On Wednesday, 22 April 2020 at 16:51, Richard Shaw wrote: > On Wed, Apr 22, 2020 at 9:28 AM Artur Iwicki <s...@fedoraproject.org> wrote: > > > Regarding x86_64 and AVX2, last year we had a very heated discussion about > > this on the mailing list. > > > > > > https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/MPFXH4Y5LDC5L2VXWKUHAX3WAKBQXR4U/#MPFXH4Y5LDC5L2VXWKUHAX3WAKBQXR4U > > > > tl;dr: there was a proposal to make "x86_64" in Fedora mean "must support > > at least AVX2" and it met with a lot of backlash. > > > > Now that you mention it that does tickle some brain cells... > > So it seems what's really needed is a method to support software with > optimizations above the baseline without leaving other people behind. > > The only way I can think of to do that that would be to have optional > "enhanced" repos available that people can enable if their system supports > it. The hard part would be keeping it in sync with the main repo. It would > have to be a parallel build process and similar to the current process if > one fails the build is a NOGO across the board. > > Could we treat them like arches? > Something like: > X86_64 & X86_64-AVX2
If upstream doesn't support runtime selection of SIMD-optimized code paths based on CPU capabilities, you can build several versions and have glibc handle that by putting each version in a special subdirectory of /usr/lib64, e.g.: /usr/lib64/haswell /usr/lib64/haswell/avx512_1/ See https://clearlinux.org/news-blogs/transparent-use-library-packages-optimized-intel-architecture for some details. > armv7hf & armv7fh-NEON There already is armv7hnl (=ARMv7 with NEON) and RPM Fusion makes use of it, for example. Fedora builders don't support this as far as I know. Hope that helps. Regards, Dominik -- Fedora https://getfedora.org | RPM Fusion http://rpmfusion.org There should be a science of discontent. People need hard times and oppression to develop psychic muscles. -- from "Collected Sayings of Muad'Dib" by the Princess Irulan _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
