Instruction.cpp revision 355940 
1//===-- Instruction.cpp - Implement the Instruction class -----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the Instruction class for the IR library.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/IR/Instruction.h"
14#include "llvm/IR/IntrinsicInst.h"
15#include "llvm/ADT/DenseSet.h"
16#include "llvm/IR/Constants.h"
17#include "llvm/IR/Instructions.h"
18#include "llvm/IR/MDBuilder.h"
19#include "llvm/IR/Operator.h"
20#include "llvm/IR/Type.h"
21using namespace llvm;
22
23Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
24                         Instruction *InsertBefore)
25  : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
26
27  // If requested, insert this instruction into a basic block...
28  if (InsertBefore) {
29    BasicBlock *BB = InsertBefore->getParent();
30    assert(BB && "Instruction to insert before is not in a basic block!");
31    BB->getInstList().insert(InsertBefore->getIterator(), this);
32  }
33}
34
35Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
36                         BasicBlock *InsertAtEnd)
37  : User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
38
39  // append this instruction into the basic block
40  assert(InsertAtEnd && "Basic block to append to may not be NULL!");
41  InsertAtEnd->getInstList().push_back(this);
42}
43
44Instruction::~Instruction() {
45  assert(!Parent && "Instruction still linked in the program!");
46  if (hasMetadataHashEntry())
47    clearMetadataHashEntries();
48}
49
50
51void Instruction::setParent(BasicBlock *P) {
52  Parent = P;
53}
54
55const Module *Instruction::getModule() const {
56  return getParent()->getModule();
57}
58
59const Function *Instruction::getFunction() const {
60  return getParent()->getParent();
61}
62
63void Instruction::removeFromParent() {
64  getParent()->getInstList().remove(getIterator());
65}
66
67iplist<Instruction>::iterator Instruction::eraseFromParent() {
68  return getParent()->getInstList().erase(getIterator());
69}
70
71/// Insert an unlinked instruction into a basic block immediately before the
72/// specified instruction.
73void Instruction::insertBefore(Instruction *InsertPos) {
74  InsertPos->getParent()->getInstList().insert(InsertPos->getIterator(), this);
75}
76
77/// Insert an unlinked instruction into a basic block immediately after the
78/// specified instruction.
79void Instruction::insertAfter(Instruction *InsertPos) {
80  InsertPos->getParent()->getInstList().insertAfter(InsertPos->getIterator(),
81                                                    this);
82}
83
84/// Unlink this instruction from its current basic block and insert it into the
85/// basic block that MovePos lives in, right before MovePos.
86void Instruction::moveBefore(Instruction *MovePos) {
87  moveBefore(*MovePos->getParent(), MovePos->getIterator());
88}
89
90void Instruction::moveAfter(Instruction *MovePos) {
91  moveBefore(*MovePos->getParent(), ++MovePos->getIterator());
92}
93
94void Instruction::moveBefore(BasicBlock &BB,
95                             SymbolTableList<Instruction>::iterator I) {
96  assert(I == BB.end() || I->getParent() == &BB);
97  BB.getInstList().splice(I, getParent()->getInstList(), getIterator());
98}
99
100void Instruction::setHasNoUnsignedWrap(bool b) {
101  cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(b);
102}
103
104void Instruction::setHasNoSignedWrap(bool b) {
105  cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(b);
106}
107
108void Instruction::setIsExact(bool b) {
109  cast<PossiblyExactOperator>(this)->setIsExact(b);
110}
111
112bool Instruction::hasNoUnsignedWrap() const {
113  return cast<OverflowingBinaryOperator>(this)->hasNoUnsignedWrap();
114}
115
116bool Instruction::hasNoSignedWrap() const {
117  return cast<OverflowingBinaryOperator>(this)->hasNoSignedWrap();
118}
119
120void Instruction::dropPoisonGeneratingFlags() {
121  switch (getOpcode()) {
122  case Instruction::Add:
123  case Instruction::Sub:
124  case Instruction::Mul:
125  case Instruction::Shl:
126    cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(false);
127    cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(false);
128    break;
129
130  case Instruction::UDiv:
131  case Instruction::SDiv:
132  case Instruction::AShr:
133  case Instruction::LShr:
134    cast<PossiblyExactOperator>(this)->setIsExact(false);
135    break;
136
137  case Instruction::GetElementPtr:
138    cast<GetElementPtrInst>(this)->setIsInBounds(false);
139    break;
140  }
141  // TODO: FastMathFlags!
