64#define DEBUG_TYPE "memcpyopt"
67 "enable-memcpyopt-without-libcalls",
cl::Hidden,
68 cl::desc(
"Enable memcpyopt even when libcalls are disabled"));
70STATISTIC(NumMemCpyInstr,
"Number of memcpy instructions deleted");
71STATISTIC(NumMemSetInfer,
"Number of memsets inferred");
72STATISTIC(NumMoveToCpy,
"Number of memmoves converted to memcpy");
73STATISTIC(NumCpyToSet,
"Number of memcpys converted to memset");
74STATISTIC(NumCallSlot,
"Number of call slot optimizations performed");
75STATISTIC(NumStackMove,
"Number of stack-move optimizations performed");
104 bool isProfitableToUseMemset(
const DataLayout &
DL)
const;
109bool MemsetRange::isProfitableToUseMemset(
const DataLayout &
DL)
const {
111 if (TheStores.size() >= 4 ||
End - Start >= 16)
115 if (TheStores.size() < 2)
121 if (!isa<StoreInst>(SI))
126 if (TheStores.size() == 2)
140 unsigned MaxIntSize =
DL.getLargestLegalIntTypeSizeInBits() / 8;
143 unsigned NumPointerStores = Bytes / MaxIntSize;
146 unsigned NumByteStores = Bytes % MaxIntSize;
151 return TheStores.size() > NumPointerStores + NumByteStores;
171 bool empty()
const {
return Ranges.empty(); }
173 void addInst(int64_t OffsetFromFirst,
Instruction *Inst) {
174 if (
auto *SI = dyn_cast<StoreInst>(Inst))
175 addStore(OffsetFromFirst, SI);
177 addMemSet(OffsetFromFirst, cast<MemSetInst>(Inst));
180 void addStore(int64_t OffsetFromFirst,
StoreInst *SI) {
181 TypeSize StoreSize =
DL.getTypeStoreSize(
SI->getOperand(0)->getType());
184 SI->getPointerOperand(),
SI->getAlign(), SI);
187 void addMemSet(int64_t OffsetFromFirst,
MemSetInst *MSI) {
188 int64_t
Size = cast<ConstantInt>(MSI->
getLength())->getZExtValue();
201void MemsetRanges::addRange(int64_t Start, int64_t
Size,
Value *
Ptr,
206 Ranges, [=](
const MemsetRange &O) {
return O.End < Start; });
211 if (
I ==
Ranges.end() || End < I->Start) {
212 MemsetRange &
R = *
Ranges.insert(
I, MemsetRange());
216 R.Alignment = Alignment;
217 R.TheStores.push_back(Inst);
222 I->TheStores.push_back(Inst);
226 if (
I->Start <= Start &&
I->End >=
End)
235 if (Start < I->Start) {
238 I->Alignment = Alignment;
246 range_iterator NextI =
I;
247 while (++NextI !=
Ranges.end() &&
End >= NextI->Start) {
249 I->TheStores.append(NextI->TheStores.begin(), NextI->TheStores.end());
250 if (NextI->End >
I->End)
266 assert(Start->getParent() ==
End->getParent() &&
"Must be in same block");
268 if (Start->getFunction()->doesNotThrow())
273 bool RequiresNoCaptureBeforeUnwind;
275 RequiresNoCaptureBeforeUnwind) &&
276 !RequiresNoCaptureBeforeUnwind)
286 I->eraseFromParent();
297 assert(Start->getBlock() ==
End->getBlock() &&
"Only local supported");
300 Instruction *
I = cast<MemoryUseOrDef>(MA).getMemoryInst();
302 auto *II = dyn_cast<IntrinsicInst>(
I);
303 if (II && II->getIntrinsicID() == Intrinsic::lifetime_start &&
304 SkippedLifetimeStart && !*SkippedLifetimeStart) {
305 *SkippedLifetimeStart =
I;
320 if (isa<MemoryUse>(
End)) {
324 return Start->getBlock() !=
End->getBlock() ||
326 make_range(std::next(Start->getIterator()),
End->getIterator()),
328 if (isa<MemoryUse>(&Acc))
330 Instruction *AccInst =
331 cast<MemoryUseOrDef>(&Acc)->getMemoryInst();
332 return isModSet(AA.getModRefInfo(AccInst, Loc));
338 End->getDefiningAccess(), Loc, AA);
346 unsigned KnownIDs[] = {LLVMContext::MD_tbaa, LLVMContext::MD_alias_scope,
347 LLVMContext::MD_noalias,
348 LLVMContext::MD_invariant_group,
349 LLVMContext::MD_access_group};
363 if (
auto *SI = dyn_cast<StoreInst>(StartInst))
364 if (
DL.getTypeStoreSize(
SI->getOperand(0)->getType()).isScalable())
379 for (++BI; !BI->isTerminator(); ++BI) {
380 auto *CurrentAcc = cast_or_null<MemoryUseOrDef>(
383 MemInsertPoint = CurrentAcc;
387 if (
auto *CB = dyn_cast<CallBase>(BI)) {
388 if (CB->onlyAccessesInaccessibleMemory())
392 if (!isa<StoreInst>(BI) && !isa<MemSetInst>(BI)) {
396 if (BI->mayWriteToMemory() || BI->mayReadFromMemory())
401 if (
auto *NextStore = dyn_cast<StoreInst>(BI)) {
403 if (!NextStore->isSimple())
406 Value *StoredVal = NextStore->getValueOperand();
414 if (
DL.getTypeStoreSize(StoredVal->
getType()).isScalable())
419 if (isa<UndefValue>(ByteVal) && StoredByte)
420 ByteVal = StoredByte;
421 if (ByteVal != StoredByte)
425 std::optional<int64_t>
Offset =
426 NextStore->getPointerOperand()->getPointerOffsetFrom(StartPtr,
DL);
432 auto *MSI = cast<MemSetInst>(BI);
434 if (MSI->isVolatile() || ByteVal != MSI->getValue() ||
435 !isa<ConstantInt>(MSI->getLength()))
439 std::optional<int64_t>
Offset =
440 MSI->getDest()->getPointerOffsetFrom(StartPtr,
DL);
456 Ranges.addInst(0, StartInst);
466 for (
const MemsetRange &Range : Ranges) {
467 if (
Range.TheStores.size() == 1)
471 if (!
