diff options
Diffstat (limited to 'lib/Transforms/Scalar/GVN.cpp')
-rw-r--r-- | lib/Transforms/Scalar/GVN.cpp | 313 |
1 files changed, 165 insertions, 148 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index 6af269d..106eba0 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -15,35 +15,34 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "gvn" #include "llvm/Transforms/Scalar.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DepthFirstIterator.h" #include "llvm/ADT/Hashing.h" -#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/MapVector.h" #include "llvm/ADT/SetVector.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/CFG.h" #include "llvm/Analysis/ConstantFolding.h" -#include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/Loads.h" #include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Analysis/MemoryDependenceAnalysis.h" #include "llvm/Analysis/PHITransAddr.h" #include "llvm/Analysis/ValueTracking.h" -#include "llvm/Assembly/Writer.h" #include "llvm/IR/DataLayout.h" +#include "llvm/IR/Dominators.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/IRBuilder.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/LLVMContext.h" #include "llvm/IR/Metadata.h" +#include "llvm/IR/PatternMatch.h" #include "llvm/Support/Allocator.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/PatternMatch.h" #include "llvm/Target/TargetLibraryInfo.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/SSAUpdater.h" @@ -51,6 +50,8 @@ using namespace llvm; using namespace PatternMatch; +#define DEBUG_TYPE "gvn" + STATISTIC(NumGVNInstr, "Number of instructions deleted"); STATISTIC(NumGVNLoad, "Number of loads deleted"); STATISTIC(NumGVNPRE, "Number of instructions PRE'd"); @@ -214,13 +215,13 @@ Expression ValueTable::create_cmp_expression(unsigned Opcode, } Expression ValueTable::create_extractvalue_expression(ExtractValueInst *EI) { - assert(EI != 0 && "Not an ExtractValueInst?"); + assert(EI && "Not an ExtractValueInst?"); Expression e; e.type = EI->getType(); e.opcode = 0; IntrinsicInst *I = dyn_cast<IntrinsicInst>(EI->getAggregateOperand()); - if (I != 0 && EI->getNumIndices() == 1 && *EI->idx_begin() == 0 ) { + if (I != nullptr && EI->getNumIndices() == 1 && *EI->idx_begin() == 0 ) { // EI might be an extract from one of our recognised intrinsics. If it // is we'll synthesize a semantically equivalent expression instead on // an extract value expression. @@ -328,7 +329,7 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) { const MemoryDependenceAnalysis::NonLocalDepInfo &deps = MD->getNonLocalCallDependency(CallSite(C)); // FIXME: Move the checking logic to MemDep! - CallInst* cdep = 0; + CallInst* cdep = nullptr; // Check to see if we have a single dominating call instruction that is // identical to C. @@ -339,8 +340,8 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) { // We don't handle non-definitions. If we already have a call, reject // instruction dependencies. - if (!I->getResult().isDef() || cdep != 0) { - cdep = 0; + if (!I->getResult().isDef() || cdep != nullptr) { + cdep = nullptr; break; } @@ -351,7 +352,7 @@ uint32_t ValueTable::lookup_or_add_call(CallInst *C) { continue; } - cdep = 0; + cdep = nullptr; break; } @@ -552,7 +553,7 @@ namespace { static AvailableValueInBlock getUndef(BasicBlock *BB) { AvailableValueInBlock Res; Res.BB = BB; - Res.Val.setPointer(0); + Res.Val.setPointer(nullptr); Res.Val.setInt(UndefVal); Res.Offset = 0; return Res; @@ -587,7 +588,7 @@ namespace { bool NoLoads; MemoryDependenceAnalysis *MD; DominatorTree *DT; - const DataLayout *TD; + const DataLayout *DL; const TargetLibraryInfo *TLI; SetVector<BasicBlock *> DeadBlocks; @@ -612,11 +613,11 @@ namespace { public: static char ID; // Pass identification, replacement for typeid explicit GVN(bool noloads = false) - : FunctionPass(ID), NoLoads(noloads), MD(0) { + : FunctionPass(ID), NoLoads(noloads), MD(nullptr) { initializeGVNPass(*PassRegistry::getPassRegistry()); } - bool runOnFunction(Function &F); + bool runOnFunction(Function &F) override; /// markInstructionForDeletion - This removes the specified instruction from /// our various maps and marks it for deletion. @@ -625,7 +626,7 @@ namespace { InstrsToErase.push_back(I); } - const DataLayout *getDataLayout() const { return TD; } + const DataLayout *getDataLayout() const { return DL; } DominatorTree &getDominatorTree() const { return *DT; } AliasAnalysis *getAliasAnalysis() const { return VN.getAliasAnalysis(); } MemoryDependenceAnalysis &getMemDep() const { return *MD; } @@ -650,7 +651,7 @@ namespace { /// removeFromLeaderTable - Scan the list of values corresponding to a given /// value number, and remove the given instruction if encountered. void removeFromLeaderTable(uint32_t N, Instruction *I, BasicBlock *BB) { - LeaderTableEntry* Prev = 0; + LeaderTableEntry* Prev = nullptr; LeaderTableEntry* Curr = &LeaderTable[N]; while (Curr->Val != I || Curr->BB != BB) { @@ -662,8 +663,8 @@ namespace { Prev->Next = Curr->Next; } else { if (!Curr->Next) { - Curr->Val = 0; - Curr->BB = 0; + Curr->Val = nullptr; + Curr->BB = nullptr; } else { LeaderTableEntry* Next = Curr->Next; Curr->Val = Next->Val; @@ -677,14 +678,14 @@ namespace { SmallVector<std::pair<TerminatorInst*, unsigned>, 4> toSplit; // This transformation requires dominator postdominator info - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addRequired<DominatorTree>(); + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addRequired<DominatorTreeWrapperPass>(); AU.addRequired<TargetLibraryInfo>(); if (!NoLoads) AU.addRequired<MemoryDependenceAnalysis>(); AU.addRequired<AliasAnalysis>(); - AU.addPreserved<DominatorTree>(); + AU.addPreserved<DominatorTreeWrapperPass>(); AU.addPreserved<AliasAnalysis>(); } @@ -727,7 +728,7 @@ FunctionPass *llvm::createGVNPass(bool NoLoads) { INITIALIZE_PASS_BEGIN(GVN, "gvn", "Global Value Numbering", false, false) INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis) -INITIALIZE_PASS_DEPENDENCY(DominatorTree) +INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo) INITIALIZE_AG_DEPENDENCY(AliasAnalysis) INITIALIZE_PASS_END(GVN, "gvn", "Global Value Numbering", false, false) @@ -818,8 +819,7 @@ SpeculationFailure: // Mark as unavailable. EntryVal = 0; - for (succ_iterator I = succ_begin(Entry), E = succ_end(Entry); I != E; ++I) - BBWorklist.push_back(*I); + BBWorklist.append(succ_begin(Entry), succ_end(Entry)); } while (!BBWorklist.empty()); return false; @@ -830,7 +830,7 @@ SpeculationFailure: /// CoerceAvailableValueToLoadType will succeed. static bool CanCoerceMustAliasedValueToLoad(Value *StoredVal, Type *LoadTy, - const DataLayout &TD) { + const DataLayout &DL) { // If the loaded or stored value is an first class array or struct, don't try // to transform them. We need to be able to bitcast to integer. if (LoadTy->isStructTy() || LoadTy->isArrayTy() || @@ -839,8 +839,8 @@ static bool CanCoerceMustAliasedValueToLoad(Value *StoredVal, return false; // The store has to be at least as big as the load. - if (TD.getTypeSizeInBits(StoredVal->getType()) < - TD.getTypeSizeInBits(LoadTy)) + if (DL.getTypeSizeInBits(StoredVal->getType()) < + DL.getTypeSizeInBits(LoadTy)) return false; return true; @@ -855,15 +855,15 @@ static bool CanCoerceMustAliasedValueToLoad(Value *StoredVal, static Value *CoerceAvailableValueToLoadType(Value *StoredVal, Type *LoadedTy, Instruction *InsertPt, - const DataLayout &TD) { - if (!CanCoerceMustAliasedValueToLoad(StoredVal, LoadedTy, TD)) - return 0; + const DataLayout &DL) { + if (!CanCoerceMustAliasedValueToLoad(StoredVal, LoadedTy, DL)) + return nullptr; // If this is already the right type, just return it. Type *StoredValTy = StoredVal->getType(); - uint64_t StoreSize = TD.getTypeSizeInBits(StoredValTy); - uint64_t LoadSize = TD.getTypeSizeInBits(LoadedTy); + uint64_t StoreSize = DL.getTypeSizeInBits(StoredValTy); + uint64_t LoadSize = DL.getTypeSizeInBits(LoadedTy); // If the store and reload are the same size, we can always reuse it. if (StoreSize == LoadSize) { @@ -874,13 +874,13 @@ static Value *CoerceAvailableValueToLoadType(Value *StoredVal, // Convert source pointers to integers, which can be bitcast. if (StoredValTy->getScalarType()->isPointerTy()) { - StoredValTy = TD.getIntPtrType(StoredValTy); + StoredValTy = DL.getIntPtrType(StoredValTy); StoredVal = new PtrToIntInst(StoredVal, StoredValTy, "", InsertPt); } Type *TypeToCastTo = LoadedTy; if (TypeToCastTo->getScalarType()->isPointerTy()) - TypeToCastTo = TD.getIntPtrType(TypeToCastTo); + TypeToCastTo = DL.getIntPtrType(TypeToCastTo); if (StoredValTy != TypeToCastTo) StoredVal = new BitCastInst(StoredVal, TypeToCastTo, "", InsertPt); @@ -899,7 +899,7 @@ static Value *CoerceAvailableValueToLoadType(Value *StoredVal, // Convert source pointers to integers, which can be manipulated. if (StoredValTy->getScalarType()->isPointerTy()) { - StoredValTy = TD.getIntPtrType(StoredValTy); + StoredValTy = DL.getIntPtrType(StoredValTy); StoredVal = new PtrToIntInst(StoredVal, StoredValTy, "", InsertPt); } @@ -911,7 +911,7 @@ static Value *CoerceAvailableValueToLoadType(Value *StoredVal, // If this is a big-endian system, we