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1 //===-- Instruction.cpp - Implement the Instruction class -----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the Instruction class for the IR library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/IR/Instruction.h"
15 #include "llvm/IR/IntrinsicInst.h"
16 #include "llvm/ADT/DenseSet.h"
17 #include "llvm/IR/Constants.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/MDBuilder.h"
20 #include "llvm/IR/Operator.h"
21 #include "llvm/IR/Type.h"
22 using namespace llvm;
23 
Instruction(Type * ty,unsigned it,Use * Ops,unsigned NumOps,Instruction * InsertBefore)24 Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
25                          Instruction *InsertBefore)
26   : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
27 
28   // If requested, insert this instruction into a basic block...
29   if (InsertBefore) {
30     BasicBlock *BB = InsertBefore->getParent();
31     assert(BB && "Instruction to insert before is not in a basic block!");
32     BB->getInstList().insert(InsertBefore->getIterator(), this);
33   }
34 }
35 
Instruction(Type * ty,unsigned it,Use * Ops,unsigned NumOps,BasicBlock * InsertAtEnd)36 Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
37                          BasicBlock *InsertAtEnd)
38   : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
39 
40   // append this instruction into the basic block
41   assert(InsertAtEnd && "Basic block to append to may not be NULL!");
42   InsertAtEnd->getInstList().push_back(this);
43 }
44 
~Instruction()45 Instruction::~Instruction() {
46   assert(!Parent && "Instruction still linked in the program!");
47   if (hasMetadataHashEntry())
48     clearMetadataHashEntries();
49 }
50 
51 
setParent(BasicBlock * P)52 void Instruction::setParent(BasicBlock *P) {
53   Parent = P;
54 }
55 
getModule() const56 const Module *Instruction::getModule() const {
57   return getParent()->getModule();
58 }
59 
getFunction() const60 const Function *Instruction::getFunction() const {
61   return getParent()->getParent();
62 }
63 
removeFromParent()64 void Instruction::removeFromParent() {
65   getParent()->getInstList().remove(getIterator());
66 }
67 
eraseFromParent()68 iplist<Instruction>::iterator Instruction::eraseFromParent() {
69   return getParent()->getInstList().erase(getIterator());
70 }
71 
72 /// Insert an unlinked instruction into a basic block immediately before the
73 /// specified instruction.
insertBefore(Instruction * InsertPos)74 void Instruction::insertBefore(Instruction *InsertPos) {
75   InsertPos->getParent()->getInstList().insert(InsertPos->getIterator(), this);
76 }
77 
78 /// Insert an unlinked instruction into a basic block immediately after the
79 /// specified instruction.
insertAfter(Instruction * InsertPos)80 void Instruction::insertAfter(Instruction *InsertPos) {
81   InsertPos->getParent()->getInstList().insertAfter(InsertPos->getIterator(),
82                                                     this);
83 }
84 
85 /// Unlink this instruction from its current basic block and insert it into the
86 /// basic block that MovePos lives in, right before MovePos.
moveBefore(Instruction * MovePos)87 void Instruction::moveBefore(Instruction *MovePos) {
88   moveBefore(*MovePos->getParent(), MovePos->getIterator());
89 }
90 
moveAfter(Instruction * MovePos)91 void Instruction::moveAfter(Instruction *MovePos) {
92   moveBefore(*MovePos->getParent(), ++MovePos->getIterator());
93 }
94 
moveBefore(BasicBlock & BB,SymbolTableList<Instruction>::iterator I)95 void Instruction::moveBefore(BasicBlock &BB,
96                              SymbolTableList<Instruction>::iterator I) {
97   assert(I == BB.end() || I->getParent() == &BB);
98   BB.getInstList().splice(I, getParent()->getInstList(), getIterator());
99 }
100 
setHasNoUnsignedWrap(bool b)101 void Instruction::setHasNoUnsignedWrap(bool b) {
102   cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(b);
103 }
104 
setHasNoSignedWrap(bool b)105 void Instruction::setHasNoSignedWrap(bool b) {
106   cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(b);
107 }
108 
setIsExact(bool b)109 void Instruction::setIsExact(bool b) {
110   cast<PossiblyExactOperator>(this)->setIsExact(b);
111 }
112 
hasNoUnsignedWrap() const113 bool Instruction::hasNoUnsignedWrap() const {
114   return cast<OverflowingBinaryOperator>(this)->hasNoUnsignedWrap();
115 }
116 
hasNoSignedWrap() const117 bool Instruction::hasNoSignedWrap() const {
118   return cast<OverflowingBinaryOperator>(this)->hasNoSignedWrap();
119 }
120 
dropPoisonGeneratingFlags()121 void Instruction::dropPoisonGeneratingFlags() {
122   switch (getOpcode()) {
