xref: /llvm-project/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp (revision dd860bcfb57df429c0a1ad2e2d869ff3b795bc4d)
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   bool selectExtInst(Register ResVReg, const SPIRVType *RestType,
274                      MachineInstr &I, GL::GLSLExtInst GLInst) const;
275   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
276                      MachineInstr &I, CL::OpenCLExtInst CLInst) const;
277   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
278                      MachineInstr &I, CL::OpenCLExtInst CLInst,
279                      GL::GLSLExtInst GLInst) const;
280   bool selectExtInst(Register ResVReg, const SPIRVType *ResType,
281                      MachineInstr &I, const ExtInstList &ExtInsts) const;
282 
283   bool selectLog10(Register ResVReg, const SPIRVType *ResType,
284                    MachineInstr &I) const;
285 
286   bool selectSaturate(Register ResVReg, const SPIRVType *ResType,
287                       MachineInstr &I) const;
288 
289   bool selectWaveOpInst(Register ResVReg, const SPIRVType *ResType,
290                         MachineInstr &I, unsigned Opcode) const;
291 
292   bool selectWaveActiveCountBits(Register ResVReg, const SPIRVType *ResType,
293                                  MachineInstr &I) const;
294 
295   bool selectUnmergeValues(MachineInstr &I) const;
296 
297   bool selectHandleFromBinding(Register &ResVReg, const SPIRVType *ResType,
298                                MachineInstr &I) const;
299 
300   bool selectReadImageIntrinsic(Register &ResVReg, const SPIRVType *ResType,
301                                 MachineInstr &I) const;
302   bool selectImageWriteIntrinsic(MachineInstr &I) const;
303   bool selectResourceGetPointer(Register &ResVReg, const SPIRVType *ResType,
304                                 MachineInstr &I) const;
305 
306   // Utilities
307   std::pair<Register, bool>
308   buildI32Constant(uint32_t Val, MachineInstr &I,
309                    const SPIRVType *ResType = nullptr) const;
310 
311   Register buildZerosVal(const SPIRVType *ResType, MachineInstr &I) const;
312   Register buildZerosValF(const SPIRVType *ResType, MachineInstr &I) const;
313   Register buildOnesVal(bool AllOnes, const SPIRVType *ResType,
314                         MachineInstr &I) const;
315   Register buildOnesValF(const SPIRVType *ResType, MachineInstr &I) const;
316 
317   bool wrapIntoSpecConstantOp(MachineInstr &I,
318                               SmallVector<Register> &CompositeArgs) const;
319 
320   Register getUcharPtrTypeReg(MachineInstr &I,
321                               SPIRV::StorageClass::StorageClass SC) const;
322   MachineInstrBuilder buildSpecConstantOp(MachineInstr &I, Register Dest,
323                                           Register Src, Register DestType,
324                                           uint32_t Opcode) const;
325   MachineInstrBuilder buildConstGenericPtr(MachineInstr &I, Register SrcPtr,
326                                            SPIRVType *SrcPtrTy) const;
327   Register buildPointerToResource(const SPIRVType *ResType, uint32_t Set,
328                                   uint32_t Binding, uint32_t ArraySize,
329                                   Register IndexReg, bool IsNonUniform,
330                                   MachineIRBuilder MIRBuilder) const;
331   SPIRVType *widenTypeToVec4(const SPIRVType *Type, MachineInstr &I) const;
332   bool extractSubvector(Register &ResVReg, const SPIRVType *ResType,
333                         Register &ReadReg, MachineInstr &InsertionPoint) const;
334   bool generateImageRead(Register &ResVReg, const SPIRVType *ResType,
335                          Register ImageReg, Register IdxReg, DebugLoc Loc,
336                          MachineInstr &Pos) const;
337   bool BuildCOPY(Register DestReg, Register SrcReg, MachineInstr &I) const;
338   bool loadVec3BuiltinInputID(SPIRV::BuiltIn::BuiltIn BuiltInValue,
339                               Register ResVReg, const SPIRVType *ResType,
340                               MachineInstr &I) const;
341   bool loadHandleBeforePosition(Register &HandleReg, const SPIRVType *ResType,
342                                 GIntrinsic &HandleDef, MachineInstr &Pos) const;
343 };
344 
345 } // end anonymous namespace
346 
347 #define GET_GLOBALISEL_IMPL
348 #include "SPIRVGenGlobalISel.inc"
349 #undef GET_GLOBALISEL_IMPL
350 
351 SPIRVInstructionSelector::SPIRVInstructionSelector(const SPIRVTargetMachine &TM,
352                                                    const SPIRVSubtarget &ST,
353                                                    const RegisterBankInfo &RBI)
354     : InstructionSelector(), STI(ST), TII(*ST.getInstrInfo()),
355       TRI(*ST.getRegisterInfo()), RBI(RBI), GR(*ST.getSPIRVGlobalRegistry()),
356 #define GET_GLOBALISEL_PREDICATES_INIT
357 #include "SPIRVGenGlobalISel.inc"
358 #undef GET_GLOBALISEL_PREDICATES_INIT
359 #define GET_GLOBALISEL_TEMPORARIES_INIT
360 #include "SPIRVGenGlobalISel.inc"
361 #undef GET_GLOBALISEL_TEMPORARIES_INIT
362 {
363 }
364 
365 void SPIRVInstructionSelector::setupMF(MachineFunction &MF, GISelKnownBits *KB,
366                                        CodeGenCoverage *CoverageInfo,
367                                        ProfileSummaryInfo *PSI,
368                                        BlockFrequencyInfo *BFI) {
369   MRI = &MF.getRegInfo();
370   GR.setCurrentFunc(MF);
371   InstructionSelector::setupMF(MF, KB, CoverageInfo, PSI, BFI);
372 }
373 
374 // Ensure that register classes correspond to pattern matching rules.
375 void SPIRVInstructionSelector::resetVRegsType(MachineFunction &MF) {
376   if (HasVRegsReset == &MF)
377     return;
378   HasVRegsReset = &MF;
379 
380   MachineRegisterInfo &MRI = MF.getRegInfo();
381   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
382     Register Reg = Register::index2VirtReg(I);
383     LLT RegType = MRI.getType(Reg);
384     if (RegType.isScalar())
385       MRI.setType(Reg, LLT::scalar(64));
386     else if (RegType.isPointer())
387       MRI.setType(Reg, LLT::pointer(0, 64));
388     else if (RegType.isVector())
389       MRI.setType(Reg, LLT::fixed_vector(2, LLT::scalar(64)));
390   }
391   for (const auto &MBB : MF) {
392     for (const auto &MI : MBB) {
393       if (MI.getOpcode() != SPIRV::ASSIGN_TYPE)
394         continue;
395       Register DstReg = MI.getOperand(0).getReg();
396       LLT DstType = MRI.getType(DstReg);
397       Register SrcReg = MI.getOperand(1).getReg();
398       LLT SrcType = MRI.getType(SrcReg);
399       if (DstType != SrcType)
400         MRI.setType(DstReg, MRI.getType(SrcReg));
401 
402       const TargetRegisterClass *DstRC = MRI.getRegClassOrNull(DstReg);
403       const TargetRegisterClass *SrcRC = MRI.getRegClassOrNull(SrcReg);
404       if (DstRC != SrcRC && SrcRC)
405         MRI.setRegClass(DstReg, SrcRC);
406     }
407   }
408 }
409 
410 static bool isImm(const MachineOperand &MO, MachineRegisterInfo *MRI);
411 
412 // Defined in SPIRVLegalizerInfo.cpp.
413 extern bool isTypeFoldingSupported(unsigned Opcode);
414 
415 bool isDead(const MachineInstr &MI, const MachineRegisterInfo &MRI) {
416   for (const auto &MO : MI.all_defs()) {
417     Register Reg = MO.getReg();
418     if (Reg.isPhysical() || !MRI.use_nodbg_empty(Reg))
419       return false;
420   }
421   if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE || MI.isFakeUse() ||
422       MI.isLifetimeMarker())
423     return false;
424   if (MI.isPHI())
425     return true;
426   if (MI.mayStore() || MI.isCall() ||
427       (MI.mayLoad() && MI.hasOrderedMemoryRef()) || MI.isPosition() ||
428       MI.isDebugInstr() || MI.isTerminator() || MI.isJumpTableDebugInfo())
429     return false;
430   return true;
431 }
432 
433 bool SPIRVInstructionSelector::select(MachineInstr &I) {
434   resetVRegsType(*I.getParent()->getParent());
435 
436   assert(I.getParent() && "Instruction should be in a basic block!");
437   assert(I.getParent()->getParent() && "Instruction should be in a function!");
438 
439   Register Opcode = I.getOpcode();
440   // If it's not a GMIR instruction, we've selected it already.
441   if (!isPreISelGenericOpcode(Opcode)) {
442     if (Opcode == SPIRV::ASSIGN_TYPE) { // These pseudos aren't needed any more.
443       Register DstReg = I.getOperand(0).getReg();
444       Register SrcReg = I.getOperand(1).getReg();
445       auto *Def = MRI->getVRegDef(SrcReg);
446       if (isTypeFoldingSupported(Def->getOpcode())) {
447         bool Res = selectImpl(I, *CoverageInfo);
448         LLVM_DEBUG({
449           if (!Res && Def->getOpcode() != TargetOpcode::G_CONSTANT) {
450             dbgs() << "Unexpected pattern in ASSIGN_TYPE.\nInstruction: ";
451             I.print(dbgs());
452           }
453         });
454         assert(Res || Def->getOpcode() == TargetOpcode::G_CONSTANT);
455         if (Res) {
456           if (!isTriviallyDead(*Def, *MRI) && isDead(*Def, *MRI))
457             DeadMIs.insert(Def);
458           return Res;
459         }
460       }
461       MRI->setRegClass(SrcReg, MRI->getRegClass(DstReg));
462       MRI->replaceRegWith(SrcReg, DstReg);
463       GR.invalidateMachineInstr(&I);
464       I.removeFromParent();
465       return true;
466     } else if (I.getNumDefs() == 1) {
467       // Make all vregs 64 bits (for SPIR-V IDs).
468       MRI->setType(I.getOperand(0).getReg(), LLT::scalar(64));
469     }
470     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
471   }
472 
473   if (DeadMIs.contains(&I)) {
474     // if the instruction has been already made dead by folding it away
475     // erase it
476     LLVM_DEBUG(dbgs() << "Instruction is folded and dead.\n");
477     salvageDebugInfo(*MRI, I);
478     GR.invalidateMachineInstr(&I);
479     I.eraseFromParent();
480     return true;
481   }
482 
483   if (I.getNumOperands() != I.getNumExplicitOperands()) {
484     LLVM_DEBUG(errs() << "Generic instr has unexpected implicit operands\n");
485     return false;
486   }
487 
488   // Common code for getting return reg+type, and removing selected instr
489   // from parent occurs here. Instr-specific selection happens in spvSelect().
490   bool HasDefs = I.getNumDefs() > 0;
491   Register ResVReg = HasDefs ? I.getOperand(0).getReg() : Register(0);
492   SPIRVType *ResType = HasDefs ? GR.getSPIRVTypeForVReg(ResVReg) : nullptr;
493   assert(!HasDefs || ResType || I.getOpcode() == TargetOpcode::G_GLOBAL_VALUE);
494   if (spvSelect(ResVReg, ResType, I)) {
495     if (HasDefs) // Make all vregs 64 bits (for SPIR-V IDs).
496       for (unsigned i = 0; i < I.getNumDefs(); ++i)
497         MRI->setType(I.getOperand(i).getReg(), LLT::scalar(64));
498     GR.invalidateMachineInstr(&I);
499     I.removeFromParent();
500     return true;
501   }
502   return false;
503 }
504 
505 static bool mayApplyGenericSelection(unsigned Opcode) {
506   switch (Opcode) {
507   case TargetOpcode::G_CONSTANT:
508     return false;
509   case TargetOpcode::G_SADDO:
510   case TargetOpcode::G_SSUBO:
511     return true;
512   }
513   return isTypeFoldingSupported(Opcode);
514 }
515 
516 bool SPIRVInstructionSelector::BuildCOPY(Register DestReg, Register SrcReg,
517                                          MachineInstr &I) const {
518   const TargetRegisterClass *DstRC = MRI->getRegClassOrNull(DestReg);
519   const TargetRegisterClass *SrcRC = MRI->getRegClassOrNull(SrcReg);
520   if (DstRC != SrcRC && SrcRC)
521     MRI->setRegClass(DestReg, SrcRC);
522   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
523                  TII.get(TargetOpcode::COPY))
524       .addDef(DestReg)
525       .addUse(SrcReg)
526       .constrainAllUses(TII, TRI, RBI);
527 }
528 
529 bool SPIRVInstructionSelector::spvSelect(Register ResVReg,
530                                          const SPIRVType *ResType,
531                                          MachineInstr &I) const {
532   const unsigned Opcode = I.getOpcode();
533   if (mayApplyGenericSelection(Opcode))
534     return selectImpl(I, *CoverageInfo);
535   switch (Opcode) {
536   case TargetOpcode::G_CONSTANT:
537     return selectConst(ResVReg, ResType, I.getOperand(1).getCImm()->getValue(),
538                        I);
539   case TargetOpcode::G_GLOBAL_VALUE:
540     return selectGlobalValue(ResVReg, I);
541   case TargetOpcode::G_IMPLICIT_DEF:
542     return selectOpUndef(ResVReg, ResType, I);
543   case TargetOpcode::G_FREEZE:
544     return selectFreeze(ResVReg, ResType, I);
545 
546   case TargetOpcode::G_INTRINSIC:
547   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
548   case TargetOpcode::G_INTRINSIC_CONVERGENT:
549   case TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS:
550     return selectIntrinsic(ResVReg, ResType, I);
551   case TargetOpcode::G_BITREVERSE:
552     return selectBitreverse(ResVReg, ResType, I);
553 
554   case TargetOpcode::G_BUILD_VECTOR:
555     return selectBuildVector(ResVReg, ResType, I);
556   case TargetOpcode::G_SPLAT_VECTOR:
557     return selectSplatVector(ResVReg, ResType, I);
558 
559   case TargetOpcode::G_SHUFFLE_VECTOR: {
560     MachineBasicBlock &BB = *I.getParent();
561     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorShuffle))
562                    .addDef(ResVReg)
563                    .addUse(GR.getSPIRVTypeID(ResType))
564                    .addUse(I.getOperand(1).getReg())
565                    .addUse(I.getOperand(2).getReg());
566     for (auto V : I.getOperand(3).getShuffleMask())
567       MIB.addImm(V);
568     return MIB.constrainAllUses(TII, TRI, RBI);
569   }
570   case TargetOpcode::G_MEMMOVE:
571   case TargetOpcode::G_MEMCPY:
572   case TargetOpcode::G_MEMSET:
573     return selectMemOperation(ResVReg, I);
574 
575   case TargetOpcode::G_ICMP:
576     return selectICmp(ResVReg, ResType, I);
577   case TargetOpcode::G_FCMP:
578     return selectFCmp(ResVReg, ResType, I);
579 
580   case TargetOpcode::G_FRAME_INDEX:
581     return selectFrameIndex(ResVReg, ResType, I);
582 
583   case TargetOpcode::G_LOAD:
584     return selectLoad(ResVReg, ResType, I);
585   case TargetOpcode::G_STORE:
586     return selectStore(I);
587 
588   case TargetOpcode::G_BR:
589     return selectBranch(I);
590   case TargetOpcode::G_BRCOND:
591     return selectBranchCond(I);
592 
593   case TargetOpcode::G_PHI:
594     return selectPhi(ResVReg, ResType, I);
595 
596   case TargetOpcode::G_FPTOSI:
597     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertFToS);
598   case TargetOpcode::G_FPTOUI:
599     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertFToU);
600 
601   case TargetOpcode::G_SITOFP:
602     return selectIToF(ResVReg, ResType, I, true, SPIRV::OpConvertSToF);
603   case TargetOpcode::G_UITOFP:
604     return selectIToF(ResVReg, ResType, I, false, SPIRV::OpConvertUToF);
605 
606   case TargetOpcode::G_CTPOP:
607     return selectUnOp(ResVReg, ResType, I, SPIRV::OpBitCount);
608   case TargetOpcode::G_SMIN:
609     return selectExtInst(ResVReg, ResType, I, CL::s_min, GL::SMin);
610   case TargetOpcode::G_UMIN:
611     return selectExtInst(ResVReg, ResType, I, CL::u_min, GL::UMin);
612 
613   case TargetOpcode::G_SMAX:
614     return selectExtInst(ResVReg, ResType, I, CL::s_max, GL::SMax);
615   case TargetOpcode::G_UMAX:
616     return selectExtInst(ResVReg, ResType, I, CL::u_max, GL::UMax);
617 
618   case TargetOpcode::G_SCMP:
619     return selectSUCmp(ResVReg, ResType, I, true);
620   case TargetOpcode::G_UCMP:
621     return selectSUCmp(ResVReg, ResType, I, false);
622 
623   case TargetOpcode::G_STRICT_FMA:
624   case TargetOpcode::G_FMA:
625     return selectExtInst(ResVReg, ResType, I, CL::fma, GL::Fma);
626 
627   case TargetOpcode::G_STRICT_FLDEXP:
628     return selectExtInst(ResVReg, ResType, I, CL::ldexp);
629 
630   case TargetOpcode::G_FPOW:
631     return selectExtInst(ResVReg, ResType, I, CL::pow, GL::Pow);
632   case TargetOpcode::G_FPOWI:
633     return selectExtInst(ResVReg, ResType, I, CL::pown);
634 
635   case TargetOpcode::G_FEXP:
636     return selectExtInst(ResVReg, ResType, I, CL::exp, GL::Exp);
637   case TargetOpcode::G_FEXP2:
638     return selectExtInst(ResVReg, ResType, I, CL::exp2, GL::Exp2);
639 
640   case TargetOpcode::G_FLOG:
641     return selectExtInst(ResVReg, ResType, I, CL::log, GL::Log);
642   case TargetOpcode::G_FLOG2:
643     return selectExtInst(ResVReg, ResType, I, CL::log2, GL::Log2);
644   case TargetOpcode::G_FLOG10:
645     return selectLog10(ResVReg, ResType, I);
646 
647   case TargetOpcode::G_FABS:
648     return selectExtInst(ResVReg, ResType, I, CL::fabs, GL::FAbs);
649   case TargetOpcode::G_ABS:
650     return selectExtInst(ResVReg, ResType, I, CL::s_abs, GL::SAbs);
651 
652   case TargetOpcode::G_FMINNUM:
653   case TargetOpcode::G_FMINIMUM:
654     return selectExtInst(ResVReg, ResType, I, CL::fmin, GL::NMin);
655   case TargetOpcode::G_FMAXNUM:
656   case TargetOpcode::G_FMAXIMUM:
657     return selectExtInst(ResVReg, ResType, I, CL::fmax, GL::NMax);
658 
659   case TargetOpcode::G_FCOPYSIGN:
660     return selectExtInst(ResVReg, ResType, I, CL::copysign);
661 
662   case TargetOpcode::G_FCEIL:
663     return selectExtInst(ResVReg, ResType, I, CL::ceil, GL::Ceil);
664   case TargetOpcode::G_FFLOOR:
665     return selectExtInst(ResVReg, ResType, I, CL::floor, GL::Floor);
666 
667   case TargetOpcode::G_FCOS:
668     return selectExtInst(ResVReg, ResType, I, CL::cos, GL::Cos);
669   case TargetOpcode::G_FSIN:
670     return selectExtInst(ResVReg, ResType, I, CL::sin, GL::Sin);
671   case TargetOpcode::G_FTAN:
672     return selectExtInst(ResVReg, ResType, I, CL::tan, GL::Tan);
673   case TargetOpcode::G_FACOS:
674     return selectExtInst(ResVReg, ResType, I, CL::acos, GL::Acos);
675   case TargetOpcode::G_FASIN:
676     return selectExtInst(ResVReg, ResType, I, CL::asin, GL::Asin);
677   case TargetOpcode::G_FATAN:
678     return selectExtInst(ResVReg, ResType, I, CL::atan, GL::Atan);
679   case TargetOpcode::G_FATAN2:
680     return selectExtInst(ResVReg, ResType, I, CL::atan2, GL::Atan2);
681   case TargetOpcode::G_FCOSH:
682     return selectExtInst(ResVReg, ResType, I, CL::cosh, GL::Cosh);
683   case TargetOpcode::G_FSINH:
684     return selectExtInst(ResVReg, ResType, I, CL::sinh, GL::Sinh);
685   case TargetOpcode::G_FTANH:
686     return selectExtInst(ResVReg, ResType, I, CL::tanh, GL::Tanh);
687 
688   case TargetOpcode::G_STRICT_FSQRT:
689   case TargetOpcode::G_FSQRT:
690     return selectExtInst(ResVReg, ResType, I, CL::sqrt, GL::Sqrt);
691 
692   case TargetOpcode::G_CTTZ:
693   case TargetOpcode::G_CTTZ_ZERO_UNDEF:
694     return selectExtInst(ResVReg, ResType, I, CL::ctz);
695   case TargetOpcode::G_CTLZ:
696   case TargetOpcode::G_CTLZ_ZERO_UNDEF:
697     return selectExtInst(ResVReg, ResType, I, CL::clz);
698 
699   case TargetOpcode::G_INTRINSIC_ROUND:
700     return selectExtInst(ResVReg, ResType, I, CL::round, GL::Round);
701   case TargetOpcode::G_INTRINSIC_ROUNDEVEN:
702     return selectExtInst(ResVReg, ResType, I, CL::rint, GL::RoundEven);
703   case TargetOpcode::G_INTRINSIC_TRUNC:
704     return selectExtInst(ResVReg, ResType, I, CL::trunc, GL::Trunc);
705   case TargetOpcode::G_FRINT:
706   case TargetOpcode::G_FNEARBYINT:
707     return selectExtInst(ResVReg, ResType, I, CL::rint, GL::RoundEven);
708 
709   case TargetOpcode::G_SMULH:
710     return selectExtInst(ResVReg, ResType, I, CL::s_mul_hi);
711   case TargetOpcode::G_UMULH:
712     return selectExtInst(ResVReg, ResType, I, CL::u_mul_hi);
713 
714   case TargetOpcode::G_SADDSAT:
715     return selectExtInst(ResVReg, ResType, I, CL::s_add_sat);
716   case TargetOpcode::G_UADDSAT:
717     return selectExtInst(ResVReg, ResType, I, CL::u_add_sat);
718   case TargetOpcode::G_SSUBSAT:
719     return selectExtInst(ResVReg, ResType, I, CL::s_sub_sat);
720   case TargetOpcode::G_USUBSAT:
721     return selectExtInst(ResVReg, ResType, I, CL::u_sub_sat);
722 
723   case TargetOpcode::G_UADDO:
724     return selectOverflowArith(ResVReg, ResType, I,
725                                ResType->getOpcode() == SPIRV::OpTypeVector
726                                    ? SPIRV::OpIAddCarryV
727                                    : SPIRV::OpIAddCarryS);
728   case TargetOpcode::G_USUBO:
729     return selectOverflowArith(ResVReg, ResType, I,
730                                ResType->getOpcode() == SPIRV::OpTypeVector
731                                    ? SPIRV::OpISubBorrowV
732                                    : SPIRV::OpISubBorrowS);
733   case TargetOpcode::G_UMULO:
734     return selectOverflowArith(ResVReg, ResType, I, SPIRV::OpUMulExtended);
735   case TargetOpcode::G_SMULO:
736     return selectOverflowArith(ResVReg, ResType, I, SPIRV::OpSMulExtended);
737 
738   case TargetOpcode::G_SEXT:
739     return selectExt(ResVReg, ResType, I, true);
740   case TargetOpcode::G_ANYEXT:
741   case TargetOpcode::G_ZEXT:
742     return selectExt(ResVReg, ResType, I, false);
743   case TargetOpcode::G_TRUNC:
744     return selectTrunc(ResVReg, ResType, I);
745   case TargetOpcode::G_FPTRUNC:
746   case TargetOpcode::G_FPEXT:
747     return selectUnOp(ResVReg, ResType, I, SPIRV::OpFConvert);
748 
749   case TargetOpcode::G_PTRTOINT:
750     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertPtrToU);
751   case TargetOpcode::G_INTTOPTR:
752     return selectUnOp(ResVReg, ResType, I, SPIRV::OpConvertUToPtr);
753   case TargetOpcode::G_BITCAST:
754     return selectBitcast(ResVReg, ResType, I);
755   case TargetOpcode::G_ADDRSPACE_CAST:
756     return selectAddrSpaceCast(ResVReg, ResType, I);
757   case TargetOpcode::G_PTR_ADD: {
758     // Currently, we get G_PTR_ADD only applied to global variables.
