From: Evan Cheng <evan.cheng@apple.com>
Date: Fri, 19 Jun 2009 07:06:07 +0000 (+0000)
Subject: Add comments.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=b1019480b6806c38432ad3357ae7d756573c0835;p=oota-llvm.git

Add comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73761 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 345f172deb7..2443625d4bd 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -294,6 +294,10 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
 
   if (!Subtarget->isThumb()) {
     // Use branch latency information to determine if-conversion limits.
+    // FIXME: If-converter should use instruction latency of the branch being
+    // eliminated to compute the threshold. For ARMv6, the branch "latency"
+    // varies depending on whether it's dynamically or statically predicted
+    // and on whether the destination is in the prefetch buffer.
     const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
     const InstrItineraryData &InstrItins = Subtarget->getInstrItineraryData();
     unsigned Latency= InstrItins.getLatency(TII->get(ARM::Bcc).getSchedClass());