123   case Instruction::Add:
124   case Instruction::Sub:
125   case Instruction::Mul:
126   case Instruction::Shl:
127     cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(false);
128     cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(false);
129     break;
130 
131   case Instruction::UDiv:
132   case Instruction::SDiv:
133   case Instruction::AShr:
134   case Instruction::LShr:
135     cast<PossiblyExactOperator>(this)->setIsExact(false);
136     break;
137 
138   case Instruction::GetElementPtr:
139     cast<GetElementPtrInst>(this)->setIsInBounds(false);
140     break;
141   }
142 }
143 
isExact() const144 bool Instruction::isExact() const {
145   return cast<PossiblyExactOperator>(this)->isExact();
146 }
147 
setFast(bool B)148 void Instruction::setFast(bool B) {
149   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
150   cast<FPMathOperator>(this)->setFast(B);
151 }
152 
setHasAllowReassoc(bool B)153 void Instruction::setHasAllowReassoc(bool B) {
154   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
155   cast<FPMathOperator>(this)->setHasAllowReassoc(B);
156 }
157 
setHasNoNaNs(bool B)158 void Instruction::setHasNoNaNs(bool B) {
159   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
160   cast<FPMathOperator>(this)->setHasNoNaNs(B);
161 }
162 
setHasNoInfs(bool B)163 void Instruction::setHasNoInfs(bool B) {
164   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
165   cast<FPMathOperator>(this)->setHasNoInfs(B);
166 }
167 
setHasNoSignedZeros(bool B)168 void Instruction::setHasNoSignedZeros(bool B) {
169   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
170   cast<FPMathOperator>(this)->setHasNoSignedZeros(B);
171 }
172 
setHasAllowReciprocal(bool B)173 void Instruction::setHasAllowReciprocal(bool B) {
174   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
175   cast<FPMathOperator>(this)->setHasAllowReciprocal(B);
176 }
177 
setHasApproxFunc(bool B)178 void Instruction::setHasApproxFunc(bool B) {
179   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
180   cast<FPMathOperator>(this)->setHasApproxFunc(B);
181 }
182 
setFastMathFlags(FastMathFlags FMF)183 void Instruction::setFastMathFlags(FastMathFlags FMF) {
184   assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
185   cast<FPMathOperator>(this)->setFastMathFlags(FMF);
186 }
187 
copyFastMathFlags(FastMathFlags FMF)188 void Instruction::copyFastMathFlags(FastMathFlags FMF) {
189   assert(isa<FPMathOperator>(this) && "copying fast-math flag on invalid op");
190   cast<FPMathOperator>(this)->copyFastMathFlags(FMF);
191 }
192 
isFast() const193 bool Instruction::isFast() const {
194   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
195   return cast<FPMathOperator>(this)->isFast();
196 }
197 
hasAllowReassoc() const198 bool Instruction::hasAllowReassoc() const {
199   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
200   return cast<FPMathOperator>(this)->hasAllowReassoc();
201 }
202 
hasNoNaNs() const203 bool Instruction::hasNoNaNs() const {
204   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
205   return cast<FPMathOperator>(this)->hasNoNaNs();
206 }
207 
hasNoInfs() const208 bool Instruction::hasNoInfs() const {
209   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
210   return cast<FPMathOperator>(this)->hasNoInfs();
211 }
212 
hasNoSignedZeros() const213 bool Instruction::hasNoSignedZeros() const {
214   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
215   return cast<FPMathOperator>(this)->hasNoSignedZeros();
216 }
217 
hasAllowReciprocal() const218 bool Instruction::hasAllowReciprocal() const {
219   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
220   return cast<FPMathOperator>(this)->hasAllowReciprocal();
221 }
222 
hasAllowContract() const223 bool Instruction::hasAllowContract() const {
224   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
225   return cast<FPMathOperator>(this)->hasAllowContract();
226 }
227 
hasApproxFunc() const228 bool Instruction::hasApproxFunc() const {
229   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
230   return cast<FPMathOperator>(this)->hasApproxFunc();
231 }
232 
getFastMathFlags() const233 FastMathFlags Instruction::getFastMathFlags() const {
234   assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
235   return cast<FPMathOperator>(this)->getFastMathFlags();
236 }
237 
copyFastMathFlags(const Instruction * I)238 void Instruction::copyFastMathFlags(const Instruction *I) {
239   copyFastMathFlags(I->getFastMathFlags());
240 }
241 
copyIRFlags(const Value * V,bool IncludeWrapFlags)242 void Instruction::copyIRFlags(const Value *V, bool IncludeWrapFlags) {
243   // Copy the wrapping flags.
