From 3e50c68956c96c95182a78c4e29bbf3b638baf4a Mon Sep 17 00:00:00 2001
From: Nadav Rotem <nrotem@apple.com>
Date: Sat, 27 Jul 2013 23:28:47 +0000
Subject: [PATCH] Update the comment

llvm-svn: 187316
---
 llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 50e37e99169d..db1a91ec9e34 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -900,6 +900,7 @@ int BoUpSLP::getTreeCost() {
 
   // Don't vectorize tiny trees. Small load/store chains or consecutive stores
   // of constants will be vectoried in SelectionDAG in MergeConsecutiveStores.
+  // The SelectionDAG vectorizer can only handle pairs (trees of height = 2).
   if (VectorizableTree.size() < 3) {
     if (!VectorizableTree.size()) {
       assert(!ExternalUses.size() && "We should not have any external users");