Fix integer undefined behavior due to signed left shift overflow in LLVM.
Reviewed offline by chandlerc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162623 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index cea34e1..491224a 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -1614,7 +1614,7 @@
// right.
unsigned PtrSize = TD.getPointerSizeInBits();
if (PtrSize < 64)
- Offset = (Offset << (64-PtrSize)) >> (64-PtrSize);
+ Offset = SignExtend64(Offset, PtrSize);
return GetPointerBaseWithConstantOffset(GEP->getPointerOperand(), Offset, TD);
}