On Mon, Jun 15, 2009 at 6:01 PM, Bill Nottingham<notting@xxxxxxxxxx> wrote: > Gregory Maxwell (gmaxwell@xxxxxxxxx) said: >> I doubt having consistently lower FP precision is anything many users >> are asking for. The few that do can usually take care of themselves. > > And yet you say we should push them all to x86_64, which has > the same lower precision? You misunderstand me. I don't think people care. Code that depends on the order of FPU register spills on it is broken. I'm saying it's not a feature. It's neutral. Or nearly so. >> > - More clearly delineates our support set of targets, sticking true >> > to forwards innovation, not necessarily legacy support >> >> If thats the case why maintain x86 at all? > > Because it's 58% of our userbase (source: F11 torrent stats.) The relevant break down is what percentage is x86 no sse2 vs x86 no x86_64 vs x86 w/ x86_64. >> Take your answer and now apply it to why fedora should maintain >> support for x86 CPUs without SSE2. > > Because that's significantly less of our userbase. I'd love to have > harder numbers, but we're still talking about a set of CPUs that > (outside of corner cases like the Geode and C3) ceased production > anywhere from 4 (Athlon) to 6 (P3) to 10 (P2) years ago. 'outside'. Please don't just dismiss these recent systems, they are a real issue. I have low power x86 which I purchased *recently* (geode box for audio conferencing, this year; and a via box from ~two years ago) without SSE2. Most of my systems are x86_64, but what is x86 is not sse capable. Anything of mine that needed performance became x86_64 a long time ago. On Mon, Jun 15, 2009 at 6:04 PM, Bill Nottingham<notting@xxxxxxxxxx> wrote: >> It would probably be most interesting to perform that test on the >> x86-only ATOM, since I can see CMOV being a bigger win on an in-order >> CPU. >> (I can't personally protest: I think all the x86 stuff I have has CMOV). > Last time I profiled it (using the bits of openbench that actually worked), > i586 -> i686 was an improvement of 1% (Core2Duo) to 2% (Atom). Athlon64 was > essentially equal. > SPECCPU results showed similar. That sounds about right to me. -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
