On Thu, Nov 29, 2018 at 09:39:52PM +0000, Strasser, Kevin wrote: > Ville Syrjälä wrote: > > On Wed, Nov 28, 2018 at 10:38:10PM -0800, Kevin Strasser wrote: > >> This series defines new formats and adds a plane property to be used for > >> floating point framebuffer content. Implementation is then added to i915. > >> > >> I have shared an IGT branch which adds test coverage for the new formats: > >> https://github.com/strassek/xorg-intel-gpu-tools/tree/fp16 > > > > Looks about similar as what I had written. I wrote my half<->full > > conversion thing from scratch which probably means it has more rounding > > errors and whatnot. The speed of mine wasn't exactly stellar and looks > > like your version probably has the same issue. So I was actually > > thinking of using the sse<something> instructions meant for this > > could provide a nice speedup. I guess we might want the pure c version > > as a backup though. Hmm. Now I also seem to recall that I noticed > > there being a compiler intrinsic even for single value half<->full > > precision conversion. Did you look into using that (if I didn't imagine > > it)? > > You are thinking of vcvtps2ph and vcvtph2ps, I haven't yet had a chance to > give them a try, but I agree it seems like a good idea. > > > BTW I just rebased my fp16 for pre-icl platforms: > > git://github.com/vsyrjala/linux.git fp16_scanout_2 > > > > Apart from the ivb/hsw w/a there isn't all that much unexpected > > when it comes to fp16 on those platforms either. > > I don't mean to step on your toes with this series, were you waiting for / > working on a real usecase before pushing that code? I pretty much just did it so that I could test >10bpc gamma LUTs. But I got sidetracked by other things so I didn't really get even that far. Also another problem is that igt depends on cairo which didn't support rendering at >10bpc, so I couldn't really test that stuff properly even if I wanted to. Maarten has patches to wire up floats into cairo but I think he just said that it still kinda uses 8bpc precision only :( Anyways, the fact that you did icl and I did pre-icl is pretty good division of labour. Sometimes things work out by accident :) -- Ville Syrjälä Intel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
