From 8ca5b2a6d2a599161500c8403bc95823beebf877 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Wed, 24 Aug 2005 17:55:32 +0000
Subject: [PATCH] Fix Regression/Transforms/Reassociate/2005-08-24-Crash.ll

llvm-svn: 23019
---
 llvm/lib/Transforms/Scalar/Reassociate.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp
index c55bce0d7e8c..60722ef68ffb 100644
--- a/llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -496,9 +496,15 @@ void Reassociate::OptimizeExpression(unsigned Opcode,
           ++NumAnnihil;
         } else {
           assert(Opcode == Instruction::Xor);
+          if (e == 2) {
+            Ops[0].Op = Constant::getNullValue(Ops[0].Op->getType());
+            Ops.erase(Ops.begin()+1, Ops.end());
+            ++NumAnnihil;
+            return;
+          }
           // ... X^X -> ...
           Ops.erase(Ops.begin()+i, Ops.begin()+i+2);
-          i -= 2; e -= 2;
+          i -= 1; e -= 2;
           IterateOptimization = true;
           ++NumAnnihil;
         }