Range.isProfitableToUseMemset(
DL))
476 StartPtr =
Range.StartPtr;
478 AMemSet = Builder.CreateMemSet(StartPtr, ByteVal,
Range.End -
Range.Start,
485 dbgs() <<
"With: " << *AMemSet <<
'\n');
486 if (!
Range.TheStores.empty())
489 auto *NewDef = cast<MemoryDef>(
494 MemInsertPoint = NewDef;
498 eraseInstruction(SI);
519 auto AddArg = [&](
Value *Arg) {
520 auto *
I = dyn_cast<Instruction>(Arg);
521 if (
I &&
I->getParent() ==
SI->getParent()) {
529 if (!AddArg(
SI->getPointerOperand()))
543 for (
auto I = --
SI->getIterator(), E =
P->getIterator();
I != E; --
I) {
553 bool NeedLift =
false;
575 else if (
const auto *Call = dyn_cast<CallBase>(
C)) {
581 }
else if (isa<LoadInst>(
C) || isa<StoreInst>(
C) || isa<VAArgInst>(
C)) {
587 MemLocs.push_back(
ML);
608 MemInsertPoint = cast<MemoryUseOrDef>(--MA->getIterator());
624 assert(MemInsertPoint &&
"Must have found insert point");
645 if (
T->isAggregateType() &&
647 (TLI->
has(LibFunc_memcpy) && TLI->
has(LibFunc_memmove)))) {
668 if (!moveUp(SI,
P, LI))
679 bool UseMemMove =
false;
685 Builder.CreateTypeSize(Builder.getInt64Ty(),
DL.getTypeStoreSize(
T));
688 M = Builder.CreateMemMove(
SI->getPointerOperand(),
SI->getAlign(),
692 M = Builder.CreateMemCpy(
SI->getPointerOperand(),
SI->getAlign(),
694 M->copyMetadata(*SI, LLVMContext::MD_DIAssignID);
696 LLVM_DEBUG(
dbgs() <<
"Promoting " << *LI <<
" to " << *SI <<
" => " << *M
702 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
true);
704 eraseInstruction(SI);
705 eraseInstruction(LI);
709 BBI =
M->getIterator();
718 auto GetCall = [&]() ->
CallInst * {
721 if (
auto *LoadClobber = dyn_cast<MemoryUseOrDef>(
723 return dyn_cast_or_null<CallInst>(LoadClobber->getMemoryInst());
727 bool Changed = performCallSlotOptzn(
728 LI, SI,
SI->getPointerOperand()->stripPointerCasts(),
730 DL.getTypeStoreSize(
SI->getOperand(0)->getType()),
731 std::min(
SI->getAlign(), LI->
getAlign()), BAA, GetCall);
733 eraseInstruction(SI);
734 eraseInstruction(LI);
742 if (
auto *DestAlloca = dyn_cast<AllocaInst>(
SI->getPointerOperand())) {
744 if (performStackMoveOptzn(LI, SI, DestAlloca, SrcAlloca,
745 DL.getTypeStoreSize(
T), BAA)) {
747 BBI =
SI->getNextNonDebugInstruction()->getIterator();
748 eraseInstruction(SI);
749 eraseInstruction(LI);
769 if (
SI->getMetadata(LLVMContext::MD_nontemporal))
774 Value *StoredVal =
SI->getValueOperand();
782 if (
auto *LI = dyn_cast<LoadInst>(StoredVal))
783 return processStoreOfLoad(SI, LI,
DL, BBI);
798 auto *
V =
SI->getOperand(0);
801 tryMergingIntoMemset(SI,
SI->getPointerOperand(), ByteVal)) {
802 BBI =
I->getIterator();
809 auto *
T =
V->getType();
810 if (
T->isAggregateType()) {
813 auto *
M = Builder.CreateMemSet(
SI->getPointerOperand(), ByteVal,
Size,
815 M->copyMetadata(*SI, LLVMContext::MD_DIAssignID);
817 LLVM_DEBUG(
dbgs() <<
"Promoting " << *SI <<
" to " << *M <<
"\n");
823 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
false);
825 eraseInstruction(SI);
829 BBI =
M->getIterator();
843 BBI =
I->getIterator();
852bool MemCpyOptPass::performCallSlotOptzn(
Instruction *cpyLoad,
877 auto *srcAlloca = dyn_cast<AllocaInst>(cpySrc);
881 ConstantInt *srcArraySize = dyn_cast<ConstantInt>(srcAlloca->getArraySize());
886 TypeSize SrcAllocaSize =
DL.getTypeAllocSize(srcAlloca->getAllocatedType());
892 if (cpySize < srcSize)
901 if (
F->isIntrinsic() &&
F->getIntrinsicID() == Intrinsic::lifetime_start)
