From f6069577fa6e20500de9bb6af3579e7872acf321 Mon Sep 17 00:00:00 2001
From: Duncan Sands <baldrick@free.fr>
Date: Mon, 29 Dec 2008 20:51:17 +0000
Subject: [PATCH] Experiments show that looking through phi nodes and select
 instructions doesn't buy anything here except extra complexity: the only
 difference in the entire testsuite was that a readonly function became
 readnone in MiBench/consumer-typeset.  Add a comment about this.

llvm-svn: 61478
---
 llvm/lib/Transforms/IPO/AddReadAttrs.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/llvm/lib/Transforms/IPO/AddReadAttrs.cpp b/llvm/lib/Transforms/IPO/AddReadAttrs.cpp
index 2835d5e9f361..96c1427e0e0f 100644
--- a/llvm/lib/Transforms/IPO/AddReadAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/AddReadAttrs.cpp
@@ -64,6 +64,8 @@ bool AddReadAttrs::PointsToLocalMemory(Value *V) {
   // A global constant counts as local memory for our purposes.
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
     return GV->isConstant();
+  // Could look through phi nodes and selects here, but it doesn't seem
+  // to be useful in practice.
   return false;
 }