Micro-optimize GroupByComplexity.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112431 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 176de3a..863f8a6 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -704,8 +704,9 @@
   if (Ops.size() == 2) {
     // This is the common case, which also happens to be trivially simple.
     // Special case it.
-    if (SCEVComplexityCompare(LI)(Ops[1], Ops[0]))
-      std::swap(Ops[0], Ops[1]);
+    const SCEV *&LHS = Ops[0], *&RHS = Ops[1];
+    if (SCEVComplexityCompare(LI)(RHS, LHS))
+      std::swap(LHS, RHS);
     return;
   }