904 if (
C->getParent() != cpyStore->
getParent()) {
910 isa<StoreInst>(cpyStore)
919 LLVM_DEBUG(
dbgs() <<
"Call Slot: Dest pointer modified after call\n");
926 if (SkippedLifetimeStart) {
928 dyn_cast<Instruction>(SkippedLifetimeStart->
getOperand(1));
929 if (LifetimeArg && LifetimeArg->getParent() ==
C->getParent() &&
930 C->comesBefore(LifetimeArg))
936 bool ExplicitlyDereferenceableOnly;
938 ExplicitlyDereferenceableOnly) ||
941 LLVM_DEBUG(
dbgs() <<
"Call Slot: Dest pointer not dereferenceable\n");
960 LLVM_DEBUG(
dbgs() <<
"Call Slot: Dest may be visible through unwinding\n");
965 Align srcAlign = srcAlloca->getAlign();
966 bool isDestSufficientlyAligned = srcAlign <= cpyDestAlign;
969 if (!isDestSufficientlyAligned && !isa<AllocaInst>(cpyDest)) {
970 LLVM_DEBUG(
dbgs() <<
"Call Slot: Dest not sufficiently aligned\n");
979 while (!srcUseList.empty()) {
980 User *
U = srcUseList.pop_back_val();
982 if (isa<BitCastInst>(U) || isa<AddrSpaceCastInst>(U)) {
986 if (
const auto *
G = dyn_cast<GetElementPtrInst>(U)) {
987 if (!
G->hasAllZeroIndices())
993 if (
const auto *
IT = dyn_cast<IntrinsicInst>(U))
994 if (
IT->isLifetimeStartOrEnd())
997 if (U !=
C && U != cpyLoad)
1003 bool SrcIsCaptured =
any_of(
C->args(), [&](
Use &U) {
1004 return U->stripPointerCasts() == cpySrc &&
1005 !C->doesNotCapture(C->getArgOperandNo(&U));
1011 if (SrcIsCaptured) {
1026 make_range(++
C->getIterator(),
C->getParent()->end())) {
1028 if (
auto *II = dyn_cast<IntrinsicInst>(&
I)) {
1029 if (II->getIntrinsicID() == Intrinsic::lifetime_end &&
1030 II->getArgOperand(1)->stripPointerCasts() == srcAlloca &&
1031 cast<ConstantInt>(II->getArgOperand(0))->uge(srcSize))
1036 if (isa<ReturnInst>(&
I))
1054 bool NeedMoveGEP =
false;
1057 auto *
GEP = dyn_cast<GetElementPtrInst>(cpyDest);
1058 if (
GEP &&
GEP->hasAllConstantIndices() &&
1081 for (
unsigned ArgI = 0; ArgI <
C->arg_size(); ++ArgI)
1082 if (
C->getArgOperand(ArgI)->stripPointerCasts() == cpySrc &&
1083 cpySrc->
getType() !=
C->getArgOperand(ArgI)->getType())
1087 bool changedArgument =
false;
1088 for (
unsigned ArgI = 0; ArgI <
C->arg_size(); ++ArgI)
1089 if (
C->getArgOperand(ArgI)->stripPointerCasts() == cpySrc) {
1090 changedArgument =
true;
1091 C->setArgOperand(ArgI, cpyDest);
1094 if (!changedArgument)
1098 if (!isDestSufficientlyAligned) {
1099 assert(isa<AllocaInst>(cpyDest) &&
"Can only increase alloca alignment!");
1100 cast<AllocaInst>(cpyDest)->setAlignment(srcAlign);
1104 auto *
GEP = dyn_cast<GetElementPtrInst>(cpyDest);
1108 if (SkippedLifetimeStart) {
1115 if (cpyLoad != cpyStore)
1124bool MemCpyOptPass::processMemCpyMemCpyDependence(
MemCpyInst *M,
1143 auto *MDepLen = dyn_cast<ConstantInt>(MDep->
getLength());
1144 auto *MLen = dyn_cast<ConstantInt>(
M->getLength());
1145 if (!MDepLen || !MLen || MDepLen->getZExtValue() < MLen->getZExtValue())
1169 bool UseMemMove =
false;
1174 if (isa<MemCpyInlineInst>(M))
1180 LLVM_DEBUG(
dbgs() <<
"MemCpyOptPass: Forwarding memcpy->memcpy src:\n"
1189 NewM = Builder.CreateMemMove(
M->getRawDest(),
M->getDestAlign(),
1191 M->getLength(),
M->isVolatile());
1192 else if (isa<MemCpyInlineInst>(M)) {
1196 NewM = Builder.CreateMemCpyInline(
1200 NewM = Builder.CreateMemCpy(
M->getRawDest(),
M->getDestAlign(),
1202 M->getLength(),
M->isVolatile());
1208 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
true);
1211 eraseInstruction(M);
