From 2a0cd9c9b56d0fff66183967951e592e2aec0dba Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Wed, 8 Dec 2004 22:20:34 +0000
Subject: [PATCH] Fix Transforms/InstCombine/2004-12-08-RemInfiniteLoop.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18670 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/InstructionCombining.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 8915598da11..9eb30549f47 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -309,7 +309,8 @@ static inline Value *dyn_castNegVal(Value *V) {
 
   // Constants can be considered to be negated values if they can be folded...
   if (Constant *C = dyn_cast<Constant>(V))
-    return ConstantExpr::getNeg(C);
+    if (!isa<UndefValue>(C))
+      return ConstantExpr::getNeg(C);
   return 0;
 }