diff options
| author | Dan Gohman <gohman@apple.com> | 2010-02-23 16:35:41 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-02-23 16:35:41 +0000 |
| commit | b80a2a686fe76496d71397f8bdda394d5718ab01 (patch) | |
| tree | 3bc7be4268bf1d153ff66df0d6d2d61e89611511 /lib/Analysis/ConstantFolding.cpp | |
| parent | c80a1f7721823c081d80afa1345e4dc512cd97d7 (diff) | |
Remove the code which constant-folded ptrtoint(inttoptr(x)+c) to
getelementptr. Despite only doing so in the case where x is a known
array object and c can be converted to an index within range, this
could still be invalid if c is actually the address of an object
allocated outside of LLVM. Also, SCEVExpander, the original motivation
for this code, has since been improved to avoid inttoptr+ptroint in
more cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96950 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/ConstantFolding.cpp')
| -rw-r--r-- | lib/Analysis/ConstantFolding.cpp | 42 |
1 files changed, 5 insertions, 37 deletions
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 1d23fe0b6c..114db2d370 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -783,44 +783,12 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if // the int size is >= the ptr size. This requires knowing the width of a // pointer, so it can't be done in ConstantExpr::getCast. - if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) { + if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) if (TD && - TD->getPointerSizeInBits() <= - CE->getType()->getScalarSizeInBits()) { - if (CE->getOpcode() == Instruction::PtrToInt) - return FoldBitCast(CE->getOperand(0), DestTy, *TD); - - // If there's a constant offset added to the integer value before - // it is casted back to a pointer, see if the expression can be - // converted into a GEP. - if (CE->getOpcode() == Instruction::Add) - if (ConstantInt *L = dyn_cast<ConstantInt>(CE->getOperand(1))) - if (ConstantExpr *R = dyn_cast<ConstantExpr>(CE->getOperand(0))) - if (R->getOpcode() == Instruction::PtrToInt) - if (GlobalVariable *GV = - dyn_cast<GlobalVariable>(R->getOperand(0))) { - const PointerType *GVTy = cast<PointerType>(GV->getType()); - if (const ArrayType *AT = - dyn_cast<ArrayType>(GVTy->getElementType())) { - const Type *ElTy = AT->getElementType(); - uint64_t AllocSize = TD->getTypeAllocSize(ElTy); - APInt PSA(L->getValue().getBitWidth(), AllocSize); - if (ElTy == cast<PointerType>(DestTy)->getElementType() && - L->getValue().urem(PSA) == 0) { - APInt ElemIdx = L->getValue().udiv(PSA); - if (ElemIdx.ult(APInt(ElemIdx.getBitWidth(), - AT->getNumElements()))) { - Constant *Index[] = { - Constant::getNullValue(CE->getType()), - ConstantInt::get(ElTy->getContext(), ElemIdx) - }; - return ConstantExpr::getGetElementPtr(GV, &Index[0], 2); - } - } - } - } - } - } + TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() && + CE->getOpcode() == Instruction::PtrToInt) + return FoldBitCast(CE->getOperand(0), DestTy, *TD); + return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::Trunc: case Instruction::ZExt: |