diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCalls.cpp')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCalls.cpp | 53 |
1 files changed, 38 insertions, 15 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index e7f3b21b15..23c08699ff 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -29,6 +29,26 @@ static Type *getPromotedType(Type *Ty) { return Ty; } +/// reduceToSingleValueType - Given an aggregate type which ultimately holds a +/// single scalar element, like {{{type}}} or [1 x type], return type. +static Type *reduceToSingleValueType(Type *T) { + while (!T->isSingleValueType()) { + if (StructType *STy = dyn_cast<StructType>(T)) { + if (STy->getNumElements() == 1) + T = STy->getElementType(0); + else + break; + } else if (ArrayType *ATy = dyn_cast<ArrayType>(T)) { + if (ATy->getNumElements() == 1) + T = ATy->getElementType(); + else + break; + } else + break; + } + + return T; +} Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), TD); @@ -74,35 +94,34 @@ Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { // dest address will be promotable. See if we can find a better type than the // integer datatype. Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts(); + MDNode *CopyMD = 0; if (StrippedDest != MI->getArgOperand(0)) { Type *SrcETy = cast<PointerType>(StrippedDest->getType()) ->getElementType(); if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) { // The SrcETy might be something like {{{double}}} or [1 x double]. Rip // down through these levels if so. - while (!SrcETy->isSingleValueType()) { - if (StructType *STy = dyn_cast<StructType>(SrcETy)) { - if (STy->getNumElements() == 1) - SrcETy = STy->getElementType(0); - else - break; - } else if (ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) { - if (ATy->getNumElements() == 1) - SrcETy = ATy->getElementType(); - else - break; - } else - break; - } + SrcETy = reduceToSingleValueType(SrcETy); if (SrcETy->isSingleValueType()) { NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp); NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp); + + // If the memcpy has metadata describing the members, see if we can + // get the TBAA tag describing our copy. + if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) { + if (M->getNumOperands() == 3 && + isa<ConstantInt>(M->getOperand(0)) && + cast<ConstantInt>(M->getOperand(0))->isNullValue() && + isa<ConstantInt>(M->getOperand(1)) && + cast<ConstantInt>(M->getOperand(1))->getValue() == Size && + isa<MDNode>(M->getOperand(2))) + CopyMD = cast<MDNode>(M->getOperand(2)); + } } } } - // If the memcpy/memmove provides better alignment info than we can // infer, use it. SrcAlign = std::max(SrcAlign, CopyAlign); @@ -112,8 +131,12 @@ Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy); LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile()); L->setAlignment(SrcAlign); + if (CopyMD) + L->setMetadata(LLVMContext::MD_tbaa, CopyMD); StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile()); S->setAlignment(DstAlign); + if (CopyMD) + S->setMetadata(LLVMContext::MD_tbaa, CopyMD); // Set the size of the copy to 0, it will be deleted on the next iteration. MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType())); |