On Thu, Jan 5, 2012 at 12:45 AM, Eric Anholt <e...@anholt.net> wrote: > On Wed, 04 Jan 2012 03:28:12 -0800, Kenneth Graunke <kenn...@whitecape.org> > wrote: >> On 01/03/2012 09:43 PM, Marek Olšák wrote: >> > This ProgramStringNotify call causes excessive shader recompilations >> > in the game Cogs (from some Humble Bundle). Approximately 25% of >> > in-game CPU time is spent on translating shaders and register >> > allocation. If the shaders were larger, it would be much worse. >> > Moreover, I have realized calling ProgramStringNotify is not needed >> > for st/mesa in this case at all (I just comment it out if I want >> > higher frame rates), because it doesn't use the prog->SamplerUnits >> > array when translating shaders. The array is only used when we set >> > samplers, so setting _NEW_TEXTURE is sufficient. It seems that i965 >> > could do the same thing. Another option would be to cache precompiled >> > shaders, but that seems more complicated than doing what st/mesa does. >> > >> > Marek >> >> Yeah, I noticed that a while back too, but we never arrived at a >> solution and it slipped off my radar. I agree completely, >> ProgramStringNotify is completely overkill and bogus. >> >> We actually already rely on _NEW_TEXTURE for all shader programs. Since >> the uniform code already flags _NEW_TEXTURE, we should be able to just >> add the SamplerUnits array to the program key (specifically, >> brw_sampler_prog_key_data), and that should take care of any state >> dependent recompiles. Then we wouldn't need ProgramStringNotify at all. >> >> Right? > > Well, since the data stored is part of the program, and when just > changing programs _NEW_TEXTURE wouldn't get set, I think _NEW_PROGRAM is > the flag you mean. That would make a ton of sense to me -- if you > depend on SamplerUnits for your program handling, go look at it when > _NEW_PROGRAM is flagged.
I don't think this is about what makes sense in theory, but how each driver handles SamplerUnits. st/mesa just rebinds textures, so it expects _NEW_TEXTURE. i965 recompiles the fragment program, so it expects _NEW_PROGRAM. The worst option would be to set both, but at the same time it's the only option which would work for everybody now. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
