Ühel kenal päeval, T, 02.08.2016 kell 15:25, kirjutas Michał Górny: > On Mon, 1 Aug 2016 17:15:41 -0400 > Mike Gilbert <flop...@gentoo.org> wrote: > > > On Mon, Aug 1, 2016 at 5:08 PM, David Seifert <s...@gentoo.org> > > wrote: > > > Dear friends, > > > while version bumping sci-libs/fftw, I've noticed our > > > CPU_FLAGS_X86 > > > list could be expanded a bit: > > > > > > avx512 - introduced with Skylake and Knights Landing > > > > According to Wikipedia, "AVX-512 consists of multiple extensions > > not > > all meant to be supported by all processors implementing them." > > > > https://en.wikipedia.org/wiki/AVX-512 > > > > https://en.wikipedia.org/wiki/CPUID#EAX.3D7.2C_ECX.3D0:_Extended_Fe > > atures > > Also https://bugs.gentoo.org/show_bug.cgi?id=588628.
Do we actually want to be fast in adding these things, or do we want to wait for any actual consumers to be possible to start consuming it right away? Like with all these different variants, will consumers actually group the variants in the same way and will we be able to map things cleanly in ebuilds in the future? Though I guess there are already potential consumers out there that people have already looked at and I've just not kept up with IRC or something :) Also, how are they exposed in cpuinfo, do we have first patches for cpuid2cpuflags? Since what kernel version are they exposed in cpuinfo, is it a flag for each CPUID capability? What variants do each CPU implementing any expose, maybe all CPUs doing e.g avx512f all also do avx512dq - perhaps all consumers would make such assumptions and assume things based on real world CPUs? Or maybe all consumers of some of the variants will always do runtime detection themselves and we won't even use that flag in an IUSE ever? tl;dr: Concerned about prematurely adding things without knowing of consumer examples Mart