142}
143
144
145bool Instruction::isExact() const {
146  return cast<PossiblyExactOperator>(this)->isExact();
147}
148
149void Instruction::setFast(bool B) {
150  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
151  cast<FPMathOperator>(this)->setFast(B);
152}
153
154void Instruction::setHasAllowReassoc(bool B) {
155  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
156  cast<FPMathOperator>(this)->setHasAllowReassoc(B);
157}
158
159void Instruction::setHasNoNaNs(bool B) {
160  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
161  cast<FPMathOperator>(this)->setHasNoNaNs(B);
162}
163
164void Instruction::setHasNoInfs(bool B) {
165  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
166  cast<FPMathOperator>(this)->setHasNoInfs(B);
167}
168
169void Instruction::setHasNoSignedZeros(bool B) {
170  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
171  cast<FPMathOperator>(this)->setHasNoSignedZeros(B);
172}
173
174void Instruction::setHasAllowReciprocal(bool B) {
175  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
176  cast<FPMathOperator>(this)->setHasAllowReciprocal(B);
177}
178
179void Instruction::setHasApproxFunc(bool B) {
180  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
181  cast<FPMathOperator>(this)->setHasApproxFunc(B);
182}
183
184void Instruction::setFastMathFlags(FastMathFlags FMF) {
185  assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
186  cast<FPMathOperator>(this)->setFastMathFlags(FMF);
187}
188
189void Instruction::copyFastMathFlags(FastMathFlags FMF) {
190  assert(isa<FPMathOperator>(this) && "copying fast-math flag on invalid op");
191  cast<FPMathOperator>(this)->copyFastMathFlags(FMF);
192}
193
194bool Instruction::isFast() const {
195  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
196  return cast<FPMathOperator>(this)->isFast();
197}
198
199bool Instruction::hasAllowReassoc() const {
200  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
201  return cast<FPMathOperator>(this)->hasAllowReassoc();
202}
203
204bool Instruction::hasNoNaNs() const {
205  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
206  return cast<FPMathOperator>(this)->hasNoNaNs();
207}
208
209bool Instruction::hasNoInfs() const {
210  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
211  return cast<FPMathOperator>(this)->hasNoInfs();
212}
213
214bool Instruction::hasNoSignedZeros() const {
215  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
216  return cast<FPMathOperator>(this)->hasNoSignedZeros();
217}
218
219bool Instruction::hasAllowReciprocal() const {
220  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
221  return cast<FPMathOperator>(this)->hasAllowReciprocal();
222}
223
224bool Instruction::hasAllowContract() const {
225  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
226  return cast<FPMathOperator>(this)->hasAllowContract();
227}
228
229bool Instruction::hasApproxFunc() const {
230  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
231  return cast<FPMathOperator>(this)->hasApproxFunc();
232}
233
234FastMathFlags Instruction::getFastMathFlags() const {
235  assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
236  return cast<FPMathOperator>(this)->getFastMathFlags();
237}
238
239void Instruction::copyFastMathFlags(const Instruction *I) {
240  copyFastMathFlags(I->getFastMathFlags());
241}
242
243void Instruction::copyIRFlags(const Value *V, bool IncludeWrapFlags) {
244  // Copy the wrapping flags.
245  if (IncludeWrapFlags && isa<OverflowingBinaryOperator>(this)) {
246    if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
247      setHasNoSignedWrap(OB->hasNoSignedWrap());
248      setHasNoUnsignedWrap(OB->hasNoUnsignedWrap());
249    }
250  }
251
252  // Copy the exact flag.
253  if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
254    if (isa<PossiblyExactOperator>(this))
255      setIsExact(PE->isExact());
256
257  // Copy the fast-math flags.
