Index: include/llvm/IR/Value.h =================================================================== --- include/llvm/IR/Value.h +++ include/llvm/IR/Value.h @@ -500,6 +500,12 @@ return const_cast(this)->stripInBoundsOffsets(); } + /// \brief Returns an alignment of the pointer value. + /// + /// Returns an alignment which is either specified explicitly, e.g. via + /// align attribute of a function argument, or guaranteed by DataLayout. + unsigned getPointerAlignment(const DataLayout &DL) const; + /// \brief Translate PHI node to its predecessor from the given basic block. /// /// If this value is a PHI node with CurBB as its parent, return the value in Index: lib/Analysis/ValueTracking.cpp =================================================================== --- lib/Analysis/ValueTracking.cpp +++ lib/Analysis/ValueTracking.cpp @@ -1566,46 +1566,6 @@ } } -static unsigned getAlignment(const Value *V, const DataLayout &DL) { - unsigned Align = 0; - if (auto *GO = dyn_cast(V)) { - Align = GO->getAlignment(); - if (Align == 0) { - if (auto *GVar = dyn_cast(GO)) { - Type *ObjectType = GVar->getValueType(); - if (ObjectType->isSized()) { - // If the object is defined in the current Module, we'll be giving - // it the preferred alignment. Otherwise, we have to assume that it - // may only have the minimum ABI alignment. - if (GVar->isStrongDefinitionForLinker()) - Align = DL.getPreferredAlignment(GVar); - else - Align = DL.getABITypeAlignment(ObjectType); - } - } - } - } else if (const Argument *A = dyn_cast(V)) { - Align = A->getType()->isPointerTy() ? A->getParamAlignment() : 0; - - if (!Align && A->hasStructRetAttr()) { - // An sret parameter has at least the ABI alignment of the return type. - Type *EltTy = cast(A->getType())->getElementType(); - if (EltTy->isSized()) - Align = DL.getABITypeAlignment(EltTy); - } - } else if (const AllocaInst *AI = dyn_cast(V)) - Align = AI->getAlignment(); - else if (auto CS = ImmutableCallSite(V)) - Align = CS.getAttributes().getParamAlignment(AttributeSet::ReturnIndex); - else if (const LoadInst *LI = dyn_cast(V)) - if (MDNode *MD = LI->getMetadata(LLVMContext::MD_align)) { - ConstantInt *CI = mdconst::extract(MD->getOperand(0)); - Align = CI->getLimitedValue(); - } - - return Align; -} - /// Determine which bits of V are known to be either zero or one and return /// them in the KnownZero/KnownOne bit sets. /// @@ -1688,7 +1648,7 @@ // Aligned pointers have trailing zeros - refine KnownZero set if (V->getType()->isPointerTy()) { - unsigned Align = getAlignment(V, Q.DL); + unsigned Align = V->getPointerAlignment(Q.DL); if (Align) KnownZero |= APInt::getLowBitsSet(BitWidth, countTrailingZeros(Align)); } @@ -3203,7 +3163,7 @@ static bool isAligned(const Value *Base, APInt Offset, unsigned Align, const DataLayout &DL) { - APInt BaseAlign(Offset.getBitWidth(), getAlignment(Base, DL)); + APInt BaseAlign(Offset.getBitWidth(), Base->getPointerAlignment(DL)); if (!BaseAlign) { Type *Ty = Base->getType()->getPointerElementType(); Index: lib/IR/Value.cpp =================================================================== --- lib/IR/Value.cpp +++ lib/IR/Value.cpp @@ -519,6 +519,48 @@ return stripPointerCastsAndOffsets(this); } +unsigned Value::getPointerAlignment(const DataLayout &DL) const { + assert(getType()->isPointerTy() && "must be pointer"); + + unsigned Align = 0; + if (auto *GO = dyn_cast(this)) { + Align = GO->getAlignment(); + if (Align == 0) { + if (auto *GVar = dyn_cast(GO)) { + Type *ObjectType = GVar->getValueType(); + if (ObjectType->isSized()) { + // If the object is defined in the current Module, we'll be giving + // it the preferred alignment. Otherwise, we have to assume that it + // may only have the minimum ABI alignment. + if (GVar->isStrongDefinitionForLinker()) + Align = DL.getPreferredAlignment(GVar); + else + Align = DL.getABITypeAlignment(ObjectType); + } + } + } + } else if (const Argument *A = dyn_cast(this)) { + Align = A->getType()->isPointerTy() ? A->getParamAlignment() : 0; + + if (!Align && A->hasStructRetAttr()) { + // An sret parameter has at least the ABI alignment of the return type. + Type *EltTy = cast(A->getType())->getElementType(); + if (EltTy->isSized()) + Align = DL.getABITypeAlignment(EltTy); + } + } else if (const AllocaInst *AI = dyn_cast(this)) + Align = AI->getAlignment(); + else if (auto CS = ImmutableCallSite(this)) + Align = CS.getAttributes().getParamAlignment(AttributeSet::ReturnIndex); + else if (const LoadInst *LI = dyn_cast(this)) + if (MDNode *MD = LI->getMetadata(LLVMContext::MD_align)) { + ConstantInt *CI = mdconst::extract(MD->getOperand(0)); + Align = CI->getLimitedValue(); + } + + return Align; +} + Value *Value::DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB) { PHINode *PN = dyn_cast(this);