<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">FWIW, I'd be happy to help mentoring such a project if a student is interested.<div class=""><br class=""></div><div class="">During the last LLVM Dev Meeting (the US one), I think better AA was number one in the list of requested features during the BoF on "Sophisticated Program Analysis on LLVM IR" ( <a href="http://devmtg15.llvm.org/event/4VNY/sophisticated-program-analysis-on-llvm-ir" class="">http://devmtg15.llvm.org/event/4VNY/sophisticated-program-analysis-on-llvm-ir</a> ). </div><div class="">CC John, I don't remember if there was a summary of the BoF posted online.</div><div class=""><div class=""><br class=""></div><div class="">-- </div><div class="">Mehdi</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Mar 22, 2016, at 11:55 AM, Philip Reames via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" class="">
<div text="#000000" bgcolor="#FFFFFF" class="">
It's found more and more like "get CFL-AA turned on by default"
might be a viable GSoC project for the right student. It would
require someone with existing knowledge of AA and a willingness to
debug nasty problems, but it sounds like there's definitely interest
in the community in seeing this happen.<br class="">
<br class="">
If the student finished early (unlikely), they could start on
SCEV-AA as well. <br class="">
<br class="">
Philip<br class="">
<br class="">
<div class="moz-cite-prefix">On 03/21/2016 01:10 PM, George Burgess
IV via llvm-dev wrote:<br class="">
</div>
<blockquote cite="mid:CAKh6zBE6m31RNz1DXNU56j9asZpZAAHnbLUB0qigpduJGXaPVw@mail.gmail.com" type="cite" class="">
<div dir="ltr" class="">
<div class=""><span style="font-family: arial, helvetica, sans-serif; font-size: 13.3333px;" class="">As
of late-August 2015, putting CFL-AA behind BasicAA caused
miscompiles when trying to bootstrap Clang/LLVM, yeah. It
didn't seem that there were many new errors (I think it
caused ~10 tests to fail, where fail = either segv or
produce the wrong output), but it did end up breaking
things. I don't recall if standalone CFL-AA causes
miscompiles, but I highly doubt the breakages I observed
were BasicAA's fault.</span></div>
<div class=""><span style="font-family: arial, helvetica, sans-serif; font-size: 13.3333px;" class=""><br class="">
</span></div>
<div class=""><font face="arial, helvetica, sans-serif" class=""><span style="font-size:13.3333px" class="">WRT speed, `time make -j14` on
my box (6c/12t) didn't show a meaningful increase in
compile time when CFL-AA gets enabled (read: it got lost
in the noise). So, I agree that it's probably fast enough
at the moment; if we want to enhance it, we should focus
on making it bootstrap clang+LLVM/making it more accurate.</span></font></div>
<div class="gmail_extra"><br class="">
<div class="gmail_quote">On Mon, Mar 21, 2016 at 12:26 PM, Hal
Finkel <span dir="ltr" class=""><<a moz-do-not-send="true" href="mailto:hfinkel@anl.gov" target="_blank" class="">hfinkel@anl.gov</a>></span>
wrote:<br class="">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="">
<div style="font-family: arial, helvetica, sans-serif; font-size: 10pt;" class=""><br class="">
<hr class="">
<blockquote style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica, Arial, sans-serif; font-size: 12pt;" class=""><b class="">From:
</b>"Daniel Berlin via llvm-dev" <<a moz-do-not-send="true" href="mailto:llvm-dev@lists.llvm.org" target="_blank" class=""></a><a class="moz-txt-link-abbreviated" href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>><br class="">
<b class="">To: </b>"Renato Golin" <<a moz-do-not-send="true" href="mailto:renato.golin@linaro.org" target="_blank" class=""></a><a class="moz-txt-link-abbreviated" href="mailto:renato.golin@linaro.org">renato.golin@linaro.org</a>>,
"George Burgess IV" <<a moz-do-not-send="true" href="mailto:george.burgess.iv@gmail.com" target="_blank" class="">george.burgess.iv@gmail.com</a>><br class="">
<b class="">Cc: </b>"llvm-dev" <<a moz-do-not-send="true" href="mailto:llvm-dev@lists.llvm.org" target="_blank" class="">llvm-dev@lists.llvm.org</a>>,
"Jia Chen" <<a moz-do-not-send="true" href="mailto:jchen@cs.utexas.edu" target="_blank" class="">jchen@cs.utexas.edu</a>><br class="">
<b class="">Sent: </b>Monday, March 21, 2016 2:07:44 PM<br class="">
