Do GEP offset calculations with unsigned math rather than signed math

to avoid undefined behavior on overflow, noticed by John Regehr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109594 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-07-28 17:11:36 +00:00
parent dc7a235363
commit 67d0498d53

View File

@ -625,7 +625,7 @@ uint64_t TargetData::getIndexedOffset(const Type *ptrTy, Value* const* Indices,
// Get the array index and the size of each array element.
if (int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue())
Result += arrayIdx * (int64_t)getTypeAllocSize(Ty);
Result += (uint64_t)arrayIdx * getTypeAllocSize(Ty);
}
}