[prev in list] [next in list] [prev in thread] [next in thread]
List: cfe-dev
Subject: Re: [cfe-dev] Clangs equivalent to GCCs -Og flag?
From: Xinliang David Li <xinliangli () gmail ! com>
Date: 2015-07-31 18:49:07
Message-ID: CALRgJCP-_CnwETqOzuojgO=StzAFDL8CYCjyCjYh+PVZ4MxX8g () mail ! gmail ! com
[Download RAW message or body]
[Attachment #2 (multipart/alternative)]
On Fri, Jul 31, 2015 at 7:27 AM, Robinson, Paul <
Paul_Robinson@playstation.sony.com> wrote:
> People ask about this from time to time, but we've never done anything
> about it.
>
> One thing I noticed about GCC –Og is that it's 99% identical to their –O1.
>
Not really. The optimization level is set to 1, but the pass pipeline setup
is very different between O1 and Og.
David
> I'd be curious about people's experience using Clang –O1 –g and whether
> that experience is somewhere close to reasonable.
>
> --paulr
>
>
>
> *From:* cfe-dev-bounces@cs.uiuc.edu [mailto:cfe-dev-bounces@cs.uiuc.edu] *On
> Behalf Of *David Blaikie
> *Sent:* Wednesday, July 29, 2015 10:13 AM
> *To:* Dan Walmsley; cfe-dev Developers
> *Subject:* Re: [cfe-dev] Clangs equivalent to GCCs -Og flag?
>
>
>
>
>
>
>
> On Wed, Jul 29, 2015 at 8:42 AM, Dan Walmsley <dan@walms.co.uk> wrote:
>
> Thanks,
>
>
>
> Perhaps there might be some documentation somewhere that would give me
> an idea of which optimizations to enable individually?
>
>
> Not really - optimized debug info is still pretty lacking in Clang. Even
> the most common/basic optimizations (SROA, for example) are going to pretty
> heavily impact debuggability today.
>
> - Dave
>
>
>
>
> Dan
> ------------------------------
>
> Date: Wed, 29 Jul 2015 06:40:06 -0700
> Subject: Re: [cfe-dev] Clangs equivalent to GCCs -Og flag?
> From: dblaikie@gmail.com
> To: dan@walms.co.uk
> CC: cfe-dev@cs.uiuc.edu
>
>
>
>
> On Jul 29, 2015 3:23 AM, "Dan Walmsley" <dan@walms.co.uk> wrote:
> >
> > GCC has a debug level flag of -Og which enables all optimizers that
> won't degrade the debugging experience greatly.
> >
> > Does clang have an equivalent?
>
> No, clang had no equivalent at this time.
>
> >
> > Thanks in advance.
> >
> > Dan
> >
> > _______________________________________________
> > cfe-dev mailing list
> > cfe-dev@cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
> >
>
>
>
> _______________________________________________
> cfe-dev mailing list
> cfe-dev@cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
>
[Attachment #5 (text/html)]
<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jul 31, 2015 at 7:27 AM, \
Robinson, Paul <span dir="ltr"><<a href="mailto:Paul_Robinson@playstation.sony.com" \
target="_blank">Paul_Robinson@playstation.sony.com</a>></span> wrote:<br><blockquote \
class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple">
<div>
<p class="MsoNormal"><span \
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">People ask \
about this from time to time, but we've never done anything about it.<u></u><u></u></span></p> <p \
class="MsoNormal"><span \
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">One thing I \
noticed about GCC –Og is that it's 99% identical to their –O1. \
</span></p></div></div></blockquote><div><br></div><div>Not really. The optimization level is set to 1, \
but the pass pipeline setup is very different between O1 and \
Og.</div><div><br></div><div>David</div><div><br></div><div> </div><blockquote class="gmail_quote" \
style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" \
vlink="purple"><div><p class="MsoNormal"><span \
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> I'd be \
curious about people's experience using Clang –O1 –g and whether that experience is somewhere \
close to reasonable.<u></u><u></u></span></p> <p class="MsoNormal"><span \