759     assert(I.getOperand(1).isReg() && I.getOperand(2).isReg());
760     Register GV = I.getOperand(1).getReg();
761     MachineRegisterInfo::def_instr_iterator II = MRI->def_instr_begin(GV);
762     (void)II;
763     assert(((*II).getOpcode() == TargetOpcode::G_GLOBAL_VALUE ||
764             (*II).getOpcode() == TargetOpcode::COPY ||
765             (*II).getOpcode() == SPIRV::OpVariable) &&
766            isImm(I.getOperand(2), MRI));
767     // It may be the initialization of a global variable.
768     bool IsGVInit = false;
769     for (MachineRegisterInfo::use_instr_iterator
770              UseIt = MRI->use_instr_begin(I.getOperand(0).getReg()),
771              UseEnd = MRI->use_instr_end();
772          UseIt != UseEnd; UseIt = std::next(UseIt)) {
773       if ((*UseIt).getOpcode() == TargetOpcode::G_GLOBAL_VALUE ||
774           (*UseIt).getOpcode() == SPIRV::OpVariable) {
775         IsGVInit = true;
776         break;
777       }
778     }
779     MachineBasicBlock &BB = *I.getParent();
780     if (!IsGVInit) {
781       SPIRVType *GVType = GR.getSPIRVTypeForVReg(GV);
782       SPIRVType *GVPointeeType = GR.getPointeeType(GVType);
783       SPIRVType *ResPointeeType = GR.getPointeeType(ResType);
784       if (GVPointeeType && ResPointeeType && GVPointeeType != ResPointeeType) {
785         // Build a new virtual register that is associated with the required
786         // data type.
787         Register NewVReg = MRI->createGenericVirtualRegister(MRI->getType(GV));
788         MRI->setRegClass(NewVReg, MRI->getRegClass(GV));
789         //  Having a correctly typed base we are ready to build the actually
790         //  required GEP. It may not be a constant though, because all Operands
791         //  of OpSpecConstantOp is to originate from other const instructions,
792         //  and only the AccessChain named opcodes accept a global OpVariable
793         //  instruction. We can't use an AccessChain opcode because of the type
794         //  mismatch between result and base types.
795         if (!GR.isBitcastCompatible(ResType, GVType))
796           report_fatal_error(
797               "incompatible result and operand types in a bitcast");
798         Register ResTypeReg = GR.getSPIRVTypeID(ResType);
799         MachineInstrBuilder MIB =
800             BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpBitcast))
801                 .addDef(NewVReg)
802                 .addUse(ResTypeReg)
803                 .addUse(GV);
804         return MIB.constrainAllUses(TII, TRI, RBI) &&
805                BuildMI(BB, I, I.getDebugLoc(),
806                        TII.get(STI.isVulkanEnv()
807                                    ? SPIRV::OpInBoundsAccessChain
808                                    : SPIRV::OpInBoundsPtrAccessChain))
809                    .addDef(ResVReg)
810                    .addUse(ResTypeReg)
811                    .addUse(NewVReg)
812                    .addUse(I.getOperand(2).getReg())
813                    .constrainAllUses(TII, TRI, RBI);
814       } else {
815         return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
816             .addDef(ResVReg)
817             .addUse(GR.getSPIRVTypeID(ResType))
818             .addImm(
819                 static_cast<uint32_t>(SPIRV::Opcode::InBoundsPtrAccessChain))
820             .addUse(GV)
821             .addUse(I.getOperand(2).getReg())
822             .constrainAllUses(TII, TRI, RBI);
823       }
824     }
825     // It's possible to translate G_PTR_ADD to OpSpecConstantOp: either to
826     // initialize a global variable with a constant expression (e.g., the test
827     // case opencl/basic/progvar_prog_scope_init.ll), or for another use case
828     Register Idx = buildZerosVal(GR.getOrCreateSPIRVIntegerType(32, I, TII), I);
829     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
830                    .addDef(ResVReg)
831                    .addUse(GR.getSPIRVTypeID(ResType))
832                    .addImm(static_cast<uint32_t>(
833                        SPIRV::Opcode::InBoundsPtrAccessChain))
834                    .addUse(GV)
835                    .addUse(Idx)
836                    .addUse(I.getOperand(2).getReg());
837     return MIB.constrainAllUses(TII, TRI, RBI);
838   }
839 
840   case TargetOpcode::G_ATOMICRMW_OR:
841     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicOr);
842   case TargetOpcode::G_ATOMICRMW_ADD:
843     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicIAdd);
844   case TargetOpcode::G_ATOMICRMW_AND:
845     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicAnd);
846   case TargetOpcode::G_ATOMICRMW_MAX:
847     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicSMax);
848   case TargetOpcode::G_ATOMICRMW_MIN:
849     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicSMin);
850   case TargetOpcode::G_ATOMICRMW_SUB:
851     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicISub);
852   case TargetOpcode::G_ATOMICRMW_XOR:
853     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicXor);
854   case TargetOpcode::G_ATOMICRMW_UMAX:
855     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicUMax);
856   case TargetOpcode::G_ATOMICRMW_UMIN:
857     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicUMin);
858   case TargetOpcode::G_ATOMICRMW_XCHG:
859     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicExchange);
860   case TargetOpcode::G_ATOMIC_CMPXCHG:
861     return selectAtomicCmpXchg(ResVReg, ResType, I);
862 
863   case TargetOpcode::G_ATOMICRMW_FADD:
864     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFAddEXT);
865   case TargetOpcode::G_ATOMICRMW_FSUB:
866     // Translate G_ATOMICRMW_FSUB to OpAtomicFAddEXT with negative value operand
867     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFAddEXT,
868                            SPIRV::OpFNegate);
869   case TargetOpcode::G_ATOMICRMW_FMIN:
870     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFMinEXT);
871   case TargetOpcode::G_ATOMICRMW_FMAX:
872     return selectAtomicRMW(ResVReg, ResType, I, SPIRV::OpAtomicFMaxEXT);
873 
874   case TargetOpcode::G_FENCE:
875     return selectFence(I);
876 
877   case TargetOpcode::G_STACKSAVE:
878     return selectStackSave(ResVReg, ResType, I);
879   case TargetOpcode::G_STACKRESTORE:
880     return selectStackRestore(I);
881 
882   case TargetOpcode::G_UNMERGE_VALUES:
883     return selectUnmergeValues(I);
884 
885   // Discard gen opcodes for intrinsics which we do not expect to actually
886   // represent code after lowering or intrinsics which are not implemented but
887   // should not crash when found in a customer's LLVM IR input.
888   case TargetOpcode::G_TRAP:
889   case TargetOpcode::G_DEBUGTRAP:
890   case TargetOpcode::G_UBSANTRAP:
891   case TargetOpcode::DBG_LABEL:
892     return true;
893 
894   default:
895     return false;
896   }
897 }
898 
899 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
900                                              const SPIRVType *ResType,
901                                              MachineInstr &I,
902                                              GL::GLSLExtInst GLInst) const {
903   if (!STI.canUseExtInstSet(
904           SPIRV::InstructionSet::InstructionSet::GLSL_std_450)) {
905     std::string DiagMsg;
906     raw_string_ostream OS(DiagMsg);
907     I.print(OS, true, false, false, false);
908     DiagMsg += " is only supported with the GLSL extended instruction set.\n";
909     report_fatal_error(DiagMsg.c_str(), false);
910   }
911   return selectExtInst(ResVReg, ResType, I,
912                        {{SPIRV::InstructionSet::GLSL_std_450, GLInst}});
913 }
914 
915 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
916                                              const SPIRVType *ResType,
917                                              MachineInstr &I,
918                                              CL::OpenCLExtInst CLInst) const {
919   return selectExtInst(ResVReg, ResType, I,
920                        {{SPIRV::InstructionSet::OpenCL_std, CLInst}});
921 }
922 
923 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
924                                              const SPIRVType *ResType,
925                                              MachineInstr &I,
926                                              CL::OpenCLExtInst CLInst,
927                                              GL::GLSLExtInst GLInst) const {
928   ExtInstList ExtInsts = {{SPIRV::InstructionSet::OpenCL_std, CLInst},
929                           {SPIRV::InstructionSet::GLSL_std_450, GLInst}};
930   return selectExtInst(ResVReg, ResType, I, ExtInsts);
931 }
932 
933 bool SPIRVInstructionSelector::selectExtInst(Register ResVReg,
934                                              const SPIRVType *ResType,
935                                              MachineInstr &I,
936                                              const ExtInstList &Insts) const {
937 
938   for (const auto &Ex : Insts) {
939     SPIRV::InstructionSet::InstructionSet Set = Ex.first;
940     uint32_t Opcode = Ex.second;
941     if (STI.canUseExtInstSet(Set)) {
942       MachineBasicBlock &BB = *I.getParent();
943       auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
944                      .addDef(ResVReg)
945                      .addUse(GR.getSPIRVTypeID(ResType))
946                      .addImm(static_cast<uint32_t>(Set))
947                      .addImm(Opcode);
948       const unsigned NumOps = I.getNumOperands();
949       unsigned Index = 1;
950       if (Index < NumOps &&
951           I.getOperand(Index).getType() ==
952               MachineOperand::MachineOperandType::MO_IntrinsicID)
953         Index = 2;
954       for (; Index < NumOps; ++Index)
955         MIB.add(I.getOperand(Index));
956       return MIB.constrainAllUses(TII, TRI, RBI);
957     }
958   }
959   return false;
960 }
961 
962 bool SPIRVInstructionSelector::selectOpWithSrcs(Register ResVReg,
963                                                 const SPIRVType *ResType,
964                                                 MachineInstr &I,
965                                                 std::vector<Register> Srcs,
966                                                 unsigned Opcode) const {
967   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
968                  .addDef(ResVReg)
969                  .addUse(GR.getSPIRVTypeID(ResType));
970   for (Register SReg : Srcs) {
971     MIB.addUse(SReg);
972   }
973   return MIB.constrainAllUses(TII, TRI, RBI);
974 }
975 
976 bool SPIRVInstructionSelector::selectUnOp(Register ResVReg,
977                                           const SPIRVType *ResType,
978                                           MachineInstr &I,
979                                           unsigned Opcode) const {
980   if (STI.isOpenCLEnv() && I.getOperand(1).isReg()) {
981     Register SrcReg = I.getOperand(1).getReg();
982     bool IsGV = false;
983     for (MachineRegisterInfo::def_instr_iterator DefIt =
984              MRI->def_instr_begin(SrcReg);
985          DefIt != MRI->def_instr_end(); DefIt = std::next(DefIt)) {
986       if ((*DefIt).getOpcode() == TargetOpcode::G_GLOBAL_VALUE) {
987         IsGV = true;
988         break;
989       }
990     }
991     if (IsGV) {
992       uint32_t SpecOpcode = 0;
993       switch (Opcode) {
994       case SPIRV::OpConvertPtrToU:
995         SpecOpcode = static_cast<uint32_t>(SPIRV::Opcode::ConvertPtrToU);
996         break;
997       case SPIRV::OpConvertUToPtr:
998         SpecOpcode = static_cast<uint32_t>(SPIRV::Opcode::ConvertUToPtr);
999         break;
1000       }
1001       if (SpecOpcode)
1002         return BuildMI(*I.getParent(), I, I.getDebugLoc(),
1003                        TII.get(SPIRV::OpSpecConstantOp))
1004             .addDef(ResVReg)
1005             .addUse(GR.getSPIRVTypeID(ResType))
1006             .addImm(SpecOpcode)
1007             .addUse(SrcReg)
1008             .constrainAllUses(TII, TRI, RBI);
1009     }
1010   }
1011   return selectOpWithSrcs(ResVReg, ResType, I, {I.getOperand(1).getReg()},
1012                           Opcode);
1013 }
1014 
1015 bool SPIRVInstructionSelector::selectBitcast(Register ResVReg,
1016                                              const SPIRVType *ResType,
1017                                              MachineInstr &I) const {
1018   Register OpReg = I.getOperand(1).getReg();
1019   SPIRVType *OpType = OpReg.isValid() ? GR.getSPIRVTypeForVReg(OpReg) : nullptr;
1020   if (!GR.isBitcastCompatible(ResType, OpType))
1021     report_fatal_error("incompatible result and operand types in a bitcast");
1022   return selectUnOp(ResVReg, ResType, I, SPIRV::OpBitcast);
1023 }
1024 
1025 static void addMemoryOperands(MachineMemOperand *MemOp,
1026                               MachineInstrBuilder &MIB) {
1027   uint32_t SpvMemOp = static_cast<uint32_t>(SPIRV::MemoryOperand::None);
1028   if (MemOp->isVolatile())
1029     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Volatile);
1030   if (MemOp->isNonTemporal())
1031     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Nontemporal);
1032   if (MemOp->getAlign().value())
1033     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Aligned);
1034 
1035   if (SpvMemOp != static_cast<uint32_t>(SPIRV::MemoryOperand::None)) {
1036     MIB.addImm(SpvMemOp);
1037     if (SpvMemOp & static_cast<uint32_t>(SPIRV::MemoryOperand::Aligned))
1038       MIB.addImm(MemOp->getAlign().value());
1039   }
1040 }
1041 
1042 static void addMemoryOperands(uint64_t Flags, MachineInstrBuilder &MIB) {
1043   uint32_t SpvMemOp = static_cast<uint32_t>(SPIRV::MemoryOperand::None);
1044   if (Flags & MachineMemOperand::Flags::MOVolatile)
1045     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Volatile);
1046   if (Flags & MachineMemOperand::Flags::MONonTemporal)
1047     SpvMemOp |= static_cast<uint32_t>(SPIRV::MemoryOperand::Nontemporal);
1048 
1049   if (SpvMemOp != static_cast<uint32_t>(SPIRV::MemoryOperand::None))
1050     MIB.addImm(SpvMemOp);
1051 }
1052 
1053 bool SPIRVInstructionSelector::selectLoad(Register ResVReg,
1054                                           const SPIRVType *ResType,
1055                                           MachineInstr &I) const {
1056   unsigned OpOffset = isa<GIntrinsic>(I) ? 1 : 0;
1057   Register Ptr = I.getOperand(1 + OpOffset).getReg();
1058 
1059   auto *PtrDef = getVRegDef(*MRI, Ptr);
1060   auto *IntPtrDef = dyn_cast<GIntrinsic>(PtrDef);
1061   if (IntPtrDef &&
1062       IntPtrDef->getIntrinsicID() == Intrinsic::spv_resource_getpointer) {
1063     Register ImageReg = IntPtrDef->getOperand(2).getReg();
1064     Register NewImageReg =
1065         MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
1066     auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
1067     if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
1068                                   *ImageDef, I)) {
1069       return false;
1070     }
1071 
1072     Register IdxReg = IntPtrDef->getOperand(3).getReg();
1073     return generateImageRead(ResVReg, ResType, NewImageReg, IdxReg,
1074                              I.getDebugLoc(), I);
1075   }
1076 
1077   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpLoad))
1078                  .addDef(ResVReg)
1079                  .addUse(GR.getSPIRVTypeID(ResType))
1080                  .addUse(Ptr);
1081   if (!I.getNumMemOperands()) {
1082     assert(I.getOpcode() == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS ||
1083            I.getOpcode() ==
1084                TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS);
1085     addMemoryOperands(I.getOperand(2 + OpOffset).getImm(), MIB);
1086   } else {
1087     addMemoryOperands(*I.memoperands_begin(), MIB);
1088   }
1089   return MIB.constrainAllUses(TII, TRI, RBI);
1090 }
1091 
1092 bool SPIRVInstructionSelector::selectStore(MachineInstr &I) const {
1093   unsigned OpOffset = isa<GIntrinsic>(I) ? 1 : 0;
1094   Register StoreVal = I.getOperand(0 + OpOffset).getReg();
1095   Register Ptr = I.getOperand(1 + OpOffset).getReg();
1096 
1097   auto *PtrDef = getVRegDef(*MRI, Ptr);
1098   auto *IntPtrDef = dyn_cast<GIntrinsic>(PtrDef);
1099   if (IntPtrDef &&
1100       IntPtrDef->getIntrinsicID() == Intrinsic::spv_resource_getpointer) {
1101     Register ImageReg = IntPtrDef->getOperand(2).getReg();
1102     Register NewImageReg =
1103         MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
1104     auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
1105     if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
1106                                   *ImageDef, I)) {
1107       return false;
1108     }
1109 
1110     Register IdxReg = IntPtrDef->getOperand(3).getReg();
1111     return BuildMI(*I.getParent(), I, I.getDebugLoc(),
1112                    TII.get(SPIRV::OpImageWrite))
1113         .addUse(NewImageReg)
1114         .addUse(IdxReg)
1115         .addUse(StoreVal)
1116         .constrainAllUses(TII, TRI, RBI);
1117   }
1118 
1119   MachineBasicBlock &BB = *I.getParent();
1120   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpStore))
1121                  .addUse(Ptr)
1122                  .addUse(StoreVal);
1123   if (!I.getNumMemOperands()) {
1124     assert(I.getOpcode() == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS ||
1125            I.getOpcode() ==
1126                TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS);
1127     addMemoryOperands(I.getOperand(2 + OpOffset).getImm(), MIB);
1128   } else {
1129     addMemoryOperands(*I.memoperands_begin(), MIB);
1130   }
1131   return MIB.constrainAllUses(TII, TRI, RBI);
1132 }
1133 
1134 bool SPIRVInstructionSelector::selectStackSave(Register ResVReg,
1135                                                const SPIRVType *ResType,
1136                                                MachineInstr &I) const {
1137   if (!STI.canUseExtension(SPIRV::Extension::SPV_INTEL_variable_length_array))
1138     report_fatal_error(
1139         "llvm.stacksave intrinsic: this instruction requires the following "
1140         "SPIR-V extension: SPV_INTEL_variable_length_array",
1141         false);
1142   MachineBasicBlock &BB = *I.getParent();
1143   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSaveMemoryINTEL))
1144       .addDef(ResVReg)
1145       .addUse(GR.getSPIRVTypeID(ResType))
1146       .constrainAllUses(TII, TRI, RBI);
1147 }
1148 
1149 bool SPIRVInstructionSelector::selectStackRestore(MachineInstr &I) const {
1150   if (!STI.canUseExtension(SPIRV::Extension::SPV_INTEL_variable_length_array))
1151     report_fatal_error(
1152         "llvm.stackrestore intrinsic: this instruction requires the following "
1153         "SPIR-V extension: SPV_INTEL_variable_length_array",
1154         false);
1155   if (!I.getOperand(0).isReg())
1156     return false;
1157   MachineBasicBlock &BB = *I.getParent();
1158   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpRestoreMemoryINTEL))
1159       .addUse(I.getOperand(0).getReg())
1160       .constrainAllUses(TII, TRI, RBI);
1161 }
1162 
1163 bool SPIRVInstructionSelector::selectMemOperation(Register ResVReg,
1164                                                   MachineInstr &I) const {
1165   MachineBasicBlock &BB = *I.getParent();
1166   Register SrcReg = I.getOperand(1).getReg();
1167   bool Result = true;
1168   if (I.getOpcode() == TargetOpcode::G_MEMSET) {
1169     assert(I.getOperand(1).isReg() && I.getOperand(2).isReg());
1170     unsigned Val = getIConstVal(I.getOperand(1).getReg(), MRI);
1171     unsigned Num = getIConstVal(I.getOperand(2).getReg(), MRI);
1172     SPIRVType *ValTy = GR.getOrCreateSPIRVIntegerType(8, I, TII);
1173     SPIRVType *ArrTy = GR.getOrCreateSPIRVArrayType(ValTy, Num, I, TII);
1174     Register Const = GR.getOrCreateConstIntArray(Val, Num, I, ArrTy, TII);
1175     SPIRVType *VarTy = GR.getOrCreateSPIRVPointerType(
1176         ArrTy, I, TII, SPIRV::StorageClass::UniformConstant);
1177     // TODO: check if we have such GV, add init, use buildGlobalVariable.
1178     Function &CurFunction = GR.CurMF->getFunction();
1179     Type *LLVMArrTy =
1180         ArrayType::get(IntegerType::get(CurFunction.getContext(), 8), Num);
1181     // Module takes ownership of the global var.