258  if (auto *FP = dyn_cast<FPMathOperator>(V))
259    if (isa<FPMathOperator>(this))
260      copyFastMathFlags(FP->getFastMathFlags());
261
262  if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
263    if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
264      DestGEP->setIsInBounds(SrcGEP->isInBounds() | DestGEP->isInBounds());
265}
266
267void Instruction::andIRFlags(const Value *V) {
268  if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
269    if (isa<OverflowingBinaryOperator>(this)) {
270      setHasNoSignedWrap(hasNoSignedWrap() & OB->hasNoSignedWrap());
271      setHasNoUnsignedWrap(hasNoUnsignedWrap() & OB->hasNoUnsignedWrap());
272    }
273  }
274
275  if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
276    if (isa<PossiblyExactOperator>(this))
277      setIsExact(isExact() & PE->isExact());
278
279  if (auto *FP = dyn_cast<FPMathOperator>(V)) {
280    if (isa<FPMathOperator>(this)) {
281      FastMathFlags FM = getFastMathFlags();
282      FM &= FP->getFastMathFlags();
283      copyFastMathFlags(FM);
284    }
285  }
286
287  if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
288    if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
289      DestGEP->setIsInBounds(SrcGEP->isInBounds() & DestGEP->isInBounds());
290}
291
292const char *Instruction::getOpcodeName(unsigned OpCode) {
293  switch (OpCode) {
294  // Terminators
295  case Ret:    return "ret";
296  case Br:     return "br";
297  case Switch: return "switch";
298  case IndirectBr: return "indirectbr";
299  case Invoke: return "invoke";
300  case Resume: return "resume";
301  case Unreachable: return "unreachable";
302  case CleanupRet: return "cleanupret";
303  case CatchRet: return "catchret";
304  case CatchPad: return "catchpad";
305  case CatchSwitch: return "catchswitch";
306  case CallBr: return "callbr";
307
308  // Standard unary operators...
309  case FNeg: return "fneg";
310
311  // Standard binary operators...
312  case Add: return "add";
313  case FAdd: return "fadd";
314  case Sub: return "sub";
315  case FSub: return "fsub";
316  case Mul: return "mul";
317  case FMul: return "fmul";
318  case UDiv: return "udiv";
319  case SDiv: return "sdiv";
320  case FDiv: return "fdiv";
321  case URem: return "urem";
322  case SRem: return "srem";
323  case FRem: return "frem";
324
325  // Logical operators...
326  case And: return "and";
327  case Or : return "or";
328  case Xor: return "xor";
329
330  // Memory instructions...
331  case Alloca:        return "alloca";
332  case Load:          return "load";
333  case Store:         return "store";
334  case AtomicCmpXchg: return "cmpxchg";
335  case AtomicRMW:     return "atomicrmw";
336  case Fence:         return "fence";
337  case GetElementPtr: return "getelementptr";
338
339  // Convert instructions...
340  case Trunc:         return "trunc";
341  case ZExt:          return "zext";
342  case SExt:          return "sext";
343  case FPTrunc:       return "fptrunc";
344  case FPExt:         return "fpext";
345  case FPToUI:        return "fptoui";
346  case FPToSI:        return "fptosi";
347  case UIToFP:        return "uitofp";
348  case SIToFP:        return "sitofp";
349  case IntToPtr:      return "inttoptr";
350  case PtrToInt:      return "ptrtoint";
351  case BitCast:       return "bitcast";
352  case AddrSpaceCast: return "addrspacecast";
353
354  // Other instructions...
355  case ICmp:           return "icmp";
356  case FCmp:           return "fcmp";
357  case PHI:            return "phi";
358  case Select:         return "select";
359  case Call:           return "call";
360  case Shl:            return "shl";
361  case LShr:           return "lshr";
362  case AShr:           return "ashr";
363  case VAArg:          return "va_arg";
364  case ExtractElement: return "extractelement";
365  case InsertElement:  return "insertelement";
366  case ShuffleVector:  return "shufflevector";
367  case ExtractValue:   return "extractvalue";
368  case InsertValue:    return "insertvalue";
369  case LandingPad:     return "landingpad";
370  case CleanupPad:     return "cleanuppad";
371
372  default: return "<Invalid operator> ";
373  }
374}
375
376/// Return true if both instructions have the same special state. This must be
377/// kept in sync with FunctionComparator::cmpOperations in
378/// lib/Transforms/IPO/MergeFunctions.cpp.
