diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 2311f1eb5a3..5ff971427de 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -7669,6 +7669,52 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { MI->setAlignment(ConstantInt::get(Type::Int32Ty, Align)); Changed = true; } + + // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with load/store + ConstantInt *MemOpLength = dyn_cast<ConstantInt>(CI.getOperand(3)); + if (isa<MemCpyInst>(MI)) + if (MemOpLength) { + unsigned Size = MemOpLength->getZExtValue(); + unsigned Align = cast<ConstantInt>(CI.getOperand(4))->getZExtValue(); + const PointerType *PTy = cast<PointerType>(CI.getOperand(1)->getType()); + const Type *MTy = PTy->getElementType(); + PointerType *NewPtrTy = NULL; + if (MTy == Type::Int8Ty) { + if (Size == 8) + NewPtrTy = PointerType::get(Type::Int64Ty); + else if (Size == 4) + NewPtrTy = PointerType::get(Type::Int32Ty); + else if (Size == 2) + NewPtrTy = PointerType::get(Type::Int16Ty); + else if (Size == 1) + NewPtrTy = PointerType::get(Type::Int8Ty); + } else if (MTy == Type::Int16Ty) { + if (Size == 4) + NewPtrTy = PointerType::get(Type::Int64Ty); + else if (Size == 2) + NewPtrTy = PointerType::get(Type::Int32Ty); + else if (Size == 1) + NewPtrTy = PointerType::get(Type::Int16Ty); + } else if (MTy == Type::Int32Ty) { + if (Size == 2) + NewPtrTy = PointerType::get(Type::Int64Ty); + else if (Size == 1) + NewPtrTy = PointerType::get(Type::Int32Ty); + } else if (MTy == Type::Int64Ty) { + if (Size == 1) + NewPtrTy = PointerType::get(Type::Int64Ty); + } + if (NewPtrTy) + { + Value *Src = InsertCastBefore(Instruction::BitCast, CI.getOperand(2), NewPtrTy, CI); + Value *Dest = InsertCastBefore(Instruction::BitCast, CI.getOperand(1), NewPtrTy, CI); + Value *L = new LoadInst(Src, "tmp", false, Align, &CI); + Value *NS = new StoreInst(L, Dest, false, Align, &CI); + CI.replaceAllUsesWith(NS); + Changed = true; + return EraseInstFromFunction(CI); + } + } } else if (isa<MemSetInst>(MI)) { unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest(), TD); if (MI->getAlignment()->getZExtValue() < Alignment) { |