1182     GlobalVariable *GV = new GlobalVariable(*CurFunction.getParent(), LLVMArrTy,
1183                                             true, GlobalValue::InternalLinkage,
1184                                             Constant::getNullValue(LLVMArrTy));
1185     Register VarReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1186     GR.add(GV, GR.CurMF, VarReg);
1187     GR.addGlobalObject(GV, GR.CurMF, VarReg);
1188 
1189     Result &=
1190         BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpVariable))
1191             .addDef(VarReg)
1192             .addUse(GR.getSPIRVTypeID(VarTy))
1193             .addImm(SPIRV::StorageClass::UniformConstant)
1194             .addUse(Const)
1195             .constrainAllUses(TII, TRI, RBI);
1196     buildOpDecorate(VarReg, I, TII, SPIRV::Decoration::Constant, {});
1197     SPIRVType *SourceTy = GR.getOrCreateSPIRVPointerType(
1198         ValTy, I, TII, SPIRV::StorageClass::UniformConstant);
1199     SrcReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1200     selectOpWithSrcs(SrcReg, SourceTy, I, {VarReg}, SPIRV::OpBitcast);
1201   }
1202   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCopyMemorySized))
1203                  .addUse(I.getOperand(0).getReg())
1204                  .addUse(SrcReg)
1205                  .addUse(I.getOperand(2).getReg());
1206   if (I.getNumMemOperands())
1207     addMemoryOperands(*I.memoperands_begin(), MIB);
1208   Result &= MIB.constrainAllUses(TII, TRI, RBI);
1209   if (ResVReg.isValid() && ResVReg != MIB->getOperand(0).getReg())
1210     Result &= BuildCOPY(ResVReg, MIB->getOperand(0).getReg(), I);
1211   return Result;
1212 }
1213 
1214 bool SPIRVInstructionSelector::selectAtomicRMW(Register ResVReg,
1215                                                const SPIRVType *ResType,
1216                                                MachineInstr &I,
1217                                                unsigned NewOpcode,
1218                                                unsigned NegateOpcode) const {
1219   bool Result = true;
1220   assert(I.hasOneMemOperand());
1221   const MachineMemOperand *MemOp = *I.memoperands_begin();
1222   uint32_t Scope = static_cast<uint32_t>(getMemScope(
1223       GR.CurMF->getFunction().getContext(), MemOp->getSyncScopeID()));
1224   auto ScopeConstant = buildI32Constant(Scope, I);
1225   Register ScopeReg = ScopeConstant.first;
1226   Result &= ScopeConstant.second;
1227 
1228   Register Ptr = I.getOperand(1).getReg();
1229   // TODO: Changed as it's implemented in the translator. See test/atomicrmw.ll
1230   // auto ScSem =
1231   // getMemSemanticsForStorageClass(GR.getPointerStorageClass(Ptr));
1232   AtomicOrdering AO = MemOp->getSuccessOrdering();
1233   uint32_t MemSem = static_cast<uint32_t>(getMemSemantics(AO));
1234   auto MemSemConstant = buildI32Constant(MemSem /*| ScSem*/, I);
1235   Register MemSemReg = MemSemConstant.first;
1236   Result &= MemSemConstant.second;
1237 
1238   Register ValueReg = I.getOperand(2).getReg();
1239   if (NegateOpcode != 0) {
1240     // Translation with negative value operand is requested
1241     Register TmpReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1242     Result &= selectOpWithSrcs(TmpReg, ResType, I, {ValueReg}, NegateOpcode);
1243     ValueReg = TmpReg;
1244   }
1245 
1246   return Result &&
1247          BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(NewOpcode))
1248              .addDef(ResVReg)
1249              .addUse(GR.getSPIRVTypeID(ResType))
1250              .addUse(Ptr)
1251              .addUse(ScopeReg)
1252              .addUse(MemSemReg)
1253              .addUse(ValueReg)
1254              .constrainAllUses(TII, TRI, RBI);
1255 }
1256 
1257 bool SPIRVInstructionSelector::selectUnmergeValues(MachineInstr &I) const {
1258   unsigned ArgI = I.getNumOperands() - 1;
1259   Register SrcReg =
1260       I.getOperand(ArgI).isReg() ? I.getOperand(ArgI).getReg() : Register(0);
1261   SPIRVType *DefType =
1262       SrcReg.isValid() ? GR.getSPIRVTypeForVReg(SrcReg) : nullptr;
1263   if (!DefType || DefType->getOpcode() != SPIRV::OpTypeVector)
1264     report_fatal_error(
1265         "cannot select G_UNMERGE_VALUES with a non-vector argument");
1266 
1267   SPIRVType *ScalarType =
1268       GR.getSPIRVTypeForVReg(DefType->getOperand(1).getReg());
1269   MachineBasicBlock &BB = *I.getParent();
1270   bool Res = false;
1271   for (unsigned i = 0; i < I.getNumDefs(); ++i) {
1272     Register ResVReg = I.getOperand(i).getReg();
1273     SPIRVType *ResType = GR.getSPIRVTypeForVReg(ResVReg);
1274     if (!ResType) {
1275       // There was no "assign type" actions, let's fix this now
1276       ResType = ScalarType;
1277       MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
1278       MRI->setType(ResVReg, LLT::scalar(GR.getScalarOrVectorBitWidth(ResType)));
1279       GR.assignSPIRVTypeToVReg(ResType, ResVReg, *GR.CurMF);
1280     }
1281     auto MIB =
1282         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1283             .addDef(ResVReg)
1284             .addUse(GR.getSPIRVTypeID(ResType))
1285             .addUse(SrcReg)
1286             .addImm(static_cast<int64_t>(i));
1287     Res |= MIB.constrainAllUses(TII, TRI, RBI);
1288   }
1289   return Res;
1290 }
1291 
1292 bool SPIRVInstructionSelector::selectFence(MachineInstr &I) const {
1293   AtomicOrdering AO = AtomicOrdering(I.getOperand(0).getImm());
1294   uint32_t MemSem = static_cast<uint32_t>(getMemSemantics(AO));
1295   auto MemSemConstant = buildI32Constant(MemSem, I);
1296   Register MemSemReg = MemSemConstant.first;
1297   bool Result = MemSemConstant.second;
1298   SyncScope::ID Ord = SyncScope::ID(I.getOperand(1).getImm());
1299   uint32_t Scope = static_cast<uint32_t>(
1300       getMemScope(GR.CurMF->getFunction().getContext(), Ord));
1301   auto ScopeConstant = buildI32Constant(Scope, I);
1302   Register ScopeReg = ScopeConstant.first;
1303   Result &= ScopeConstant.second;
1304   MachineBasicBlock &BB = *I.getParent();
1305   return Result &&
1306          BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpMemoryBarrier))
1307              .addUse(ScopeReg)
1308              .addUse(MemSemReg)
1309              .constrainAllUses(TII, TRI, RBI);
1310 }
1311 
1312 bool SPIRVInstructionSelector::selectOverflowArith(Register ResVReg,
1313                                                    const SPIRVType *ResType,
1314                                                    MachineInstr &I,
1315                                                    unsigned Opcode) const {
1316   Type *ResTy = nullptr;
1317   StringRef ResName;
1318   if (!GR.findValueAttrs(&I, ResTy, ResName))
1319     report_fatal_error(
1320         "Not enough info to select the arithmetic with overflow instruction");
1321   if (!ResTy || !ResTy->isStructTy())
1322     report_fatal_error("Expect struct type result for the arithmetic "
1323                        "with overflow instruction");
1324   // "Result Type must be from OpTypeStruct. The struct must have two members,
1325   // and the two members must be the same type."
1326   Type *ResElemTy = cast<StructType>(ResTy)->getElementType(0);
1327   ResTy = StructType::get(ResElemTy, ResElemTy);
1328   // Build SPIR-V types and constant(s) if needed.
1329   MachineIRBuilder MIRBuilder(I);
1330   SPIRVType *StructType = GR.getOrCreateSPIRVType(
1331       ResTy, MIRBuilder, SPIRV::AccessQualifier::ReadWrite, false);
1332   assert(I.getNumDefs() > 1 && "Not enought operands");
1333   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
1334   unsigned N = GR.getScalarOrVectorComponentCount(ResType);
1335   if (N > 1)
1336     BoolType = GR.getOrCreateSPIRVVectorType(BoolType, N, I, TII);
1337   Register BoolTypeReg = GR.getSPIRVTypeID(BoolType);
1338   Register ZeroReg = buildZerosVal(ResType, I);
1339   // A new virtual register to store the result struct.
1340   Register StructVReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1341   MRI->setRegClass(StructVReg, &SPIRV::IDRegClass);
1342   // Build the result name if needed.
1343   if (ResName.size() > 0)
1344     buildOpName(StructVReg, ResName, MIRBuilder);
1345   // Build the arithmetic with overflow instruction.
1346   MachineBasicBlock &BB = *I.getParent();
1347   auto MIB =
1348       BuildMI(BB, MIRBuilder.getInsertPt(), I.getDebugLoc(), TII.get(Opcode))
1349           .addDef(StructVReg)
1350           .addUse(GR.getSPIRVTypeID(StructType));
1351   for (unsigned i = I.getNumDefs(); i < I.getNumOperands(); ++i)
1352     MIB.addUse(I.getOperand(i).getReg());
1353   bool Result = MIB.constrainAllUses(TII, TRI, RBI);
1354   // Build instructions to extract fields of the instruction's result.
1355   // A new virtual register to store the higher part of the result struct.
1356   Register HigherVReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
1357   MRI->setRegClass(HigherVReg, &SPIRV::iIDRegClass);
1358   for (unsigned i = 0; i < I.getNumDefs(); ++i) {
1359     auto MIB =
1360         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1361             .addDef(i == 1 ? HigherVReg : I.getOperand(i).getReg())
1362             .addUse(GR.getSPIRVTypeID(ResType))
1363             .addUse(StructVReg)
1364             .addImm(i);
1365     Result &= MIB.constrainAllUses(TII, TRI, RBI);
1366   }
1367   // Build boolean value from the higher part.
1368   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpINotEqual))
1369                        .addDef(I.getOperand(1).getReg())
1370                        .addUse(BoolTypeReg)
1371                        .addUse(HigherVReg)
1372                        .addUse(ZeroReg)
1373                        .constrainAllUses(TII, TRI, RBI);
1374 }
1375 
1376 bool SPIRVInstructionSelector::selectAtomicCmpXchg(Register ResVReg,
1377                                                    const SPIRVType *ResType,
1378                                                    MachineInstr &I) const {
1379   bool Result = true;
1380   Register ScopeReg;
1381   Register MemSemEqReg;
1382   Register MemSemNeqReg;
1383   Register Ptr = I.getOperand(2).getReg();
1384   if (!isa<GIntrinsic>(I)) {
1385     assert(I.hasOneMemOperand());
1386     const MachineMemOperand *MemOp = *I.memoperands_begin();
1387     unsigned Scope = static_cast<uint32_t>(getMemScope(
1388         GR.CurMF->getFunction().getContext(), MemOp->getSyncScopeID()));
1389     auto ScopeConstant = buildI32Constant(Scope, I);
1390     ScopeReg = ScopeConstant.first;
1391     Result &= ScopeConstant.second;
1392 
1393     unsigned ScSem = static_cast<uint32_t>(
1394         getMemSemanticsForStorageClass(GR.getPointerStorageClass(Ptr)));
1395     AtomicOrdering AO = MemOp->getSuccessOrdering();
1396     unsigned MemSemEq = static_cast<uint32_t>(getMemSemantics(AO)) | ScSem;
1397     auto MemSemEqConstant = buildI32Constant(MemSemEq, I);
1398     MemSemEqReg = MemSemEqConstant.first;
1399     Result &= MemSemEqConstant.second;
1400     AtomicOrdering FO = MemOp->getFailureOrdering();
1401     unsigned MemSemNeq = static_cast<uint32_t>(getMemSemantics(FO)) | ScSem;
1402     if (MemSemEq == MemSemNeq)
1403       MemSemNeqReg = MemSemEqReg;
1404     else {
1405       auto MemSemNeqConstant = buildI32Constant(MemSemEq, I);
1406       MemSemNeqReg = MemSemNeqConstant.first;
1407       Result &= MemSemNeqConstant.second;
1408     }
1409   } else {
1410     ScopeReg = I.getOperand(5).getReg();
1411     MemSemEqReg = I.getOperand(6).getReg();
1412     MemSemNeqReg = I.getOperand(7).getReg();
1413   }
1414 
1415   Register Cmp = I.getOperand(3).getReg();
1416   Register Val = I.getOperand(4).getReg();
1417   SPIRVType *SpvValTy = GR.getSPIRVTypeForVReg(Val);
1418   Register ACmpRes = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1419   const DebugLoc &DL = I.getDebugLoc();
1420   Result &=
1421       BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpAtomicCompareExchange))
1422           .addDef(ACmpRes)
1423           .addUse(GR.getSPIRVTypeID(SpvValTy))
1424           .addUse(Ptr)
1425           .addUse(ScopeReg)
1426           .addUse(MemSemEqReg)
1427           .addUse(MemSemNeqReg)
1428           .addUse(Val)
1429           .addUse(Cmp)
1430           .constrainAllUses(TII, TRI, RBI);
1431   Register CmpSuccReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1432   SPIRVType *BoolTy = GR.getOrCreateSPIRVBoolType(I, TII);
1433   Result &= BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpIEqual))
1434                 .addDef(CmpSuccReg)
1435                 .addUse(GR.getSPIRVTypeID(BoolTy))
1436                 .addUse(ACmpRes)
1437                 .addUse(Cmp)
1438                 .constrainAllUses(TII, TRI, RBI);
1439   Register TmpReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1440   Result &= BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpCompositeInsert))
1441                 .addDef(TmpReg)
1442                 .addUse(GR.getSPIRVTypeID(ResType))
1443                 .addUse(ACmpRes)
1444                 .addUse(GR.getOrCreateUndef(I, ResType, TII))
1445                 .addImm(0)
1446                 .constrainAllUses(TII, TRI, RBI);
1447   return Result &&
1448          BuildMI(*I.getParent(), I, DL, TII.get(SPIRV::OpCompositeInsert))
1449              .addDef(ResVReg)
1450              .addUse(GR.getSPIRVTypeID(ResType))
1451              .addUse(CmpSuccReg)
1452              .addUse(TmpReg)
1453              .addImm(1)
1454              .constrainAllUses(TII, TRI, RBI);
1455 }
1456 
1457 static bool isGenericCastablePtr(SPIRV::StorageClass::StorageClass SC) {
1458   switch (SC) {
1459   case SPIRV::StorageClass::Workgroup:
1460   case SPIRV::StorageClass::CrossWorkgroup:
1461   case SPIRV::StorageClass::Function:
1462     return true;
1463   default:
1464     return false;
1465   }
1466 }
1467 
1468 static bool isUSMStorageClass(SPIRV::StorageClass::StorageClass SC) {
1469   switch (SC) {
1470   case SPIRV::StorageClass::DeviceOnlyINTEL:
1471   case SPIRV::StorageClass::HostOnlyINTEL:
1472     return true;
1473   default:
1474     return false;
1475   }
1476 }
1477 
1478 // Returns true ResVReg is referred only from global vars and OpName's.
1479 static bool isASCastInGVar(MachineRegisterInfo *MRI, Register ResVReg) {
1480   bool IsGRef = false;
1481   bool IsAllowedRefs =
1482       std::all_of(MRI->use_instr_begin(ResVReg), MRI->use_instr_end(),
1483                   [&IsGRef](auto const &It) {
1484                     unsigned Opcode = It.getOpcode();
1485                     if (Opcode == SPIRV::OpConstantComposite ||
1486                         Opcode == SPIRV::OpVariable ||
1487                         isSpvIntrinsic(It, Intrinsic::spv_init_global))
1488                       return IsGRef = true;
1489                     return Opcode == SPIRV::OpName;
1490                   });
1491   return IsAllowedRefs && IsGRef;
1492 }
1493 
1494 Register SPIRVInstructionSelector::getUcharPtrTypeReg(
1495     MachineInstr &I, SPIRV::StorageClass::StorageClass SC) const {
1496   return GR.getSPIRVTypeID(GR.getOrCreateSPIRVPointerType(
1497       GR.getOrCreateSPIRVIntegerType(8, I, TII), I, TII, SC));
1498 }
1499 
1500 MachineInstrBuilder
1501 SPIRVInstructionSelector::buildSpecConstantOp(MachineInstr &I, Register Dest,
1502                                               Register Src, Register DestType,
1503                                               uint32_t Opcode) const {
1504   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
1505                  TII.get(SPIRV::OpSpecConstantOp))
1506       .addDef(Dest)
1507       .addUse(DestType)
1508       .addImm(Opcode)
1509       .addUse(Src);
1510 }
1511 
1512 MachineInstrBuilder
1513 SPIRVInstructionSelector::buildConstGenericPtr(MachineInstr &I, Register SrcPtr,
1514                                                SPIRVType *SrcPtrTy) const {
1515   SPIRVType *GenericPtrTy = GR.getOrCreateSPIRVPointerType(
1516       GR.getPointeeType(SrcPtrTy), I, TII, SPIRV::StorageClass::Generic);
1517   Register Tmp = MRI->createVirtualRegister(&SPIRV::pIDRegClass);
1518   MRI->setType(Tmp, LLT::pointer(storageClassToAddressSpace(
1519                                      SPIRV::StorageClass::Generic),
1520                                  GR.getPointerSize()));
1521   MachineFunction *MF = I.getParent()->getParent();
1522   GR.assignSPIRVTypeToVReg(GenericPtrTy, Tmp, *MF);
1523   MachineInstrBuilder MIB = buildSpecConstantOp(
1524       I, Tmp, SrcPtr, GR.getSPIRVTypeID(GenericPtrTy),
1525       static_cast<uint32_t>(SPIRV::Opcode::PtrCastToGeneric));
1526   GR.add(MIB.getInstr(), MF, Tmp);
1527   return MIB;
1528 }
1529 
1530 // In SPIR-V address space casting can only happen to and from the Generic
1531 // storage class. We can also only cast Workgroup, CrossWorkgroup, or Function
1532 // pointers to and from Generic pointers. As such, we can convert e.g. from
1533 // Workgroup to Function by going via a Generic pointer as an intermediary. All
1534 // other combinations can only be done by a bitcast, and are probably not safe.
1535 bool SPIRVInstructionSelector::selectAddrSpaceCast(Register ResVReg,
1536                                                    const SPIRVType *ResType,
1537                                                    MachineInstr &I) const {
1538   MachineBasicBlock &BB = *I.getParent();
1539   const DebugLoc &DL = I.getDebugLoc();
1540 
1541   Register SrcPtr = I.getOperand(1).getReg();
1542   SPIRVType *SrcPtrTy = GR.getSPIRVTypeForVReg(SrcPtr);
1543 
1544   // don't generate a cast for a null that may be represented by OpTypeInt
1545   if (SrcPtrTy->getOpcode() != SPIRV::OpTypePointer ||
1546       ResType->getOpcode() != SPIRV::OpTypePointer)
1547     return BuildCOPY(ResVReg, SrcPtr, I);
1548 
1549   SPIRV::StorageClass::StorageClass SrcSC = GR.getPointerStorageClass(SrcPtrTy);
1550   SPIRV::StorageClass::StorageClass DstSC = GR.getPointerStorageClass(ResType);
1551 
1552   if (isASCastInGVar(MRI, ResVReg)) {
1553     // AddrSpaceCast uses within OpVariable and OpConstantComposite instructions
1554     // are expressed by OpSpecConstantOp with an Opcode.
1555     // TODO: maybe insert a check whether the Kernel capability was declared and
1556     // so PtrCastToGeneric/GenericCastToPtr are available.
1557     unsigned SpecOpcode =
1558         DstSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(SrcSC)
1559             ? static_cast<uint32_t>(SPIRV::Opcode::PtrCastToGeneric)
1560             : (SrcSC == SPIRV::StorageClass::Generic &&
1561                        isGenericCastablePtr(DstSC)
1562                    ? static_cast<uint32_t>(SPIRV::Opcode::GenericCastToPtr)
1563                    : 0);
1564     // TODO: OpConstantComposite expects i8*, so we are forced to forget a
1565     // correct value of ResType and use general i8* instead. Maybe this should
1566     // be addressed in the emit-intrinsic step to infer a correct
1567     // OpConstantComposite type.
1568     if (SpecOpcode) {
1569       return buildSpecConstantOp(I, ResVReg, SrcPtr,
1570                                  getUcharPtrTypeReg(I, DstSC), SpecOpcode)
1571           .constrainAllUses(TII, TRI, RBI);
1572     } else if (isGenericCastablePtr(SrcSC) && isGenericCastablePtr(DstSC)) {
1573       MachineInstrBuilder MIB = buildConstGenericPtr(I, SrcPtr, SrcPtrTy);
1574       return MIB.constrainAllUses(TII, TRI, RBI) &&
1575              buildSpecConstantOp(
1576                  I, ResVReg, MIB->getOperand(0).getReg(),
1577                  getUcharPtrTypeReg(I, DstSC),
1578                  static_cast<uint32_t>(SPIRV::Opcode::GenericCastToPtr))
1579                  .constrainAllUses(TII, TRI, RBI);
1580     }
1581   }
1582 
1583   // don't generate a cast between identical storage classes
1584   if (SrcSC == DstSC)
1585     return BuildCOPY(ResVReg, SrcPtr, I);
1586 
1587   if ((SrcSC == SPIRV::StorageClass::Function &&
1588        DstSC == SPIRV::StorageClass::Private) ||
1589       (DstSC == SPIRV::StorageClass::Function &&
1590        SrcSC == SPIRV::StorageClass::Private))
1591     return BuildCOPY(ResVReg, SrcPtr, I);
1592 
1593   // Casting from an eligible pointer to Generic.
1594   if (DstSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(SrcSC))
1595     return selectUnOp(ResVReg, ResType, I, SPIRV::OpPtrCastToGeneric);
1596   // Casting from Generic to an eligible pointer.
1597   if (SrcSC == SPIRV::StorageClass::Generic && isGenericCastablePtr(DstSC))
1598     return selectUnOp(ResVReg, ResType, I, SPIRV::OpGenericCastToPtr);
1599   // Casting between 2 eligible pointers using Generic as an intermediary.
1600   if (isGenericCastablePtr(SrcSC) && isGenericCastablePtr(DstSC)) {
1601     Register Tmp = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1602     SPIRVType *GenericPtrTy = GR.getOrCreateSPIRVPointerType(
1603         GR.getPointeeType(SrcPtrTy), I, TII, SPIRV::StorageClass::Generic);
1604     bool Result = BuildMI(BB, I, DL, TII.get(SPIRV::OpPtrCastToGeneric))
1605                       .addDef(Tmp)
1606                       .addUse(GR.getSPIRVTypeID(GenericPtrTy))
1607                       .addUse(SrcPtr)
1608                       .constrainAllUses(TII, TRI, RBI);
1609     return Result && BuildMI(BB, I, DL, TII.get(SPIRV::OpGenericCastToPtr))
1610                          .addDef(ResVReg)
1611                          .addUse(GR.getSPIRVTypeID(ResType))
1612                          .addUse(Tmp)
1613                          .constrainAllUses(TII, TRI, RBI);
1614   }
1615 
1616   // Check if instructions from the SPV_INTEL_usm_storage_classes extension may
1617   // be applied
1618   if (isUSMStorageClass(SrcSC) && DstSC == SPIRV::StorageClass::CrossWorkgroup)
1619     return selectUnOp(ResVReg, ResType, I,
1620                       SPIRV::OpPtrCastToCrossWorkgroupINTEL);
1621   if (SrcSC == SPIRV::StorageClass::CrossWorkgroup && isUSMStorageClass(DstSC))
1622     return selectUnOp(ResVReg, ResType, I,
1623                       SPIRV::OpCrossWorkgroupCastToPtrINTEL);
1624   if (isUSMStorageClass(SrcSC) && DstSC == SPIRV::StorageClass::Generic)
1625     return selectUnOp(ResVReg, ResType, I, SPIRV::OpPtrCastToGeneric);
1626   if (SrcSC == SPIRV::StorageClass::Generic && isUSMStorageClass(DstSC))
1627     return selectUnOp(ResVReg, ResType, I, SPIRV::OpGenericCastToPtr);
1628 
1629   // Bitcast for pointers requires that the address spaces must match
1630   return false;
1631 }
1632 
1633 static unsigned getFCmpOpcode(unsigned PredNum) {
1634   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1635   switch (Pred) {
1636   case CmpInst::FCMP_OEQ:
1637     return SPIRV::OpFOrdEqual;
1638   case CmpInst::FCMP_OGE:
1639     return SPIRV::OpFOrdGreaterThanEqual;
1640   case CmpInst::FCMP_OGT:
1641     return SPIRV::OpFOrdGreaterThan;
1642   case CmpInst::FCMP_OLE:
1643     return SPIRV::OpFOrdLessThanEqual;
1644   case CmpInst::FCMP_OLT:
1645     return SPIRV::OpFOrdLessThan;
1646   case CmpInst::FCMP_ONE:
1647     return SPIRV::OpFOrdNotEqual;
1648   case CmpInst::FCMP_ORD:
1649     return SPIRV::OpOrdered;
1650   case CmpInst::FCMP_UEQ:
1651     return SPIRV::OpFUnordEqual;
1652   case CmpInst::FCMP_UGE:
1653     return SPIRV::OpFUnordGreaterThanEqual;
1654   case CmpInst::FCMP_UGT:
1655     return SPIRV::OpFUnordGreaterThan;
1656   case CmpInst::FCMP_ULE:
1657     return SPIRV::OpFUnordLessThanEqual;
1658   case CmpInst::FCMP_ULT:
1659     return SPIRV::OpFUnordLessThan;
1660   case CmpInst::FCMP_UNE:
1661     return SPIRV::OpFUnordNotEqual;
1662   case CmpInst::FCMP_UNO:
1663     return SPIRV::OpUnordered;
1664   default:
1665     llvm_unreachable("Unknown predicate type for FCmp");
1666   }
1667 }
1668 
1669 static unsigned getICmpOpcode(unsigned PredNum) {
1670   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1671   switch (Pred) {
1672   case CmpInst::ICMP_EQ:
1673     return SPIRV::OpIEqual;
1674   case CmpInst::ICMP_NE:
1675     return SPIRV::OpINotEqual;
1676   case CmpInst::ICMP_SGE:
1677     return SPIRV::OpSGreaterThanEqual;
1678   case CmpInst::ICMP_SGT:
1679     return SPIRV::OpSGreaterThan;
1680   case CmpInst::ICMP_SLE:
1681     return SPIRV::OpSLessThanEqual;
1682   case CmpInst::ICMP_SLT:
1683     return SPIRV::OpSLessThan;
1684   case CmpInst::ICMP_UGE:
1685     return SPIRV::OpUGreaterThanEqual;
1686   case CmpInst::ICMP_UGT:
1687     return SPIRV::OpUGreaterThan;
1688   case CmpInst::ICMP_ULE:
1689     return SPIRV::OpULessThanEqual;
1690   case CmpInst::ICMP_ULT:
1691     return SPIRV::OpULessThan;
1692   default:
1693     llvm_unreachable("Unknown predicate type for ICmp");
1694   }
1695 }
1696 
1697 static unsigned getPtrCmpOpcode(unsigned Pred) {
1698   switch (static_cast<CmpInst::Predicate>(Pred)) {
1699   case CmpInst::ICMP_EQ:
1700     return SPIRV::OpPtrEqual;
1701   case CmpInst::ICMP_NE:
1702     return SPIRV::OpPtrNotEqual;
1703   default:
1704     llvm_unreachable("Unknown predicate type for pointer comparison");
1705   }
1706 }
1707 
1708 // Return the logical operation, or abort if none exists.
