diff options
Diffstat (limited to 'lib/Transforms/Scalar/MemCpyOptimizer.cpp')
-rw-r--r-- | lib/Transforms/Scalar/MemCpyOptimizer.cpp | 86 |
1 files changed, 39 insertions, 47 deletions
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp index 006b885..2b5a078 100644 --- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -18,6 +18,7 @@ #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/AssumptionCache.h" #include "llvm/Analysis/MemoryDependenceAnalysis.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/Dominators.h" @@ -28,7 +29,6 @@ #include "llvm/IR/IntrinsicInst.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Transforms/Utils/Local.h" #include <list> using namespace llvm; @@ -41,7 +41,8 @@ STATISTIC(NumMoveToCpy, "Number of memmoves converted to memcpy"); STATISTIC(NumCpyToSet, "Number of memcpys converted to memset"); static int64_t GetOffsetFromIndex(const GEPOperator *GEP, unsigned Idx, - bool &VariableIdxFound, const DataLayout &TD){ + bool &VariableIdxFound, + const DataLayout &DL) { // Skip over the first indices. gep_type_iterator GTI = gep_type_begin(GEP); for (unsigned i = 1; i != Idx; ++i, ++GTI) @@ -57,13 +58,13 @@ static int64_t GetOffsetFromIndex(const GEPOperator *GEP, unsigned Idx, // Handle struct indices, which add their field offset to the pointer. if (StructType *STy = dyn_cast<StructType>(*GTI)) { - Offset += TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue()); + Offset += DL.getStructLayout(STy)->getElementOffset(OpC->getZExtValue()); continue; } // Otherwise, we have a sequential type like an array or vector. Multiply // the index by the ElementSize. - uint64_t Size = TD.getTypeAllocSize(GTI.getIndexedType()); + uint64_t Size = DL.getTypeAllocSize(GTI.getIndexedType()); Offset += Size*OpC->getSExtValue(); } @@ -74,7 +75,7 @@ static int64_t GetOffsetFromIndex(const GEPOperator *GEP, unsigned Idx, /// constant offset, and return that constant offset. For example, Ptr1 might /// be &A[42], and Ptr2 might be &A[40]. In this case offset would be -8. static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset, - const DataLayout &TD) { + const DataLayout &DL) { Ptr1 = Ptr1->stripPointerCasts(); Ptr2 = Ptr2->stripPointerCasts(); @@ -92,12 +93,12 @@ static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset, // If one pointer is a GEP and the other isn't, then see if the GEP is a // constant offset from the base, as in "P" and "gep P, 1". if (GEP1 && !GEP2 && GEP1->getOperand(0)->stripPointerCasts() == Ptr2) { - Offset = -GetOffsetFromIndex(GEP1, 1, VariableIdxFound, TD); + Offset = -GetOffsetFromIndex(GEP1, 1, VariableIdxFound, DL); return !VariableIdxFound; } if (GEP2 && !GEP1 && GEP2->getOperand(0)->stripPointerCasts() == Ptr1) { - Offset = GetOffsetFromIndex(GEP2, 1, VariableIdxFound, TD); + Offset = GetOffsetFromIndex(GEP2, 1, VariableIdxFound, DL); return !VariableIdxFound; } @@ -115,8 +116,8 @@ static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset, if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx)) break; - int64_t Offset1 = GetOffsetFromIndex(GEP1, Idx, VariableIdxFound, TD); - int64_t Offset2 = GetOffsetFromIndex(GEP2, Idx, VariableIdxFound, TD); + int64_t Offset1 = GetOffsetFromIndex(GEP1, Idx, VariableIdxFound, DL); + int64_t Offset2 = GetOffsetFromIndex(GEP2, Idx, VariableIdxFound, DL); if (VariableIdxFound) return false; Offset = Offset2-Offset1; @@ -150,12 +151,11 @@ struct MemsetRange { /// TheStores - The actual stores that make up this range. SmallVector<Instruction*, 16> TheStores; - bool isProfitableToUseMemset(const DataLayout &TD) const; - + bool isProfitableToUseMemset(const DataLayout &DL) const; }; } // end anon namespace -bool MemsetRange::isProfitableToUseMemset(const DataLayout &TD) const { +bool MemsetRange::isProfitableToUseMemset(const DataLayout &DL) const { // If we found