379static bool haveSameSpecialState(const Instruction *I1, const Instruction *I2,
380                                 bool IgnoreAlignment = false) {
381  assert(I1->getOpcode() == I2->getOpcode() &&
382         "Can not compare special state of different instructions");
383
384  if (const AllocaInst *AI = dyn_cast<AllocaInst>(I1))
385    return AI->getAllocatedType() == cast<AllocaInst>(I2)->getAllocatedType() &&
386           (AI->getAlignment() == cast<AllocaInst>(I2)->getAlignment() ||
387            IgnoreAlignment);
388  if (const LoadInst *LI = dyn_cast<LoadInst>(I1))
389    return LI->isVolatile() == cast<LoadInst>(I2)->isVolatile() &&
390           (LI->getAlignment() == cast<LoadInst>(I2)->getAlignment() ||
391            IgnoreAlignment) &&
392           LI->getOrdering() == cast<LoadInst>(I2)->getOrdering() &&
393           LI->getSyncScopeID() == cast<LoadInst>(I2)->getSyncScopeID();
394  if (const StoreInst *SI = dyn_cast<StoreInst>(I1))
395    return SI->isVolatile() == cast<StoreInst>(I2)->isVolatile() &&
396           (SI->getAlignment() == cast<StoreInst>(I2)->getAlignment() ||
397            IgnoreAlignment) &&
398           SI->getOrdering() == cast<StoreInst>(I2)->getOrdering() &&
399           SI->getSyncScopeID() == cast<StoreInst>(I2)->getSyncScopeID();
400  if (const CmpInst *CI = dyn_cast<CmpInst>(I1))
401    return CI->getPredicate() == cast<CmpInst>(I2)->getPredicate();
402  if (const CallInst *CI = dyn_cast<CallInst>(I1))
403    return CI->isTailCall() == cast<CallInst>(I2)->isTailCall() &&
404           CI->getCallingConv() == cast<CallInst>(I2)->getCallingConv() &&
405           CI->getAttributes() == cast<CallInst>(I2)->getAttributes() &&
406           CI->hasIdenticalOperandBundleSchema(*cast<CallInst>(I2));
407  if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1))
408    return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() &&
409           CI->getAttributes() == cast<InvokeInst>(I2)->getAttributes() &&
410           CI->hasIdenticalOperandBundleSchema(*cast<InvokeInst>(I2));
411  if (const CallBrInst *CI = dyn_cast<CallBrInst>(I1))
412    return CI->getCallingConv() == cast<CallBrInst>(I2)->getCallingConv() &&
413           CI->getAttributes() == cast<CallBrInst>(I2)->getAttributes() &&
414           CI->hasIdenticalOperandBundleSchema(*cast<CallBrInst>(I2));
415  if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(I1))
416    return IVI->getIndices() == cast<InsertValueInst>(I2)->getIndices();
417  if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I1))
418    return EVI->getIndices() == cast<ExtractValueInst>(I2)->getIndices();
419  if (const FenceInst *FI = dyn_cast<FenceInst>(I1))
420    return FI->getOrdering() == cast<FenceInst>(I2)->getOrdering() &&
421           FI->getSyncScopeID() == cast<FenceInst>(I2)->getSyncScopeID();
422  if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I1))
423    return CXI->isVolatile() == cast<AtomicCmpXchgInst>(I2)->isVolatile() &&
424           CXI->isWeak() == cast<AtomicCmpXchgInst>(I2)->isWeak() &&
425           CXI->getSuccessOrdering() ==
426               cast<AtomicCmpXchgInst>(I2)->getSuccessOrdering() &&
427           CXI->getFailureOrdering() ==
428               cast<AtomicCmpXchgInst>(I2)->getFailureOrdering() &&
429           CXI->getSyncScopeID() ==
430               cast<AtomicCmpXchgInst>(I2)->getSyncScopeID();
431  if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I1))
432    return RMWI->getOperation() == cast<AtomicRMWInst>(I2)->getOperation() &&
433           RMWI->isVolatile() == cast<AtomicRMWInst>(I2)->isVolatile() &&
434           RMWI->getOrdering() == cast<AtomicRMWInst>(I2)->getOrdering() &&
435           RMWI->getSyncScopeID() == cast<AtomicRMWInst>(I2)->getSyncScopeID();
436
437  return true;
438}
439
440bool Instruction::isIdenticalTo(const Instruction *I) const {
441  return isIdenticalToWhenDefined(I) &&
442         SubclassOptionalData == I->SubclassOptionalData;
443}
444
445bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
446  if (getOpcode() != I->getOpcode() ||
447      getNumOperands() != I->getNumOperands() ||
448      getType() != I->getType())
449    return false;
450
451  // If both instructions have no operands, they are identical.
