From 394b624215ae3f4841209b27df149023d81df618 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Fri, 9 Apr 2010 18:20:03 +0000
Subject: [PATCH] Add a comment.

llvm-svn: 100874
---
 llvm/lib/Analysis/ScalarEvolutionExpander.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
index dd8ab431f344..24825bf5e565 100644
--- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -705,7 +705,8 @@ Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) {
       Sum = expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, Sum);
     } else if (const PointerType *PTy = dyn_cast<PointerType>(Op->getType())) {
       // The running sum is an integer, and there's a pointer at this level.
-      // Try to form a getelementptr.
+      // Try to form a getelementptr. Use a SCEVUnknown so that we don't
+      // re-analyze the instructions that we just emitted.
       SmallVector<const SCEV *, 4> NewOps;
       NewOps.push_back(SE.getUnknown(Sum));
       for (++I; I != E && I->first == CurLoop; ++I)