[InstructionSimplify] Apply sext/trunc after pointer stripping

Summary:
- As the pointer stripping could trace through `addrspacecast` now, need
  to sext/trunc the offset to ensure it has the same width as the
  pointer after stripping.

Reviewers: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64768

llvm-svn: 366162

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index c0d69f9275d..e34bf6f4e43 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -660,6 +660,10 @@ static Constant *stripAndComputeConstantOffsets(const DataLayout &DL, Value *&V,
   APInt Offset = APInt::getNullValue(IntPtrTy->getIntegerBitWidth());
 
   V = V->stripAndAccumulateConstantOffsets(DL, Offset, AllowNonInbounds);
+  // As that strip may trace through `addrspacecast`, need to sext or trunc
+  // the offset calculated.
+  IntPtrTy = DL.getIntPtrType(V->getType())->getScalarType();
+  Offset = Offset.sextOrTrunc(IntPtrTy->getIntegerBitWidth());
 
   Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset);
   if (V->getType()->isVectorTy())