452  if (getNumOperands() == 0 && I->getNumOperands() == 0)
453    return haveSameSpecialState(this, I);
454
455  // We have two instructions of identical opcode and #operands.  Check to see
456  // if all operands are the same.
457  if (!std::equal(op_begin(), op_end(), I->op_begin()))
458    return false;
459
460  if (const PHINode *thisPHI = dyn_cast<PHINode>(this)) {
461    const PHINode *otherPHI = cast<PHINode>(I);
462    return std::equal(thisPHI->block_begin(), thisPHI->block_end(),
463                      otherPHI->block_begin());
464  }
465
466  return haveSameSpecialState(this, I);
467}
468
469// Keep this in sync with FunctionComparator::cmpOperations in
470// lib/Transforms/IPO/MergeFunctions.cpp.
471bool Instruction::isSameOperationAs(const Instruction *I,
472                                    unsigned flags) const {
473  bool IgnoreAlignment = flags & CompareIgnoringAlignment;
474  bool UseScalarTypes  = flags & CompareUsingScalarTypes;
475
476  if (getOpcode() != I->getOpcode() ||
477      getNumOperands() != I->getNumOperands() ||
478      (UseScalarTypes ?
479       getType()->getScalarType() != I->getType()->getScalarType() :
480       getType() != I->getType()))
481    return false;
482
483  // We have two instructions of identical opcode and #operands.  Check to see
484  // if all operands are the same type
485  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
486    if (UseScalarTypes ?
487        getOperand(i)->getType()->getScalarType() !=
488          I->getOperand(i)->getType()->getScalarType() :
489        getOperand(i)->getType() != I->getOperand(i)->getType())
490      return false;
491
492  return haveSameSpecialState(this, I, IgnoreAlignment);
493}
494
495bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
496  for (const Use &U : uses()) {
497    // PHI nodes uses values in the corresponding predecessor block.  For other
498    // instructions, just check to see whether the parent of the use matches up.
