From: Chris Lattner <sabre@nondot.org>
Date: Sat, 31 Oct 2009 17:48:31 +0000 (+0000)
Subject: add a comment.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=28f3d34a9bf9060b68abef97845cf89bc6e2c403;p=oota-llvm.git

add a comment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85671 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index c2194c460fd..d1561d68c62 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -10998,6 +10998,10 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) {
         PN.setIncomingValue(i, VB);
         PN.setIncomingBlock(j, BBA);
         PN.setIncomingValue(j, VA);
+        // NOTE: Instcombine normally would want us to "return &PN" if we
+        // modified any of the operands of an instruction.  However, since we
+        // aren't adding or removing uses (just rearranging them) we don't do
+        // this in this case.
       }
     }