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">--paulr<u></u><u></u></span></p>
<p class="MsoNormal"><a name="14ee486554f0e0c1__MailEndCompose"><span \
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> \
<u></u></span></a></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span \
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span \
style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a \
href="mailto:cfe-dev-bounces@cs.uiuc.edu" target="_blank">cfe-dev-bounces@cs.uiuc.edu</a> [mailto:<a \
href="mailto:cfe-dev-bounces@cs.uiuc.edu" target="_blank">cfe-dev-bounces@cs.uiuc.edu</a>] <b>On Behalf \
Of </b>David Blaikie<br> <b>Sent:</b> Wednesday, July 29, 2015 10:13 AM<br>
<b>To:</b> Dan Walmsley; cfe-dev Developers<span class=""><br>
<b>Subject:</b> Re: [cfe-dev] Clangs equivalent to GCCs -Og flag?<u></u><u></u></span></span></p>
</div>
</div><span class="">
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">On Wed, Jul 29, 2015 at 8:42 AM, Dan Walmsley <<a href="mailto:dan@walms.co.uk" \
target="_blank">dan@walms.co.uk</a>> wrote:<u></u><u></u></p> <div>
<div>
<div>
<p class="MsoNormal">Thanks, <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal"> Perhaps there might be some documentation somewhere that would give me an \
idea of which optimizations to enable individually?<u></u><u></u></p> </div>
</div>
</div>
<div>
<p class="MsoNormal"><br>
Not really - optimized debug info is still pretty lacking in Clang. Even the most common/basic \
optimizations (SROA, for example) are going to pretty heavily impact debuggability today.<br> <br>
- Dave<br>
<u></u><u></u></p>
</div>
<blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in \
6.0pt;margin-left:4.8pt;margin-right:0in"> <div>
<div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">Dan<u></u><u></u></p>
</div>
<div>
<div class="MsoNormal" align="center" style="text-align:center">
<hr size="3" width="100%" align="center">
</div>
<p class="MsoNormal">Date: Wed, 29 Jul 2015 06:40:06 -0700<br>
Subject: Re: [cfe-dev] Clangs equivalent to GCCs -Og flag?<br>
From: <a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a><br>
To: <a href="mailto:dan@walms.co.uk" target="_blank">dan@walms.co.uk</a><br>
CC: <a href="mailto:cfe-dev@cs.uiuc.edu" target="_blank">cfe-dev@cs.uiuc.edu</a><u></u><u></u></p>
<div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><u></u> <u></u></p>
<p><br>
On Jul 29, 2015 3:23 AM, "Dan Walmsley" <<a href="mailto:dan@walms.co.uk" \
target="_blank">dan@walms.co.uk</a>> wrote:<br> ><br>
> GCC has a debug level flag of -Og which enables all optimizers that won't degrade the debugging \
experience greatly.<br> ><br>
> Does clang have an equivalent?<u></u><u></u></p>
<p>No, clang had no equivalent at this time.<u></u><u></u></p>
<p>><br>
> Thanks in advance.<br>
><br>
> Dan<br>
><br>
> _______________________________________________<br>
> cfe-dev mailing list<br>
> <a href="mailto:cfe-dev@cs.uiuc.edu" target="_blank">cfe-dev@cs.uiuc.edu</a><br>
> <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev" \
target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev</a><br> ><u></u><u></u></p>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
</span></div>
</div>
</div>
<br>_______________________________________________<br>
cfe-dev mailing list<br>
<a href="mailto:cfe-dev@cs.uiuc.edu">cfe-dev@cs.uiuc.edu</a><br>
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev" rel="noreferrer" \
target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev</a><br> \
<br></blockquote></div><br></div></div>
_______________________________________________
cfe-dev mailing list
cfe-dev@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic