Fix integer undefined behavior due to signed left shift overflow in LLVM.
Reviewed offline by chandlerc.
llvm-svn: 162623
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 375bd7e..aa5d140 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1475,10 +1475,9 @@
return Base;
// Truncate/sext the offset to the pointer size.
- if (TD.getPointerSizeInBits() != 64) {
- int SExtAmount = 64-TD.getPointerSizeInBits();
- Offset = (Offset << SExtAmount) >> SExtAmount;
- }
+ unsigned Width = TD.getPointerSizeInBits();
+ if (Width < 64)
+ Offset = SignExtend64(Offset, Width);
return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
Ctx);