From 612fa8e6f3bf93751807512287f377ae9a227d3c Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 30 Mar 2006 22:02:40 +0000
Subject: [PATCH] Fix Transforms/InstCombine/2006-03-30-ExtractElement.ll

llvm-svn: 27261
---
 llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index 397c6d6ecd6a..cd734568ba56 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -6704,9 +6704,13 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
         if (IE->getOperand(2) == EI.getOperand(1))
           return ReplaceInstUsesWith(EI, IE->getOperand(1));
         // If the inserted and extracted elements are constants, they must not
-        // be the same value, replace with the pre-inserted value.
-        if (isa<Constant>(IE->getOperand(2)) && isa<Constant>(EI.getOperand(1)))
-          return ReplaceInstUsesWith(EI, IE->getOperand(0));
+        // be the same value, extract from the pre-inserted value instead.
+        if (isa<Constant>(IE->getOperand(2)) &&
+            isa<Constant>(EI.getOperand(1))) {
+          AddUsesToWorkList(EI);
+          EI.setOperand(0, IE->getOperand(0));
+          return &EI;
+        }
       }
     }
   return 0;