more than 4 stores to merge or 16 bytes, use memset. if (TheStores.size() >= 4 || End-Start >= 16) return true; @@ -183,7 +183,7 @@ bool MemsetRange::isProfitableToUseMemset(const DataLayout &TD) const { // size. If so, check to see whether we will end up actually reducing the // number of stores used. unsigned Bytes = unsigned(End-Start); - unsigned MaxIntSize = TD.getLargestLegalIntTypeSize(); + unsigned MaxIntSize = DL.getLargestLegalIntTypeSize(); if (MaxIntSize == 0) MaxIntSize = 1; unsigned NumPointerStores = Bytes / MaxIntSize; @@ -314,14 +314,12 @@ namespace { class MemCpyOpt : public FunctionPass { MemoryDependenceAnalysis *MD; TargetLibraryInfo *TLI; - const DataLayout *DL; public: static char ID; // Pass identification, replacement for typeid MemCpyOpt() : FunctionPass(ID) { initializeMemCpyOptPass(*PassRegistry::getPassRegistry()); MD = nullptr; TLI = nullptr; - DL = nullptr; } bool runOnFunction(Function &F) override; @@ -377,13 +375,13 @@ INITIALIZE_PASS_END(MemCpyOpt, "memcpyopt", "MemCpy Optimization", /// attempts to merge them together into a memcpy/memset. Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, Value *StartPtr, Value *ByteVal) { - if (!DL) return nullptr; + const DataLayout &DL = StartInst->getModule()->getDataLayout(); // Okay, so we now have a single store that can be splatable. Scan to find // all subsequent stores of the same value to offset from the same pointer. // Join these together into ranges, so we can decide whether contiguous blocks // are stored. - MemsetRanges Ranges(*DL); + MemsetRanges Ranges(DL); BasicBlock::iterator BI = StartInst; for (++BI; !isa<TerminatorInst>(BI); ++BI) { @@ -406,8 +404,8 @@ Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, // Check to see if this store is to a constant offset from the start ptr. int64_t Offset; - if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), - Offset, *DL)) + if (!IsPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset, + DL)) break; Ranges.addStore(Offset, NextStore); @@ -420,7 +418,7 @@ Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, // Check to see if this store is to a constant offset from the start ptr. int64_t Offset; - if (!IsPointerOffset(StartPtr, MSI->getDest(), Offset, *DL)) + if (!IsPointerOffset(StartPtr, MSI->getDest(), Offset, DL)) break; Ranges.addMemSet(Offset, MSI); @@ -452,7 +450,7 @@ Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, if (Range.TheStores.size() == 1) continue; // If it is profitable to lower this range to memset, do so now. - if (!Range.isProfitableToUseMemset(*DL)) + if (!Range.isProfitableToUseMemset(DL)) continue; // Otherwise, we do want to transform this! Create a new memset. @@ -464,7 +462,7 @@ Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, if (Alignment == 0) { Type *EltType = cast<PointerType>(StartPtr->getType())->getElementType(); - Alignment = DL->getABITypeAlignment(EltType); + Alignment = DL.getABITypeAlignment(EltType); } AMemSet = @@ -494,8 +492,7 @@ Instruction *MemCpyOpt::tryMergingIntoMemset(Instruction *StartInst, bool MemCpyOpt::processStore(StoreInst *SI, BasicBlock::iterator &BBI) { if (!SI->isSimple()) return false; - - if (!DL) return false; + const DataLayout &DL = SI->getModule()->getDataLayout(); // Detect cases where we're performing call slot forwarding, but // happen to be using a load-store pair to implement it, rather than @@ -525,16 +522,16 @@ bool MemCpyOpt::processStore(StoreInst *SI, BasicBlock::iterator &BBI) { if (C) { unsigned storeAlign = SI->getAlignment(); if (!storeAlign) - storeAlign = DL->getABITypeAlignment(SI->getOperand(0)->getType()); + storeAlign = DL.getABITypeAlignment(SI->getOperand(0)->getType()); unsigned loadAlign = LI->getAlignment(); if (!loadAlign) - loadAlign = DL->getABITypeAlignment(LI->getType()); + loadAlign = DL.getABITypeAlignment(LI->getType()); - bool