1709 static unsigned getBoolCmpOpcode(unsigned PredNum) {
1710   auto Pred = static_cast<CmpInst::Predicate>(PredNum);
1711   switch (Pred) {
1712   case CmpInst::ICMP_EQ:
1713     return SPIRV::OpLogicalEqual;
1714   case CmpInst::ICMP_NE:
1715     return SPIRV::OpLogicalNotEqual;
1716   default:
1717     llvm_unreachable("Unknown predicate type for Bool comparison");
1718   }
1719 }
1720 
1721 static APFloat getZeroFP(const Type *LLVMFloatTy) {
1722   if (!LLVMFloatTy)
1723     return APFloat::getZero(APFloat::IEEEsingle());
1724   switch (LLVMFloatTy->getScalarType()->getTypeID()) {
1725   case Type::HalfTyID:
1726     return APFloat::getZero(APFloat::IEEEhalf());
1727   default:
1728   case Type::FloatTyID:
1729     return APFloat::getZero(APFloat::IEEEsingle());
1730   case Type::DoubleTyID:
1731     return APFloat::getZero(APFloat::IEEEdouble());
1732   }
1733 }
1734 
1735 static APFloat getOneFP(const Type *LLVMFloatTy) {
1736   if (!LLVMFloatTy)
1737     return APFloat::getOne(APFloat::IEEEsingle());
1738   switch (LLVMFloatTy->getScalarType()->getTypeID()) {
1739   case Type::HalfTyID:
1740     return APFloat::getOne(APFloat::IEEEhalf());
1741   default:
1742   case Type::FloatTyID:
1743     return APFloat::getOne(APFloat::IEEEsingle());
1744   case Type::DoubleTyID:
1745     return APFloat::getOne(APFloat::IEEEdouble());
1746   }
1747 }
1748 
1749 bool SPIRVInstructionSelector::selectAnyOrAll(Register ResVReg,
1750                                               const SPIRVType *ResType,
1751                                               MachineInstr &I,
1752                                               unsigned OpAnyOrAll) const {
1753   assert(I.getNumOperands() == 3);
1754   assert(I.getOperand(2).isReg());
1755   MachineBasicBlock &BB = *I.getParent();
1756   Register InputRegister = I.getOperand(2).getReg();
1757   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
1758 
1759   if (!InputType)
1760     report_fatal_error("Input Type could not be determined.");
1761 
1762   bool IsBoolTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeBool);
1763   bool IsVectorTy = InputType->getOpcode() == SPIRV::OpTypeVector;
1764   if (IsBoolTy && !IsVectorTy) {
1765     assert(ResVReg == I.getOperand(0).getReg());
1766     return BuildCOPY(ResVReg, InputRegister, I);
1767   }
1768 
1769   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
1770   unsigned SpirvNotEqualId =
1771       IsFloatTy ? SPIRV::OpFOrdNotEqual : SPIRV::OpINotEqual;
1772   SPIRVType *SpvBoolScalarTy = GR.getOrCreateSPIRVBoolType(I, TII);
1773   SPIRVType *SpvBoolTy = SpvBoolScalarTy;
1774   Register NotEqualReg = ResVReg;
1775 
1776   if (IsVectorTy) {
1777     NotEqualReg = IsBoolTy ? InputRegister
1778                            : MRI->createVirtualRegister(&SPIRV::iIDRegClass);
1779     const unsigned NumElts = InputType->getOperand(2).getImm();
1780     SpvBoolTy = GR.getOrCreateSPIRVVectorType(SpvBoolTy, NumElts, I, TII);
1781   }
1782 
1783   bool Result = true;
1784   if (!IsBoolTy) {
1785     Register ConstZeroReg =
1786         IsFloatTy ? buildZerosValF(InputType, I) : buildZerosVal(InputType, I);
1787 
1788     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SpirvNotEqualId))
1789                   .addDef(NotEqualReg)
1790                   .addUse(GR.getSPIRVTypeID(SpvBoolTy))
1791                   .addUse(InputRegister)
1792                   .addUse(ConstZeroReg)
1793                   .constrainAllUses(TII, TRI, RBI);
1794   }
1795 
1796   if (!IsVectorTy)
1797     return Result;
1798 
1799   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(OpAnyOrAll))
1800                        .addDef(ResVReg)
1801                        .addUse(GR.getSPIRVTypeID(SpvBoolScalarTy))
1802                        .addUse(NotEqualReg)
1803                        .constrainAllUses(TII, TRI, RBI);
1804 }
1805 
1806 bool SPIRVInstructionSelector::selectAll(Register ResVReg,
1807                                          const SPIRVType *ResType,
1808                                          MachineInstr &I) const {
1809   return selectAnyOrAll(ResVReg, ResType, I, SPIRV::OpAll);
1810 }
1811 
1812 bool SPIRVInstructionSelector::selectAny(Register ResVReg,
1813                                          const SPIRVType *ResType,
1814                                          MachineInstr &I) const {
1815   return selectAnyOrAll(ResVReg, ResType, I, SPIRV::OpAny);
1816 }
1817 
1818 // Select the OpDot instruction for the given float dot
1819 bool SPIRVInstructionSelector::selectFloatDot(Register ResVReg,
1820                                               const SPIRVType *ResType,
1821                                               MachineInstr &I) const {
1822   assert(I.getNumOperands() == 4);
1823   assert(I.getOperand(2).isReg());
1824   assert(I.getOperand(3).isReg());
1825 
1826   [[maybe_unused]] SPIRVType *VecType =
1827       GR.getSPIRVTypeForVReg(I.getOperand(2).getReg());
1828 
1829   assert(VecType->getOpcode() == SPIRV::OpTypeVector &&
1830          GR.getScalarOrVectorComponentCount(VecType) > 1 &&
1831          "dot product requires a vector of at least 2 components");
1832 
1833   [[maybe_unused]] SPIRVType *EltType =
1834       GR.getSPIRVTypeForVReg(VecType->getOperand(1).getReg());
1835 
1836   assert(EltType->getOpcode() == SPIRV::OpTypeFloat);
1837 
1838   MachineBasicBlock &BB = *I.getParent();
1839   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpDot))
1840       .addDef(ResVReg)
1841       .addUse(GR.getSPIRVTypeID(ResType))
1842       .addUse(I.getOperand(2).getReg())
1843       .addUse(I.getOperand(3).getReg())
1844       .constrainAllUses(TII, TRI, RBI);
1845 }
1846 
1847 bool SPIRVInstructionSelector::selectIntegerDot(Register ResVReg,
1848                                                 const SPIRVType *ResType,
1849                                                 MachineInstr &I,
1850                                                 bool Signed) const {
1851   assert(I.getNumOperands() == 4);
1852   assert(I.getOperand(2).isReg());
1853   assert(I.getOperand(3).isReg());
1854   MachineBasicBlock &BB = *I.getParent();
1855 
1856   auto DotOp = Signed ? SPIRV::OpSDot : SPIRV::OpUDot;
1857   return BuildMI(BB, I, I.getDebugLoc(), TII.get(DotOp))
1858       .addDef(ResVReg)
1859       .addUse(GR.getSPIRVTypeID(ResType))
1860       .addUse(I.getOperand(2).getReg())
1861       .addUse(I.getOperand(3).getReg())
1862       .constrainAllUses(TII, TRI, RBI);
1863 }
1864 
1865 // Since pre-1.6 SPIRV has no integer dot implementation,
1866 // expand by piecewise multiplying and adding the results
1867 bool SPIRVInstructionSelector::selectIntegerDotExpansion(
1868     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
1869   assert(I.getNumOperands() == 4);
1870   assert(I.getOperand(2).isReg());
1871   assert(I.getOperand(3).isReg());
1872   MachineBasicBlock &BB = *I.getParent();
1873 
1874   // Multiply the vectors, then sum the results
1875   Register Vec0 = I.getOperand(2).getReg();
1876   Register Vec1 = I.getOperand(3).getReg();
1877   Register TmpVec = MRI->createVirtualRegister(GR.getRegClass(ResType));
1878   SPIRVType *VecType = GR.getSPIRVTypeForVReg(Vec0);
1879 
1880   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIMulV))
1881                     .addDef(TmpVec)
1882                     .addUse(GR.getSPIRVTypeID(VecType))
1883                     .addUse(Vec0)
1884                     .addUse(Vec1)
1885                     .constrainAllUses(TII, TRI, RBI);
1886 
1887   assert(VecType->getOpcode() == SPIRV::OpTypeVector &&
1888          GR.getScalarOrVectorComponentCount(VecType) > 1 &&
1889          "dot product requires a vector of at least 2 components");
1890 
1891   Register Res = MRI->createVirtualRegister(GR.getRegClass(ResType));
1892   Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1893                 .addDef(Res)
1894                 .addUse(GR.getSPIRVTypeID(ResType))
1895                 .addUse(TmpVec)
1896                 .addImm(0)
1897                 .constrainAllUses(TII, TRI, RBI);
1898 
1899   for (unsigned i = 1; i < GR.getScalarOrVectorComponentCount(VecType); i++) {
1900     Register Elt = MRI->createVirtualRegister(GR.getRegClass(ResType));
1901 
1902     Result &=
1903         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
1904             .addDef(Elt)
1905             .addUse(GR.getSPIRVTypeID(ResType))
1906             .addUse(TmpVec)
1907             .addImm(i)
1908             .constrainAllUses(TII, TRI, RBI);
1909 
1910     Register Sum = i < GR.getScalarOrVectorComponentCount(VecType) - 1
1911                        ? MRI->createVirtualRegister(GR.getRegClass(ResType))
1912                        : ResVReg;
1913 
1914     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
1915                   .addDef(Sum)
1916                   .addUse(GR.getSPIRVTypeID(ResType))
1917                   .addUse(Res)
1918                   .addUse(Elt)
1919                   .constrainAllUses(TII, TRI, RBI);
1920     Res = Sum;
1921   }
1922 
1923   return Result;
1924 }
1925 
1926 template <bool Signed>
1927 bool SPIRVInstructionSelector::selectDot4AddPacked(Register ResVReg,
1928                                                    const SPIRVType *ResType,
1929                                                    MachineInstr &I) const {
1930   assert(I.getNumOperands() == 5);
1931   assert(I.getOperand(2).isReg());
1932   assert(I.getOperand(3).isReg());
1933   assert(I.getOperand(4).isReg());
1934   MachineBasicBlock &BB = *I.getParent();
1935 
1936   auto DotOp = Signed ? SPIRV::OpSDot : SPIRV::OpUDot;
1937   Register Dot = MRI->createVirtualRegister(GR.getRegClass(ResType));
1938   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(DotOp))
1939                     .addDef(Dot)
1940                     .addUse(GR.getSPIRVTypeID(ResType))
1941                     .addUse(I.getOperand(2).getReg())
1942                     .addUse(I.getOperand(3).getReg())
1943                     .constrainAllUses(TII, TRI, RBI);
1944 
1945   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
1946                        .addDef(ResVReg)
1947                        .addUse(GR.getSPIRVTypeID(ResType))
1948                        .addUse(Dot)
1949                        .addUse(I.getOperand(4).getReg())
1950                        .constrainAllUses(TII, TRI, RBI);
1951 }
1952 
1953 // Since pre-1.6 SPIRV has no DotProductInput4x8BitPacked implementation,
1954 // extract the elements of the packed inputs, multiply them and add the result
1955 // to the accumulator.
1956 template <bool Signed>
1957 bool SPIRVInstructionSelector::selectDot4AddPackedExpansion(
1958     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
1959   assert(I.getNumOperands() == 5);
1960   assert(I.getOperand(2).isReg());
1961   assert(I.getOperand(3).isReg());
1962   assert(I.getOperand(4).isReg());
1963   MachineBasicBlock &BB = *I.getParent();
1964 
1965   bool Result = true;
1966 
1967   // Acc = C
1968   Register Acc = I.getOperand(4).getReg();
1969   SPIRVType *EltType = GR.getOrCreateSPIRVIntegerType(8, I, TII);
1970   auto ExtractOp =
1971       Signed ? SPIRV::OpBitFieldSExtract : SPIRV::OpBitFieldUExtract;
1972 
1973   // Extract the i8 element, multiply and add it to the accumulator
1974   for (unsigned i = 0; i < 4; i++) {
1975     // A[i]
1976     Register AElt = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1977     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
1978                   .addDef(AElt)
1979                   .addUse(GR.getSPIRVTypeID(ResType))
1980                   .addUse(I.getOperand(2).getReg())
1981                   .addUse(GR.getOrCreateConstInt(i * 8, I, EltType, TII))
1982                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
1983                   .constrainAllUses(TII, TRI, RBI);
1984 
1985     // B[i]
1986     Register BElt = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1987     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
1988                   .addDef(BElt)
1989                   .addUse(GR.getSPIRVTypeID(ResType))
1990                   .addUse(I.getOperand(3).getReg())
1991                   .addUse(GR.getOrCreateConstInt(i * 8, I, EltType, TII))
1992                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
1993                   .constrainAllUses(TII, TRI, RBI);
1994 
1995     // A[i] * B[i]
1996     Register Mul = MRI->createVirtualRegister(&SPIRV::IDRegClass);
1997     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIMulS))
1998                   .addDef(Mul)
1999                   .addUse(GR.getSPIRVTypeID(ResType))
2000                   .addUse(AElt)
2001                   .addUse(BElt)
2002                   .constrainAllUses(TII, TRI, RBI);
2003 
2004     // Discard 24 highest-bits so that stored i32 register is i8 equivalent
2005     Register MaskMul = MRI->createVirtualRegister(&SPIRV::IDRegClass);
2006     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(ExtractOp))
2007                   .addDef(MaskMul)
2008                   .addUse(GR.getSPIRVTypeID(ResType))
2009                   .addUse(Mul)
2010                   .addUse(GR.getOrCreateConstInt(0, I, EltType, TII))
2011                   .addUse(GR.getOrCreateConstInt(8, I, EltType, TII))
2012                   .constrainAllUses(TII, TRI, RBI);
2013 
2014     // Acc = Acc + A[i] * B[i]
2015     Register Sum =
2016         i < 3 ? MRI->createVirtualRegister(&SPIRV::IDRegClass) : ResVReg;
2017     Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpIAddS))
2018                   .addDef(Sum)
2019                   .addUse(GR.getSPIRVTypeID(ResType))
2020                   .addUse(Acc)
2021                   .addUse(MaskMul)
2022                   .constrainAllUses(TII, TRI, RBI);
2023 
2024     Acc = Sum;
2025   }
2026 
2027   return Result;
2028 }
2029 
2030 /// Transform saturate(x) to clamp(x, 0.0f, 1.0f) as SPIRV
2031 /// does not have a saturate builtin.
2032 bool SPIRVInstructionSelector::selectSaturate(Register ResVReg,
2033                                               const SPIRVType *ResType,
2034                                               MachineInstr &I) const {
2035   assert(I.getNumOperands() == 3);
2036   assert(I.getOperand(2).isReg());
2037   MachineBasicBlock &BB = *I.getParent();
2038   Register VZero = buildZerosValF(ResType, I);
2039   Register VOne = buildOnesValF(ResType, I);
2040 
2041   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
2042       .addDef(ResVReg)
2043       .addUse(GR.getSPIRVTypeID(ResType))
2044       .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
2045       .addImm(GL::FClamp)
2046       .addUse(I.getOperand(2).getReg())
2047       .addUse(VZero)
2048       .addUse(VOne)
2049       .constrainAllUses(TII, TRI, RBI);
2050 }
2051 
2052 bool SPIRVInstructionSelector::selectSign(Register ResVReg,
2053                                           const SPIRVType *ResType,
2054                                           MachineInstr &I) const {
2055   assert(I.getNumOperands() == 3);
2056   assert(I.getOperand(2).isReg());
2057   MachineBasicBlock &BB = *I.getParent();
2058   Register InputRegister = I.getOperand(2).getReg();
2059   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
2060   auto &DL = I.getDebugLoc();
2061 
2062   if (!InputType)
2063     report_fatal_error("Input Type could not be determined.");
2064 
2065   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
2066 
2067   unsigned SignBitWidth = GR.getScalarOrVectorBitWidth(InputType);
2068   unsigned ResBitWidth = GR.getScalarOrVectorBitWidth(ResType);
2069 
2070   bool NeedsConversion = IsFloatTy || SignBitWidth != ResBitWidth;
2071 
2072   auto SignOpcode = IsFloatTy ? GL::FSign : GL::SSign;
2073   Register SignReg = NeedsConversion
2074                          ? MRI->createVirtualRegister(&SPIRV::IDRegClass)
2075                          : ResVReg;
2076 
2077   bool Result =
2078       BuildMI(BB, I, DL, TII.get(SPIRV::OpExtInst))
2079           .addDef(SignReg)
2080           .addUse(GR.getSPIRVTypeID(InputType))
2081           .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
2082           .addImm(SignOpcode)
2083           .addUse(InputRegister)
2084           .constrainAllUses(TII, TRI, RBI);
2085 
2086   if (NeedsConversion) {
2087     auto ConvertOpcode = IsFloatTy ? SPIRV::OpConvertFToS : SPIRV::OpSConvert;
2088     Result &= BuildMI(*I.getParent(), I, DL, TII.get(ConvertOpcode))
2089                   .addDef(ResVReg)
2090                   .addUse(GR.getSPIRVTypeID(ResType))
2091                   .addUse(SignReg)
2092                   .constrainAllUses(TII, TRI, RBI);
2093   }
2094 
2095   return Result;
2096 }
2097 
2098 bool SPIRVInstructionSelector::selectWaveOpInst(Register ResVReg,
2099                                                 const SPIRVType *ResType,
2100                                                 MachineInstr &I,
2101                                                 unsigned Opcode) const {
2102   MachineBasicBlock &BB = *I.getParent();
2103   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2104 
2105   auto BMI = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2106                  .addDef(ResVReg)
2107                  .addUse(GR.getSPIRVTypeID(ResType))
2108                  .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I,
2109                                                 IntTy, TII));
2110 
2111   for (unsigned J = 2; J < I.getNumOperands(); J++) {
2112     BMI.addUse(I.getOperand(J).getReg());
2113   }
2114 
2115   return BMI.constrainAllUses(TII, TRI, RBI);
2116 }
2117 
2118 bool SPIRVInstructionSelector::selectWaveActiveCountBits(
2119     Register ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
2120 
2121   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2122   SPIRVType *BallotType = GR.getOrCreateSPIRVVectorType(IntTy, 4, I, TII);
2123   Register BallotReg = MRI->createVirtualRegister(GR.getRegClass(BallotType));
2124   bool Result = selectWaveOpInst(BallotReg, BallotType, I,
2125                                  SPIRV::OpGroupNonUniformBallot);
2126 
2127   MachineBasicBlock &BB = *I.getParent();
2128   Result &=
2129       BuildMI(BB, I, I.getDebugLoc(),
2130               TII.get(SPIRV::OpGroupNonUniformBallotBitCount))
2131           .addDef(ResVReg)
2132           .addUse(GR.getSPIRVTypeID(ResType))
2133           .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I, IntTy, TII))
2134           .addImm(SPIRV::GroupOperation::Reduce)
2135           .addUse(BallotReg)
2136           .constrainAllUses(TII, TRI, RBI);
2137 
2138   return Result;
2139 }
2140 
2141 bool SPIRVInstructionSelector::selectWaveReduceSum(Register ResVReg,
2142                                                    const SPIRVType *ResType,
2143                                                    MachineInstr &I) const {
2144   assert(I.getNumOperands() == 3);
2145   assert(I.getOperand(2).isReg());
2146   MachineBasicBlock &BB = *I.getParent();
2147   Register InputRegister = I.getOperand(2).getReg();
2148   SPIRVType *InputType = GR.getSPIRVTypeForVReg(InputRegister);
2149 
2150   if (!InputType)
2151     report_fatal_error("Input Type could not be determined.");
2152 
2153   SPIRVType *IntTy = GR.getOrCreateSPIRVIntegerType(32, I, TII);
2154   // Retreive the operation to use based on input type
2155   bool IsFloatTy = GR.isScalarOrVectorOfType(InputRegister, SPIRV::OpTypeFloat);
2156   auto Opcode =
2157       IsFloatTy ? SPIRV::OpGroupNonUniformFAdd : SPIRV::OpGroupNonUniformIAdd;
2158   return BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2159       .addDef(ResVReg)
2160       .addUse(GR.getSPIRVTypeID(ResType))
2161       .addUse(GR.getOrCreateConstInt(SPIRV::Scope::Subgroup, I, IntTy, TII))
2162       .addImm(SPIRV::GroupOperation::Reduce)
2163       .addUse(I.getOperand(2).getReg());
2164 }
2165 
2166 bool SPIRVInstructionSelector::selectBitreverse(Register ResVReg,
2167                                                 const SPIRVType *ResType,
2168                                                 MachineInstr &I) const {
2169   MachineBasicBlock &BB = *I.getParent();
2170   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpBitReverse))
2171       .addDef(ResVReg)
2172       .addUse(GR.getSPIRVTypeID(ResType))
2173       .addUse(I.getOperand(1).getReg())
2174       .constrainAllUses(TII, TRI, RBI);
2175 }
2176 
2177 bool SPIRVInstructionSelector::selectFreeze(Register ResVReg,
2178                                             const SPIRVType *ResType,
2179                                             MachineInstr &I) const {
2180   // There is no way to implement `freeze` correctly without support on SPIR-V
2181   // standard side, but we may at least address a simple (static) case when
2182   // undef/poison value presence is obvious. The main benefit of even
2183   // incomplete `freeze` support is preventing of translation from crashing due
2184   // to lack of support on legalization and instruction selection steps.
