[Mesa-dev] [PATCH 0/9] Skip automatic execsize for instructions with a width of 4

[Iago Toral]

On Tue, 2016-03-15 at 11:04 +0200, Pohjolainen, Topi wrote:
> On Tue, Mar 15, 2016 at 07:44:43AM +0100, Iago Toral wrote:
> > On Mon, 2016-03-14 at 11:15 -0700, Mark Janes wrote:
> > > Iago Toral <itoral at igalia.com> writes:
> > > 
> > > > On Wed, 2016-03-09 at 09:54 +0200, Pohjolainen, Topi wrote:
> > > >> On Mon, Mar 07, 2016 at 10:48:49AM +0100, Samuel Iglesias Gons?lvez wrote:
> > > >> > Hello,
> > > >> > 
> > > >> > There is only one patch from this series that has been reviewed (patch
> > > >> > 1).
> > > >> > 
> > > >> > Our plans is to start sending patches for adding fp64 support to i965
> > > >> > driver in the coming weeks but they depend on these patches.
> > > >> > 
> > > >> > Can someone take a look at them? ;)
> > > >> > 
> > > >> > Sam
> > > >> > 
> > > >> > 
> > > >> > On Thu, 2015-12-17 at 14:44 +0100, Samuel Iglesias Gonsálvez wrote:
> > > >> > > Hello,
> > > >> > > 
> > > >> > > This patch series is a updated version of the one Iago sent last
> > > >> > > week [0] that includes patches for gen6 too, as suggested by Jason.
> > > >> > > 
> > > >> > > We checked the gen9 code paths that work with a horizontal width of 4
> > > >> > > and we think there won't be any regression on gen9... but we don't
> > > >> > > have any gen9 machine to run piglit with these patches. Can someone
> > > >> > > check it?
> > > >> 
> > > >> I rebased it and ran it through the test system, gen9 seems to be fine, I
> > > >> only got one regression, and that was on old g965:
> > > >> 
> > > >> /tmp/build_root/m64/lib/piglit/bin/ext_framebuffer_multisample-accuracy all_samples srgb depthstencil -auto -fbo
> > > >> Pixels that should be unlit
> > > >>   count = 236444
> > > >>   RMS error = 0.025355
> > > >> Pixels that should be totally lit
> > > >>   count = 13308
> > > >>   Perfect output
> > > >> The error threshold for unlit and totally lit pixels test is 0.016650
> > > >> Pixels that should be partially lit
> > > >>   count = 12392
> > > >>   RMS error = 0.273876
> > > >> The error threshold for partially lit pixels is 0.333000
> > > >> Samples = 0, Result = fail
> > > >
> > > > I managed to borrow gen4 hardware to test this. According to glxinfo:
> > > > Mesa DRI Mobile Intel GM45 Express Chipset
> > > >
> > > > but it does not fail for me... never. I left this test running in a loop
> > > > for 5 minutes and it never failed. Also, looking at the problem
> > > > described in the output you pasted above, it seems that the problem was
> > > > related to precision calculations and it looks rather odd that our
> > > > execsize patches could've compromised the precision of anything...
> > > >
> > > > Mark, would it be possible for you or someone else to run the piglit
> > > > test mentioned by Topi above on gen4 hardware against this Mesa branch?:
> > > > https://github.com/Igalia/mesa/tree/i965-fix-execsize
> > > 
> > > I ran this branch through our CI, and it passed all tests.  My
> > > recollection is that ext_framebuffer_multisample-accuracy occasionally
> > > fails on g965.  I would not attribute any failure of that test to this
> > > branch.
> > 
> > Great, thanks Matt!
> > 
> > Topi: in that case I guess we can say there are no regressions in any
> > gen, right? Do you have any other comments to the branch? We have merged
> > the comments you made so far in case you want to double-check that we
> > did not miss anything.
> 
> Right. We identified two piglit failures, one on hsw and this one on g965.
> The former is intermittent and reproducible with current mesa master. Now
> that we have answer for the latter also, I concur, your series should be
> regression free.
> 
> I can take a look if you have a branch somewhere. I only had a few minor
> comments in the first place and the series looks good to me. But I'll double
> check.

Thanks! You can see the updated patches in this branch:
https://github.com/Igalia/mesa/tree/i965-fix-execsize

Iago