From: Vitaly Buka <vitalybuka@google.com>
Date: Tue, 17 Oct 2017 18:33:15 +0000 (+0000)
Subject: Fix signed overflow detected by ubsan
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a1dafe0b863f4439c10936628f1839a1da40ec02;p=llvm

Fix signed overflow detected by ubsan

This overflow does not affect algorithm, so just suppress it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316018 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 63bf68e4cee..e7388f63864 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -5439,7 +5439,7 @@ static bool ReduceSwitchRange(SwitchInst *SI, IRBuilder<> &Builder,
   // First, transform the values such that they start at zero and ascend.
   int64_t Base = Values[0];
   for (auto &V : Values)
-    V -= Base;
+    V -= (uint64_t)(Base);
 
   // Now we have signed numbers that have been shifted so that, given enough
   // precision, there are no negative values. Since the rest of the transform