diff options
Diffstat (limited to 'lib/Transforms')
-rw-r--r-- | lib/Transforms/Scalar/DeadStoreElimination.cpp | 50 |
1 files changed, 20 insertions, 30 deletions
diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp index 8f5f157..f5688cb 100644 --- a/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -274,43 +274,35 @@ static Value *getStoredPointerOperand(Instruction *I) { } } -static uint64_t getPointerSize(Value *V, AliasAnalysis &AA) { +static uint64_t getPointerSize(const Value *V, AliasAnalysis &AA) { const TargetData *TD = AA.getTargetData(); - if (CallInst *CI = dyn_cast<CallInst>(V)) { - assert(isMalloc(CI) && "Expected Malloc call!"); - if (ConstantInt *C = dyn_cast<ConstantInt>(CI->getArgOperand(0))) + if (const CallInst *CI = extractMallocCall(V)) { + if (const ConstantInt *C = dyn_cast<ConstantInt>(CI->getArgOperand(0))) return C->getZExtValue(); - return AliasAnalysis::UnknownSize; } if (TD == 0) return AliasAnalysis::UnknownSize; - if (AllocaInst *A = dyn_cast<AllocaInst>(V)) { + if (const AllocaInst *A = dyn_cast<AllocaInst>(V)) { // Get size information for the alloca - if (ConstantInt *C = dyn_cast<ConstantInt>(A->getArraySize())) + if (const ConstantInt *C = dyn_cast<ConstantInt>(A->getArraySize())) return C->getZExtValue() * TD->getTypeAllocSize(A->getAllocatedType()); - return AliasAnalysis::UnknownSize; } - assert(isa<Argument>(V) && "Expected AllocaInst, malloc call or Argument!"); - PointerType *PT = cast<PointerType>(V->getType()); - return TD->getTypeAllocSize(PT->getElementType()); -} + if (const Argument *A = dyn_cast<Argument>(V)) { + if (A->hasByValAttr()) + if (PointerType *PT = dyn_cast<PointerType>(A->getType())) + return TD->getTypeAllocSize(PT->getElementType()); + } -/// isObjectPointerWithTrustworthySize - Return true if the specified Value* is -/// pointing to an object with a pointer size we can trust. -static bool isObjectPointerWithTrustworthySize(const Value *V) { - if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) - return !AI->isArrayAllocation(); - if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) - return !GV->mayBeOverridden(); - if (const Argument *A = dyn_cast<Argument>(V)) - return A->hasByValAttr(); - if (isMalloc(V)) - return true; - return false; + if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) { + if (!GV->mayBeOverridden()) + return TD->getTypeAllocSize(GV->getType()->getElementType()); + } + + return AliasAnalysis::UnknownSize; } namespace { @@ -329,8 +321,8 @@ namespace { static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later, const AliasAnalysis::Location &Earlier, AliasAnalysis &AA, - int64_t& EarlierOff, - int64_t& LaterOff) { + int64_t &EarlierOff, + int64_t &LaterOff) { const Value *P1 = Earlier.Ptr->stripPointerCasts(); const Value *P2 = Later.Ptr->stripPointerCasts(); @@ -377,12 +369,10 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later, return OverwriteUnknown; // If the "Later" store is to a recognizable object, get its size. - if (isObjectPointerWithTrustworthySize(UO2)) { - uint64_t ObjectSize = - TD.getTypeAllocSize(cast<PointerType>(UO2->getType())->getElementType()); + uint64_t ObjectSize = getPointerSize(UO2, AA); + if (ObjectSize != AliasAnalysis::UnknownSize) if (ObjectSize == Later.Size && ObjectSize >= Earlier.Size) return OverwriteComplete; - } // Okay, we have stores to two completely different pointers. Try to // decompose the pointer into a "base + constant_offset" form. If the base |