244   if (IncludeWrapFlags && isa<OverflowingBinaryOperator>(this)) {
245     if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
246       setHasNoSignedWrap(OB->hasNoSignedWrap());
247       setHasNoUnsignedWrap(OB->hasNoUnsignedWrap());
248     }
249   }
250 
251   // Copy the exact flag.
252   if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
253     if (isa<PossiblyExactOperator>(this))
254       setIsExact(PE->isExact());
255 
256   // Copy the fast-math flags.
257   if (auto *FP = dyn_cast<FPMathOperator>(V))
258     if (isa<FPMathOperator>(this))
259       copyFastMathFlags(FP->getFastMathFlags());
260 
261   if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
262     if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
263       DestGEP->setIsInBounds(SrcGEP->isInBounds() | DestGEP->isInBounds());
264 }
265 
andIRFlags(const Value * V)266 void Instruction::andIRFlags(const Value *V) {
267   if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
268     if (isa<OverflowingBinaryOperator>(this)) {
269       setHasNoSignedWrap(hasNoSignedWrap() & OB->hasNoSignedWrap());
270       setHasNoUnsignedWrap(hasNoUnsignedWrap() & OB->hasNoUnsignedWrap());
271     }
272   }
273 
274   if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
275     if (isa<PossiblyExactOperator>(this))
276       setIsExact(isExact() & PE->isExact());
277 
278   if (auto *FP = dyn_cast<FPMathOperator>(V)) {
279     if (isa<FPMathOperator>(this)) {
280       FastMathFlags FM = getFastMathFlags();
281       FM &= FP->getFastMathFlags();
282       copyFastMathFlags(FM);
283     }
284   }
285 
286   if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
287     if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
288       DestGEP->setIsInBounds(SrcGEP->isInBounds() & DestGEP->isInBounds());
289 }
290 
getOpcodeName(unsigned OpCode)291 const char *Instruction::getOpcodeName(unsigned OpCode) {
292   switch (OpCode) {
293   // Terminators
294   case Ret:    return "ret";
295   case Br:     return "br";
296   case Switch: return "switch";
297   case IndirectBr: return "indirectbr";
298   case Invoke: return "invoke";
299   case Resume: return "resume";
300   case Unreachable: return "unreachable";
301   case CleanupRet: return "cleanupret";
302   case CatchRet: return "catchret";
303   case CatchPad: return "catchpad";
304   case CatchSwitch: return "catchswitch";
305 
306   // Standard binary operators...
307   case Add: return "add";
308   case FAdd: return "fadd";
309   case Sub: return "sub";
310   case FSub: return "fsub";
311   case Mul: return "mul";
312   case FMul: return "fmul";
313   case UDiv: return "udiv";
314   case SDiv: return "sdiv";
315   case FDiv: return "fdiv";
316   case URem: return "urem";
317   case SRem: return "srem";
318   case FRem: return "frem";
319 
320   // Logical operators...
321   case And: return "and";
322   case Or : return "or";
323   case Xor: return "xor";
324 
325   // Memory instructions...
326   case Alloca:        return "alloca";
327   case Load:          return "load";
328   case Store:         return "store";
329   case AtomicCmpXchg: return "cmpxchg";
330   case AtomicRMW:     return "atomicrmw";
331   case Fence:         return "fence";
332   case GetElementPtr: return "getelementptr";
333 
334   // Convert instructions...
335   case Trunc:         return "trunc";
336   case ZExt:          return "zext";
337   case SExt:          return "sext";
338   case FPTrunc:       return "fptrunc";
339   case FPExt:         return "fpext";
340   case FPToUI:        return "fptoui";
341   case FPToSI:        return "fptosi";
342   case UIToFP:        return "uitofp";
343   case SIToFP:        return "sitofp";
344   case IntToPtr:      return "inttoptr";
345   case PtrToInt:      return "ptrtoint";
346   case BitCast:       return "bitcast";
347   case AddrSpaceCast: return "addrspacecast";
348 
349   // Other instructions...
