From 67d0498d533eedab90e5b6399669c420abbde7c6 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 28 Jul 2010 17:11:36 +0000
Subject: [PATCH] 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
---
 lib/Target/TargetData.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index 9b207c1f28c..65f514c2647 100644
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -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);
     }
   }