Clear a bit in this file that was causing a miscompilation of 178.galgel.

llvm-svn: 23980
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index ee6f8dd..0ccd038 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2472,7 +2472,7 @@
           if (N0.getOperand(0) == N1.getOperand(1))
             return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(0), Cond);
           if (N0.getOperand(1) == N1.getOperand(0))
-            return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(1), Cond);
+            return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(1), Cond);
         }
       }