350   case ICmp:           return "icmp";
351   case FCmp:           return "fcmp";
352   case PHI:            return "phi";
353   case Select:         return "select";
354   case Call:           return "call";
355   case Shl:            return "shl";
356   case LShr:           return "lshr";
357   case AShr:           return "ashr";
358   case VAArg:          return "va_arg";
359   case ExtractElement: return "extractelement";
360   case InsertElement:  return "insertelement";
361   case ShuffleVector:  return "shufflevector";
362   case ExtractValue:   return "extractvalue";
363   case InsertValue:    return "insertvalue";
364   case LandingPad:     return "landingpad";
365   case CleanupPad:     return "cleanuppad";
366 
367   default: return "<Invalid operator> ";
368   }
369 }
370 
371 /// Return true if both instructions have the same special state. This must be
372 /// kept in sync with FunctionComparator::cmpOperations in
373 /// lib/Transforms/IPO/MergeFunctions.cpp.
haveSameSpecialState(const Instruction * I1,const Instruction * I2,bool IgnoreAlignment=false)374 static bool haveSameSpecialState(const Instruction *I1, const Instruction *I2,
375                                  bool IgnoreAlignment = false) {
376   assert(I1->getOpcode() == I2->getOpcode() &&
377          "Can not compare special state of different instructions");
378 
379   if (const AllocaInst *AI = dyn_cast<AllocaInst>(I1))
380     return AI->getAllocatedType() == cast<AllocaInst>(I2)->getAllocatedType() &&
381            (AI->getAlignment() == cast<AllocaInst>(I2)->getAlignment() ||
382             IgnoreAlignment);
383   if (const LoadInst *LI = dyn_cast<LoadInst>(I1))
384     return LI->isVolatile() == cast<LoadInst>(I2)->isVolatile() &&
385            (LI->getAlignment() == cast<LoadInst>(I2)->getAlignment() ||
386             IgnoreAlignment) &&
387            LI->getOrdering() == cast<LoadInst>(I2)->getOrdering() &&
388            LI->getSyncScopeID() == cast<LoadInst>(I2)->getSyncScopeID();
389   if (const StoreInst *SI = dyn_cast<StoreInst>(I1))
390     return SI->isVolatile() == cast<StoreInst>(I2)->isVolatile() &&
391            (SI->getAlignment() == cast<StoreInst>(I2)->getAlignment() ||
392             IgnoreAlignment) &&
393            SI->getOrdering() == cast<StoreInst>(I2)->getOrdering() &&
394            SI->getSyncScopeID() == cast<StoreInst>(I2)->getSyncScopeID();
395   if (const CmpInst *CI = dyn_cast<CmpInst>(I1))
396     return CI->getPredicate() == cast<CmpInst>(I2)->getPredicate();
397   if (const CallInst *CI = dyn_cast<CallInst>(I1))
398     return CI->isTailCall() == cast<CallInst>(I2)->isTailCall() &&
399            CI->getCallingConv() == cast<CallInst>(I2)->getCallingConv() &&
400            CI->getAttributes() == cast<CallInst>(I2)->getAttributes() &&
401            CI->hasIdenticalOperandBundleSchema(*cast<CallInst>(I2));
402   if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1))
403     return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() &&
404            CI->getAttributes() == cast<InvokeInst>(I2)->getAttributes() &&
405            CI->hasIdenticalOperandBundleSchema(*cast<InvokeInst>(I2));
406   if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(I1))
407     return IVI->getIndices() == cast<InsertValueInst>(I2)->getIndices();
408   if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I1))
409     return EVI->getIndices() == cast<ExtractValueInst>(I2)->getIndices();
410   if (const FenceInst *FI = dyn_cast<FenceInst>(I1))
411     return FI->getOrdering() == cast<FenceInst>(I2)->getOrdering() &&
412            FI->getSyncScopeID() == cast<FenceInst>(I2)->getSyncScopeID();