2185   if (!I.getOperand(0).isReg() || !I.getOperand(1).isReg())
2186     return false;
2187   Register OpReg = I.getOperand(1).getReg();
2188   if (MachineInstr *Def = MRI->getVRegDef(OpReg)) {
2189     Register Reg;
2190     switch (Def->getOpcode()) {
2191     case SPIRV::ASSIGN_TYPE:
2192       if (MachineInstr *AssignToDef =
2193               MRI->getVRegDef(Def->getOperand(1).getReg())) {
2194         if (AssignToDef->getOpcode() == TargetOpcode::G_IMPLICIT_DEF)
2195           Reg = Def->getOperand(2).getReg();
2196       }
2197       break;
2198     case SPIRV::OpUndef:
2199       Reg = Def->getOperand(1).getReg();
2200       break;
2201     }
2202     unsigned DestOpCode;
2203     if (Reg.isValid()) {
2204       DestOpCode = SPIRV::OpConstantNull;
2205     } else {
2206       DestOpCode = TargetOpcode::COPY;
2207       Reg = OpReg;
2208     }
2209     return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(DestOpCode))
2210         .addDef(I.getOperand(0).getReg())
2211         .addUse(Reg)
2212         .constrainAllUses(TII, TRI, RBI);
2213   }
2214   return false;
2215 }
2216 
2217 static unsigned getArrayComponentCount(MachineRegisterInfo *MRI,
2218                                        const SPIRVType *ResType) {
2219   Register OpReg = ResType->getOperand(2).getReg();
2220   SPIRVType *OpDef = MRI->getVRegDef(OpReg);
2221   if (!OpDef)
2222     return 0;
2223   if (OpDef->getOpcode() == SPIRV::ASSIGN_TYPE &&
2224       OpDef->getOperand(1).isReg()) {
2225     if (SPIRVType *RefDef = MRI->getVRegDef(OpDef->getOperand(1).getReg()))
2226       OpDef = RefDef;
2227   }
2228   unsigned N = OpDef->getOpcode() == TargetOpcode::G_CONSTANT
2229                    ? OpDef->getOperand(1).getCImm()->getValue().getZExtValue()
2230                    : 0;
2231   return N;
2232 }
2233 
2234 // Return true if the type represents a constant register
2235 static bool isConstReg(MachineRegisterInfo *MRI, SPIRVType *OpDef,
2236                        SmallPtrSet<SPIRVType *, 4> &Visited) {
2237   if (OpDef->getOpcode() == SPIRV::ASSIGN_TYPE &&
2238       OpDef->getOperand(1).isReg()) {
2239     if (SPIRVType *RefDef = MRI->getVRegDef(OpDef->getOperand(1).getReg()))
2240       OpDef = RefDef;
2241   }
2242 
2243   if (Visited.contains(OpDef))
2244     return true;
2245   Visited.insert(OpDef);
2246 
2247   unsigned Opcode = OpDef->getOpcode();
2248   switch (Opcode) {
2249   case TargetOpcode::G_CONSTANT:
2250   case TargetOpcode::G_FCONSTANT:
2251     return true;
2252   case TargetOpcode::G_INTRINSIC:
2253   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
2254   case TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS:
2255     return cast<GIntrinsic>(*OpDef).getIntrinsicID() ==
2256            Intrinsic::spv_const_composite;
2257   case TargetOpcode::G_BUILD_VECTOR:
2258   case TargetOpcode::G_SPLAT_VECTOR: {
2259     for (unsigned i = OpDef->getNumExplicitDefs(); i < OpDef->getNumOperands();
2260          i++) {
2261       SPIRVType *OpNestedDef =
2262           OpDef->getOperand(i).isReg()
2263               ? MRI->getVRegDef(OpDef->getOperand(i).getReg())
2264               : nullptr;
2265       if (OpNestedDef && !isConstReg(MRI, OpNestedDef, Visited))
2266         return false;
2267     }
2268     return true;
2269   }
2270   }
2271   return false;
2272 }
2273 
2274 // Return true if the virtual register represents a constant
2275 static bool isConstReg(MachineRegisterInfo *MRI, Register OpReg) {
2276   SmallPtrSet<SPIRVType *, 4> Visited;
2277   if (SPIRVType *OpDef = MRI->getVRegDef(OpReg))
2278     return isConstReg(MRI, OpDef, Visited);
2279   return false;
2280 }
2281 
2282 bool SPIRVInstructionSelector::selectBuildVector(Register ResVReg,
2283                                                  const SPIRVType *ResType,
2284                                                  MachineInstr &I) const {
2285   unsigned N = 0;
2286   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2287     N = GR.getScalarOrVectorComponentCount(ResType);
2288   else if (ResType->getOpcode() == SPIRV::OpTypeArray)
2289     N = getArrayComponentCount(MRI, ResType);
2290   else
2291     report_fatal_error("Cannot select G_BUILD_VECTOR with a non-vector result");
2292   if (I.getNumExplicitOperands() - I.getNumExplicitDefs() != N)
2293     report_fatal_error("G_BUILD_VECTOR and the result type are inconsistent");
2294 
2295   // check if we may construct a constant vector
2296   bool IsConst = true;
2297   for (unsigned i = I.getNumExplicitDefs();
2298        i < I.getNumExplicitOperands() && IsConst; ++i)
2299     if (!isConstReg(MRI, I.getOperand(i).getReg()))
2300       IsConst = false;
2301 
2302   if (!IsConst && N < 2)
2303     report_fatal_error(
2304         "There must be at least two constituent operands in a vector");
2305 
2306   MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2307   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
2308                      TII.get(IsConst ? SPIRV::OpConstantComposite
2309                                      : SPIRV::OpCompositeConstruct))
2310                  .addDef(ResVReg)
2311                  .addUse(GR.getSPIRVTypeID(ResType));
2312   for (unsigned i = I.getNumExplicitDefs(); i < I.getNumExplicitOperands(); ++i)
2313     MIB.addUse(I.getOperand(i).getReg());
2314   return MIB.constrainAllUses(TII, TRI, RBI);
2315 }
2316 
2317 bool SPIRVInstructionSelector::selectSplatVector(Register ResVReg,
2318                                                  const SPIRVType *ResType,
2319                                                  MachineInstr &I) const {
2320   unsigned N = 0;
2321   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2322     N = GR.getScalarOrVectorComponentCount(ResType);
2323   else if (ResType->getOpcode() == SPIRV::OpTypeArray)
2324     N = getArrayComponentCount(MRI, ResType);
2325   else
2326     report_fatal_error("Cannot select G_SPLAT_VECTOR with a non-vector result");
2327 
2328   unsigned OpIdx = I.getNumExplicitDefs();
2329   if (!I.getOperand(OpIdx).isReg())
2330     report_fatal_error("Unexpected argument in G_SPLAT_VECTOR");
2331 
2332   // check if we may construct a constant vector
2333   Register OpReg = I.getOperand(OpIdx).getReg();
2334   bool IsConst = isConstReg(MRI, OpReg);
2335 
2336   if (!IsConst && N < 2)
2337     report_fatal_error(
2338         "There must be at least two constituent operands in a vector");
2339 
2340   MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2341   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
2342                      TII.get(IsConst ? SPIRV::OpConstantComposite
2343                                      : SPIRV::OpCompositeConstruct))
2344                  .addDef(ResVReg)
2345                  .addUse(GR.getSPIRVTypeID(ResType));
2346   for (unsigned i = 0; i < N; ++i)
2347     MIB.addUse(OpReg);
2348   return MIB.constrainAllUses(TII, TRI, RBI);
2349 }
2350 
2351 bool SPIRVInstructionSelector::selectDiscard(Register ResVReg,
2352                                              const SPIRVType *ResType,
2353                                              MachineInstr &I) const {
2354 
2355   unsigned Opcode;
2356 
2357   if (STI.canUseExtension(
2358           SPIRV::Extension::SPV_EXT_demote_to_helper_invocation) ||
2359       STI.isAtLeastSPIRVVer(llvm::VersionTuple(1, 6))) {
2360     Opcode = SPIRV::OpDemoteToHelperInvocation;
2361   } else {
2362     Opcode = SPIRV::OpKill;
2363     // OpKill must be the last operation of any basic block.
2364     if (MachineInstr *NextI = I.getNextNode()) {
2365       GR.invalidateMachineInstr(NextI);
2366       NextI->removeFromParent();
2367     }
2368   }
2369 
2370   MachineBasicBlock &BB = *I.getParent();
2371   return BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2372       .constrainAllUses(TII, TRI, RBI);
2373 }
2374 
2375 bool SPIRVInstructionSelector::selectCmp(Register ResVReg,
2376                                          const SPIRVType *ResType,
2377                                          unsigned CmpOpc,
2378                                          MachineInstr &I) const {
2379   Register Cmp0 = I.getOperand(2).getReg();
2380   Register Cmp1 = I.getOperand(3).getReg();
2381   assert(GR.getSPIRVTypeForVReg(Cmp0)->getOpcode() ==
2382              GR.getSPIRVTypeForVReg(Cmp1)->getOpcode() &&
2383          "CMP operands should have the same type");
2384   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(CmpOpc))
2385       .addDef(ResVReg)
2386       .addUse(GR.getSPIRVTypeID(ResType))
2387       .addUse(Cmp0)
2388       .addUse(Cmp1)
2389       .constrainAllUses(TII, TRI, RBI);
2390 }
2391 
2392 bool SPIRVInstructionSelector::selectICmp(Register ResVReg,
2393                                           const SPIRVType *ResType,
2394                                           MachineInstr &I) const {
2395   auto Pred = I.getOperand(1).getPredicate();
2396   unsigned CmpOpc;
2397 
2398   Register CmpOperand = I.getOperand(2).getReg();
2399   if (GR.isScalarOfType(CmpOperand, SPIRV::OpTypePointer))
2400     CmpOpc = getPtrCmpOpcode(Pred);
2401   else if (GR.isScalarOrVectorOfType(CmpOperand, SPIRV::OpTypeBool))
2402     CmpOpc = getBoolCmpOpcode(Pred);
2403   else
2404     CmpOpc = getICmpOpcode(Pred);
2405   return selectCmp(ResVReg, ResType, CmpOpc, I);
2406 }
2407 
2408 void SPIRVInstructionSelector::renderFImm64(MachineInstrBuilder &MIB,
2409                                             const MachineInstr &I,
2410                                             int OpIdx) const {
2411   assert(I.getOpcode() == TargetOpcode::G_FCONSTANT && OpIdx == -1 &&
2412          "Expected G_FCONSTANT");
2413   const ConstantFP *FPImm = I.getOperand(1).getFPImm();
2414   addNumImm(FPImm->getValueAPF().bitcastToAPInt(), MIB);
2415 }
2416 
2417 void SPIRVInstructionSelector::renderImm32(MachineInstrBuilder &MIB,
2418                                            const MachineInstr &I,
2419                                            int OpIdx) const {
2420   assert(I.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
2421          "Expected G_CONSTANT");
2422   addNumImm(I.getOperand(1).getCImm()->getValue(), MIB);
2423 }
2424 
2425 std::pair<Register, bool>
2426 SPIRVInstructionSelector::buildI32Constant(uint32_t Val, MachineInstr &I,
2427                                            const SPIRVType *ResType) const {
2428   Type *LLVMTy = IntegerType::get(GR.CurMF->getFunction().getContext(), 32);
2429   const SPIRVType *SpvI32Ty =
2430       ResType ? ResType : GR.getOrCreateSPIRVIntegerType(32, I, TII);
2431   // Find a constant in DT or build a new one.
2432   auto ConstInt = ConstantInt::get(LLVMTy, Val);
2433   Register NewReg = GR.find(ConstInt, GR.CurMF);
2434   bool Result = true;
2435   if (!NewReg.isValid()) {
2436     NewReg = MRI->createGenericVirtualRegister(LLT::scalar(64));
2437     GR.add(ConstInt, GR.CurMF, NewReg);
2438     MachineInstr *MI;
2439     MachineBasicBlock &BB = *I.getParent();
2440     if (Val == 0) {
2441       MI = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
2442                .addDef(NewReg)
2443                .addUse(GR.getSPIRVTypeID(SpvI32Ty));
2444     } else {
2445       MI = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantI))
2446                .addDef(NewReg)
2447                .addUse(GR.getSPIRVTypeID(SpvI32Ty))
2448                .addImm(APInt(32, Val).getZExtValue());
2449     }
2450     Result &= constrainSelectedInstRegOperands(*MI, TII, TRI, RBI);
2451   }
2452   return {NewReg, Result};
2453 }
2454 
2455 bool SPIRVInstructionSelector::selectFCmp(Register ResVReg,
2456                                           const SPIRVType *ResType,
2457                                           MachineInstr &I) const {
2458   unsigned CmpOp = getFCmpOpcode(I.getOperand(1).getPredicate());
2459   return selectCmp(ResVReg, ResType, CmpOp, I);
2460 }
2461 
2462 Register SPIRVInstructionSelector::buildZerosVal(const SPIRVType *ResType,
2463                                                  MachineInstr &I) const {
2464   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2465   bool ZeroAsNull = STI.isOpenCLEnv();
2466   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2467     return GR.getOrCreateConstVector(0UL, I, ResType, TII, ZeroAsNull);
2468   return GR.getOrCreateConstInt(0, I, ResType, TII, ZeroAsNull);
2469 }
2470 
2471 Register SPIRVInstructionSelector::buildZerosValF(const SPIRVType *ResType,
2472                                                   MachineInstr &I) const {
2473   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2474   bool ZeroAsNull = STI.isOpenCLEnv();
2475   APFloat VZero = getZeroFP(GR.getTypeForSPIRVType(ResType));
2476   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2477     return GR.getOrCreateConstVector(VZero, I, ResType, TII, ZeroAsNull);
2478   return GR.getOrCreateConstFP(VZero, I, ResType, TII, ZeroAsNull);
2479 }
2480 
2481 Register SPIRVInstructionSelector::buildOnesValF(const SPIRVType *ResType,
2482                                                  MachineInstr &I) const {
2483   // OpenCL uses nulls for Zero. In HLSL we don't use null constants.
2484   bool ZeroAsNull = STI.isOpenCLEnv();
2485   APFloat VOne = getOneFP(GR.getTypeForSPIRVType(ResType));
2486   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2487     return GR.getOrCreateConstVector(VOne, I, ResType, TII, ZeroAsNull);
2488   return GR.getOrCreateConstFP(VOne, I, ResType, TII, ZeroAsNull);
2489 }
2490 
2491 Register SPIRVInstructionSelector::buildOnesVal(bool AllOnes,
2492                                                 const SPIRVType *ResType,
2493                                                 MachineInstr &I) const {
2494   unsigned BitWidth = GR.getScalarOrVectorBitWidth(ResType);
2495   APInt One =
2496       AllOnes ? APInt::getAllOnes(BitWidth) : APInt::getOneBitSet(BitWidth, 0);
2497   if (ResType->getOpcode() == SPIRV::OpTypeVector)
2498     return GR.getOrCreateConstVector(One.getZExtValue(), I, ResType, TII);
2499   return GR.getOrCreateConstInt(One.getZExtValue(), I, ResType, TII);
2500 }
2501 
2502 bool SPIRVInstructionSelector::selectSelect(Register ResVReg,
2503                                             const SPIRVType *ResType,
2504                                             MachineInstr &I,
2505                                             bool IsSigned) const {
2506   // To extend a bool, we need to use OpSelect between constants.
2507   Register ZeroReg = buildZerosVal(ResType, I);
2508   Register OneReg = buildOnesVal(IsSigned, ResType, I);
2509   bool IsScalarBool =
2510       GR.isScalarOfType(I.getOperand(1).getReg(), SPIRV::OpTypeBool);
2511   unsigned Opcode =
2512       IsScalarBool ? SPIRV::OpSelectSISCond : SPIRV::OpSelectVIVCond;
2513   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
2514       .addDef(ResVReg)
2515       .addUse(GR.getSPIRVTypeID(ResType))
2516       .addUse(I.getOperand(1).getReg())
2517       .addUse(OneReg)
2518       .addUse(ZeroReg)
2519       .constrainAllUses(TII, TRI, RBI);
2520 }
2521 
2522 bool SPIRVInstructionSelector::selectIToF(Register ResVReg,
2523                                           const SPIRVType *ResType,
2524                                           MachineInstr &I, bool IsSigned,
2525                                           unsigned Opcode) const {
2526   Register SrcReg = I.getOperand(1).getReg();
2527   // We can convert bool value directly to float type without OpConvert*ToF,
2528   // however the translator generates OpSelect+OpConvert*ToF, so we do the same.
2529   if (GR.isScalarOrVectorOfType(I.getOperand(1).getReg(), SPIRV::OpTypeBool)) {
2530     unsigned BitWidth = GR.getScalarOrVectorBitWidth(ResType);
2531     SPIRVType *TmpType = GR.getOrCreateSPIRVIntegerType(BitWidth, I, TII);
2532     if (ResType->getOpcode() == SPIRV::OpTypeVector) {
2533       const unsigned NumElts = ResType->getOperand(2).getImm();
2534       TmpType = GR.getOrCreateSPIRVVectorType(TmpType, NumElts, I, TII);
2535     }
2536     SrcReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
2537     selectSelect(SrcReg, TmpType, I, false);
2538   }
2539   return selectOpWithSrcs(ResVReg, ResType, I, {SrcReg}, Opcode);
2540 }
2541 
2542 bool SPIRVInstructionSelector::selectExt(Register ResVReg,
2543                                          const SPIRVType *ResType,
2544                                          MachineInstr &I, bool IsSigned) const {
2545   Register SrcReg = I.getOperand(1).getReg();
2546   if (GR.isScalarOrVectorOfType(SrcReg, SPIRV::OpTypeBool))
2547     return selectSelect(ResVReg, ResType, I, IsSigned);
2548 
2549   SPIRVType *SrcType = GR.getSPIRVTypeForVReg(SrcReg);
2550   if (SrcType == ResType)
2551     return BuildCOPY(ResVReg, SrcReg, I);
2552 
2553   unsigned Opcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
2554   return selectUnOp(ResVReg, ResType, I, Opcode);
2555 }
2556 
2557 bool SPIRVInstructionSelector::selectSUCmp(Register ResVReg,
2558                                            const SPIRVType *ResType,
2559                                            MachineInstr &I,
2560                                            bool IsSigned) const {
2561   MachineIRBuilder MIRBuilder(I);
2562   MachineRegisterInfo *MRI = MIRBuilder.getMRI();
2563   MachineBasicBlock &BB = *I.getParent();
2564   // Ensure we have bool.
2565   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
2566   unsigned N = GR.getScalarOrVectorComponentCount(ResType);
2567   if (N > 1)
2568     BoolType = GR.getOrCreateSPIRVVectorType(BoolType, N, I, TII);
2569   Register BoolTypeReg = GR.getSPIRVTypeID(BoolType);
2570   // Build less-than-equal and less-than.
2571   // TODO: replace with one-liner createVirtualRegister() from
2572   // llvm/lib/Target/SPIRV/SPIRVUtils.cpp when PR #116609 is merged.
2573   Register IsLessEqReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
2574   MRI->setType(IsLessEqReg, LLT::scalar(64));
2575   GR.assignSPIRVTypeToVReg(ResType, IsLessEqReg, MIRBuilder.getMF());
2576   bool Result = BuildMI(BB, I, I.getDebugLoc(),
2577                         TII.get(IsSigned ? SPIRV::OpSLessThanEqual
2578                                          : SPIRV::OpULessThanEqual))
2579                     .addDef(IsLessEqReg)
2580                     .addUse(BoolTypeReg)
2581                     .addUse(I.getOperand(1).getReg())
2582                     .addUse(I.getOperand(2).getReg())
2583                     .constrainAllUses(TII, TRI, RBI);
2584   Register IsLessReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
2585   MRI->setType(IsLessReg, LLT::scalar(64));
2586   GR.assignSPIRVTypeToVReg(ResType, IsLessReg, MIRBuilder.getMF());
2587   Result &= BuildMI(BB, I, I.getDebugLoc(),
2588                     TII.get(IsSigned ? SPIRV::OpSLessThan : SPIRV::OpULessThan))
2589                 .addDef(IsLessReg)
2590                 .addUse(BoolTypeReg)
2591                 .addUse(I.getOperand(1).getReg())
2592                 .addUse(I.getOperand(2).getReg())
2593                 .constrainAllUses(TII, TRI, RBI);
2594   // Build selects.
2595   Register ResTypeReg = GR.getSPIRVTypeID(ResType);
2596   Register NegOneOrZeroReg =
2597       MRI->createVirtualRegister(GR.getRegClass(ResType));
2598   MRI->setType(NegOneOrZeroReg, LLT::scalar(64));
2599   GR.assignSPIRVTypeToVReg(ResType, NegOneOrZeroReg, MIRBuilder.getMF());
2600   unsigned SelectOpcode =
2601       N > 1 ? SPIRV::OpSelectVIVCond : SPIRV::OpSelectSISCond;
2602   Result &= BuildMI(BB, I, I.getDebugLoc(), TII.get(SelectOpcode))
2603                 .addDef(NegOneOrZeroReg)
2604                 .addUse(ResTypeReg)
2605                 .addUse(IsLessReg)
2606                 .addUse(buildOnesVal(true, ResType, I)) // -1
2607                 .addUse(buildZerosVal(ResType, I))
2608                 .constrainAllUses(TII, TRI, RBI);
2609   return Result & BuildMI(BB, I, I.getDebugLoc(), TII.get(SelectOpcode))
2610                       .addDef(ResVReg)
2611                       .addUse(ResTypeReg)
2612                       .addUse(IsLessEqReg)
2613                       .addUse(NegOneOrZeroReg) // -1 or 0
2614                       .addUse(buildOnesVal(false, ResType, I))
2615                       .constrainAllUses(TII, TRI, RBI);
2616 }
2617 
2618 bool SPIRVInstructionSelector::selectIntToBool(Register IntReg,
2619                                                Register ResVReg,
2620                                                MachineInstr &I,
2621                                                const SPIRVType *IntTy,
2622                                                const SPIRVType *BoolTy) const {
2623   // To truncate to a bool, we use OpBitwiseAnd 1 and OpINotEqual to zero.
