On Wed, Feb 13, 2019 at 12:47 PM Elie Tournier <tournier.e...@gmail.com> wrote: > > On Fri, Jan 25, 2019 at 11:52:56AM -0800, Stéphane Marchesin 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 :) > > > > > > > > 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. > > I spent a bit of time on the project recently. > My thinking so far: > * FP64 is bad . But everyone knows that. :) > * Using the current soft fp64 require to emulate int64. > * Soft fp64 and int64 involve function call which is, iiuc, not really > supported in TGSI. > * Soft fp64 is tied to NIR. Some pass/hack need to be port to GLSLIR. > > So the project will require a lot of work.
But what's the alternative? Let's say you make a spec to expose "proper" fp64 in GLES. No one outside mesa will implement this (why bother). Certainly not the Adreno/Mali proprietary stacks of the world. And if you are on a stack that implements this in GLES, you might as well be using desktop GL anyways... So going back to the original -- what use-case are you trying to cover that's not already covered some other way? -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