1235bool MemCpyOptPass::processMemSetMemCpyDependence(
MemCpyInst *MemCpy,
1265 if (DestSize == SrcSize) {
1266 eraseInstruction(MemSet);
1277 if (
auto *SrcSizeC = dyn_cast<ConstantInt>(SrcSize))
1288 "Preserving debug location based on moving memset within BB.");
1289 Builder.SetCurrentDebugLocation(MemSet->
getDebugLoc());
1295 SrcSize = Builder.CreateZExt(SrcSize, DestSize->
getType());
1297 DestSize = Builder.CreateZExt(DestSize, SrcSize->
getType());
1300 Value *Ule = Builder.CreateICmpULE(DestSize, SrcSize);
1301 Value *SizeDiff = Builder.CreateSub(DestSize, SrcSize);
1302 Value *MemsetLen = Builder.CreateSelect(
1305 Builder.CreateMemSet(Builder.CreatePtrAdd(Dest, SrcSize),
1306 MemSet->
getOperand(1), MemsetLen, Alignment);
1309 "MemCpy must be a MemoryDef");
1316 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
true);
1318 eraseInstruction(MemSet);
1329 if (
auto *II = dyn_cast_or_null<IntrinsicInst>(Def->getMemoryInst())) {
1330 if (II->getIntrinsicID() == Intrinsic::lifetime_start) {
1331 auto *LTSize = cast<ConstantInt>(II->getArgOperand(0));
1333 if (
auto *CSize = dyn_cast<ConstantInt>(
Size)) {
1335 LTSize->getZExtValue() >= CSize->getZExtValue())
1345 const DataLayout &
DL = Alloca->getModule()->getDataLayout();
1346 if (std::optional<TypeSize> AllocaSize =
1347 Alloca->getAllocationSize(
DL))
1348 if (*AllocaSize == LTSize->getValue())
1370bool MemCpyOptPass::performMemCpyToMemSetOptzn(
MemCpyInst *MemCpy,
1381 if (MemSetSize != CopySize) {
1386 auto *CMemSetSize = dyn_cast<ConstantInt>(MemSetSize);
1391 auto *CCopySize = dyn_cast<ConstantInt>(CopySize);
1394 if (CCopySize->getZExtValue() > CMemSetSize->getZExtValue()) {
1400 bool CanReduceSize =
false;
1404 if (
auto *MD = dyn_cast<MemoryDef>(Clobber))
1406 CanReduceSize =
true;
1410 CopySize = MemSetSize;
1421 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
true);
1454 if (!SrcSize ||
Size != *SrcSize) {
1455 LLVM_DEBUG(
dbgs() <<
"Stack Move: Source alloca size mismatch\n");
1459 if (!DestSize ||
Size != *DestSize) {
1460 LLVM_DEBUG(
dbgs() <<
"Stack Move: Destination alloca size mismatch\n");
1474 bool SrcNotDom =
false;
1478 bool CanBeNull, CanBeFreed;
1479 return V->getPointerDereferenceableBytes(
DL, CanBeNull, CanBeFreed);
1482 auto CaptureTrackingWithModRef =
1488 Worklist.
reserve(MaxUsesToExplore);
1490 while (!Worklist.
empty()) {
1493 for (
const Use &U :
I->uses()) {
1494 auto *UI = cast<Instruction>(
U.getUser());
1500 if (Visited.
size() >= MaxUsesToExplore) {
1503 <<
"Stack Move: Exceeded max uses to see ModRef, bailing\n");
1506 if (!Visited.
insert(&U).second)
1516 if (UI->isLifetimeStartOrEnd()) {
1522 int64_t
Size = cast<ConstantInt>(UI->getOperand(0))->getSExtValue();
1523 if (
Size < 0 ||
Size == DestSize) {
1528 if (UI->hasMetadata(LLVMContext::MD_noalias))
1529 NoAliasInstrs.
insert(UI);
1530 if (!ModRefCallback(UI))
1545 auto DestModRefCallback = [&](
Instruction *UI) ->
bool {
1555 if (UI->getParent() ==
Store->getParent()) {
1564 if (UI->comesBefore(Store))
1574 ReachabilityWorklist.
push_back(UI->getParent());
1580 if (!CaptureTrackingWithModRef(DestAlloca, DestModRefCallback))
1583 if (!ReachabilityWorklist.
empty() &&
1585 nullptr, DT,
nullptr))
1593 auto SrcModRefCallback = [&](
Instruction *UI) ->
bool {
1606 if (!CaptureTrackingWithModRef(SrcAlloca, SrcModRefCallback))
1620 eraseInstruction(DestAlloca);
1628 if (!LifetimeMarkers.
