From 011cf687d7d942f41f1cfb3a6fd480898160d4b2 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Sun, 14 Jun 2009 22:53:57 +0000
Subject: [PATCH] Check for the short-circuiting condition before performing
 the potentially expensive erase.

llvm-svn: 73359
---
 llvm/lib/Analysis/ScalarEvolution.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index ee077d56b628..a2ab6e63da6f 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -1012,8 +1012,8 @@ SCEVHandle ScalarEvolution::getAddExpr(SmallVectorImpl<SCEVHandle> &Ops) {
       // We found two constants, fold them together!
       Ops[0] = getConstant(LHSC->getValue()->getValue() +
                            RHSC->getValue()->getValue());
+      if (Ops.size() == 2) return Ops[0];
       Ops.erase(Ops.begin()+1);  // Erase the folded element
-      if (Ops.size() == 1) return Ops[0];
       LHSC = cast<SCEVConstant>(Ops[0]);
     }