From ac83b0301ea5ce0e1092fad8f294fe7f046832ff 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23019 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/Reassociate.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index c55bce0d7e8..60722ef68ff 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/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;
         }