499    const Instruction *I = cast<Instruction>(U.getUser());
500    const PHINode *PN = dyn_cast<PHINode>(I);
501    if (!PN) {
502      if (I->getParent() != BB)
503        return true;
504      continue;
505    }
506
507    if (PN->getIncomingBlock(U) != BB)
508      return true;
509  }
510  return false;
511}
512
513bool Instruction::mayReadFromMemory() const {
514  switch (getOpcode()) {
515  default: return false;
516  case Instruction::VAArg:
517  case Instruction::Load:
518  case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
519  case Instruction::AtomicCmpXchg:
520  case Instruction::AtomicRMW:
521  case Instruction::CatchPad:
522  case Instruction::CatchRet:
523    return true;
524  case Instruction::Call:
525  case Instruction::Invoke:
526  case Instruction::CallBr:
527    return !cast<CallBase>(this)->doesNotAccessMemory();
528  case Instruction::Store:
529    return !cast<StoreInst>(this)->isUnordered();
530  }
531}
532
533bool Instruction::mayWriteToMemory() const {
534  switch (getOpcode()) {
535  default: return false;
536  case Instruction::Fence: // FIXME: refine definition of mayWriteToMemory
537  case Instruction::Store:
538  case Instruction::VAArg:
539  case Instruction::AtomicCmpXchg:
540  case Instruction::AtomicRMW:
541  case Instruction::CatchPad:
542  case Instruction::CatchRet:
543    return true;
544  case Instruction::Call:
545  case Instruction::Invoke:
546  case Instruction::CallBr:
547    return !cast<CallBase>(this)->onlyReadsMemory();
548  case Instruction::Load:
549    return !cast<LoadInst>(this)->isUnordered();
550  }
551}
552
553bool Instruction::isAtomic() const {
554  switch (getOpcode()) {
555  default:
556    return false;
557  case Instruction::AtomicCmpXchg:
558  case Instruction::AtomicRMW:
559  case Instruction::Fence:
560    return true;
561  case Instruction::Load:
562    return cast<LoadInst>(this)->getOrdering() != AtomicOrdering::NotAtomic;
563  case Instruction::Store:
564    return cast<StoreInst>(this)->getOrdering() != AtomicOrdering::NotAtomic;
565  }
566}
567
568bool Instruction::hasAtomicLoad() const {
569  assert(isAtomic());
570  switch (getOpcode()) {
571  default:
572    return false;
573  case Instruction::AtomicCmpXchg:
574  case Instruction::AtomicRMW:
575  case Instruction::Load:
576    return true;
577  }
578}
579
580bool Instruction::hasAtomicStore() const {
581  assert(isAtomic());
582  switch (getOpcode()) {
583  default:
584    return false;
585  case Instruction::AtomicCmpXchg:
586  case Instruction::AtomicRMW:
587  case Instruction::Store:
588    return true;
589  }
590}
591
592bool Instruction::mayThrow() const {
593  if (const CallInst *CI = dyn_cast<CallInst>(this))
594    return !CI->doesNotThrow();
595  if (const auto *CRI = dyn_cast<CleanupReturnInst>(this))
596    return CRI->unwindsToCaller();
597  if (const auto *CatchSwitch = dyn_cast<CatchSwitchInst>(this))
598    return CatchSwitch->unwindsToCaller();
599  return isa<ResumeInst>(this);
600}
601
602bool Instruction::isSafeToRemove() const {
603  return (!isa<CallInst>(this) || !this->mayHaveSideEffects()) &&
604         !this->isTerminator();
605}
606
607bool Instruction::isLifetimeStartOrEnd() const {
608  auto II = dyn_cast<IntrinsicInst>(this);
609  if (!II)
610    return false;
611  Intrinsic::ID ID = II->getIntrinsicID();
612  return ID == Intrinsic::lifetime_start || ID == Intrinsic::lifetime_end;
613}
614
615const Instruction *Instruction::getNextNonDebugInstruction() const {
616  for (const Instruction *I = getNextNode(); I; I = I->getNextNode())
617    if (!isa<DbgInfoIntrinsic>(I))
618      return I;
619  return nullptr;
620}
621
622const Instruction *Instruction::getPrevNonDebugInstruction() const {
623  for (const Instruction *I = getPrevNode(); I; I = I->getPrevNode())
624    if (!isa<DbgInfoIntrinsic>(I))
625      return I;
626  return nullptr;
627}
628
629bool Instruction::isAssociative() const {
630  unsigned Opcode = getOpcode();
631  if (isAssociative(Opcode))
632    return true;
633
634  switch (Opcode) {
635  case FMul:
636  case FAdd:
637    return cast<FPMathOperator>(this)->hasAllowReassoc() &&