empty()) {
1630 eraseInstruction(
I);
1638 I->setMetadata(LLVMContext::MD_noalias,
nullptr);
1640 LLVM_DEBUG(
dbgs() <<
"Stack Move: Performed staack-move optimization\n");
1646 if (
auto *
I = dyn_cast<Instruction>(
Size))
1650 if (
auto *
C = dyn_cast<Constant>(
Size))
1651 return isa<UndefValue>(
C) ||
C->isNullValue();
1662 if (
M->isVolatile())
1666 if (
M->getSource() ==
M->getDest()) {
1668 eraseInstruction(M);
1676 eraseInstruction(M);
1686 if (
auto *GV = dyn_cast<GlobalVariable>(
M->getSource()))
1687 if (GV->isConstant() && GV->hasDefinitiveInitializer())
1689 M->getModule()->getDataLayout())) {
1692 M->getRawDest(), ByteVal,
M->getLength(),
M->getDestAlign(),
false);
1693 auto *LastDef = cast<MemoryDef>(MA);
1696 MSSAU->
insertDef(cast<MemoryDef>(NewAccess),
true);
1698 eraseInstruction(M);
1714 if (
auto *MD = dyn_cast<MemoryDef>(DestClobber))
1715 if (
auto *MDep = dyn_cast_or_null<MemSetInst>(MD->getMemoryInst()))
1716 if (DestClobber->
getBlock() ==
M->getParent())
1717 if (processMemSetMemCpyDependence(M, MDep, BAA))
1731 if (
auto *MD = dyn_cast<MemoryDef>(SrcClobber)) {
1733 if (
auto *CopySize = dyn_cast<ConstantInt>(
M->getLength())) {
1734 if (
auto *
C = dyn_cast<CallInst>(
MI)) {
1735 if (performCallSlotOptzn(M, M,
M->getDest(),
M->getSource(),
1737 M->getDestAlign().valueOrOne(), BAA,
1740 <<
" call: " << *
C <<
"\n"
1741 <<
" memcpy: " << *M <<
"\n");
1742 eraseInstruction(M);
1748 if (
auto *MDep = dyn_cast<MemCpyInst>(
MI))
1749 if (processMemCpyMemCpyDependence(M, MDep, BAA))
1751 if (
auto *MDep = dyn_cast<MemSetInst>(
MI)) {
1752 if (performMemCpyToMemSetOptzn(M, MDep, BAA)) {
1754 eraseInstruction(M);
1763 eraseInstruction(M);
1772 auto *DestAlloca = dyn_cast<AllocaInst>(
M->getDest());
1775 auto *SrcAlloca = dyn_cast<AllocaInst>(
M->getSource());
1781 if (performStackMoveOptzn(M, M, DestAlloca, SrcAlloca,
1784 BBI =
M->getNextNonDebugInstruction()->getIterator();
1785 eraseInstruction(M);
1795bool MemCpyOptPass::processMemMove(
MemMoveInst *M) {
1800 LLVM_DEBUG(
dbgs() <<
"MemCpyOptPass: Optimizing memmove -> memcpy: " << *M
1804 Type *ArgTys[3] = {
M->getRawDest()->getType(),
M->getRawSource()->getType(),
1805 M->getLength()->getType()};
1806 M->setCalledFunction(
1817bool MemCpyOptPass::processByValArgument(
CallBase &CB,
unsigned ArgNo) {
1822 TypeSize ByValSize =
DL.getTypeAllocSize(ByValTy);
1831 if (
auto *MD = dyn_cast<MemoryDef>(Clobber))
1832 MDep = dyn_cast_or_null<MemCpyInst>(MD->getMemoryInst());
1842 auto *C1 = dyn_cast<ConstantInt>(MDep->
getLength());
1856 if ((!MemDepAlign || *MemDepAlign < *ByValAlign) &&
1875 LLVM_DEBUG(
dbgs() <<
"MemCpyOptPass: Forwarding memcpy to byval:\n"
1876 <<
" " << *MDep <<
"\n"
1877 <<
" " << CB <<
"\n");
1900bool MemCpyOptPass::processImmutArgument(
CallBase &CB,
unsigned ArgNo) {
1915 std::optional<TypeSize> AllocaSize = AI->getAllocationSize(
DL);
1918 if (!AllocaSize || AllocaSize->isScalable())
1929 if (
auto *MD = dyn_cast<MemoryDef>(Clobber))
1930 MDep = dyn_cast_or_null<MemCpyInst>(MD->getMemoryInst());
1942 auto *MDepLen = dyn_cast<ConstantInt>(MDep->
getLength());
1943 if (!MDepLen || AllocaSize != MDepLen->getValue())
1950 Align AllocaAlign = AI->getAlign();
1951 if (MemDepAlign < AllocaAlign &&
1970 LLVM_DEBUG(
dbgs() <<
"MemCpyOptPass: Forwarding memcpy to Immut src:\n"
1971 <<
" " << *MDep <<
"\n"
1972 <<
" " << CB <<
"\n");
1982bool MemCpyOptPass::iterateOnFunction(
Function &
F) {
1983 bool MadeChange =
false;
1998 bool RepeatInstruction =
false;
2000 if (
auto *SI = dyn_cast<StoreInst>(
I))
2001 MadeChange |= processStore(SI, BI);
2002 else if (
auto *M = dyn_cast<MemSetInst>(
I))
2003 RepeatInstruction = processMemSet(M, BI);
2004 else if (
auto *M = dyn_cast<MemCpyInst>(
I))
2005 RepeatInstruction = processMemCpy(M, BI);
2006 else if (
auto *M = dyn_cast<MemMoveInst>(
I))
2007 RepeatInstruction = processMemMove(M);
2008 else if (
auto *CB = dyn_cast<CallBase>(
I)) {
2009 for (
unsigned i = 0, e = CB->
arg_size(); i != e; ++i) {
2011 MadeChange |= processByValArgument(*CB, i);
2013 MadeChange |= processImmutArgument(*CB, i);
2018 if (RepeatInstruction) {
2019 if (BI != BB.
begin())
2037 bool MadeChange =
runImpl(
F, &TLI, AA, AC, DT, PDT, &MSSA->getMSSA());
2051 bool MadeChange =
false;
2062 if (!iterateOnFunction(
F))
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
static cl::opt< ITMode > IT(cl::desc("IT block support"), cl::Hidden, cl::init(DefaultIT), cl::values(clEnumValN(DefaultIT, "arm-default-it", "Generate any type of IT block"), clEnumValN(RestrictedIT, "arm-restrict-it", "Disallow complex IT blocks")))
This file contains the declarations for the subclasses of Constant, which represent the different fla...