2624   Register BitIntReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
2625   bool IsVectorTy = IntTy->getOpcode() == SPIRV::OpTypeVector;
2626   unsigned Opcode = IsVectorTy ? SPIRV::OpBitwiseAndV : SPIRV::OpBitwiseAndS;
2627   Register Zero = buildZerosVal(IntTy, I);
2628   Register One = buildOnesVal(false, IntTy, I);
2629   MachineBasicBlock &BB = *I.getParent();
2630   bool Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2631                     .addDef(BitIntReg)
2632                     .addUse(GR.getSPIRVTypeID(IntTy))
2633                     .addUse(IntReg)
2634                     .addUse(One)
2635                     .constrainAllUses(TII, TRI, RBI);
2636   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpINotEqual))
2637                        .addDef(ResVReg)
2638                        .addUse(GR.getSPIRVTypeID(BoolTy))
2639                        .addUse(BitIntReg)
2640                        .addUse(Zero)
2641                        .constrainAllUses(TII, TRI, RBI);
2642 }
2643 
2644 bool SPIRVInstructionSelector::selectTrunc(Register ResVReg,
2645                                            const SPIRVType *ResType,
2646                                            MachineInstr &I) const {
2647   Register IntReg = I.getOperand(1).getReg();
2648   const SPIRVType *ArgType = GR.getSPIRVTypeForVReg(IntReg);
2649   if (GR.isScalarOrVectorOfType(ResVReg, SPIRV::OpTypeBool))
2650     return selectIntToBool(IntReg, ResVReg, I, ArgType, ResType);
2651   if (ArgType == ResType)
2652     return BuildCOPY(ResVReg, IntReg, I);
2653   bool IsSigned = GR.isScalarOrVectorSigned(ResType);
2654   unsigned Opcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
2655   return selectUnOp(ResVReg, ResType, I, Opcode);
2656 }
2657 
2658 bool SPIRVInstructionSelector::selectConst(Register ResVReg,
2659                                            const SPIRVType *ResType,
2660                                            const APInt &Imm,
2661                                            MachineInstr &I) const {
2662   unsigned TyOpcode = ResType->getOpcode();
2663   assert(TyOpcode != SPIRV::OpTypePointer || Imm.isZero());
2664   MachineBasicBlock &BB = *I.getParent();
2665   if ((TyOpcode == SPIRV::OpTypePointer || TyOpcode == SPIRV::OpTypeEvent) &&
2666       Imm.isZero())
2667     return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
2668         .addDef(ResVReg)
2669         .addUse(GR.getSPIRVTypeID(ResType))
2670         .constrainAllUses(TII, TRI, RBI);
2671   if (TyOpcode == SPIRV::OpTypeInt) {
2672     assert(Imm.getBitWidth() <= 64 && "Unsupported integer width!");
2673     Register Reg = GR.getOrCreateConstInt(Imm.getZExtValue(), I, ResType, TII);
2674     return Reg == ResVReg ? true : BuildCOPY(ResVReg, Reg, I);
2675   }
2676   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantI))
2677                  .addDef(ResVReg)
2678                  .addUse(GR.getSPIRVTypeID(ResType));
2679   // <=32-bit integers should be caught by the sdag pattern.
2680   assert(Imm.getBitWidth() > 32);
2681   addNumImm(Imm, MIB);
2682   return MIB.constrainAllUses(TII, TRI, RBI);
2683 }
2684 
2685 bool SPIRVInstructionSelector::selectOpUndef(Register ResVReg,
2686                                              const SPIRVType *ResType,
2687                                              MachineInstr &I) const {
2688   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
2689       .addDef(ResVReg)
2690       .addUse(GR.getSPIRVTypeID(ResType))
2691       .constrainAllUses(TII, TRI, RBI);
2692 }
2693 
2694 static bool isImm(const MachineOperand &MO, MachineRegisterInfo *MRI) {
2695   assert(MO.isReg());
2696   const SPIRVType *TypeInst = MRI->getVRegDef(MO.getReg());
2697   if (TypeInst->getOpcode() == SPIRV::ASSIGN_TYPE) {
2698     assert(TypeInst->getOperand(1).isReg());
2699     MachineInstr *ImmInst = MRI->getVRegDef(TypeInst->getOperand(1).getReg());
2700     return ImmInst->getOpcode() == TargetOpcode::G_CONSTANT;
2701   }
2702   return TypeInst->getOpcode() == SPIRV::OpConstantI;
2703 }
2704 
2705 static int64_t foldImm(const MachineOperand &MO, MachineRegisterInfo *MRI) {
2706   const SPIRVType *TypeInst = MRI->getVRegDef(MO.getReg());
2707   if (TypeInst->getOpcode() == SPIRV::OpConstantI)
2708     return TypeInst->getOperand(2).getImm();
2709   MachineInstr *ImmInst = MRI->getVRegDef(TypeInst->getOperand(1).getReg());
2710   assert(ImmInst->getOpcode() == TargetOpcode::G_CONSTANT);
2711   return ImmInst->getOperand(1).getCImm()->getZExtValue();
2712 }
2713 
2714 bool SPIRVInstructionSelector::selectInsertVal(Register ResVReg,
2715                                                const SPIRVType *ResType,
2716                                                MachineInstr &I) const {
2717   MachineBasicBlock &BB = *I.getParent();
2718   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeInsert))
2719                  .addDef(ResVReg)
2720                  .addUse(GR.getSPIRVTypeID(ResType))
2721                  // object to insert
2722                  .addUse(I.getOperand(3).getReg())
2723                  // composite to insert into
2724                  .addUse(I.getOperand(2).getReg());
2725   for (unsigned i = 4; i < I.getNumOperands(); i++)
2726     MIB.addImm(foldImm(I.getOperand(i), MRI));
2727   return MIB.constrainAllUses(TII, TRI, RBI);
2728 }
2729 
2730 bool SPIRVInstructionSelector::selectExtractVal(Register ResVReg,
2731                                                 const SPIRVType *ResType,
2732                                                 MachineInstr &I) const {
2733   MachineBasicBlock &BB = *I.getParent();
2734   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
2735                  .addDef(ResVReg)
2736                  .addUse(GR.getSPIRVTypeID(ResType))
2737                  .addUse(I.getOperand(2).getReg());
2738   for (unsigned i = 3; i < I.getNumOperands(); i++)
2739     MIB.addImm(foldImm(I.getOperand(i), MRI));
2740   return MIB.constrainAllUses(TII, TRI, RBI);
2741 }
2742 
2743 bool SPIRVInstructionSelector::selectInsertElt(Register ResVReg,
2744                                                const SPIRVType *ResType,
2745                                                MachineInstr &I) const {
2746   if (isImm(I.getOperand(4), MRI))
2747     return selectInsertVal(ResVReg, ResType, I);
2748   MachineBasicBlock &BB = *I.getParent();
2749   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorInsertDynamic))
2750       .addDef(ResVReg)
2751       .addUse(GR.getSPIRVTypeID(ResType))
2752       .addUse(I.getOperand(2).getReg())
2753       .addUse(I.getOperand(3).getReg())
2754       .addUse(I.getOperand(4).getReg())
2755       .constrainAllUses(TII, TRI, RBI);
2756 }
2757 
2758 bool SPIRVInstructionSelector::selectExtractElt(Register ResVReg,
2759                                                 const SPIRVType *ResType,
2760                                                 MachineInstr &I) const {
2761   if (isImm(I.getOperand(3), MRI))
2762     return selectExtractVal(ResVReg, ResType, I);
2763   MachineBasicBlock &BB = *I.getParent();
2764   return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpVectorExtractDynamic))
2765       .addDef(ResVReg)
2766       .addUse(GR.getSPIRVTypeID(ResType))
2767       .addUse(I.getOperand(2).getReg())
2768       .addUse(I.getOperand(3).getReg())
2769       .constrainAllUses(TII, TRI, RBI);
2770 }
2771 
2772 bool SPIRVInstructionSelector::selectGEP(Register ResVReg,
2773                                          const SPIRVType *ResType,
2774                                          MachineInstr &I) const {
2775   const bool IsGEPInBounds = I.getOperand(2).getImm();
2776 
2777   // OpAccessChain could be used for OpenCL, but the SPIRV-LLVM Translator only
2778   // relies on PtrAccessChain, so we'll try not to deviate. For Vulkan however,
2779   // we have to use Op[InBounds]AccessChain.
2780   const unsigned Opcode = STI.isVulkanEnv()
2781                               ? (IsGEPInBounds ? SPIRV::OpInBoundsAccessChain
2782                                                : SPIRV::OpAccessChain)
2783                               : (IsGEPInBounds ? SPIRV::OpInBoundsPtrAccessChain
2784                                                : SPIRV::OpPtrAccessChain);
2785 
2786   auto Res = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
2787                  .addDef(ResVReg)
2788                  .addUse(GR.getSPIRVTypeID(ResType))
2789                  // Object to get a pointer to.
2790                  .addUse(I.getOperand(3).getReg());
2791   // Adding indices.
2792   const unsigned StartingIndex =
2793       (Opcode == SPIRV::OpAccessChain || Opcode == SPIRV::OpInBoundsAccessChain)
2794           ? 5
2795           : 4;
2796   for (unsigned i = StartingIndex; i < I.getNumExplicitOperands(); ++i)
2797     Res.addUse(I.getOperand(i).getReg());
2798   return Res.constrainAllUses(TII, TRI, RBI);
2799 }
2800 
2801 // Maybe wrap a value into OpSpecConstantOp
2802 bool SPIRVInstructionSelector::wrapIntoSpecConstantOp(
2803     MachineInstr &I, SmallVector<Register> &CompositeArgs) const {
2804   bool Result = true;
2805   unsigned Lim = I.getNumExplicitOperands();
2806   for (unsigned i = I.getNumExplicitDefs() + 1; i < Lim; ++i) {
2807     Register OpReg = I.getOperand(i).getReg();
2808     SPIRVType *OpDefine = MRI->getVRegDef(OpReg);
2809     SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
2810     SmallPtrSet<SPIRVType *, 4> Visited;
2811     if (!OpDefine || !OpType || isConstReg(MRI, OpDefine, Visited) ||
2812         OpDefine->getOpcode() == TargetOpcode::G_ADDRSPACE_CAST ||
2813         GR.isAggregateType(OpType)) {
2814       // The case of G_ADDRSPACE_CAST inside spv_const_composite() is processed
2815       // by selectAddrSpaceCast()
2816       CompositeArgs.push_back(OpReg);
2817       continue;
2818     }
2819     MachineFunction *MF = I.getMF();
2820     Register WrapReg = GR.find(OpDefine, MF);
2821     if (WrapReg.isValid()) {
2822       CompositeArgs.push_back(WrapReg);
2823       continue;
2824     }
2825     // Create a new register for the wrapper
2826     WrapReg = MRI->createVirtualRegister(GR.getRegClass(OpType));
2827     GR.add(OpDefine, MF, WrapReg);
2828     CompositeArgs.push_back(WrapReg);
2829     // Decorate the wrapper register and generate a new instruction
2830     MRI->setType(WrapReg, LLT::pointer(0, 64));
2831     GR.assignSPIRVTypeToVReg(OpType, WrapReg, *MF);
2832     MachineBasicBlock &BB = *I.getParent();
2833     Result = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSpecConstantOp))
2834                  .addDef(WrapReg)
2835                  .addUse(GR.getSPIRVTypeID(OpType))
2836                  .addImm(static_cast<uint32_t>(SPIRV::Opcode::Bitcast))
2837                  .addUse(OpReg)
2838                  .constrainAllUses(TII, TRI, RBI);
2839     if (!Result)
2840       break;
2841   }
2842   return Result;
2843 }
2844 
2845 bool SPIRVInstructionSelector::selectIntrinsic(Register ResVReg,
2846                                                const SPIRVType *ResType,
2847                                                MachineInstr &I) const {
2848   MachineBasicBlock &BB = *I.getParent();
2849   Intrinsic::ID IID = cast<GIntrinsic>(I).getIntrinsicID();
2850   switch (IID) {
2851   case Intrinsic::spv_load:
2852     return selectLoad(ResVReg, ResType, I);
2853   case Intrinsic::spv_store:
2854     return selectStore(I);
2855   case Intrinsic::spv_extractv:
2856     return selectExtractVal(ResVReg, ResType, I);
2857   case Intrinsic::spv_insertv:
2858     return selectInsertVal(ResVReg, ResType, I);
2859   case Intrinsic::spv_extractelt:
2860     return selectExtractElt(ResVReg, ResType, I);
2861   case Intrinsic::spv_insertelt:
2862     return selectInsertElt(ResVReg, ResType, I);
2863   case Intrinsic::spv_gep:
2864     return selectGEP(ResVReg, ResType, I);
2865   case Intrinsic::spv_unref_global:
2866   case Intrinsic::spv_init_global: {
2867     MachineInstr *MI = MRI->getVRegDef(I.getOperand(1).getReg());
2868     MachineInstr *Init = I.getNumExplicitOperands() > 2
2869                              ? MRI->getVRegDef(I.getOperand(2).getReg())
2870                              : nullptr;
2871     assert(MI);
2872     return selectGlobalValue(MI->getOperand(0).getReg(), *MI, Init);
2873   }
2874   case Intrinsic::spv_undef: {
2875     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
2876                    .addDef(ResVReg)
2877                    .addUse(GR.getSPIRVTypeID(ResType));
2878     return MIB.constrainAllUses(TII, TRI, RBI);
2879   }
2880   case Intrinsic::spv_const_composite: {
2881     // If no values are attached, the composite is null constant.
2882     bool IsNull = I.getNumExplicitDefs() + 1 == I.getNumExplicitOperands();
2883     // Select a proper instruction.
2884     unsigned Opcode = SPIRV::OpConstantNull;
2885     SmallVector<Register> CompositeArgs;
2886     if (!IsNull) {
2887       Opcode = SPIRV::OpConstantComposite;
2888       if (!wrapIntoSpecConstantOp(I, CompositeArgs))
2889         return false;
2890     }
2891     MRI->setRegClass(ResVReg, GR.getRegClass(ResType));
2892     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
2893                    .addDef(ResVReg)
2894                    .addUse(GR.getSPIRVTypeID(ResType));
2895     // skip type MD node we already used when generated assign.type for this
2896     if (!IsNull) {
2897       for (Register OpReg : CompositeArgs)
2898         MIB.addUse(OpReg);
2899     }
2900     return MIB.constrainAllUses(TII, TRI, RBI);
2901   }
2902   case Intrinsic::spv_assign_name: {
2903     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpName));
2904     MIB.addUse(I.getOperand(I.getNumExplicitDefs() + 1).getReg());
2905     for (unsigned i = I.getNumExplicitDefs() + 2;
2906          i < I.getNumExplicitOperands(); ++i) {
2907       MIB.addImm(I.getOperand(i).getImm());
2908     }
2909     return MIB.constrainAllUses(TII, TRI, RBI);
2910   }
2911   case Intrinsic::spv_switch: {
2912     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSwitch));
2913     for (unsigned i = 1; i < I.getNumExplicitOperands(); ++i) {
2914       if (I.getOperand(i).isReg())
2915         MIB.addReg(I.getOperand(i).getReg());
2916       else if (I.getOperand(i).isCImm())
2917         addNumImm(I.getOperand(i).getCImm()->getValue(), MIB);
2918       else if (I.getOperand(i).isMBB())
2919         MIB.addMBB(I.getOperand(i).getMBB());
2920       else
2921         llvm_unreachable("Unexpected OpSwitch operand");
2922     }
2923     return MIB.constrainAllUses(TII, TRI, RBI);
2924   }
2925   case Intrinsic::spv_loop_merge: {
2926     auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpLoopMerge));
2927     for (unsigned i = 1; i < I.getNumExplicitOperands(); ++i) {
2928       assert(I.getOperand(i).isMBB());
2929       MIB.addMBB(I.getOperand(i).getMBB());
2930     }
2931     MIB.addImm(SPIRV::SelectionControl::None);
2932     return MIB.constrainAllUses(TII, TRI, RBI);
2933   }
2934   case Intrinsic::spv_selection_merge: {
2935     auto MIB =
2936         BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpSelectionMerge));
2937     assert(I.getOperand(1).isMBB() &&
2938            "operand 1 to spv_selection_merge must be a basic block");
2939     MIB.addMBB(I.getOperand(1).getMBB());
2940     MIB.addImm(getSelectionOperandForImm(I.getOperand(2).getImm()));
2941     return MIB.constrainAllUses(TII, TRI, RBI);
2942   }
2943   case Intrinsic::spv_cmpxchg:
2944     return selectAtomicCmpXchg(ResVReg, ResType, I);
2945   case Intrinsic::spv_unreachable:
2946     return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUnreachable))
2947         .constrainAllUses(TII, TRI, RBI);
2948   case Intrinsic::spv_alloca:
2949     return selectFrameIndex(ResVReg, ResType, I);
2950   case Intrinsic::spv_alloca_array:
2951     return selectAllocaArray(ResVReg, ResType, I);
2952   case Intrinsic::spv_assume:
2953     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_expect_assume))
2954       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpAssumeTrueKHR))
2955           .addUse(I.getOperand(1).getReg())
2956           .constrainAllUses(TII, TRI, RBI);
2957     break;
2958   case Intrinsic::spv_expect:
2959     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_expect_assume))
2960       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExpectKHR))
2961           .addDef(ResVReg)
2962           .addUse(GR.getSPIRVTypeID(ResType))
2963           .addUse(I.getOperand(2).getReg())
2964           .addUse(I.getOperand(3).getReg())
2965           .constrainAllUses(TII, TRI, RBI);
2966     break;
2967   case Intrinsic::arithmetic_fence:
2968     if (STI.canUseExtension(SPIRV::Extension::SPV_EXT_arithmetic_fence))
2969       return BuildMI(BB, I, I.getDebugLoc(),
2970                      TII.get(SPIRV::OpArithmeticFenceEXT))
2971           .addDef(ResVReg)
2972           .addUse(GR.getSPIRVTypeID(ResType))
2973           .addUse(I.getOperand(2).getReg())
2974           .constrainAllUses(TII, TRI, RBI);
2975     else
2976       return BuildCOPY(ResVReg, I.getOperand(2).getReg(), I);
2977     break;
2978   case Intrinsic::spv_thread_id:
2979     // The HLSL SV_DispatchThreadID semantic is lowered to llvm.spv.thread.id
2980     // intrinsic in LLVM IR for SPIR-V backend.
2981     //
2982     // In SPIR-V backend, llvm.spv.thread.id is now correctly translated to a
2983     // `GlobalInvocationId` builtin variable
2984     return loadVec3BuiltinInputID(SPIRV::BuiltIn::GlobalInvocationId, ResVReg,
2985                                   ResType, I);
2986   case Intrinsic::spv_thread_id_in_group:
2987     // The HLSL SV_GroupThreadId semantic is lowered to
2988     // llvm.spv.thread.id.in.group intrinsic in LLVM IR for SPIR-V backend.
2989     //
2990     // In SPIR-V backend, llvm.spv.thread.id.in.group is now correctly
2991     // translated to a `LocalInvocationId` builtin variable
2992     return loadVec3BuiltinInputID(SPIRV::BuiltIn::LocalInvocationId, ResVReg,
2993                                   ResType, I);
2994   case Intrinsic::spv_group_id:
2995     // The HLSL SV_GroupId semantic is lowered to
2996     // llvm.spv.group.id intrinsic in LLVM IR for SPIR-V backend.
2997     //
2998     // In SPIR-V backend, llvm.spv.group.id is now translated to a `WorkgroupId`
2999     // builtin variable
3000     return loadVec3BuiltinInputID(SPIRV::BuiltIn::WorkgroupId, ResVReg, ResType,
3001                                   I);
3002   case Intrinsic::spv_fdot:
3003     return selectFloatDot(ResVReg, ResType, I);
3004   case Intrinsic::spv_udot:
3005   case Intrinsic::spv_sdot:
3006     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3007         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3008       return selectIntegerDot(ResVReg, ResType, I,
3009                               /*Signed=*/IID == Intrinsic::spv_sdot);
3010     return selectIntegerDotExpansion(ResVReg, ResType, I);
3011   case Intrinsic::spv_dot4add_i8packed:
3012     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3013         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3014       return selectDot4AddPacked<true>(ResVReg, ResType, I);
3015     return selectDot4AddPackedExpansion<true>(ResVReg, ResType, I);
3016   case Intrinsic::spv_dot4add_u8packed:
3017     if (STI.canUseExtension(SPIRV::Extension::SPV_KHR_integer_dot_product) ||
3018         STI.isAtLeastSPIRVVer(VersionTuple(1, 6)))
3019       return selectDot4AddPacked<false>(ResVReg, ResType, I);
3020     return selectDot4AddPackedExpansion<false>(ResVReg, ResType, I);
3021   case Intrinsic::spv_all:
3022     return selectAll(ResVReg, ResType, I);
3023   case Intrinsic::spv_any:
3024     return selectAny(ResVReg, ResType, I);
3025   case Intrinsic::spv_cross:
3026     return selectExtInst(ResVReg, ResType, I, CL::cross, GL::Cross);
3027   case Intrinsic::spv_distance:
3028     return selectExtInst(ResVReg, ResType, I, CL::distance, GL::Distance);
3029   case Intrinsic::spv_lerp:
3030     return selectExtInst(ResVReg, ResType, I, CL::mix, GL::FMix);
3031   case Intrinsic::spv_length:
3032     return selectExtInst(ResVReg, ResType, I, CL::length, GL::Length);
3033   case Intrinsic::spv_degrees:
3034     return selectExtInst(ResVReg, ResType, I, CL::degrees, GL::Degrees);
3035   case Intrinsic::spv_frac:
3036     return selectExtInst(ResVReg, ResType, I, CL::fract, GL::Fract);
3037   case Intrinsic::spv_normalize:
3038     return selectExtInst(ResVReg, ResType, I, CL::normalize, GL::Normalize);
3039   case Intrinsic::spv_reflect:
3040     return selectExtInst(ResVReg, ResType, I, GL::Reflect);
3041   case Intrinsic::spv_rsqrt:
3042     return selectExtInst(ResVReg, ResType, I, CL::rsqrt, GL::InverseSqrt);
3043   case Intrinsic::spv_sign:
3044     return selectSign(ResVReg, ResType, I);
3045   case Intrinsic::spv_firstbituhigh: // There is no CL equivalent of FindUMsb
3046     return selectFirstBitHigh(ResVReg, ResType, I, /*IsSigned=*/false);
3047   case Intrinsic::spv_firstbitshigh: // There is no CL equivalent of FindSMsb
3048     return selectFirstBitHigh(ResVReg, ResType, I, /*IsSigned=*/true);
3049   case Intrinsic::spv_firstbitlow: // There is no CL equivlent of FindILsb
3050     return selectFirstBitLow(ResVReg, ResType, I);
3051   case Intrinsic::spv_group_memory_barrier_with_group_sync: {
3052     bool Result = true;
3053     auto MemSemConstant =
3054         buildI32Constant(SPIRV::MemorySemantics::SequentiallyConsistent, I);
3055     Register MemSemReg = MemSemConstant.first;
3056     Result &= MemSemConstant.second;
3057     auto ScopeConstant = buildI32Constant(SPIRV::Scope::Workgroup, I);
3058     Register ScopeReg = ScopeConstant.first;
3059     Result &= ScopeConstant.second;
3060     MachineBasicBlock &BB = *I.getParent();
3061     return Result &&
3062            BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpControlBarrier))
3063                .addUse(ScopeReg)
3064                .addUse(ScopeReg)
3065                .addUse(MemSemReg)
3066                .constrainAllUses(TII, TRI, RBI);
3067   }
3068   case Intrinsic::spv_lifetime_start:
3069   case Intrinsic::spv_lifetime_end: {
3070     unsigned Op = IID == Intrinsic::spv_lifetime_start ? SPIRV::OpLifetimeStart
3071                                                        : SPIRV::OpLifetimeStop;
3072     int64_t Size = I.getOperand(I.getNumExplicitDefs() + 1).getImm();
3073     Register PtrReg = I.getOperand(I.getNumExplicitDefs() + 2).getReg();
3074     if (Size == -1)
3075       Size = 0;
3076     return BuildMI(BB, I, I.getDebugLoc(), TII.get(Op))
3077         .addUse(PtrReg)
3078         .addImm(Size)
3079         .constrainAllUses(TII, TRI, RBI);
3080   }
3081   case Intrinsic::spv_saturate:
3082     return selectSaturate(ResVReg, ResType, I);
3083   case Intrinsic::spv_nclamp:
3084     return selectExtInst(ResVReg, ResType, I, CL::fclamp, GL::NClamp);
3085   case Intrinsic::spv_uclamp:
3086     return selectExtInst(ResVReg, ResType, I, CL::u_clamp, GL::UClamp);
3087   case Intrinsic::spv_sclamp:
3088     return selectExtInst(ResVReg, ResType, I, CL::s_clamp, GL::SClamp);
3089   case Intrinsic::spv_wave_active_countbits:
3090     return selectWaveActiveCountBits(ResVReg, ResType, I);
3091   case Intrinsic::spv_wave_all:
3092     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformAll);
3093   case Intrinsic::spv_wave_any:
3094     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformAny);
3095   case Intrinsic::spv_wave_is_first_lane:
3096     return selectWaveOpInst(ResVReg, ResType, I, SPIRV::OpGroupNonUniformElect);
3097   case Intrinsic::spv_wave_reduce_sum:
3098     return selectWaveReduceSum(ResVReg, ResType, I);
3099   case Intrinsic::spv_wave_readlane:
3100     return selectWaveOpInst(ResVReg, ResType, I,
3101                             SPIRV::OpGroupNonUniformShuffle);
3102   case Intrinsic::spv_step:
3103     return selectExtInst(ResVReg, ResType, I, CL::step, GL::Step);
3104   case Intrinsic::spv_radians:
3105     return selectExtInst(ResVReg, ResType, I, CL::radians, GL::Radians);
3106   // Discard intrinsics which we do not expect to actually represent code after
3107   // lowering or intrinsics which are not implemented but should not crash when
3108   // found in a customer's LLVM IR input.