413   if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I1))
414     return CXI->isVolatile() == cast<AtomicCmpXchgInst>(I2)->isVolatile() &&
415            CXI->isWeak() == cast<AtomicCmpXchgInst>(I2)->isWeak() &&
416            CXI->getSuccessOrdering() ==
417                cast<AtomicCmpXchgInst>(I2)->getSuccessOrdering() &&
418            CXI->getFailureOrdering() ==
419                cast<AtomicCmpXchgInst>(I2)->getFailureOrdering() &&
420            CXI->getSyncScopeID() ==
421                cast<AtomicCmpXchgInst>(I2)->getSyncScopeID();
422   if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I1))
423     return RMWI->getOperation() == cast<AtomicRMWInst>(I2)->getOperation() &&
424            RMWI->isVolatile() == cast<AtomicRMWInst>(I2)->isVolatile() &&
425            RMWI->getOrdering() == cast<AtomicRMWInst>(I2)->getOrdering() &&
426            RMWI->getSyncScopeID() == cast<AtomicRMWInst>(I2)->getSyncScopeID();
427 
428   return true;
429 }
430 
isIdenticalTo(const Instruction * I) const431 bool Instruction::isIdenticalTo(const Instruction *I) const {
432   return isIdenticalToWhenDefined(I) &&
433          SubclassOptionalData == I->SubclassOptionalData;
434 }
435 
isIdenticalToWhenDefined(const Instruction * I) const436 bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
437   if (getOpcode() != I->getOpcode() ||
438       getNumOperands() != I->getNumOperands() ||
439       getType() != I->getType())
440     return false;
441 
442   // If both instructions have no operands, they are identical.
443   if (getNumOperands() == 0 && I->getNumOperands() == 0)
444     return haveSameSpecialState(this, I);
445 
446   // We have two instructions of identical opcode and #operands.  Check to see
447   // if all operands are the same.
448   if (!std::equal(op_begin(), op_end(), I->op_begin()))
449     return false;
450 
451   if (const PHINode *thisPHI = dyn_cast<PHINode>(this)) {
452     const PHINode *otherPHI = cast<PHINode>(I);
453     return std::equal(thisPHI->block_begin(), thisPHI->block_end(),
454                       otherPHI->block_begin());
455   }
456 
457   return haveSameSpecialState(this, I);
458 }
459 
460 // Keep this in sync with FunctionComparator::cmpOperations in
461 // lib/Transforms/IPO/MergeFunctions.cpp.
isSameOperationAs(const Instruction * I,unsigned flags) const462 bool Instruction::isSameOperationAs(const Instruction *I,
463                                     unsigned flags) const {
464   bool IgnoreAlignment = flags & CompareIgnoringAlignment;
465   bool UseScalarTypes  = flags & CompareUsingScalarTypes;
466 
467   if (getOpcode() != I->getOpcode() ||
468       getNumOperands() != I->getNumOperands() ||
469       (UseScalarTypes ?
470        getType()->getScalarType() != I->getType()->getScalarType() :
471        getType() != I->getType()))
472     return false;
473 
474   // We have two instructions of identical opcode and #operands.  Check to see
475   // if all operands are the same type
476   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
477     if (UseScalarTypes ?
478         getOperand(i)->getType()->getScalarType() !=
479           I->getOperand(i)->getType()->getScalarType() :
480         getOperand(i)->getType() != I->getOperand(i)->getType())
481       return false;
482 
483   return haveSameSpecialState(this, I, IgnoreAlignment);
484 }
485 
isUsedOutsideOfBlock(const BasicBlock * BB) const486 bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
487   for (const Use &U : uses()) {
488     // PHI nodes uses values in the corresponding predecessor block.  For other
489     // instructions, just check to see whether the parent of the use matches up.
