The other question is does anyone test ubuntu on non SSE2 hardware anymore?
On Sun, May 13, 2018 at 11:48 AM, Henri Sivonen <hsivo...@hsivonen.fi> wrote: > On Sun, May 13, 2018 at 9:34 PM, Matthias Klose <d...@ubuntu.com> wrote: > > On 13.05.2018 05:00, Henri Sivonen wrote: > >> On Thu, May 10, 2018 at 11:25 PM, Thomas Ward <tew...@thomas-ward.net> > wrote: > >>> However, killing i386 support globally could introduce issues, > including > >>> but not limited to certain upstream softwares having to go away > >>> entirely, due to the interdependency or issues with how certain apps > >>> work (read; Wine, 32-bit support, 64-bit support being flaky, and > >>> Windows apps being general pains in that they work on 32bit but not > >>> always on 64-bit). > >> > >> If 32-bit x86 support becomes mainly a thing that's run on x86_64 > >> hardware as a compatibility measure for things like Wine, it would > >> make sense to bring the instruction set baseline to the x86_64 level. > >> Specifically, it would make sense to compile the 32-bit x86 packages > >> with SSE2 unconditionally enabled. > >> > >> This would mean dropping support for Pentium Pro and earlier or Athlon > >> XP and earlier, but it's pretty sad to leave all that performance on > >> the table in order to support the few computers still in use that have > >> Pentium Pro or earlier or Athlon XP or earlier. > >> > >> As upstream software assumes SSE2 as the baseline, it will be less and > >> less a run-time check and compiling software without SSE2 will mean > >> shipping it in a damaged form performance-wise. > > > > I disagree, until you provide data how many packages fail to build, at > least in > > the testsuites, when run without the extra x87 precision bits. > > I don't have this data, but considering that SSE2 is a mandatory part > of x86_64, it seems implausible that packages would be > SSE2-intolerant. Considering that x86_64 defaults to SSE2 > floating-point math (or does Ubuntu override this?) and considering > that ARM doesn't have x87 available, it seems implausible that > packages would rely on x87. (On the contrary, since e.g. Firefox and > Chromium upstreams don't do non-SSE2 x86 builds anymore, it seems more > plausible that there exist packages whose upstream doesn't test x87 > floating-point math anymore.) > > -- > Henri Sivonen > hsivo...@hsivonen.fi > https://hsivonen.fi/ > > -- > Ubuntu-devel-discuss mailing list > Ubuntu-devel-discuss@lists.ubuntu.com > Modify settings or unsubscribe at: https://lists.ubuntu.com/ > mailman/listinfo/ubuntu-devel-discuss >
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