need to shift the value down to the low // bits so that a truncate will work. - if (TD.isBigEndian()) { + if (DL.isBigEndian()) { Constant *Val = ConstantInt::get(StoredVal->getType(), StoreSize-LoadSize); StoredVal = BinaryOperator::CreateLShr(StoredVal, Val, "tmp", InsertPt); } @@ -942,15 +942,15 @@ static Value *CoerceAvailableValueToLoadType(Value *StoredVal, static int AnalyzeLoadFromClobberingWrite(Type *LoadTy, Value *LoadPtr, Value *WritePtr, uint64_t WriteSizeInBits, - const DataLayout &TD) { + const DataLayout &DL) { // If the loaded or stored value is a first class array or struct, don't try // to transform them. We need to be able to bitcast to integer. if (LoadTy->isStructTy() || LoadTy->isArrayTy()) return -1; int64_t StoreOffset = 0, LoadOffset = 0; - Value *StoreBase = GetPointerBaseWithConstantOffset(WritePtr,StoreOffset,&TD); - Value *LoadBase = GetPointerBaseWithConstantOffset(LoadPtr, LoadOffset, &TD); + Value *StoreBase = GetPointerBaseWithConstantOffset(WritePtr,StoreOffset,&DL); + Value *LoadBase = GetPointerBaseWithConstantOffset(LoadPtr, LoadOffset, &DL); if (StoreBase != LoadBase) return -1; @@ -972,7 +972,7 @@ static int AnalyzeLoadFromClobberingWrite(Type *LoadTy, Value *LoadPtr, // If the load and store don't overlap at all, the store doesn't provide // anything to the load. In this case, they really don't alias at all, AA // must have gotten confused. - uint64_t LoadSize = TD.getTypeSizeInBits(LoadTy); + uint64_t LoadSize = DL.getTypeSizeInBits(LoadTy); if ((WriteSizeInBits & 7) | (LoadSize & 7)) return -1; @@ -1015,61 +1015,61 @@ static int AnalyzeLoadFromClobberingWrite(Type *LoadTy, Value *LoadPtr, /// memdep query of a load that ends up being a clobbering store. static int AnalyzeLoadFromClobberingStore(Type *LoadTy, Value *LoadPtr, StoreInst *DepSI, - const DataLayout &TD) { + const DataLayout &DL) { // Cannot handle reading from store of first-class aggregate yet. if (DepSI->getValueOperand()->getType()->isStructTy() || DepSI->getValueOperand()->getType()->isArrayTy()) return -1; Value *StorePtr = DepSI->getPointerOperand(); - uint64_t StoreSize =TD.getTypeSizeInBits(DepSI->getValueOperand()->getType()); + uint64_t StoreSize =DL.getTypeSizeInBits(DepSI->getValueOperand()->getType()); return AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, - StorePtr, StoreSize, TD); + StorePtr, StoreSize, DL); } /// AnalyzeLoadFromClobberingLoad - This function is called when we have a /// memdep query of a load that ends up being clobbered by another load. See if /// the other load can feed into the second load. static int AnalyzeLoadFromClobberingLoad(Type *LoadTy, Value *LoadPtr, - LoadInst *DepLI, const DataLayout &TD){ + LoadInst *DepLI, const DataLayout &DL){ // Cannot handle reading from store of first-class aggregate yet. if (DepLI->getType()->isStructTy() || DepLI->getType()->isArrayTy()) return -1; Value *DepPtr = DepLI->getPointerOperand(); - uint64_t DepSize = TD.getTypeSizeInBits(DepLI->getType()); - int R = AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, DepPtr, DepSize, TD); + uint64_t DepSize = DL.getTypeSizeInBits(DepLI->getType()); + int R = AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, DepPtr, DepSize, DL); if (R != -1) return R; // If we have a load/load clobber an DepLI can be widened to cover this load, // then we should widen it! int64_t LoadOffs = 0; const Value *LoadBase = - GetPointerBaseWithConstantOffset(LoadPtr, LoadOffs, &TD); - unsigned LoadSize = TD.getTypeStoreSize(LoadTy); + GetPointerBaseWithConstantOffset(LoadPtr, LoadOffs, &DL); + unsigned LoadSize = DL.getTypeStoreSize(LoadTy); unsigned Size = MemoryDependenceAnalysis:: - getLoadLoadClobberFullWidthSize(LoadBase, LoadOffs, LoadSize, DepLI, TD); + getLoadLoadClobberFullWidthSize(LoadBase, LoadOffs, LoadSize, DepLI, DL); if (Size == 0) return -1; - return AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, DepPtr, Size*8, TD); + return AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, DepPtr, Size*8, DL); } static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr, MemIntrinsic *MI, - const DataLayout &TD) { + const DataLayout &DL) { // If the mem operation is a non-constant size, we can't handle it. ConstantInt *SizeCst = dyn_cast<ConstantInt>(MI->getLength()); - if (SizeCst == 0) return -1; + if (!SizeCst) return -1; uint64_t MemSizeInBits = SizeCst->getZExtValue()*8; // If this is memset, we just need to see if the offset is valid in the size // of the memset.. if (MI->getIntrinsicID() == Intrinsic::memset) return AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, MI->getDest(), - MemSizeInBits, TD); + MemSizeInBits, DL); // If we have a memcpy/memmove, the only case we can handle is if this is a // copy from constant memory. In that case, we can read directly from the @@ -1077,14 +1077,14 @@ static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr, MemTransferInst *MTI = cast<MemTransferInst>(MI); Constant *Src = dyn_cast<Constant>(MTI->getSource()); - if (Src == 0) return -1; + if (!Src) return -1; - GlobalVariable *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(Src, &TD)); - if (GV == 0 || !GV->isConstant()) return -1; + GlobalVariable *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(Src, &DL)); + if (!GV || !GV->isConstant()) return -1; // See if the access is within the bounds of the transfer. int Offset = AnalyzeLoadFromClobberingWrite(LoadTy, LoadPtr, - MI->getDest(), MemSizeInBits, TD); + MI->getDest(), MemSizeInBits, DL); if (Offset == -1) return Offset; @@ -1097,7 +1097,7 @@ static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr, ConstantInt::get(Type::getInt64Ty(Src->getContext()), (unsigned)Offset); Src = ConstantExpr::getGetElementPtr(Src, OffsetCst); Src = ConstantExpr::getBitCast(Src, PointerType::get(LoadTy, AS)); - if (ConstantFoldLoadFromConstPtr(Src, &TD)) + if (ConstantFoldLoadFromConstPtr(Src, &DL)) return Offset; return -1; } @@ -1110,11 +1110,11 @@ static int AnalyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr, /// before we give up. static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset, Type *LoadTy, - Instruction *InsertPt, const DataLayout &TD){ + Instruction *InsertPt, const DataLayout &DL){ LLVMContext &Ctx = SrcVal->getType()->getContext(); - uint64_t StoreSize = (TD.getTypeSizeInBits(SrcVal->getType()) + 7) / 8; - uint64_t LoadSize = (TD.getTypeSizeInBits(LoadTy) + 7) / 8; + uint64_t StoreSize = (DL.getTypeSizeInBits(SrcVal->getType()) + 7) / 8; + uint64_t LoadSize = (DL.getTypeSizeInBits(LoadTy) + 7) / 8; IRBuilder<> Builder(InsertPt->getParent(), InsertPt); @@ -1122,13 +1122,13 @@ static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset, // to an integer type to start with. if (SrcVal->getType()->getScalarType()->isPointerTy()) SrcVal = Builder.CreatePtrToInt(SrcVal, - TD.getIntPtrType(SrcVal->getType())); + DL.getIntPtrType(SrcVal->getType())); if (!SrcVal->getType()->isIntegerTy()) SrcVal = Builder.CreateBitCast(SrcVal, IntegerType::get(Ctx, StoreSize*8)); // Shift the bits to the least significant depending on endianness. unsigned ShiftAmt; - if (TD.isLittleEndian()) + if (DL.isLittleEndian()) ShiftAmt = Offset*8; else ShiftAmt = (StoreSize-LoadSize-Offset)*8; @@ -1139,7 +1139,7 @@ static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset, if (LoadSize != StoreSize) SrcVal = Builder.CreateTrunc(SrcVal, IntegerType::get(Ctx, LoadSize*8)); - return CoerceAvailableValueToLoadType(SrcVal, LoadTy, InsertPt, TD); + return CoerceAvailableValueToLoadType(SrcVal, LoadTy, InsertPt, DL); } /// GetLoadValueForLoad - This function is called when we have a @@ -1150,11 +1150,11 @@ static Value *GetStoreValueForLoad(Value *SrcVal, unsigned Offset, static Value *GetLoadValueForLoad(LoadInst *SrcVal, unsigned Offset, Type *LoadTy, Instruction *InsertPt, GVN &gvn) { - const DataLayout &TD = *gvn.getDataLayout(); + const DataLayout &DL = *gvn.getDataLayout(); // If Offset+LoadTy exceeds the size of SrcVal, then we must be wanting to // widen SrcVal out to a larger load. - unsigned SrcValSize = TD.getTypeStoreSize(SrcVal->getType()); - unsigned LoadSize = TD.getTypeStoreSize(LoadTy); + unsigned SrcValSize = DL.getTypeStoreSize(SrcVal->getType()); + unsigned LoadSize = DL.getTypeStoreSize(LoadTy); if (Offset+LoadSize > SrcValSize) { assert(SrcVal->isSimple() && "Cannot widen volatile/atomic load!"); assert(SrcVal->getType()->isIntegerTy() && "Can't widen non-integer load"); @@ -1186,7 +1186,7 @@ static Value *GetLoadValueForLoad(LoadInst *SrcVal, unsigned Offset, // Replace uses of the original load with the wider load. On a big endian // system, we need to shift down to get the relevant bits. Value *RV = NewLoad; - if (TD.isBigEndian()) + if (DL.isBigEndian()) RV = Builder.CreateLShr(RV, NewLoadSize*8-SrcVal->getType()->getPrimitiveSizeInBits()); RV = Builder.CreateTrunc(RV, SrcVal->getType()); @@ -1201,7 +1201,7 @@ static Value *GetLoadValueForLoad(LoadInst *SrcVal, unsigned Offset, SrcVal = NewLoad; } - return GetStoreValueForLoad(SrcVal, Offset, LoadTy, InsertPt, TD); + return GetStoreValueForLoad(SrcVal, Offset, LoadTy, InsertPt, DL); } @@ -1209,9 +1209,9 @@ static Value *GetLoadValueForLoad(LoadInst *SrcVal, unsigned Offset, /// memdep query of a load that ends up being a clobbering mem intrinsic. static Value *GetMemInstValueForLoad(MemIntrinsic *SrcInst, unsigned Offset, Type *LoadTy, Instruction *InsertPt, - const DataLayout &TD){ + const DataLayout &DL){ LLVMContext &Ctx = LoadTy->getContext(); - uint64_t LoadSize = TD.getTypeSizeInBits(LoadTy)/8; + uint64_t LoadSize = DL.getTypeSizeInBits(LoadTy)/8; IRBuilder<> Builder(InsertPt->getParent(), InsertPt); @@ -1242,7 +1242,7 @@ static Value *GetMemInstValueForLoad(MemIntrinsic *SrcInst, unsigned Offset, ++NumBytesSet; } - return CoerceAvailableValueToLoadType(Val, LoadTy, InsertPt, TD); + return CoerceAvailableValueToLoadType(Val, LoadTy, InsertPt, DL); } // Otherwise, this is a memcpy/memmove from a constant global. @@ -1258,7 +1258,7 @@ static Value *GetMemInstValueForLoad(MemIntrinsic *SrcInst, unsigned Offset, ConstantInt::get(Type::getInt64Ty(Src->getContext()), (unsigned)Offset); Src = ConstantExpr::getGetElementPtr(Src, OffsetCst); Src = ConstantExpr::getBitCast(Src, PointerType::get(LoadTy, AS)); - return ConstantFoldLoadFromConstPtr(Src, &TD); + return ConstantFoldLoadFromConstPtr(Src, &DL); } @@ -1324,10 +1324,10 @@ Value *AvailableValueInBlock::MaterializeAdjustedValue(Type *LoadTy, GVN &gvn) c if (isSimpleValue()) { Res = getSimpleValue(); if (Res->getType() != LoadTy) { - const DataLayout *TD = gvn.getDataLayout(); - assert(TD && "Need target data to handle type mismatch case"); + const DataLayout *DL = gvn.getDataLayout(); + assert(DL && "Need target data to handle type mismatch case"); Res = GetStoreValueForLoad(Res, Offset, LoadTy, BB->getTerminator(), - *TD); + *DL); DEBUG(dbgs() << "GVN COERCED NONLOCAL VAL:\nOffset: " << Offset << " " << *getSimpleValue() << '\n' @@ -1346,10 +1346,10 @@ Value *AvailableValueInBlock::MaterializeAdjustedValue(Type *LoadTy, GVN &gvn) c << *Res << '\n' << "\n\n\n"); } } else if (isMemIntrinValue()) { - const DataLayout *TD = gvn.getDataLayout(); - assert(TD && "Need target data to handle type mismatch case"); + const DataLayout *DL = gvn.getDataLayout(); + assert(DL && "Need target data to handle type mismatch case"); Res = GetMemInstValueForLoad(getMemIntrinValue(), Offset, - LoadTy, BB->getTerminator(), *TD); + LoadTy, BB->getTerminator(), *DL); DEBUG(dbgs() << "GVN COERCED NONLOCAL MEM INTRIN:\nOffset: " << Offset << " " << *getMemIntrinValue() << '\n' << *Res << '\n' << "\n\n\n"); @@ -1402,9 +1402,9 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps, // read by the load, we can extract the bits we need for the load from the // stored value. if (StoreInst *DepSI = dyn_cast<StoreInst>(DepInfo.getInst())) { - if (TD && Address) { + if (DL && Address) { int Offset = AnalyzeLoadFromClobberingStore(LI->getType(), Address, - DepSI, *TD); + DepSI, *DL); if (Offset != -1) { ValuesPerBlock.push_back(AvailableValueInBlock::get(DepBB, DepSI->getValueOperand(), @@ -1421,10 +1421,9 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps, if (LoadInst *DepLI = dyn_cast<LoadInst>(DepInfo.getInst())) { // If this is a clobber and L is the first instruction in its block, then // we have the first instruction in the entry block. - if (DepLI != LI && Address && TD) { - int Offset = AnalyzeLoadFromClobberingLoad(LI->getType(), - LI->getPointerOperand(), - DepLI, *TD); + if (DepLI != LI && Address && DL) { + int Offset = AnalyzeLoadFromClobberingLoad(LI->getType(), Address, + DepLI, *DL); if (Offset != -1) { ValuesPerBlock.push_back(AvailableValueInBlock::getLoad(DepBB,DepLI, @@ -1437,9 +1436,9 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps, // If the clobbering value is a memset/memcpy/memmove, see if we can // forward a value on from it. if (MemIntrinsic *DepMI = dyn_cast<MemIntrinsic>(DepInfo.getInst())) { - if (TD && Address) { + if (DL && Address) { int Offset = AnalyzeLoadFromClobberingMemInst(LI->getType(), Address, - DepMI, *TD); + DepMI, *DL); if (Offset != -1) { ValuesPerBlock.push_back(AvailableValueInBlock::getMI(DepBB, DepMI, Offset)); @@ -1465,14 +1464,21 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps, continue; } + // Loading from calloc (which zero initializes memory) -> zero + if (isCallocLikeFn(DepInst, TLI)) { + ValuesPerBlock.push_back(AvailableValueInBlock::get( + DepBB, Constant::getNullValue(LI->getType()))); + continue; + } + if (StoreInst *S = dyn_cast<StoreInst>(DepInst)) { // Reject loads and stores that are to the same address but are of // different types if we have to. if (S->getValueOperand()->getType() != LI->getType()) { // If the stored value is larger or equal to the loaded value, we can // reuse it. - if (TD == 0 || !CanCoerceMustAliasedValueToLoad(S->getValueOperand(), - LI->getType(), *TD)) { + if (!DL || !CanCoerceMustAliasedValueToLoad(S->getValueOperand(), + LI->getType(), *DL)) { UnavailableBlocks.push_back(DepBB); continue; } @@ -1488,7 +1494,7 @@ void GVN::AnalyzeLoadAvailability(LoadInst *LI, LoadDepVect &Deps, if (LD->getType() != LI->getType()) { // If the stored value is larger or equal to the loaded value, we can // reuse it. - if (TD == 0 || !CanCoerceMustAliasedValueToLoad(LD, LI->getType(),*TD)){ + if (!DL || !CanCoerceMustAliasedValueToLoad(LD, LI->getType(),*DL)) { UnavailableBlocks.push_back(DepBB); continue; } @@ -1541,7 +1547,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, // Check to see how many predecessors have the loaded value fully // available. - DenseMap<BasicBlock*, Value*> PredLoads; + MapVector<BasicBlock *, Value *> PredLoads; DenseMap<BasicBlock*, char> FullyAvailableBlocks; for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i) FullyAvailableBlocks[ValuesPerBlock[i].BB] = true; @@ -1555,7 +1561,6 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks, 0)) { continue; } - PredLoads[Pred] = 0; if (Pred->getTerminator()->getNumSuccessors() != 1) { if (isa<IndirectBrInst>(Pred->getTerminator())) { @@ -1572,11 +1577,14 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, } CriticalEdgePred.push_back(Pred); + } else { + // Only add the predecessors that will not be split for now. + PredLoads[Pred] = nullptr; } } // Decide whether PRE is profitable for this load. - unsigned NumUnavailablePreds = PredLoads.size(); + unsigned NumUnavailablePreds = PredLoads.size() + CriticalEdgePred.size(); assert(NumUnavailablePreds != 0 && "Fully available value should already be eliminated!"); @@ -1588,12 +1596,10 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, return false; // Split critical edges, and update the unavailable predecessors accordingly. - for (SmallVectorImpl<BasicBlock *>::iterator I = CriticalEdgePred.begin(), - E = CriticalEdgePred.end(); I != E; I++) { - BasicBlock *OrigPred = *I; + for (BasicBlock *OrigPred : CriticalEdgePred) { BasicBlock *NewPred = splitCriticalEdges(OrigPred, LoadBB); - PredLoads.erase(OrigPred); - PredLoads[NewPred] = 0; + assert(!PredLoads.count(OrigPred) && "Split edges shouldn't be in map!"); + PredLoads[NewPred] = nullptr; DEBUG(dbgs() << "Split critical edge " << OrigPred->getName() << "->" << LoadBB->getName() << '\n'); } @@ -1601,9 +1607,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, // Check if the load can safely be moved to all the unavailable predecessors. bool CanDoPRE = true; SmallVector<Instruction*, 8> NewInsts; - for (DenseMap<BasicBlock*, Value*>::iterator I = PredLoads.begin(), - E = PredLoads.end(); I != E; ++I) { - BasicBlock *UnavailablePred = I->first; + for (auto &PredLoad : PredLoads) { + BasicBlock *UnavailablePred = PredLoad.first; // Do PHI translation to get its value in the predecessor if necessary. The // returned pointer (if non-null) is guaranteed to dominate UnavailablePred. @@ -1611,21 +1616,21 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, // If all preds have a single successor, then we know it is safe to insert // the load on the pred (?!?), so we can insert code to materialize the // pointer if it is not available. - PHITransAddr Address(LI->getPointerOperand(), TD); - Value *LoadPtr = 0; + PHITransAddr Address(LI->getPointerOperand(), DL); + Value *LoadPtr = nullptr; LoadPtr = Address.PHITranslateWithInsertion(LoadBB, UnavailablePred, *DT, NewInsts); // If we couldn't find or insert a computation of this phi translated value, // we fail PRE. - if (LoadPtr == 0) { + if (!LoadPtr) { DEBUG(dbgs() << "COULDN'T INSERT PHI TRANSLATED VALUE OF: " << *LI->getPointerOperand() << "\n"); CanDoPRE = false; break; } - I->second = LoadPtr; + PredLoad.second = LoadPtr; } if (!CanDoPRE) { @@ -1634,8 +1639,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, if (MD) MD->removeInstruction(I); I->eraseFromParent(); } - // HINT:Don't revert the edge-splitting as following transformation may - // also need to split these critial edges. + // HINT: Don't revert the edge-splitting as following transformation may + // also need to split these critical edges. return !CriticalEdgePred.empty(); } @@ -1656,10 +1661,9 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock, VN.lookup_or_add(NewInsts[i]); } - for (DenseMap<BasicBlock*, Value*>::iterator I = PredLoads.begin(), - E = PredLoads.end(); I != E; ++I) { - BasicBlock *UnavailablePred = I->first; - Value *LoadPtr = I->second; + for (const auto &PredLoad : PredLoads) { + BasicBlock *UnavailablePred = PredLoad.first; + Value *LoadPtr = PredLoad.second; Instruction *NewLoad = new LoadInst(LoadPtr, LI->getName()+".pre", false, LI->getAlignment(), @@ -1712,7 +1716,7 @@ bool GVN::processNonLocalLoad(LoadInst *LI) { !Deps[0].getResult().isDef() && !Deps[0].getResult().isClobber()) { DEBUG( dbgs() << "GVN: non-local load "; - WriteAsOperand(dbgs(), LI); + LI->printAsOperand(dbgs()); dbgs() << " has unknown dependencies\n"; ); return false; @@ -1778,7 +1782,7 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) { MDNode *ReplMD = Metadata[i].second; switch(Kind) { default: - ReplInst->setMetadata(Kind, NULL); // Remove unknown metadata + ReplInst->setMetadata(Kind, nullptr); // Remove unknown metadata break; case LLVMContext::MD_dbg: llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg"); @@ -1789,11 +1793,15 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) { ReplInst->setMetadata(Kind, MDNode::getMostGenericRange(IMD, ReplMD)); break; case LLVMContext::MD_prof: - llvm_unreachable("MD_prof in a non terminator instruction"); + llvm_unreachable("MD_prof in a non-terminator instruction"); break; case LLVMContext::MD_fpmath: ReplInst->setMetadata(Kind, MDNode::getMostGenericFPMath(IMD, ReplMD)); break; + case LLVMContext::MD_invariant_load: + // Only set the !invariant.load if it is present in both instructions. + ReplInst->setMetadata(Kind, IMD); + break; } } } @@ -1823,7 +1831,7 @@ bool GVN::processLoad(LoadInst *L) { // If we have a clobber and target data is around, see if this is a clobber // that we can fix up through code synthesis. - if (Dep.isClobber() && TD) { + if (Dep.isClobber() && DL) { // Check to see if we have something like this: // store i32 123, i32* %P // %A = bitcast i32* %P to i8* @@ -1834,14 +1842,14 @@ bool GVN::processLoad(LoadInst *L) { // a common base + constant offset, and if the previous store (or memset) // completely covers this load. This sort of thing can happen in bitfield // access code. - Value *AvailVal = 0; + Value *AvailVal = nullptr; if (StoreInst *DepSI = dyn_cast<StoreInst>(Dep.getInst())) { int Offset = AnalyzeLoadFromClobberingStore(L->getType(), L->getPointerOperand(), - DepSI, *TD); + DepSI, *DL); if (Offset != -1) AvailVal = GetStoreValueForLoad(DepSI->getValueOperand(), Offset, - L->getType(), L, *TD); + L->getType(), L, *DL); } // Check to see if we have something like this: @@ -1856,7 +1864,7 @@ bool GVN::processLoad(LoadInst *L) { int Offset = AnalyzeLoadFromClobberingLoad(L->getType(), L->getPointerOperand(), - DepLI, *TD); + DepLI, *DL); if (Offset != -1) AvailVal = GetLoadValueForLoad(DepLI, Offset, L->getType(), L, *this); } @@ -1866,9 +1874,9 @@ bool GVN::processLoad(LoadInst *L) { if (MemIntrinsic *DepMI = dyn_cast<MemIntrinsic>(Dep.getInst())) { int Offset = AnalyzeLoadFromClobberingMemInst(L->getType(), L->getPointerOperand(), - DepMI, *TD); + DepMI, *DL); if (Offset != -1) - AvailVal = GetMemInstValueForLoad(DepMI, Offset, L->getType(), L, *TD); + AvailVal = GetMemInstValueForLoad(DepMI, Offset, L->getType(), L, *DL); } if (AvailVal) { @@ -1890,7 +1898,7 @@ bool GVN::processLoad(LoadInst *L) { DEBUG( // fast print dep, using operator<< on instruction is too slow. dbgs() << "GVN: load "; - WriteAsOperand(dbgs(), L); + L->printAsOperand(dbgs()); Instruction *I = Dep.getInst(); dbgs() << " is clobbered by " << *I << '\n'; ); @@ -1905,7 +1913,7 @@ bool GVN::processLoad(LoadInst *L) { DEBUG( // fast print dep, using operator<< on instruction is too slow. dbgs() << "GVN: load "; - WriteAsOperand(dbgs(), L); + L->printAsOperand(dbgs()); dbgs() << " has unknown dependence\n"; ); return false; @@ -1919,10 +1927,10 @@ bool GVN::processLoad(LoadInst *L) { // actually have the same type. See if we know how to reuse the stored // value (depending on its type). if (StoredVal->getType() != L->getType()) { - if (TD) { + if (DL) { StoredVal = CoerceAvailableValueToLoadType(StoredVal, L->getType(), - L, *TD); - if (StoredVal == 0) + L, *DL); + if (!StoredVal) return false; DEBUG(dbgs() << "GVN COERCED STORE:\n" << *DepSI << '\n' << *StoredVal @@ -1948,10 +1956,10 @@ bool GVN::processLoad(LoadInst *L) { // the same type. See if we know how to reuse the previously loaded value // (depending on its type). if (DepLI->getType() != L->getType()) { - if (TD) { + if (DL) { AvailableVal = CoerceAvailableValueToLoadType(DepLI, L->getType(), - L, *TD); - if (AvailableVal == 0) + L, *DL); + if (!AvailableVal) return false; DEBUG(dbgs() << "GVN COERCED LOAD:\n" << *DepLI << "\n" << *AvailableVal @@ -1991,6 +1999,15 @@ bool GVN::processLoad(LoadInst *L) { } } + // If this load follows a calloc (which zero initializes memory), + // then the loaded value is zero + if (isCallocLikeFn(DepInst, TLI)) { + L->replaceAllUsesWith(Constant::getNullValue(L->getType())); + markInstructionForDeletion(L); + ++NumGVNLoad; + return true; + } + return false; } @@ -2001,9 +2018,9 @@ bool GVN::processLoad(LoadInst *L) { // a few comparisons of DFS numbers. Value *GVN::findLeader(const BasicBlock *BB, uint32_t num) { LeaderTableEntry Vals = LeaderTable[num]; - if (!Vals.Val) return 0; + if (!Vals.Val) return nullptr; - Value *Val = 0; + Value *Val = nullptr; if (DT->dominates(Vals.BB, BB)) { Val = Vals.Val; if (isa<Constant>(Val)) return Val; @@ -2030,7 +2047,7 @@ unsigned GVN::replaceAllDominatedUsesWith(Value *From, Value *To, unsigned Count = 0; for (Value::use_iterator UI = From->use_begin(), UE = From->use_end(); UI != UE; ) { - Use &U = (UI++).getUse(); + Use &U = *UI++; if (DT->dominates(Root, U)) { U.set(To); @@ -2054,7 +2071,7 @@ static bool isOnlyReachableViaThisEdge(const BasicBlockEdge &E, const BasicBlock *Src = E.getStart(); assert((!Pred || Pred == Src) && "No edge between these basic blocks!"); (void)Src; - return Pred != 0; + return Pred != nullptr; } /// propagateEquality - The given values are known to be equal in every block @@ -2202,7 +2219,7 @@ bool GVN::processInstruction(Instruction *I) { // to value numbering it. Value numbering often exposes redundancies, for // example if it determines that %y is equal to %x then the instruction // "%z = and i32 %x, %y" becomes "%z = and i32 %x, %x" which we now simplify. - if (Value *V = SimplifyInstruction(I, TD, TLI, DT)) { + if (Value *V = SimplifyInstruction(I, DL, TLI, DT)) { I->replaceAllUsesWith(V); if (MD && V->getType()->getScalarType()->isPointerTy()) MD->invalidateCachedPointerInfo(V); @@ -2298,7 +2315,7 @@ bool GVN::processInstruction(Instruction *I) { // Perform fast-path value-number based elimination of values inherited from // dominators. Value *repl = findLeader(I->getParent(), Num); - if (repl == 0) { + if (!repl) { // Failure, just remember this instance for future use. addToLeaderTable(Num, I, I->getParent()); return false; @@ -2314,10 +2331,14 @@ bool GVN::processInstruction(Instruction *I) { /// runOnFunction - This is the main transformation entry point for a function. bool GVN::runOnFunction(Function& F) { + if (skipOptnoneFunction(F)) + return false; + if (!NoLoads) MD = &getAnalysis<MemoryDependenceAnalysis>(); - DT = &getAnalysis<DominatorTree>(); - TD = getAnalysisIfAvailable<DataLayout>(); + DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); + DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); + DL = DLP ? &DLP->getDataLayout() : nullptr; TLI = &getAnalysis<TargetLibraryInfo>(); VN.setAliasAnalysis(&getAnalysis<AliasAnalysis>()); VN.setMemDep(MD); @@ -2419,10 +2440,7 @@ bool GVN::processBlock(BasicBlock *BB) { bool GVN::performPRE(Function &F) { bool Changed = false; SmallVector<std::pair<Value*, BasicBlock*>, 8> predMap; - for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()), - DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) { - BasicBlock *CurrentBlock = *DI; - + for (BasicBlock *CurrentBlock : depth_first(&F.getEntryBlock())) { // Nothing to PRE in the entry block. if (CurrentBlock == &F.getEntryBlock()) continue; @@ -2462,7 +2480,7 @@ bool GVN::performPRE(Function &F) { // more complicated to get right. unsigned NumWith = 0; unsigned NumWithout = 0; - BasicBlock *PREPred = 0; + BasicBlock *PREPred = nullptr; predMap.clear(); for (pred_iterator PI = pred_begin(CurrentBlock), @@ -2480,8 +2498,8 @@ bool GVN::performPRE(Function &F) { } Value* predV = findLeader(P, ValNo); - if (predV == 0) { - predMap.push_back(std::make_pair(static_cast<Value *>(0), P)); + if (!predV) { + predMap.push_back(std::make_pair(static_cast<Value *>(nullptr), P)); PREPred = P; ++NumWithout; } else if (predV == CurInst) { @@ -2635,9 +2653,8 @@ bool GVN::iterateOnFunction(Function &F) { // std::vector<BasicBlock *> BBVect; BBVect.reserve(256); - for (df_iterator<DomTreeNode*> DI = df_begin(DT->getRootNode()), - DE = df_end(DT->getRootNode()); DI != DE; ++DI) - BBVect.push_back(DI->getBlock()); + for (DomTreeNode *x : depth_first(DT->getRootNode())) + BBVect.push_back(x->getBlock()); for (std::vector<BasicBlock *>::iterator I = BBVect.begin(), E = BBVect.end(); I != E; I++) |