3109   case Intrinsic::instrprof_increment:
3110   case Intrinsic::instrprof_increment_step:
3111   case Intrinsic::instrprof_value_profile:
3112     break;
3113   // Discard internal intrinsics.
3114   case Intrinsic::spv_value_md:
3115     break;
3116   case Intrinsic::spv_resource_handlefrombinding: {
3117     return selectHandleFromBinding(ResVReg, ResType, I);
3118   }
3119   case Intrinsic::spv_resource_store_typedbuffer: {
3120     return selectImageWriteIntrinsic(I);
3121   }
3122   case Intrinsic::spv_resource_load_typedbuffer: {
3123     return selectReadImageIntrinsic(ResVReg, ResType, I);
3124   }
3125   case Intrinsic::spv_resource_getpointer: {
3126     return selectResourceGetPointer(ResVReg, ResType, I);
3127   }
3128   case Intrinsic::spv_discard: {
3129     return selectDiscard(ResVReg, ResType, I);
3130   }
3131   default: {
3132     std::string DiagMsg;
3133     raw_string_ostream OS(DiagMsg);
3134     I.print(OS);
3135     DiagMsg = "Intrinsic selection not implemented: " + DiagMsg;
3136     report_fatal_error(DiagMsg.c_str(), false);
3137   }
3138   }
3139   return true;
3140 }
3141 
3142 bool SPIRVInstructionSelector::selectHandleFromBinding(Register &ResVReg,
3143                                                        const SPIRVType *ResType,
3144                                                        MachineInstr &I) const {
3145   return true;
3146 }
3147 
3148 bool SPIRVInstructionSelector::selectReadImageIntrinsic(
3149     Register &ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
3150 
3151   // If the load of the image is in a different basic block, then
3152   // this will generate invalid code. A proper solution is to move
3153   // the OpLoad from selectHandleFromBinding here. However, to do
3154   // that we will need to change the return type of the intrinsic.
3155   // We will do that when we can, but for now trying to move forward with other
3156   // issues.
3157   Register ImageReg = I.getOperand(2).getReg();
3158   auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
3159   Register NewImageReg = MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
3160   if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
3161                                 *ImageDef, I)) {
3162     return false;
3163   }
3164 
3165   Register IdxReg = I.getOperand(3).getReg();
3166   DebugLoc Loc = I.getDebugLoc();
3167   MachineInstr &Pos = I;
3168 
3169   return generateImageRead(ResVReg, ResType, NewImageReg, IdxReg, Loc, Pos);
3170 }
3171 
3172 bool SPIRVInstructionSelector::generateImageRead(Register &ResVReg,
3173                                                  const SPIRVType *ResType,
3174                                                  Register ImageReg,
3175                                                  Register IdxReg, DebugLoc Loc,
3176                                                  MachineInstr &Pos) const {
3177   uint64_t ResultSize = GR.getScalarOrVectorComponentCount(ResType);
3178   if (ResultSize == 4) {
3179     return BuildMI(*Pos.getParent(), Pos, Loc, TII.get(SPIRV::OpImageRead))
3180         .addDef(ResVReg)
3181         .addUse(GR.getSPIRVTypeID(ResType))
3182         .addUse(ImageReg)
3183         .addUse(IdxReg)
3184         .constrainAllUses(TII, TRI, RBI);
3185   }
3186 
3187   SPIRVType *ReadType = widenTypeToVec4(ResType, Pos);
3188   Register ReadReg = MRI->createVirtualRegister(GR.getRegClass(ReadType));
3189   bool Succeed =
3190       BuildMI(*Pos.getParent(), Pos, Loc, TII.get(SPIRV::OpImageRead))
3191           .addDef(ReadReg)
3192           .addUse(GR.getSPIRVTypeID(ReadType))
3193           .addUse(ImageReg)
3194           .addUse(IdxReg)
3195           .constrainAllUses(TII, TRI, RBI);
3196   if (!Succeed)
3197     return false;
3198 
3199   if (ResultSize == 1) {
3200     return BuildMI(*Pos.getParent(), Pos, Loc,
3201                    TII.get(SPIRV::OpCompositeExtract))
3202         .addDef(ResVReg)
3203         .addUse(GR.getSPIRVTypeID(ResType))
3204         .addUse(ReadReg)
3205         .addImm(0)
3206         .constrainAllUses(TII, TRI, RBI);
3207   }
3208   return extractSubvector(ResVReg, ResType, ReadReg, Pos);
3209 }
3210 
3211 bool SPIRVInstructionSelector::selectResourceGetPointer(
3212     Register &ResVReg, const SPIRVType *ResType, MachineInstr &I) const {
3213 #ifdef ASSERT
3214   // For now, the operand is an image. This will change once we start handling
3215   // more resource types.
3216   Register ResourcePtr = I.getOperand(2).getReg();
3217   SPIRVType *RegType = GR.getResultType(ResourcePtr);
3218   assert(RegType->getOpcode() == SPIRV::OpTypeImage &&
3219          "Can only handle texel buffers for now.");
3220 #endif
3221 
3222   // For texel buffers, the index into the image is part of the OpImageRead or
3223   // OpImageWrite instructions. So we will do nothing in this case. This
3224   // intrinsic will be combined with the load or store when selecting the load
3225   // or store.
3226   return true;
3227 }
3228 
3229 bool SPIRVInstructionSelector::extractSubvector(
3230     Register &ResVReg, const SPIRVType *ResType, Register &ReadReg,
3231     MachineInstr &InsertionPoint) const {
3232   SPIRVType *InputType = GR.getResultType(ReadReg);
3233   [[maybe_unused]] uint64_t InputSize =
3234       GR.getScalarOrVectorComponentCount(InputType);
3235   uint64_t ResultSize = GR.getScalarOrVectorComponentCount(ResType);
3236   assert(InputSize > 1 && "The input must be a vector.");
3237   assert(ResultSize > 1 && "The result must be a vector.");
3238   assert(ResultSize < InputSize &&
3239          "Cannot extract more element than there are in the input.");
3240   SmallVector<Register> ComponentRegisters;
3241   SPIRVType *ScalarType = GR.getScalarOrVectorComponentType(ResType);
3242   const TargetRegisterClass *ScalarRegClass = GR.getRegClass(ScalarType);
3243   for (uint64_t I = 0; I < ResultSize; I++) {
3244     Register ComponentReg = MRI->createVirtualRegister(ScalarRegClass);
3245     bool Succeed = BuildMI(*InsertionPoint.getParent(), InsertionPoint,
3246                            InsertionPoint.getDebugLoc(),
3247                            TII.get(SPIRV::OpCompositeExtract))
3248                        .addDef(ComponentReg)
3249                        .addUse(ScalarType->getOperand(0).getReg())
3250                        .addUse(ReadReg)
3251                        .addImm(I)
3252                        .constrainAllUses(TII, TRI, RBI);
3253     if (!Succeed)
3254       return false;
3255     ComponentRegisters.emplace_back(ComponentReg);
3256   }
3257 
3258   MachineInstrBuilder MIB = BuildMI(*InsertionPoint.getParent(), InsertionPoint,
3259                                     InsertionPoint.getDebugLoc(),
3260                                     TII.get(SPIRV::OpCompositeConstruct))
3261                                 .addDef(ResVReg)
3262                                 .addUse(GR.getSPIRVTypeID(ResType));
3263 
3264   for (Register ComponentReg : ComponentRegisters)
3265     MIB.addUse(ComponentReg);
3266   return MIB.constrainAllUses(TII, TRI, RBI);
3267 }
3268 
3269 bool SPIRVInstructionSelector::selectImageWriteIntrinsic(
3270     MachineInstr &I) const {
3271   // If the load of the image is in a different basic block, then
3272   // this will generate invalid code. A proper solution is to move
3273   // the OpLoad from selectHandleFromBinding here. However, to do
3274   // that we will need to change the return type of the intrinsic.
3275   // We will do that when we can, but for now trying to move forward with other
3276   // issues.
3277   Register ImageReg = I.getOperand(1).getReg();
3278   auto *ImageDef = cast<GIntrinsic>(getVRegDef(*MRI, ImageReg));
3279   Register NewImageReg = MRI->createVirtualRegister(MRI->getRegClass(ImageReg));
3280   if (!loadHandleBeforePosition(NewImageReg, GR.getSPIRVTypeForVReg(ImageReg),
3281                                 *ImageDef, I)) {
3282     return false;
3283   }
3284 
3285   Register CoordinateReg = I.getOperand(2).getReg();
3286   Register DataReg = I.getOperand(3).getReg();
3287   assert(GR.getResultType(DataReg)->getOpcode() == SPIRV::OpTypeVector);
3288   assert(GR.getScalarOrVectorComponentCount(GR.getResultType(DataReg)) == 4);
3289   return BuildMI(*I.getParent(), I, I.getDebugLoc(),
3290                  TII.get(SPIRV::OpImageWrite))
3291       .addUse(NewImageReg)
3292       .addUse(CoordinateReg)
3293       .addUse(DataReg)
3294       .constrainAllUses(TII, TRI, RBI);
3295 }
3296 
3297 Register SPIRVInstructionSelector::buildPointerToResource(
3298     const SPIRVType *ResType, uint32_t Set, uint32_t Binding,
3299     uint32_t ArraySize, Register IndexReg, bool IsNonUniform,
3300     MachineIRBuilder MIRBuilder) const {
3301   if (ArraySize == 1)
3302     return GR.getOrCreateGlobalVariableWithBinding(ResType, Set, Binding,
3303                                                    MIRBuilder);
3304 
3305   const SPIRVType *VarType = GR.getOrCreateSPIRVArrayType(
3306       ResType, ArraySize, *MIRBuilder.getInsertPt(), TII);
3307   Register VarReg = GR.getOrCreateGlobalVariableWithBinding(
3308       VarType, Set, Binding, MIRBuilder);
3309 
3310   SPIRVType *ResPointerType = GR.getOrCreateSPIRVPointerType(
3311       ResType, MIRBuilder, SPIRV::StorageClass::UniformConstant);
3312 
3313   Register AcReg = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
3314   if (IsNonUniform) {
3315     // It is unclear which value needs to be marked an non-uniform, so both
3316     // the index and the access changed are decorated as non-uniform.
3317     buildOpDecorate(IndexReg, MIRBuilder, SPIRV::Decoration::NonUniformEXT, {});
3318     buildOpDecorate(AcReg, MIRBuilder, SPIRV::Decoration::NonUniformEXT, {});
3319   }
3320 
3321   MIRBuilder.buildInstr(SPIRV::OpAccessChain)
3322       .addDef(AcReg)
3323       .addUse(GR.getSPIRVTypeID(ResPointerType))
3324       .addUse(VarReg)
3325       .addUse(IndexReg);
3326 
3327   return AcReg;
3328 }
3329 
3330 bool SPIRVInstructionSelector::selectFirstBitSet16(
3331     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3332     unsigned ExtendOpcode, unsigned BitSetOpcode) const {
3333   Register ExtReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3334   bool Result = selectOpWithSrcs(ExtReg, ResType, I, {I.getOperand(2).getReg()},
3335                                  ExtendOpcode);
3336 
3337   return Result &&
3338          selectFirstBitSet32(ResVReg, ResType, I, ExtReg, BitSetOpcode);
3339 }
3340 
3341 bool SPIRVInstructionSelector::selectFirstBitSet32(
3342     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3343     Register SrcReg, unsigned BitSetOpcode) const {
3344   return BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
3345       .addDef(ResVReg)
3346       .addUse(GR.getSPIRVTypeID(ResType))
3347       .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
3348       .addImm(BitSetOpcode)
3349       .addUse(SrcReg)
3350       .constrainAllUses(TII, TRI, RBI);
3351 }
3352 
3353 bool SPIRVInstructionSelector::selectFirstBitSet64Overflow(
3354     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3355     Register SrcReg, unsigned BitSetOpcode, bool SwapPrimarySide) const {
3356 
3357   // SPIR-V allow vectors of size 2,3,4 only. Calling with a larger vectors
3358   // requires creating a param register and return register with an invalid
3359   // vector size. If that is resolved, then this function can be used for
3360   // vectors of any component size.
3361   unsigned ComponentCount = GR.getScalarOrVectorComponentCount(ResType);
3362   assert(ComponentCount < 5 && "Vec 5+ will generate invalid SPIR-V ops");
3363 
3364   MachineIRBuilder MIRBuilder(I);
3365   SPIRVType *BaseType = GR.retrieveScalarOrVectorIntType(ResType);
3366   SPIRVType *I64Type = GR.getOrCreateSPIRVIntegerType(64, MIRBuilder);
3367   SPIRVType *I64x2Type = GR.getOrCreateSPIRVVectorType(I64Type, 2, MIRBuilder);
3368   SPIRVType *Vec2ResType =
3369       GR.getOrCreateSPIRVVectorType(BaseType, 2, MIRBuilder);
3370 
3371   std::vector<Register> PartialRegs;
3372 
3373   // Loops 0, 2, 4, ... but stops one loop early when ComponentCount is odd
3374   unsigned CurrentComponent = 0;
3375   for (; CurrentComponent + 1 < ComponentCount; CurrentComponent += 2) {
3376     // This register holds the firstbitX result for each of the i64x2 vectors
3377     // extracted from SrcReg
3378     Register BitSetResult =
3379         MRI->createVirtualRegister(GR.getRegClass(I64x2Type));
3380 
3381     auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3382                        TII.get(SPIRV::OpVectorShuffle))
3383                    .addDef(BitSetResult)
3384                    .addUse(GR.getSPIRVTypeID(I64x2Type))
3385                    .addUse(SrcReg)
3386                    .addUse(SrcReg)
3387                    .addImm(CurrentComponent)
3388                    .addImm(CurrentComponent + 1);
3389 
3390     if (!MIB.constrainAllUses(TII, TRI, RBI))
3391       return false;
3392 
3393     Register SubVecBitSetReg =
3394         MRI->createVirtualRegister(GR.getRegClass(Vec2ResType));
3395 
3396     if (!selectFirstBitSet64(SubVecBitSetReg, Vec2ResType, I, BitSetResult,
3397                              BitSetOpcode, SwapPrimarySide))
3398       return false;
3399 
3400     PartialRegs.push_back(SubVecBitSetReg);
3401   }
3402 
3403   // On odd component counts we need to handle one more component
3404   if (CurrentComponent != ComponentCount) {
3405     bool ZeroAsNull = STI.isOpenCLEnv();
3406     Register FinalElemReg = MRI->createVirtualRegister(GR.getRegClass(I64Type));
3407     Register ConstIntLastIdx = GR.getOrCreateConstInt(
3408         ComponentCount - 1, I, BaseType, TII, ZeroAsNull);
3409 
3410     if (!selectOpWithSrcs(FinalElemReg, I64Type, I, {SrcReg, ConstIntLastIdx},
3411                           SPIRV::OpVectorExtractDynamic))
3412       return false;
3413 
3414     Register FinalElemBitSetReg =
3415         MRI->createVirtualRegister(GR.getRegClass(BaseType));
3416 
3417     if (!selectFirstBitSet64(FinalElemBitSetReg, BaseType, I, FinalElemReg,
3418                              BitSetOpcode, SwapPrimarySide))
3419       return false;
3420 
3421     PartialRegs.push_back(FinalElemBitSetReg);
3422   }
3423 
3424   // Join all the resulting registers back into the return type in order
3425   // (ie i32x2, i32x2, i32x1 -> i32x5)
3426   return selectOpWithSrcs(ResVReg, ResType, I, PartialRegs,
3427                           SPIRV::OpCompositeConstruct);
3428 }
3429 
3430 bool SPIRVInstructionSelector::selectFirstBitSet64(
3431     Register ResVReg, const SPIRVType *ResType, MachineInstr &I,
3432     Register SrcReg, unsigned BitSetOpcode, bool SwapPrimarySide) const {
3433   unsigned ComponentCount = GR.getScalarOrVectorComponentCount(ResType);
3434   SPIRVType *BaseType = GR.retrieveScalarOrVectorIntType(ResType);
3435   bool ZeroAsNull = STI.isOpenCLEnv();
3436   Register ConstIntZero =
3437       GR.getOrCreateConstInt(0, I, BaseType, TII, ZeroAsNull);
3438   Register ConstIntOne =
3439       GR.getOrCreateConstInt(1, I, BaseType, TII, ZeroAsNull);
3440 
3441   // SPIRV doesn't support vectors with more than 4 components. Since the
3442   // algoritm below converts i64 -> i32x2 and i64x4 -> i32x8 it can only
3443   // operate on vectors with 2 or less components. When largers vectors are
3444   // seen. Split them, recurse, then recombine them.
3445   if (ComponentCount > 2) {
3446     return selectFirstBitSet64Overflow(ResVReg, ResType, I, SrcReg,
3447                                        BitSetOpcode, SwapPrimarySide);
3448   }
3449 
3450   // 1. Split int64 into 2 pieces using a bitcast
3451   MachineIRBuilder MIRBuilder(I);
3452   SPIRVType *PostCastType =
3453       GR.getOrCreateSPIRVVectorType(BaseType, 2 * ComponentCount, MIRBuilder);
3454   Register BitcastReg =
3455       MRI->createVirtualRegister(GR.getRegClass(PostCastType));
3456 
3457   if (!selectOpWithSrcs(BitcastReg, PostCastType, I, {SrcReg},
3458                         SPIRV::OpBitcast))
3459     return false;
3460 
3461   // 2. Find the first set bit from the primary side for all the pieces in #1
3462   Register FBSReg = MRI->createVirtualRegister(GR.getRegClass(PostCastType));
3463   if (!selectFirstBitSet32(FBSReg, PostCastType, I, BitcastReg, BitSetOpcode))
3464     return false;
3465 
3466   // 3. Split result vector into high bits and low bits
3467   Register HighReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3468   Register LowReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3469 
3470   bool IsScalarRes = ResType->getOpcode() != SPIRV::OpTypeVector;
3471   if (IsScalarRes) {
3472     // if scalar do a vector extract
3473     if (!selectOpWithSrcs(HighReg, ResType, I, {FBSReg, ConstIntZero},
3474                           SPIRV::OpVectorExtractDynamic))
3475       return false;
3476     if (!selectOpWithSrcs(LowReg, ResType, I, {FBSReg, ConstIntOne},
3477                           SPIRV::OpVectorExtractDynamic))
3478       return false;
3479   } else {
3480     // if vector do a shufflevector
3481     auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3482                        TII.get(SPIRV::OpVectorShuffle))
3483                    .addDef(HighReg)
3484                    .addUse(GR.getSPIRVTypeID(ResType))
3485                    .addUse(FBSReg)
3486                    // Per the spec, repeat the vector if only one vec is needed
3487                    .addUse(FBSReg);
3488 
3489     // high bits are stored in even indexes. Extract them from FBSReg
3490     for (unsigned J = 0; J < ComponentCount * 2; J += 2) {
3491       MIB.addImm(J);
3492     }
3493 
3494     if (!MIB.constrainAllUses(TII, TRI, RBI))
3495       return false;
3496 
3497     MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(),
3498                   TII.get(SPIRV::OpVectorShuffle))
3499               .addDef(LowReg)
3500               .addUse(GR.getSPIRVTypeID(ResType))
3501               .addUse(FBSReg)
3502               // Per the spec, repeat the vector if only one vec is needed
3503               .addUse(FBSReg);
3504 
3505     // low bits are stored in odd indexes. Extract them from FBSReg
3506     for (unsigned J = 1; J < ComponentCount * 2; J += 2) {
3507       MIB.addImm(J);
3508     }
3509     if (!MIB.constrainAllUses(TII, TRI, RBI))
3510       return false;
3511   }
3512 
3513   // 4. Check the result. When primary bits == -1 use secondary, otherwise use
3514   // primary
3515   SPIRVType *BoolType = GR.getOrCreateSPIRVBoolType(I, TII);
3516   Register NegOneReg;
3517   Register Reg0;
3518   Register Reg32;
3519   unsigned SelectOp;
3520   unsigned AddOp;
3521 
3522   if (IsScalarRes) {
3523     NegOneReg =
3524         GR.getOrCreateConstInt((unsigned)-1, I, ResType, TII, ZeroAsNull);
3525     Reg0 = GR.getOrCreateConstInt(0, I, ResType, TII, ZeroAsNull);
3526     Reg32 = GR.getOrCreateConstInt(32, I, ResType, TII, ZeroAsNull);
3527     SelectOp = SPIRV::OpSelectSISCond;
3528     AddOp = SPIRV::OpIAddS;
3529   } else {
3530     BoolType =
3531         GR.getOrCreateSPIRVVectorType(BoolType, ComponentCount, MIRBuilder);
3532     NegOneReg =
3533         GR.getOrCreateConstVector((unsigned)-1, I, ResType, TII, ZeroAsNull);
3534     Reg0 = GR.getOrCreateConstVector(0, I, ResType, TII, ZeroAsNull);
3535     Reg32 = GR.getOrCreateConstVector(32, I, ResType, TII, ZeroAsNull);
3536     SelectOp = SPIRV::OpSelectVIVCond;
3537     AddOp = SPIRV::OpIAddV;
3538   }
3539 
3540   Register PrimaryReg = HighReg;
3541   Register SecondaryReg = LowReg;
3542   Register PrimaryShiftReg = Reg32;
3543   Register SecondaryShiftReg = Reg0;
3544 
3545   // By default the emitted opcodes check for the set bit from the MSB side.