490     const Instruction *I = cast<Instruction>(U.getUser());
491     const PHINode *PN = dyn_cast<PHINode>(I);
492     if (!PN) {
493       if (I->getParent() != BB)
494         return true;
495       continue;
496     }
497 
498     if (PN->getIncomingBlock(U) != BB)
499       return true;
500   }
501   return false;
502 }
503 
mayReadFromMemory() const504 bool Instruction::mayReadFromMemory() const {
505   switch (getOpcode()) {
506   default: return false;
507   case Instruction::VAArg:
508   case Instruction::Load:
509   case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
510   case Instruction::AtomicCmpXchg:
511   case Instruction::AtomicRMW:
512   case Instruction::CatchPad:
513   case Instruction::CatchRet:
514     return true;
515   case Instruction::Call:
516     return !cast<CallInst>(this)->doesNotAccessMemory();
517   case Instruction::Invoke:
518     return !cast<InvokeInst>(this)->doesNotAccessMemory();
519   case Instruction::Store:
520     return !cast<StoreInst>(this)->isUnordered();
521   }
522 }
523 
mayWriteToMemory() const524 bool Instruction::mayWriteToMemory() const {
525   switch (getOpcode()) {
526   default: return false;
527   case Instruction::Fence: // FIXME: refine definition of mayWriteToMemory
528   case Instruction::Store:
529   case Instruction::VAArg:
530   case Instruction::AtomicCmpXchg:
531   case Instruction::AtomicRMW:
532   case Instruction::CatchPad:
533   case Instruction::CatchRet:
534     return true;
535   case Instruction::Call:
536     return !cast<CallInst>(this)->onlyReadsMemory();
537   case Instruction::Invoke:
538     return !cast<InvokeInst>(this)->onlyReadsMemory();
539   case Instruction::Load:
540     return !cast<LoadInst>(this)->isUnordered();
541   }
542 }
543 
isAtomic() const544 bool Instruction::isAtomic() const {
545   switch (getOpcode()) {
546   default:
547     return false;
548   case Instruction::AtomicCmpXchg:
549   case Instruction::AtomicRMW:
550   case Instruction::Fence:
551     return true;
552   case Instruction::Load:
553     return cast<LoadInst>(this)->getOrdering() != AtomicOrdering::NotAtomic;
554   case Instruction::Store:
555     return cast<StoreInst>(this)->getOrdering() != AtomicOrdering::NotAtomic;
556   }
557 }
558 
hasAtomicLoad() const559 bool Instruction::hasAtomicLoad() const {
560   assert(isAtomic());
561   switch (getOpcode()) {
562   default:
563     return false;
564   case Instruction::AtomicCmpXchg:
565   case Instruction::AtomicRMW:
566   case Instruction::Load:
567     return true;
568   }
569 }
570 
hasAtomicStore() const571 bool Instruction::hasAtomicStore() const {
572   assert(isAtomic());
573   switch (getOpcode()) {
574   default:
575     return false;
576   case Instruction::AtomicCmpXchg:
577   case Instruction::AtomicRMW:
578   case Instruction::Store:
579     return true;
580   }
581 }
582 
mayThrow() const583 bool Instruction::mayThrow() const {
584   if (const CallInst *CI = dyn_cast<CallInst>(this))
585     return !CI->doesNotThrow();
586   if (const auto *CRI = dyn_cast<CleanupReturnInst>(this))
587     return CRI->unwindsToCaller();
588   if (const auto *CatchSwitch = dyn_cast<CatchSwitchInst>(this))
589     return CatchSwitch->unwindsToCaller();
590   return isa<ResumeInst>(this);
591 }
592 
isSafeToRemove() const593 bool Instruction::isSafeToRemove() const {
594   return (!isa<CallInst>(this) || !this->mayHaveSideEffects()) &&
595          !isa<TerminatorInst>(this);
596 }
597 
getNextNonDebugInstruction() const598 const Instruction *Instruction::getNextNonDebugInstruction() const {
599   for (const Instruction *I = getNextNode(); I; I = I->getNextNode())
600     if (!isa<DbgInfoIntrinsic>(I))
601       return I;
602   return nullptr;
603 }
604 
isAssociative() const605 bool Instruction::isAssociative() const {
606   unsigned Opcode = getOpcode();
607   if (isAssociative(Opcode))
608     return true;
609 
610   switch (Opcode) {
611   case FMul:
612   case FAdd:
613     return cast<FPMathOperator>(this)->hasAllowReassoc() &&
614            cast<FPMathOperator>(this)->hasNoSignedZeros();
615   default:
616     return false;
617   }
618 }
619 
cloneImpl() const620 Instruction *Instruction::cloneImpl() const {
621   llvm_unreachable("Subclass of Instruction failed to implement cloneImpl");
622 }
623 
swapProfMetadata()624 void Instruction::swapProfMetadata() {
625   MDNode *ProfileData = getMetadata(LLVMContext::MD_prof);
626   if (!ProfileData || ProfileData->getNumOperands() != 3 ||
627       !isa<MDString>(ProfileData->getOperand(0)))
628     return;
629 
630   MDString *MDName = cast<MDString>(ProfileData->getOperand(0));
631   if (MDName->getString() != "branch_weights")
632     return;
633 
634   // The first operand is the name. Fetch them backwards and build a new one.