This file defines the DenseSet and SmallDenseSet classes.
This is the interface for a simple mod/ref and alias analysis over globals.
static bool mayBeVisibleThroughUnwinding(Value *V, Instruction *Start, Instruction *End)
static bool isZeroSize(Value *Size)
static void combineAAMetadata(Instruction *ReplInst, Instruction *I)
static bool accessedBetween(BatchAAResults &AA, MemoryLocation Loc, const MemoryUseOrDef *Start, const MemoryUseOrDef *End, Instruction **SkippedLifetimeStart=nullptr)
static bool hasUndefContents(MemorySSA *MSSA, BatchAAResults &AA, Value *V, MemoryDef *Def, Value *Size)
Determine whether the instruction has undefined content for the given Size, either because it was fre...
static cl::opt< bool > EnableMemCpyOptWithoutLibcalls("enable-memcpyopt-without-libcalls", cl::Hidden, cl::desc("Enable memcpyopt even when libcalls are disabled"))
static bool writtenBetween(MemorySSA *MSSA, BatchAAResults &AA, MemoryLocation Loc, const MemoryUseOrDef *Start, const MemoryUseOrDef *End)
This file provides utility analysis objects describing memory locations.
This file exposes an interface to building/using memory SSA to walk memory instructions using a use/d...
Module.h This file contains the declarations for the Module class.
This header defines various interfaces for pass management in LLVM.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the SmallVector class.
This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...
#define STATISTIC(VARNAME, DESC)
A manager for alias analyses.
ModRefInfo getModRefInfo(const Instruction *I, const std::optional< MemoryLocation > &OptLoc)
Check whether or not an instruction may read or write the optionally specified memory location.
Class for arbitrary precision integers.
an instruction to allocate memory on the stack
bool isStaticAlloca() const
Return true if this alloca is in the entry block of the function and is a constant size.
Align getAlign() const
Return the alignment of the memory that is being allocated by the instruction.
unsigned getAddressSpace() const
Return the address space for the allocation.
std::optional< TypeSize > getAllocationSize(const DataLayout &DL) const
Get allocation size in bytes.
void setAlignment(Align Align)
A container for analyses that lazily runs them and caches their results.
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
A function analysis which provides an AssumptionCache.
A cache of @llvm.assume calls within a function.
LLVM Basic Block Representation.
iterator begin()
Instruction iterator methods.
const_iterator getFirstInsertionPt() const
Returns an iterator to the first instruction in this block that is suitable for inserting a non-PHI i...
bool isEntryBlock() const
Return true if this is the entry block of the containing function.
const Function * getParent() const
Return the enclosing method, or null if none.
InstListType::iterator iterator
Instruction iterators...
This class is a wrapper over an AAResults, and it is intended to be used only when there are no IR ch...
bool isMustAlias(const MemoryLocation &LocA, const MemoryLocation &LocB)
ModRefInfo getModRefInfo(const Instruction *I, const std::optional< MemoryLocation > &OptLoc)
ModRefInfo callCapturesBefore(const Instruction *I, const MemoryLocation &MemLoc, DominatorTree *DT)
Represents analyses that only rely on functions' control flow.
Base class for all callable instructions (InvokeInst and CallInst) Holds everything related to callin...
bool paramHasAttr(unsigned ArgNo, Attribute::AttrKind Kind) const
Determine whether the argument or parameter has the given attribute.
bool isByValArgument(unsigned ArgNo) const
Determine whether this argument is passed by value.
MaybeAlign getParamAlign(unsigned ArgNo) const
Extract the alignment for a call or parameter (0=unknown).
bool onlyReadsMemory(unsigned OpNo) const
Type * getParamByValType(unsigned ArgNo) const
Extract the byval type for a call or parameter.
Value * getArgOperand(unsigned i) const
void setArgOperand(unsigned i, Value *v)
unsigned arg_size() const
Function * getCaller()
Helper to get the caller (the parent function).
This class represents a function call, abstracting a target machine's calling convention.
This is the shared class of boolean and integer constants.
uint64_t getZExtValue() const
Return the constant as a 64-bit unsigned integer value after it has been zero extended as appropriate...
static Constant * getNullValue(Type *Ty)
Constructor to create a '0' constant of arbitrary type.
This class represents an Operation in the Expression.
A parsed version of the target data layout string in and methods for querying it.
Implements a dense probed hash-table based set.
Analysis pass which computes a DominatorTree.
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
bool isReachableFromEntry(const Use &U) const
Provide an overload for a Use.
bool dominates(const BasicBlock *BB, const Use &U) const
Return true if the (end of the) basic block BB dominates the use U.
Module * getParent()
Get the module that this global value is contained inside of...
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
void mergeDIAssignID(ArrayRef< const Instruction * > SourceInstructions)
Merge the DIAssignID metadata from this instruction and those attached to instructions in SourceInstr...
const DebugLoc & getDebugLoc() const
Return the debug location for this node as a DebugLoc.