<b class="">Subject: </b>Re: [llvm-dev] Existing studies on
the benefits of pointer analysis<span class=""><br class="">
<br class="">
<div dir="ltr" class=""><br class="">
<div class="gmail_extra"><br class="">
<div class="gmail_quote">On Mon, Mar 21, 2016
at 12:05 PM, Renato Golin <span dir="ltr" class=""><<a moz-do-not-send="true" href="mailto:renato.golin@linaro.org" target="_blank" class=""></a><a class="moz-txt-link-abbreviated" href="mailto:renato.golin@linaro.org">renato.golin@linaro.org</a>></span>
wrote:<br class="">
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex"><span class="">On
21 March 2016 at 18:59, Daniel Berlin
<<a moz-do-not-send="true" href="mailto:dberlin@dberlin.org" target="_blank" class="">dberlin@dberlin.org</a>>
wrote:<br class="">
> Which is why i've never mentioned
it or used it in the community ;)<br class="">
<br class="">
</span>Makes sense. :)<br class="">
<span class=""><br class="">
<br class="">
> I would rather see someone spend
their time getting SCEV-AA on by default
or<br class="">
> CFL-AA on by default than doing
another evaluation.<br class="">
<br class="">
</span>But those may not be simple enough
for a GSOC, that's why I mentioned it.<br class="">
<br class="">
</blockquote>
<div class=""><br class="">
</div>
<div class="">CFL-AA should just be fixing
performance regressions, and maybe a
little bug fixing, which is hopefully easy
enough. It's already fast enough as a
pass.</div>
</div>
</div>
</div>
</span></blockquote>
<br class="">
My understanding from George is that there are
self-hosting miscompiles if you disable all AA except
for CFL-AA. This is what is preventing us from
enabling it by default. George, is that right?<br class="">
<br class="">
-Hal<br class="">
<blockquote style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica, Arial, sans-serif; font-size: 12pt;" class=""><span class="">
<div dir="ltr" class="">
<div class="gmail_extra">
<div class="gmail_quote">
<div class=""><br class="">
</div>
<div class="">SCEV-AA would be harder (must make
SCEV-AA faster).</div>
<div class=""><br class="">
</div>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
The analysis could not only get us a birds
view of the problem ahead,<br class="">
but also introduce new developers to AA,
which would make their future<br class="">
work on SCEV-AA or CFL-AA easier. Kind of
a teaching tool to get more<br class="">
AA-savvy people.<br class="">
</blockquote>
<div class=""><br class="">
</div>
<div class="">Sure. </div>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
<br class="">
cheers,<br class="">
--renato<br class="">
</blockquote>
</div>
<br class="">
</div>
</div>
<br class="">
</span><span class="">_______________________________________________<br class="">
LLVM Developers mailing list<br class="">
<a moz-do-not-send="true" href="mailto:llvm-dev@lists.llvm.org" target="_blank" class="">llvm-dev@lists.llvm.org</a><br class="">
<a moz-do-not-send="true" href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank" class="">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><br class="">
</span></blockquote>
<span class=""><font color="#888888" class=""><br class="">
<br class="">
<br class="">
-- <br class="">
<div class=""><span name="x" class=""></span>Hal Finkel<br class="">
Assistant Computational Scientist<br class="">
Leadership Computing Facility<br class="">
Argonne National Laboratory<span name="x" class=""></span><br class="">
</div>
</font></span></div>
</div>
</blockquote>
</div>
<br class="">
</div>
</div>
<br class="">
<fieldset class="mimeAttachmentHeader"></fieldset>
<br class="">
<pre wrap="" class="">_______________________________________________
LLVM Developers mailing list
<a class="moz-txt-link-abbreviated" href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>
<a class="moz-txt-link-freetext" href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a>
</pre>
</blockquote>
<br class="">
</div>
_______________________________________________<br class="">LLVM Developers mailing list<br class=""><a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a><br class="">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev<br class=""></div></blockquote></div><br class=""></div></div></body></html>