On Fri, Jan 25, 2019 at 02:15:25PM -0600, Jason Ekstrand wrote: > On Fri, Jan 25, 2019 at 1:53 PM Stéphane Marchesin < > stephane.marche...@gmail.com> wrote: > > > On Fri, Jan 25, 2019 at 2:25 AM Gert Wollny <gw.foss...@gmail.com> wrote: > > > > > > Am Donnerstag, den 24.01.2019, 22:25 -0800 schrieb Stéphane Marchesin: > > > > > > > > Yes, it's for running virgl on top of GLES. To emulate fp64 in GL on > > > > the guest side, we need fp64 on the host... > > > > > > BTW: we could also get it emulated from the guest side. When Elie (in > > > CC) initially proposed the fp64 emulation series it was for r600 and > > > TGSI was emitted. The created shaders are horribly long and it is > > > certainly not performant, but if it's just for getting OpenGL 4.0 > > > exposed it should be good enough. > > > > Yes, Ilia suggested this on IRC yesterday. My impression is that not > > many applications/games need high performance fp64 (it's likely mostly > > compute stuff, which is not our target). I could be wrong though. If > > anyone knows differently, please tell us :) > > > > In our experience, we have yet to see an app actually use the extension. > If we do have such apps, it'd be better to do it in hardware when > available. However, if it's just so that you can claim support, maybe a > GLES extension isn't worth the bother? I don't have a particularly strong > opinion at the moment beyond "fp64 sounds like the most non-ES thing ever".
Out of curiousity, what did you want to put in that extension? > > > > > > > > I'm not sure though how much work it would be to add this to the soft > > > fp64 as it has now landed for NIR, though. > > > > Yes, with virgl not using NIR, I am not sure how much work soft fp64 > > will require. > > > > The core of the soft fp64 stuff is a library of GLSL functions which > actually implement it. We just compile them to NIR and then lower fp64 > math to function calls and inline. You could write a lowering pass in > GLSL, TGSI, or a back-end compiler based on those easily enough. I think the best option is to write a lowering pass in GLSL to be able to use some optimizations later on. I will see if I can come up with a proof-of-concept. > > --Jason > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
