- Type *AccessTy;
- unsigned Align;
- if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
- if (!GV->hasDefinitiveInitializer())
- return AliasAnalysis::UnknownSize;
- AccessTy = GV->getType()->getElementType();
- Align = GV->getAlignment();
- } else if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
- if (!AI->isArrayAllocation())
- AccessTy = AI->getType()->getElementType();
- else
- return AliasAnalysis::UnknownSize;
- Align = AI->getAlignment();
- } else if (const CallInst* CI = extractMallocCall(V)) {
- if (!RoundToAlign && !isArrayMalloc(V, &TD))
- // The size is the argument to the malloc call.
- if (const ConstantInt* C = dyn_cast<ConstantInt>(CI->getArgOperand(0)))
- return C->getZExtValue();
- return AliasAnalysis::UnknownSize;
- } else if (const Argument *A = dyn_cast<Argument>(V)) {
- if (A->hasByValAttr()) {
- AccessTy = cast<PointerType>(A->getType())->getElementType();
- Align = A->getParamAlignment();
- } else {
- return AliasAnalysis::UnknownSize;
- }
- } else {
- return AliasAnalysis::UnknownSize;
- }
-
- if (!AccessTy->isSized())
- return AliasAnalysis::UnknownSize;
-
- uint64_t Size = TD.getTypeAllocSize(AccessTy);
- if (RoundToAlign) {
- if (!Align)
- return AliasAnalysis::UnknownSize;
- Size = RoundUpToAlignment(Size, Align);
- }
-
- return Size;