<div dir="ltr"><div dir="ltr"><div>Hi Michael,</div><div><br></div><div>FYI libEngine12 with gcc on my machine is 41MiB with clang and 120 with gcc, not sure this is normal<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mar. 23 nov. 2021 à 16:11, Michael Meeks <<a href="mailto:michael.meeks@collabora.com">michael.meeks@collabora.com</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi Arnaud,<br>
<br>
On 22/11/2021 16:28, Arnaud Versini wrote:<br>
> I just tested libreoffice performance between GCC + gold + libstdc++, <br>
> clang + lld + libstdc++ and clang + lld + libc++ and noticed that gcc <br>
> builds are slower (at least in this case).<br>
<br>
That sounds like an interesting result; thanks for measuring.<br>
<br>
> I will write a blog article <br>
> with all the process to reproduce but small version, it just converts <br>
> openDocument standart files (ODF 1.0 to 1.3) to PDF.<br>
<br>
Fair enough =) its good to see the general stability of the benchmark <br>
numbers.<br>
<br>
> There is no <br>
> significant difference between both clang builds (changing lib C++ from <br>
> libstdc++ to libc++) but gcc is slower than clang. Of course all builds <br>
> don't use system libraries in this case to compare between lib C++, and <br>
> builds are optimised and use LTO.<br>
<br>
Looks interesting.<br>
<br>
Lubos - what are our build defaults currently and do you have thoughts <br>
on changing them ? it would be great to poke at Arnaud's blog / work <br>
as/when it gets published =)<br>
<br>
> OpenSUSE 7.2 Clang + libc++ Clang + std Gcc + std<br>
> Run 1 50,923045275 45,456441587 45,878275287 49,487550577<br>
> Run 2 50,360027388 43,83441037 44,303120572 47,898307652<br>
> Run 3 50,258628137 43,552443057 44,332110013 47,596628518<br>
> Run 4 50,062155622 43,587905602 44,616728628 47,430735675<br>
> Run 5 53,567235331 43,548408389 44,561502427 47,727024813<br>
> Run 6 50,354870307 43,877387065 44,107891362 47,444552655<br>
> Run 7 49,663738973 43,92048805 44,583599634 47,293633635<br>
> Run 8 49,780141995 43,843555496 44,055990454 47,561677627<br>
> Run 9 49,763425026 43,398042427 44,011950682 47,65275752<br>
> Run 10 50,197944032 44,153460819 44,303763557 47,974880802<br>
> Average 50,4931212086 43,9172542862 44,4754932616 47,8067749474<br>
> <br>
> For information I use openSUSE Tumbleweed latest release.<br>
> <br>
> I also noticed that libengine12 is really bigger with GCC but I've not <br>
> have that data on me now.<br>
<br>
That's interesting too - how much bigger? I would assume that we use <br>
-Os to optimize for size as well as for speed: since huge binaries may <br>
be more optimal in theory but can be much slower to load and kill your <br>
cache in practice: but it sounds like this is some combination of bigger <br>
& slower.<br></blockquote><div> </div><div>FYI libEngine12 with gcc on my machine is 41MiB with clang and 120 with gcc, not sure this is normal <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
I wonder what the compile option difference is.<br>
<br>
> I hope this could be an idea of improvement ! Next crazy test I would <br>
> like to do is between MSVC and clang on windows ! But it seems harder !<br>
<br>
Ah - now that would be lovely being able to use the same compiler <br>
everywhere =) would be really interesting to compare the performance there.<br>
<br>
Good work !<br>
<br>
Michael.<br>
<br>
-- <br>
<a href="mailto:michael.meeks@collabora.com" target="_blank">michael.meeks@collabora.com</a> <><, GM Collabora Productivity<br>
Hangout: <a href="mailto:mejmeeks@gmail.com" target="_blank">mejmeeks@gmail.com</a>, Skype: mmeeks<br>
(M) +44 7795 666 147 - timezone usually UK / Europe<br>
</blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr">Arnaud Versini</div></div></div>