
3968                     {});
3969 
3970   // TODO: For now we assume the resource is an image, which needs to be
3971   // loaded to get the handle. That will not be true for storage buffers.
3972   return BuildMI(*Pos.getParent(), Pos, HandleDef.getDebugLoc(),
3973                  TII.get(SPIRV::OpLoad))
3974       .addDef(HandleReg)
3975       .addUse(GR.getSPIRVTypeID(ResType))
3976       .addUse(VarReg)
3977       .constrainAllUses(TII, TRI, RBI);
3978 }
3979 
3980 namespace llvm {
3981 InstructionSelector *
3982 createSPIRVInstructionSelector(const SPIRVTargetMachine &TM,
3983                                const SPIRVSubtarget &Subtarget,
3984                                const RegisterBankInfo &RBI) {
3985   return new SPIRVInstructionSelector(TM, Subtarget, RBI);
3986 }
3987 } // namespace llvm
3988