635   Metadata *Ops[] = {ProfileData->getOperand(0), ProfileData->getOperand(2),
636                      ProfileData->getOperand(1)};
637   setMetadata(LLVMContext::MD_prof,
638               MDNode::get(ProfileData->getContext(), Ops));
639 }
640 
copyMetadata(const Instruction & SrcInst,ArrayRef<unsigned> WL)641 void Instruction::copyMetadata(const Instruction &SrcInst,
642                                ArrayRef<unsigned> WL) {
643   if (!SrcInst.hasMetadata())
644     return;
645 
646   DenseSet<unsigned> WLS;
647   for (unsigned M : WL)
648     WLS.insert(M);
649 
650   // Otherwise, enumerate and copy over metadata from the old instruction to the
651   // new one.
652   SmallVector<std::pair<unsigned, MDNode *>, 4> TheMDs;
653   SrcInst.getAllMetadataOtherThanDebugLoc(TheMDs);
654   for (const auto &MD : TheMDs) {
655     if (WL.empty() || WLS.count(MD.first))
656       setMetadata(MD.first, MD.second);
657   }
658   if (WL.empty() || WLS.count(LLVMContext::MD_dbg))
659     setDebugLoc(SrcInst.getDebugLoc());
660 }
661 
clone() const662 Instruction *Instruction::clone() const {
663   Instruction *New = nullptr;
664   switch (getOpcode()) {
665   default:
666     llvm_unreachable("Unhandled Opcode.");
667 #define HANDLE_INST(num, opc, clas)                                            \
668   case Instruction::opc:                                                       \
669     New = cast<clas>(this)->cloneImpl();                                       \
670     break;
671 #include "llvm/IR/Instruction.def"
672 #undef HANDLE_INST
673   }
674 
675   New->SubclassOptionalData = SubclassOptionalData;
676   New->copyMetadata(*this);
677   return New;
678 }
679 
updateProfWeight(uint64_t S,uint64_t T)680 void Instruction::updateProfWeight(uint64_t S, uint64_t T) {
681   auto *ProfileData = getMetadata(LLVMContext::MD_prof);
682   if (ProfileData == nullptr)
683     return;
684 
685   auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
686   if (!ProfDataName || (!ProfDataName->getString().equals("branch_weights") &&
687                         !ProfDataName->getString().equals("VP")))
688     return;
689 
690   MDBuilder MDB(getContext());
691   SmallVector<Metadata *, 3> Vals;
692   Vals.push_back(ProfileData->getOperand(0));
693   APInt APS(128, S), APT(128, T);
694   if (ProfDataName->getString().equals("branch_weights"))
695     for (unsigned i = 1; i < ProfileData->getNumOperands(); i++) {
696       // Using APInt::div may be expensive, but most cases should fit 64 bits.
697       APInt Val(128,
698                 mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i))
699                     ->getValue()
700                     .getZExtValue());
701       Val *= APS;
702       Vals.push_back(MDB.createConstant(
703           ConstantInt::get(Type::getInt64Ty(getContext()),
704                            Val.udiv(APT).getLimitedValue())));
705     }
706   else if (ProfDataName->getString().equals("VP"))
707     for (unsigned i = 1; i < ProfileData->getNumOperands(); i += 2) {
708       // The first value is the key of the value profile, which will not change.
709       Vals.push_back(ProfileData->getOperand(i));
710       // Using APInt::div may be expensive, but most cases should fit 64 bits.
711       APInt Val(128,
712                 mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i + 1))
713                     ->getValue()
714                     .getZExtValue());
715       Val *= APS;
716       Vals.push_back(MDB.createConstant(
717           ConstantInt::get(Type::getInt64Ty(getContext()),
718                            Val.udiv(APT).getLimitedValue())));
719     }
720   setMetadata(LLVMContext::MD_prof, MDNode::get(getContext(), Vals));
721 }
722 
setProfWeight(uint64_t W)723 void Instruction::setProfWeight(uint64_t W) {
724   assert((isa<CallInst>(this) || isa<InvokeInst>(this)) &&
725          "Can only set weights for call and invoke instrucitons");
726   SmallVector<uint32_t, 1> Weights;
727   Weights.push_back(W);
728   MDBuilder MDB(getContext());
729   setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
730 }
731