638           cast<FPMathOperator>(this)->hasNoSignedZeros();
639  default:
640    return false;
641  }
642}
643
644unsigned Instruction::getNumSuccessors() const {
645  switch (getOpcode()) {
646#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
647  case Instruction::OPC:                                                       \
648    return static_cast<const CLASS *>(this)->getNumSuccessors();
649#include "llvm/IR/Instruction.def"
650  default:
651    break;
652  }
653  llvm_unreachable("not a terminator");
654}
655
656BasicBlock *Instruction::getSuccessor(unsigned idx) const {
657  switch (getOpcode()) {
658#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
659  case Instruction::OPC:                                                       \
660    return static_cast<const CLASS *>(this)->getSuccessor(idx);
661#include "llvm/IR/Instruction.def"
662  default:
663    break;
664  }
665  llvm_unreachable("not a terminator");
666}
667
668void Instruction::setSuccessor(unsigned idx, BasicBlock *B) {
669  switch (getOpcode()) {
670#define HANDLE_TERM_INST(N, OPC, CLASS)                                        \
671  case Instruction::OPC:                                                       \
672    return static_cast<CLASS *>(this)->setSuccessor(idx, B);
673#include "llvm/IR/Instruction.def"
674  default:
675    break;
676  }
677  llvm_unreachable("not a terminator");
678}
679
680void Instruction::replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB) {
681  for (unsigned Idx = 0, NumSuccessors = Instruction::getNumSuccessors();
682       Idx != NumSuccessors; ++Idx)
683    if (getSuccessor(Idx) == OldBB)
684      setSuccessor(Idx, NewBB);
685}
686
687Instruction *Instruction::cloneImpl() const {
688  llvm_unreachable("Subclass of Instruction failed to implement cloneImpl");
689}
690
691void Instruction::swapProfMetadata() {
692  MDNode *ProfileData = getMetadata(LLVMContext::MD_prof);
693  if (!ProfileData || ProfileData->getNumOperands() != 3 ||
694      !isa<MDString>(ProfileData->getOperand(0)))
695    return;
696
697  MDString *MDName = cast<MDString>(ProfileData->getOperand(0));
698  if (MDName->getString() != "branch_weights")
699    return;
700
701  // The first operand is the name. Fetch them backwards and build a new one.
702  Metadata *Ops[] = {ProfileData->getOperand(0), ProfileData->getOperand(2),
703                     ProfileData->getOperand(1)};
704  setMetadata(LLVMContext::MD_prof,
705              MDNode::get(ProfileData->getContext(), Ops));
706}
707
708void Instruction::copyMetadata(const Instruction &SrcInst,
709                               ArrayRef<unsigned> WL) {
710  if (!SrcInst.hasMetadata())
711    return;
712
713  DenseSet<unsigned> WLS;
714  for (unsigned M : WL)
715    WLS.insert(M);
716
717  // Otherwise, enumerate and copy over metadata from the old instruction to the
718  // new one.
719  SmallVector<std::pair<unsigned, MDNode *>, 4> TheMDs;
720  SrcInst.getAllMetadataOtherThanDebugLoc(TheMDs);
721  for (const auto &MD : TheMDs) {
722    if (WL.empty() || WLS.count(MD.first))
723      setMetadata(MD.first, MD.second);
724  }
725  if (WL.empty() || WLS.count(LLVMContext::MD_dbg))
726    setDebugLoc(SrcInst.getDebugLoc());
727}
728
729Instruction *Instruction::clone() const {
730  Instruction *New = nullptr;
731  switch (getOpcode()) {
732  default:
733    llvm_unreachable("Unhandled Opcode.");
734#define HANDLE_INST(num, opc, clas)                                            \
735  case Instruction::opc:                                                       \
736    New = cast<clas>(this)->cloneImpl();                                       \
737    break;
738#include "llvm/IR/Instruction.def"
739#undef HANDLE_INST
740  }
741
742  New->SubclassOptionalData = SubclassOptionalData;
743  New->copyMetadata(*this);
744  return New;
745}
746
747void Instruction::setProfWeight(uint64_t W) {
748  assert(isa<CallBase>(this) &&
749         "Can only set weights for call like instructions");
750  SmallVector<uint32_t, 1> Weights;
751  Weights.push_back(W);
752  MDBuilder MDB(getContext());
753  setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
754}
755