3546   // Setting SwapPrimarySide checks the set bit from the LSB side
3547   if (SwapPrimarySide) {
3548     PrimaryReg = LowReg;
3549     SecondaryReg = HighReg;
3550     PrimaryShiftReg = Reg0;
3551     SecondaryShiftReg = Reg32;
3552   }
3553 
3554   // Check if the primary bits are == -1
3555   Register BReg = MRI->createVirtualRegister(GR.getRegClass(BoolType));
3556   if (!selectOpWithSrcs(BReg, BoolType, I, {PrimaryReg, NegOneReg},
3557                         SPIRV::OpIEqual))
3558     return false;
3559 
3560   // Select secondary bits if true in BReg, otherwise primary bits
3561   Register TmpReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3562   if (!selectOpWithSrcs(TmpReg, ResType, I, {BReg, SecondaryReg, PrimaryReg},
3563                         SelectOp))
3564     return false;
3565 
3566   // 5. Add 32 when high bits are used, otherwise 0 for low bits
3567   Register ValReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3568   if (!selectOpWithSrcs(ValReg, ResType, I,
3569                         {BReg, SecondaryShiftReg, PrimaryShiftReg}, SelectOp))
3570     return false;
3571 
3572   return selectOpWithSrcs(ResVReg, ResType, I, {ValReg, TmpReg}, AddOp);
3573 }
3574 
3575 bool SPIRVInstructionSelector::selectFirstBitHigh(Register ResVReg,
3576                                                   const SPIRVType *ResType,
3577                                                   MachineInstr &I,
3578                                                   bool IsSigned) const {
3579   // FindUMsb and FindSMsb intrinsics only support 32 bit integers
3580   Register OpReg = I.getOperand(2).getReg();
3581   SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
3582   // zero or sign extend
3583   unsigned ExtendOpcode = IsSigned ? SPIRV::OpSConvert : SPIRV::OpUConvert;
3584   unsigned BitSetOpcode = IsSigned ? GL::FindSMsb : GL::FindUMsb;
3585 
3586   switch (GR.getScalarOrVectorBitWidth(OpType)) {
3587   case 16:
3588     return selectFirstBitSet16(ResVReg, ResType, I, ExtendOpcode, BitSetOpcode);
3589   case 32:
3590     return selectFirstBitSet32(ResVReg, ResType, I, OpReg, BitSetOpcode);
3591   case 64:
3592     return selectFirstBitSet64(ResVReg, ResType, I, OpReg, BitSetOpcode,
3593                                /*SwapPrimarySide=*/false);
3594   default:
3595     report_fatal_error(
3596         "spv_firstbituhigh and spv_firstbitshigh only support 16,32,64 bits.");
3597   }
3598 }
3599 
3600 bool SPIRVInstructionSelector::selectFirstBitLow(Register ResVReg,
3601                                                  const SPIRVType *ResType,
3602                                                  MachineInstr &I) const {
3603   // FindILsb intrinsic only supports 32 bit integers
3604   Register OpReg = I.getOperand(2).getReg();
3605   SPIRVType *OpType = GR.getSPIRVTypeForVReg(OpReg);
3606   // OpUConvert treats the operand bits as an unsigned i16 and zero extends it
3607   // to an unsigned i32. As this leaves all the least significant bits unchanged
3608   // so the first set bit from the LSB side doesn't change.
3609   unsigned ExtendOpcode = SPIRV::OpUConvert;
3610   unsigned BitSetOpcode = GL::FindILsb;
3611 
3612   switch (GR.getScalarOrVectorBitWidth(OpType)) {
3613   case 16:
3614     return selectFirstBitSet16(ResVReg, ResType, I, ExtendOpcode, BitSetOpcode);
3615   case 32:
3616     return selectFirstBitSet32(ResVReg, ResType, I, OpReg, BitSetOpcode);
3617   case 64:
3618     return selectFirstBitSet64(ResVReg, ResType, I, OpReg, BitSetOpcode,
3619                                /*SwapPrimarySide=*/true);
3620   default:
3621     report_fatal_error("spv_firstbitlow only supports 16,32,64 bits.");
3622   }
3623 }
3624 
3625 bool SPIRVInstructionSelector::selectAllocaArray(Register ResVReg,
3626                                                  const SPIRVType *ResType,
3627                                                  MachineInstr &I) const {
3628   // there was an allocation size parameter to the allocation instruction
3629   // that is not 1
3630   MachineBasicBlock &BB = *I.getParent();
3631   bool Res = BuildMI(BB, I, I.getDebugLoc(),
3632                      TII.get(SPIRV::OpVariableLengthArrayINTEL))
3633                  .addDef(ResVReg)
3634                  .addUse(GR.getSPIRVTypeID(ResType))
3635                  .addUse(I.getOperand(2).getReg())
3636                  .constrainAllUses(TII, TRI, RBI);
3637   if (!STI.isVulkanEnv()) {
3638     unsigned Alignment = I.getOperand(3).getImm();
3639     buildOpDecorate(ResVReg, I, TII, SPIRV::Decoration::Alignment, {Alignment});
3640   }
3641   return Res;
3642 }
3643 
3644 bool SPIRVInstructionSelector::selectFrameIndex(Register ResVReg,
3645                                                 const SPIRVType *ResType,
3646                                                 MachineInstr &I) const {
3647   // Change order of instructions if needed: all OpVariable instructions in a
3648   // function must be the first instructions in the first block
3649   auto It = getOpVariableMBBIt(I);
3650   bool Res = BuildMI(*It->getParent(), It, It->getDebugLoc(),
3651                      TII.get(SPIRV::OpVariable))
3652                  .addDef(ResVReg)
3653                  .addUse(GR.getSPIRVTypeID(ResType))
3654                  .addImm(static_cast<uint32_t>(SPIRV::StorageClass::Function))
3655                  .constrainAllUses(TII, TRI, RBI);
3656   if (!STI.isVulkanEnv()) {
3657     unsigned Alignment = I.getOperand(2).getImm();
3658     buildOpDecorate(ResVReg, *It, TII, SPIRV::Decoration::Alignment,
3659                     {Alignment});
3660   }
3661   return Res;
3662 }
3663 
3664 bool SPIRVInstructionSelector::selectBranch(MachineInstr &I) const {
3665   // InstructionSelector walks backwards through the instructions. We can use
3666   // both a G_BR and a G_BRCOND to create an OpBranchConditional. We hit G_BR
3667   // first, so can generate an OpBranchConditional here. If there is no
3668   // G_BRCOND, we just use OpBranch for a regular unconditional branch.
3669   const MachineInstr *PrevI = I.getPrevNode();
3670   MachineBasicBlock &MBB = *I.getParent();
3671   if (PrevI != nullptr && PrevI->getOpcode() == TargetOpcode::G_BRCOND) {
3672     return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranchConditional))
3673         .addUse(PrevI->getOperand(0).getReg())
3674         .addMBB(PrevI->getOperand(1).getMBB())
3675         .addMBB(I.getOperand(0).getMBB())
3676         .constrainAllUses(TII, TRI, RBI);
3677   }
3678   return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranch))
3679       .addMBB(I.getOperand(0).getMBB())
3680       .constrainAllUses(TII, TRI, RBI);
3681 }
3682 
3683 bool SPIRVInstructionSelector::selectBranchCond(MachineInstr &I) const {
3684   // InstructionSelector walks backwards through the instructions. For an
3685   // explicit conditional branch with no fallthrough, we use both a G_BR and a
3686   // G_BRCOND to create an OpBranchConditional. We should hit G_BR first, and
3687   // generate the OpBranchConditional in selectBranch above.
3688   //
3689   // If an OpBranchConditional has been generated, we simply return, as the work
3690   // is alread done. If there is no OpBranchConditional, LLVM must be relying on
3691   // implicit fallthrough to the next basic block, so we need to create an
3692   // OpBranchConditional with an explicit "false" argument pointing to the next
3693   // basic block that LLVM would fall through to.
3694   const MachineInstr *NextI = I.getNextNode();
3695   // Check if this has already been successfully selected.
3696   if (NextI != nullptr && NextI->getOpcode() == SPIRV::OpBranchConditional)
3697     return true;
3698   // Must be relying on implicit block fallthrough, so generate an
3699   // OpBranchConditional with the "next" basic block as the "false" target.
3700   MachineBasicBlock &MBB = *I.getParent();
3701   unsigned NextMBBNum = MBB.getNextNode()->getNumber();
3702   MachineBasicBlock *NextMBB = I.getMF()->getBlockNumbered(NextMBBNum);
3703   return BuildMI(MBB, I, I.getDebugLoc(), TII.get(SPIRV::OpBranchConditional))
3704       .addUse(I.getOperand(0).getReg())
3705       .addMBB(I.getOperand(1).getMBB())
3706       .addMBB(NextMBB)
3707       .constrainAllUses(TII, TRI, RBI);
3708 }
3709 
3710 bool SPIRVInstructionSelector::selectPhi(Register ResVReg,
3711                                          const SPIRVType *ResType,
3712                                          MachineInstr &I) const {
3713   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpPhi))
3714                  .addDef(ResVReg)
3715                  .addUse(GR.getSPIRVTypeID(ResType));
3716   const unsigned NumOps = I.getNumOperands();
3717   for (unsigned i = 1; i < NumOps; i += 2) {
3718     MIB.addUse(I.getOperand(i + 0).getReg());
3719     MIB.addMBB(I.getOperand(i + 1).getMBB());
3720   }
3721   bool Res = MIB.constrainAllUses(TII, TRI, RBI);
3722   MIB->setDesc(TII.get(TargetOpcode::PHI));
3723   MIB->removeOperand(1);
3724   return Res;
3725 }
3726 
3727 bool SPIRVInstructionSelector::selectGlobalValue(
3728     Register ResVReg, MachineInstr &I, const MachineInstr *Init) const {
3729   // FIXME: don't use MachineIRBuilder here, replace it with BuildMI.
3730   MachineIRBuilder MIRBuilder(I);
3731   const GlobalValue *GV = I.getOperand(1).getGlobal();
3732   Type *GVType = toTypedPointer(GR.getDeducedGlobalValueType(GV));
3733   SPIRVType *PointerBaseType;
3734   if (GVType->isArrayTy()) {
3735     SPIRVType *ArrayElementType =
3736         GR.getOrCreateSPIRVType(GVType->getArrayElementType(), MIRBuilder,
3737                                 SPIRV::AccessQualifier::ReadWrite, false);
3738     PointerBaseType = GR.getOrCreateSPIRVArrayType(
3739         ArrayElementType, GVType->getArrayNumElements(), I, TII);
3740   } else {
3741     PointerBaseType = GR.getOrCreateSPIRVType(
3742         GVType, MIRBuilder, SPIRV::AccessQualifier::ReadWrite, false);
3743   }
3744 
3745   std::string GlobalIdent;
3746   if (!GV->hasName()) {
3747     unsigned &ID = UnnamedGlobalIDs[GV];
3748     if (ID == 0)
3749       ID = UnnamedGlobalIDs.size();
3750     GlobalIdent = "__unnamed_" + Twine(ID).str();
3751   } else {
3752     GlobalIdent = GV->getName();
3753   }
3754 
3755   // Behaviour of functions as operands depends on availability of the
3756   // corresponding extension (SPV_INTEL_function_pointers):
3757   // - If there is an extension to operate with functions as operands:
3758   // We create a proper constant operand and evaluate a correct type for a
3759   // function pointer.
3760   // - Without the required extension:
3761   // We have functions as operands in tests with blocks of instruction e.g. in
3762   // transcoding/global_block.ll. These operands are not used and should be
3763   // substituted by zero constants. Their type is expected to be always
3764   // OpTypePointer Function %uchar.
3765   if (isa<Function>(GV)) {
3766     const Constant *ConstVal = GV;
3767     MachineBasicBlock &BB = *I.getParent();
3768     Register NewReg = GR.find(ConstVal, GR.CurMF);
3769     if (!NewReg.isValid()) {
3770       Register NewReg = ResVReg;
3771       GR.add(ConstVal, GR.CurMF, NewReg);
3772       const Function *GVFun =
3773           STI.canUseExtension(SPIRV::Extension::SPV_INTEL_function_pointers)
3774               ? dyn_cast<Function>(GV)
3775               : nullptr;
3776       SPIRVType *ResType = GR.getOrCreateSPIRVPointerType(
3777           PointerBaseType, I, TII,
3778           GVFun ? SPIRV::StorageClass::CodeSectionINTEL
3779                 : addressSpaceToStorageClass(GV->getAddressSpace(), STI));
3780       if (GVFun) {
3781         // References to a function via function pointers generate virtual
3782         // registers without a definition. We will resolve it later, during
3783         // module analysis stage.
3784         Register ResTypeReg = GR.getSPIRVTypeID(ResType);
3785         MachineRegisterInfo *MRI = MIRBuilder.getMRI();
3786         Register FuncVReg =
3787             MRI->createGenericVirtualRegister(GR.getRegType(ResType));
3788         MRI->setRegClass(FuncVReg, &SPIRV::pIDRegClass);
3789         MachineInstrBuilder MIB1 =
3790             BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpUndef))
3791                 .addDef(FuncVReg)
3792                 .addUse(ResTypeReg);
3793         MachineInstrBuilder MIB2 =
3794             BuildMI(BB, I, I.getDebugLoc(),
3795                     TII.get(SPIRV::OpConstantFunctionPointerINTEL))
3796                 .addDef(NewReg)
3797                 .addUse(ResTypeReg)
3798                 .addUse(FuncVReg);
3799         // mapping the function pointer to the used Function
3800         GR.recordFunctionPointer(&MIB2.getInstr()->getOperand(2), GVFun);
3801         return MIB1.constrainAllUses(TII, TRI, RBI) &&
3802                MIB2.constrainAllUses(TII, TRI, RBI);
3803       }
3804       return BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpConstantNull))
3805           .addDef(NewReg)
3806           .addUse(GR.getSPIRVTypeID(ResType))
3807           .constrainAllUses(TII, TRI, RBI);
3808     }
3809     assert(NewReg != ResVReg);
3810     return BuildCOPY(ResVReg, NewReg, I);
3811   }
3812   auto GlobalVar = cast<GlobalVariable>(GV);
3813   assert(GlobalVar->getName() != "llvm.global.annotations");
3814 
3815   // Skip empty declaration for GVs with initializers till we get the decl with
3816   // passed initializer.
3817   if (hasInitializer(GlobalVar) && !Init)
3818     return true;
3819 
3820   bool HasLnkTy = !GV->hasInternalLinkage() && !GV->hasPrivateLinkage();
3821   SPIRV::LinkageType::LinkageType LnkType =
3822       GV->isDeclarationForLinker()
3823           ? SPIRV::LinkageType::Import
3824           : (GV->hasLinkOnceODRLinkage() &&
3825                      STI.canUseExtension(SPIRV::Extension::SPV_KHR_linkonce_odr)
3826                  ? SPIRV::LinkageType::LinkOnceODR
3827                  : SPIRV::LinkageType::Export);
3828 
3829   const unsigned AddrSpace = GV->getAddressSpace();
3830   SPIRV::StorageClass::StorageClass StorageClass =
3831       addressSpaceToStorageClass(AddrSpace, STI);
3832   SPIRVType *ResType =
3833       GR.getOrCreateSPIRVPointerType(PointerBaseType, I, TII, StorageClass);
3834   Register Reg = GR.buildGlobalVariable(
3835       ResVReg, ResType, GlobalIdent, GV, StorageClass, Init,
3836       GlobalVar->isConstant(), HasLnkTy, LnkType, MIRBuilder, true);
3837   return Reg.isValid();
3838 }
3839 
3840 bool SPIRVInstructionSelector::selectLog10(Register ResVReg,
3841                                            const SPIRVType *ResType,
3842                                            MachineInstr &I) const {
3843   if (STI.canUseExtInstSet(SPIRV::InstructionSet::OpenCL_std)) {
3844     return selectExtInst(ResVReg, ResType, I, CL::log10);
3845   }
3846 
3847   // There is no log10 instruction in the GLSL Extended Instruction set, so it
3848   // is implemented as:
3849   // log10(x) = log2(x) * (1 / log2(10))
3850   //          = log2(x) * 0.30103
3851 
3852   MachineIRBuilder MIRBuilder(I);
3853   MachineBasicBlock &BB = *I.getParent();
3854 
3855   // Build log2(x).
3856   Register VarReg = MRI->createVirtualRegister(GR.getRegClass(ResType));
3857   bool Result =
3858       BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpExtInst))
3859           .addDef(VarReg)
3860           .addUse(GR.getSPIRVTypeID(ResType))
3861           .addImm(static_cast<uint32_t>(SPIRV::InstructionSet::GLSL_std_450))
3862           .addImm(GL::Log2)
3863           .add(I.getOperand(1))
3864           .constrainAllUses(TII, TRI, RBI);
3865 
3866   // Build 0.30103.
3867   assert(ResType->getOpcode() == SPIRV::OpTypeVector ||
3868          ResType->getOpcode() == SPIRV::OpTypeFloat);
3869   // TODO: Add matrix implementation once supported by the HLSL frontend.
3870   const SPIRVType *SpirvScalarType =
3871       ResType->getOpcode() == SPIRV::OpTypeVector
3872           ? GR.getSPIRVTypeForVReg(ResType->getOperand(1).getReg())
3873           : ResType;
3874   Register ScaleReg =
3875       GR.buildConstantFP(APFloat(0.30103f), MIRBuilder, SpirvScalarType);
3876 
3877   // Multiply log2(x) by 0.30103 to get log10(x) result.
3878   auto Opcode = ResType->getOpcode() == SPIRV::OpTypeVector
3879                     ? SPIRV::OpVectorTimesScalar
3880                     : SPIRV::OpFMulS;
3881   return Result && BuildMI(BB, I, I.getDebugLoc(), TII.get(Opcode))
3882                        .addDef(ResVReg)
3883                        .addUse(GR.getSPIRVTypeID(ResType))
3884                        .addUse(VarReg)
3885                        .addUse(ScaleReg)
3886                        .constrainAllUses(TII, TRI, RBI);
3887 }
3888 
3889 // Generate the instructions to load 3-element vector builtin input
3890 // IDs/Indices.
3891 // Like: GlobalInvocationId, LocalInvocationId, etc....
3892 bool SPIRVInstructionSelector::loadVec3BuiltinInputID(
3893     SPIRV::BuiltIn::BuiltIn BuiltInValue, Register ResVReg,
3894     const SPIRVType *ResType, MachineInstr &I) const {
3895   MachineIRBuilder MIRBuilder(I);
3896   const SPIRVType *U32Type = GR.getOrCreateSPIRVIntegerType(32, MIRBuilder);
3897   const SPIRVType *Vec3Ty =
3898       GR.getOrCreateSPIRVVectorType(U32Type, 3, MIRBuilder);
3899   const SPIRVType *PtrType = GR.getOrCreateSPIRVPointerType(
3900       Vec3Ty, MIRBuilder, SPIRV::StorageClass::Input);
3901 
3902   // Create new register for the input ID builtin variable.
3903   Register NewRegister =
3904       MIRBuilder.getMRI()->createVirtualRegister(&SPIRV::iIDRegClass);
3905   MIRBuilder.getMRI()->setType(NewRegister, LLT::pointer(0, 64));
3906   GR.assignSPIRVTypeToVReg(PtrType, NewRegister, MIRBuilder.getMF());
3907 
3908   // Build global variable with the necessary decorations for the input ID
3909   // builtin variable.
3910   Register Variable = GR.buildGlobalVariable(
3911       NewRegister, PtrType, getLinkStringForBuiltIn(BuiltInValue), nullptr,
3912       SPIRV::StorageClass::Input, nullptr, true, true,
3913       SPIRV::LinkageType::Import, MIRBuilder, false);
3914 
3915   // Create new register for loading value.
3916   MachineRegisterInfo *MRI = MIRBuilder.getMRI();
3917   Register LoadedRegister = MRI->createVirtualRegister(&SPIRV::iIDRegClass);
3918   MIRBuilder.getMRI()->setType(LoadedRegister, LLT::pointer(0, 64));
3919   GR.assignSPIRVTypeToVReg(Vec3Ty, LoadedRegister, MIRBuilder.getMF());
3920 
3921   // Load v3uint value from the global variable.
3922   bool Result =
3923       BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpLoad))
3924           .addDef(LoadedRegister)
3925           .addUse(GR.getSPIRVTypeID(Vec3Ty))
3926           .addUse(Variable);
3927 
3928   // Get the input ID index. Expecting operand is a constant immediate value,
3929   // wrapped in a type assignment.
3930   assert(I.getOperand(2).isReg());
3931   const uint32_t ThreadId = foldImm(I.getOperand(2), MRI);
3932 
3933   // Extract the input ID from the loaded vector value.
3934   MachineBasicBlock &BB = *I.getParent();
3935   auto MIB = BuildMI(BB, I, I.getDebugLoc(), TII.get(SPIRV::OpCompositeExtract))
3936                  .addDef(ResVReg)
3937                  .addUse(GR.getSPIRVTypeID(ResType))
3938                  .addUse(LoadedRegister)
3939                  .addImm(ThreadId);
3940   return Result && MIB.constrainAllUses(TII, TRI, RBI);
3941 }
3942 
3943 SPIRVType *SPIRVInstructionSelector::widenTypeToVec4(const SPIRVType *Type,
3944                                                      MachineInstr &I) const {
3945   MachineIRBuilder MIRBuilder(I);
3946   if (Type->getOpcode() != SPIRV::OpTypeVector)
3947     return GR.getOrCreateSPIRVVectorType(Type, 4, MIRBuilder);
3948 
3949   uint64_t VectorSize = Type->getOperand(2).getImm();
3950   if (VectorSize == 4)
3951     return Type;
3952 
3953   Register ScalarTypeReg = Type->getOperand(1).getReg();
3954   const SPIRVType *ScalarType = GR.getSPIRVTypeForVReg(ScalarTypeReg);
3955   return GR.getOrCreateSPIRVVectorType(ScalarType, 4, MIRBuilder);
3956 }
3957 
3958 bool SPIRVInstructionSelector::loadHandleBeforePosition(
3959     Register &HandleReg, const SPIRVType *ResType, GIntrinsic &HandleDef,
3960     MachineInstr &Pos) const {
3961 
3962   assert(HandleDef.getIntrinsicID() ==
3963          Intrinsic::spv_resource_handlefrombinding);
3964   uint32_t Set = foldImm(HandleDef.getOperand(2), MRI);
3965   uint32_t Binding = foldImm(HandleDef.getOperand(3), MRI);
3966   uint32_t ArraySize = foldImm(HandleDef.getOperand(4), MRI);
3967   Register IndexReg = HandleDef.getOperand(5).getReg();
3968   bool IsNonUniform = ArraySize > 1 && foldImm(HandleDef.getOperand(6), MRI);
3969 
3970   MachineIRBuilder MIRBuilder(HandleDef);
3971   Register VarReg = buildPointerToResource(ResType, Set, Binding, ArraySize,
3972                                            IndexReg, IsNonUniform, MIRBuilder);
3973 
3974   if (IsNonUniform)
3975     buildOpDecorate(HandleReg, HandleDef, TII, SPIRV::Decoration::NonUniformEXT,
3976                     {});
3977 
3978   // TODO: For now we assume the resource is an image, which needs to be
3979   // loaded to get the handle. That will not be true for storage buffers.
3980   return BuildMI(*Pos.getParent(), Pos, HandleDef.getDebugLoc(),
3981                  TII.get(SPIRV::OpLoad))
3982       .addDef(HandleReg)
3983       .addUse(GR.getSPIRVTypeID(ResType))
3984       .addUse(VarReg)
3985       .constrainAllUses(TII, TRI, RBI);
3986 }
3987 
3988 namespace llvm {
3989 InstructionSelector *
3990 createSPIRVInstructionSelector(const SPIRVTargetMachine &TM,
3991                                const SPIRVSubtarget &Subtarget,
3992                                const RegisterBankInfo &RBI) {
3993   return new SPIRVInstructionSelector(TM, Subtarget, RBI);
3994 }
3995 } // namespace llvm
3996