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