changed = performCallSlotOptzn(LI, - SI->getPointerOperand()->stripPointerCasts(), - LI->getPointerOperand()->stripPointerCasts(), - DL->getTypeStoreSize(SI->getOperand(0)->getType()), - std::min(storeAlign, loadAlign), C); + bool changed = performCallSlotOptzn( + LI, SI->getPointerOperand()->stripPointerCasts(), + LI->getPointerOperand()->stripPointerCasts(), + DL.getTypeStoreSize(SI->getOperand(0)->getType()), + std::min(storeAlign, loadAlign), C); if (changed) { MD->removeInstruction(SI); SI->eraseFromParent(); @@ -606,15 +603,13 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy, if (!srcAlloca) return false; - // Check that all of src is copied to dest. - if (!DL) return false; - ConstantInt *srcArraySize = dyn_cast<ConstantInt>(srcAlloca->getArraySize()); if (!srcArraySize) return false; - uint64_t srcSize = DL->getTypeAllocSize(srcAlloca->getAllocatedType()) * - srcArraySize->getZExtValue(); + const DataLayout &DL = cpy->getModule()->getDataLayout(); + uint64_t srcSize = DL.getTypeAllocSize(srcAlloca->getAllocatedType()) * + srcArraySize->getZExtValue(); if (cpyLen < srcSize) return false; @@ -628,8 +623,8 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy, if (!destArraySize) return false; - uint64_t destSize = DL->getTypeAllocSize(A->getAllocatedType()) * - destArraySize->getZExtValue(); + uint64_t destSize = DL.getTypeAllocSize(A->getAllocatedType()) * + destArraySize->getZExtValue(); if (destSize < srcSize) return false; @@ -648,7 +643,7 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy, return false; } - uint64_t destSize = DL->getTypeAllocSize(StructTy); + uint64_t destSize = DL.getTypeAllocSize(StructTy); if (destSize < srcSize) return false; } @@ -659,7 +654,7 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy, // Check that dest points to memory that is at least as aligned as src. unsigned srcAlign = srcAlloca->getAlignment(); if (!srcAlign) - srcAlign = DL->getABITypeAlignment(srcAlloca->getAllocatedType()); + srcAlign = DL.getABITypeAlignment(srcAlloca->getAllocatedType()); bool isDestSufficientlyAligned = srcAlign <= cpyAlign; // If dest is not aligned enough and we can't increase its alignment then // bail out. @@ -959,12 +954,11 @@ bool MemCpyOpt::processMemMove(MemMoveInst *M) { /// processByValArgument - This is called on every byval argument in call sites. bool MemCpyOpt::processByValArgument(CallSite CS, unsigned ArgNo) { - if (!DL) return false; - + const DataLayout &DL = CS.getCaller()->getParent()->getDataLayout(); // Find out what feeds this byval argument. Value *ByValArg = CS.getArgument(ArgNo); Type *ByValTy = cast<PointerType>(ByValArg->getType())->getElementType(); - uint64_t ByValSize = DL->getTypeAllocSize(ByValTy); + uint64_t ByValSize = DL.getTypeAllocSize(ByValTy); MemDepResult DepInfo = MD->getPointerDependencyFrom(AliasAnalysis::Location(ByValArg, ByValSize), true, CS.getInstruction(), @@ -997,8 +991,8 @@ bool MemCpyOpt::processByValArgument(CallSite CS, unsigned ArgNo) { *CS->getParent()->getParent()); DominatorTree &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree(); if (MDep->getAlignment() < ByValAlign && - getOrEnforceKnownAlignment(MDep->getSource(), ByValAlign, DL, &AC, - CS.getInstruction(), &DT) < ByValAlign) + getOrEnforceKnownAlignment(MDep->getSource(), ByValAlign, DL, + CS.getInstruction(), &AC, &DT) < ByValAlign) return false; // Verify that the copied-from memory doesn't change in between the memcpy and @@ -1077,8 +1071,6 @@ bool MemCpyOpt::runOnFunction(Function &F) { bool MadeChange = false; MD = &getAnalysis<MemoryDependenceAnalysis>(); - DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); - DL = DLP ? &DLP->getDataLayout() : nullptr; TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(); // If we don't have at least memset and memcpy, there is little point of doing |