diff options
Diffstat (limited to 'llvm/lib/Analysis/ConstantFolding.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ConstantFolding.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp index bf0cb3e..20370d2 100644 --- a/llvm/lib/Analysis/ConstantFolding.cpp +++ b/llvm/lib/Analysis/ConstantFolding.cpp @@ -845,15 +845,18 @@ Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP, // Determine which element of the array the offset points into. APInt ElemSize(BitWidth, DL.getTypeAllocSize(Ty)); - if (ElemSize == 0) + if (ElemSize == 0) { // The element size is 0. This may be [0 x Ty]*, so just use a zero // index for this level and proceed to the next level to see if it can // accommodate the offset. NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0)); - else { + } else if (ElemSize.isAllOnesValue()) { + // Avoid signed overflow. + break; + } else { // The element size is non-zero divide the offset by the element // size (rounding down), to compute the index at this level. - APInt NewIdx = Offset.udiv(ElemSize); + APInt NewIdx = Offset.sdiv(ElemSize); Offset -= NewIdx * ElemSize; NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx)); } @@ -864,7 +867,7 @@ Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP, // operand likely went through casts that are necessary to make the GEP // sensible. const StructLayout &SL = *DL.getStructLayout(STy); - if (Offset.uge(SL.getSizeInBytes())) + if (Offset.isNegative() || Offset.uge(SL.getSizeInBytes())) break; // Determine which field of the struct the offset points into. The |