<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<br>
<br>
<div class="moz-cite-prefix">On 03/02/2016 04:17 PM, Xinliang David
Li wrote:<br>
</div>
<blockquote
cite="mid:CAAkRFZLEeQ-TsoKyfvJy3Mty=BGOUq7HqdceMwLWF15O8Xkc-A@mail.gmail.com"
type="cite">
<div dir="ltr"><br>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Mar 2, 2016 at 4:12 PM,
Philip Reames <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:listmail@philipreames.com" target="_blank">listmail@philipreames.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">reames
added a comment.<br>
<span class=""><br>
In <a moz-do-not-send="true"
href="http://reviews.llvm.org/D17652#364797"
rel="noreferrer" target="_blank">http://reviews.llvm.org/D17652#364797</a>,
@davidxl wrote:<br>
<br>
> A general problem I see in address sinking
optimization is the lack of global cost analysis -- the
analysis should consider<br>
><br>
> 1. the cost of the folded instruction (if the
address can be folded in)<br>
> 2. whether the original address instruction can be
eliminated (for instance, only sunk into some of the
uses)<br>
> 3. if the address can not be folded, what is the
additional cost<br>
> 4. what is the estimated register pressure
reduction with the address sinking<br>
<br>
<br>
</span>I'm confused by your comment. Are you talking
about my changes, or the existing code? The existing code
does most of this (except 1) and my extension preserves
all of that except when duplicating into a cold call.<br>
</blockquote>
<div><br>
</div>
<div><br>
</div>
<div>Mostly the existing code, but you new code introduces a
new dimension to it. IIUC, the new code introduces the
case where address computation may not be folded away so
there is also potential size increase? Perhaps guard this
change with 'not built for Os or Oz' ?</div>
</div>
</div>
</div>
</blockquote>
Sounds reasonable.<br>
<blockquote
cite="mid:CAAkRFZLEeQ-TsoKyfvJy3Mty=BGOUq7HqdceMwLWF15O8Xkc-A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div> </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<span class=""><br>
> The above should be all weighted with the block
frequency information.<br>
<br>
<br>
</span>While I agree, that's a separate change -
particularly since CFG does not currently use profiling
info at all.<br>
</blockquote>
<div><br>
</div>
<div>Perhaps add a comment there to future cleanup ?</div>
</div>
</div>
</div>
</blockquote>
Sure.<br>
<blockquote
cite="mid:CAAkRFZLEeQ-TsoKyfvJy3Mty=BGOUq7HqdceMwLWF15O8Xkc-A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div><br>
</div>
<div>thanks,</div>
<div><br>
</div>
<div>David </div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
<br>
<a moz-do-not-send="true"
href="http://reviews.llvm.org/D17652" rel="noreferrer"
target="_blank">http://reviews.llvm.org/D17652</a><br>
<br>
<br>
<br>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote>
<br>
</body>
</html>