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
const BasicBlock * getParent() const
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
void copyMetadata(const Instruction &SrcInst, ArrayRef< unsigned > WL=ArrayRef< unsigned >())
Copy metadata from SrcInst to this instruction.
void moveBefore(Instruction *MovePos)
Unlink this instruction from its current basic block and insert it into the basic block that MovePos ...
void dropUnknownNonDebugMetadata(ArrayRef< unsigned > KnownIDs)
Drop all unknown metadata except for debug locations.
An instruction for reading from memory.
Value * getPointerOperand()
Align getAlign() const
Return the alignment of the access that is being performed.
static LocationSize precise(uint64_t Value)
This class wraps the llvm.memcpy intrinsic.
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
bool runImpl(Function &F, TargetLibraryInfo *TLI, AAResults *AA, AssumptionCache *AC, DominatorTree *DT, PostDominatorTree *PDT, MemorySSA *MSSA)
Value * getLength() const
Value * getRawDest() const
Value * getDest() const
This is just like getRawDest, but it strips off any cast instructions (including addrspacecast) that ...
MaybeAlign getDestAlign() const
This class wraps the llvm.memmove intrinsic.
This class wraps the llvm.memset and llvm.memset.inline intrinsics.
Value * getRawSource() const
Return the arguments to the instruction.
MaybeAlign getSourceAlign() const
Value * getSource() const
This is just like getRawSource, but it strips off any cast instructions that feed it,...
BasicBlock * getBlock() const
Represents a read-write access to memory, whether it is a must-alias, or a may-alias.
Representation for a specific memory location.
static MemoryLocation get(const LoadInst *LI)
Return a location with information about the memory reference by the given instruction.
static MemoryLocation getForSource(const MemTransferInst *MTI)
Return a location representing the source of a memory transfer.
static MemoryLocation getForDest(const MemIntrinsic *MI)
Return a location representing the destination of a memory set or transfer.
An analysis that produces MemorySSA for a function.
MemorySSA * getMemorySSA() const
Get handle on MemorySSA.
MemoryUseOrDef * createMemoryAccessBefore(Instruction *I, MemoryAccess *Definition, MemoryUseOrDef *InsertPt)
Create a MemoryAccess in MemorySSA before an existing MemoryAccess.
void insertDef(MemoryDef *Def, bool RenameUses=false)
Insert a definition into the MemorySSA IR.
void moveAfter(MemoryUseOrDef *What, MemoryUseOrDef *Where)
void removeMemoryAccess(MemoryAccess *, bool OptimizePhis=false)
Remove a MemoryAccess from MemorySSA, including updating all definitions and uses.
MemoryUseOrDef * createMemoryAccessAfter(Instruction *I, MemoryAccess *Definition, MemoryAccess *InsertPt)
Create a MemoryAccess in MemorySSA after an existing MemoryAccess.
void moveBefore(MemoryUseOrDef *What, MemoryUseOrDef *Where)
MemoryAccess * getClobberingMemoryAccess(const Instruction *I, BatchAAResults &AA)
Given a memory Mod/Ref/ModRef'ing instruction, calling this will give you the nearest dominating Memo...
Encapsulates MemorySSA, including all data associated with memory accesses.
bool dominates(const MemoryAccess *A, const MemoryAccess *B) const
Given two memory accesses in potentially different blocks, determine whether MemoryAccess A dominates...
void verifyMemorySSA(VerificationLevel=VerificationLevel::Fast) const
Verify that MemorySSA is self consistent (IE definitions dominate all uses, uses appear in the right ...
MemorySSAWalker * getWalker()
MemoryUseOrDef * getMemoryAccess(const Instruction *I) const
Given a memory Mod/Ref'ing instruction, get the MemorySSA access associated with it.
bool isLiveOnEntryDef(const MemoryAccess *MA) const
Return true if MA represents the live on entry value.
Class that has the common methods + fields of memory uses/defs.
MemoryAccess * getDefiningAccess() const
Get the access that produces the memory state used by this Use.
Instruction * getMemoryInst() const
Get the instruction that this MemoryUse represents.
const DataLayout & getDataLayout() const
Get the data layout for the module's target platform.
Analysis pass which computes a PostDominatorTree.
PostDominatorTree Class - Concrete subclass of DominatorTree that is used to compute the post-dominat...
bool dominates(const Instruction *I1, const Instruction *I2) const
Return true if I1 dominates I2.
A set of analyses that are preserved following a run of a transformation pass.
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
void preserveSet()
Mark an analysis set as preserved.
void preserve()
Mark an analysis as preserved.
SmallSet - This maintains a set of unique values, optimizing for the case when the set is small (less...
std::pair< const_iterator, bool > insert(const T &V)
insert - Insert an element into the set if it isn't already there.
void reserve(size_type N)
typename SuperClass::const_iterator const_iterator
void append(ItTy in_start, ItTy in_end)
Add the specified range to the end of the SmallVector.
typename SuperClass::iterator iterator
void push_back(const T &Elt)
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
An instruction for storing to memory.
Analysis pass providing the TargetLibraryInfo.
Provides information about what library functions are available for the current target.
bool has(LibFunc F) const
Tests whether a library function is available.
static constexpr TypeSize getFixed(ScalarTy ExactSize)
The instances of the Type class are immutable: once they are created, they are never changed.
unsigned getIntegerBitWidth() const
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return 'this'.
A Use represents the edge between a Value definition and its users.
Value * getOperand(unsigned i) const
LLVM Value Representation.
Type * getType() const
All values are typed, get the type of this value.
bool hasOneUse() const
Return true if there is exactly one use of this value.
