diff options
Diffstat (limited to 'lib/IR/ConstantFold.cpp')
| -rw-r--r-- | lib/IR/ConstantFold.cpp | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp index a5a9d9f3a7..bf93d4f956 100644 --- a/lib/IR/ConstantFold.cpp +++ b/lib/IR/ConstantFold.cpp @@ -1971,21 +1971,30 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C, } } - // Implement folding of: - // i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*), - // i64 0, i64 0) - // To: i32* getelementptr ([3 x i32]* %X, i64 0, i64 0) + // Attempt to fold casts to the same type away. For example, folding: // + // i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*), + // i64 0, i64 0) + // into: + // + // i32* getelementptr ([3 x i32]* %X, i64 0, i64 0) + // + // Don't fold if the cast is changing address spaces. if (CE->isCast() && Idxs.size() > 1 && Idx0->isNullValue()) { - if (PointerType *SPT = - dyn_cast<PointerType>(CE->getOperand(0)->getType())) - if (ArrayType *SAT = dyn_cast<ArrayType>(SPT->getElementType())) - if (ArrayType *CAT = - dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType())) - if (CAT->getElementType() == SAT->getElementType()) - return - ConstantExpr::getGetElementPtr((Constant*)CE->getOperand(0), - Idxs, inBounds); + PointerType *SrcPtrTy = + dyn_cast<PointerType>(CE->getOperand(0)->getType()); + PointerType *DstPtrTy = dyn_cast<PointerType>(CE->getType()); + if (SrcPtrTy && DstPtrTy) { + ArrayType *SrcArrayTy = + dyn_cast<ArrayType>(SrcPtrTy->getElementType()); + ArrayType *DstArrayTy = + dyn_cast<ArrayType>(DstPtrTy->getElementType()); + if (SrcArrayTy && DstArrayTy + && SrcArrayTy->getElementType() == DstArrayTy->getElementType() + && SrcPtrTy->getAddressSpace() == DstPtrTy->getAddressSpace()) + return ConstantExpr::getGetElementPtr((Constant*)CE->getOperand(0), + Idxs, inBounds); + } } } |