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
const Value * stripPointerCasts() const
Strip off pointer casts, all-zero GEPs and address space casts.
constexpr ScalarTy getFixedValue() const
constexpr bool isScalable() const
Returns whether the quantity is scaled by a runtime quantity (vscale).
static constexpr bool isKnownGE(const FixedOrScalableQuantity &LHS, const FixedOrScalableQuantity &RHS)
An efficient, type-erasing, non-owning reference to a callable.
reverse_self_iterator getReverseIterator()
self_iterator getIterator()
This provides a very simple, boring adaptor for a begin and end iterator into a range type.
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
@ C
The default llvm calling convention, compatible with C.
Function * getDeclaration(Module *M, ID id, ArrayRef< Type * > Tys=std::nullopt)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
const_iterator begin(StringRef path, Style style=Style::native)
Get begin iterator over path.
const_iterator end(StringRef path)
Get end iterator over path.
This is an optimization pass for GlobalISel generic memory operations.
bool isPotentiallyReachableFromMany(SmallVectorImpl< BasicBlock * > &Worklist, const BasicBlock *StopBB, const SmallPtrSetImpl< BasicBlock * > *ExclusionSet, const DominatorTree *DT=nullptr, const LoopInfo *LI=nullptr)
Determine whether there is at least one path from a block in 'Worklist' to 'StopBB' without passing t...
bool isDereferenceableAndAlignedPointer(const Value *V, Type *Ty, Align Alignment, const DataLayout &DL, const Instruction *CtxI=nullptr, AssumptionCache *AC=nullptr, const DominatorTree *DT=nullptr, const TargetLibraryInfo *TLI=nullptr)
Returns true if V is always a dereferenceable pointer with alignment greater or equal than requested.
UseCaptureKind DetermineUseCaptureKind(const Use &U, llvm::function_ref< bool(Value *, const DataLayout &)> IsDereferenceableOrNull)
Determine what kind of capture behaviour U may exhibit.
auto partition_point(R &&Range, Predicate P)
Binary search for the first iterator in a range where a predicate is false.
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
bool PointerMayBeCapturedBefore(const Value *V, bool ReturnCaptures, bool StoreCaptures, const Instruction *I, const DominatorTree *DT, bool IncludeI=false, unsigned MaxUsesToExplore=0, const LoopInfo *LI=nullptr)
PointerMayBeCapturedBefore - Return true if this pointer value may be captured by the enclosing funct...
void append_range(Container &C, Range &&R)
Wrapper function to append range R to container C.
const Value * getUnderlyingObject(const Value *V, unsigned MaxLookup=6)
This method strips off any GEP address adjustments, pointer casts or llvm.threadlocal....
unsigned getDefaultMaxUsesToExploreForCaptureTracking()
getDefaultMaxUsesToExploreForCaptureTracking - Return default value of the maximal number of uses to ...
Value * simplifyInstruction(Instruction *I, const SimplifyQuery &Q)
See if we can compute a simplified version of this instruction.
bool any_of(R &&range, UnaryPredicate P)
Provide wrappers to std::any_of which take ranges instead of having to pass begin/end explicitly.
auto reverse(ContainerTy &&C)
Align getOrEnforceKnownAlignment(Value *V, MaybeAlign PrefAlign, const DataLayout &DL, const Instruction *CxtI=nullptr, AssumptionCache *AC=nullptr, const DominatorTree *DT=nullptr)
Try to ensure that the alignment of V is at least PrefAlign bytes.
bool isModSet(const ModRefInfo MRI)
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
bool isModOrRefSet(const ModRefInfo MRI)
bool isNotVisibleOnUnwind(const Value *Object, bool &RequiresNoCaptureBeforeUnwind)
Return true if Object memory is not visible after an unwind, in the sense that program semantics cann...
void combineMetadata(Instruction *K, const Instruction *J, ArrayRef< unsigned > KnownIDs, bool DoesKMove)
Combine the metadata of two instructions so that K can replace J.
RNSuccIterator< NodeRef, BlockT, RegionT > succ_begin(NodeRef Node)
ModRefInfo
Flags indicating whether a memory access modifies or references memory.
@ NoModRef
The access neither references nor modifies the value stored in memory.
bool VerifyMemorySSA
Enables verification of MemorySSA.
RNSuccIterator< NodeRef, BlockT, RegionT > succ_end(NodeRef Node)
bool isIdentifiedFunctionLocal(const Value *V)
Return true if V is umabigously identified at the function-level.
bool isGuaranteedToTransferExecutionToSuccessor(const Instruction *I)
Return true if this function can prove that the instruction I will always transfer execution to one o...
decltype(auto) cast(const From &Val)
cast<X> - Return the argument parameter cast to the specified type.
Value * isBytewiseValue(Value *V, const DataLayout &DL)
If the specified value can be set by repeating the same byte in memory, return the i8 value that it i...
Align commonAlignment(Align A, uint64_t Offset)
Returns the alignment that satisfies both alignments.
bool isRefSet(const ModRefInfo MRI)
bool isWritableObject(const Value *Object, bool &ExplicitlyDereferenceableOnly)
Return true if the Object is writable, in the sense that any location based on this pointer that can ...
This struct is a compact representation of a valid (non-zero power of two) alignment.
This struct is a compact representation of a valid (power of two) or undefined (0) alignment.
Align valueOrOne() const
For convenience, returns a valid alignment or 1 if undefined.