[Mesa-dev] [PATCH 3/3] anv: Enable MSAA compression

[Chad Versace]

On Wed 22 Feb 2017, Jason Ekstrand wrote:
> On Wed, Feb 22, 2017 at 11:09 AM, Chad Versace <chadversary at chromium.org>
> wrote:
> 
> > On Mon 20 Feb 2017, Jason Ekstrand wrote:
> > > This just enables basic MSAA compression (no fast clears) for all
> > > multisampled surfaces.  This improves the framerate of the Sascha
> > > "multisampling" demo by 76% on my Sky Lake laptop.  Running Talos on
> > > medium settings with 8x MSAA, this improves the framerate in the
> > > benchmark by 80%.
> > > ---
> > >  src/intel/vulkan/TODO              |  2 +-
> > >  src/intel/vulkan/anv_blorp.c       |  3 ++-
> > >  src/intel/vulkan/anv_image.c       |  9 +++++++++
> > >  src/intel/vulkan/anv_pipeline.c    | 19 +++++++++++++++++++
> > >  src/intel/vulkan/genX_cmd_buffer.c |  5 +++++
> > >  5 files changed, 36 insertions(+), 2 deletions(-)
> >
> >
> > > diff --git a/src/intel/vulkan/genX_cmd_buffer.c
> > b/src/intel/vulkan/genX_cmd_buffer.c
> > > index 40a72f4..5d8c3ea 100644
> > > --- a/src/intel/vulkan/genX_cmd_buffer.c
> > > +++ b/src/intel/vulkan/genX_cmd_buffer.c
> > > @@ -222,6 +222,11 @@ color_attachment_compute_aux_usage(struct
> > anv_device *device,
> > >        att_state->input_aux_usage = ISL_AUX_USAGE_NONE;
> > >        att_state->fast_clear = false;
> > >        return;
> > > +   } else if (iview->image->aux_usage == ISL_AUX_USAGE_MCS) {
> > > +      att_state->aux_usage = ISL_AUX_USAGE_MCS;
> > > +      att_state->input_aux_usage = ISL_AUX_USAGE_MCS;
> > > +      att_state->fast_clear = false;
> > > +      return;
> > >     }
> >
> > Small nit. It feels awkward that this function, above the hunk, checks
> > iview->image->aux_surface.isl.size == 0, then the next branch checks
> > iview->image->aux_usage. It seems more natural to check aux_usage in
> > both branches.
> >
> 
> Not so much... aux_surface.isl.size == 0 implies aux_usage == NONE but not
> the other way around.  For gen7 fast clears, for instance, you get NONE in
> aux_usage because that's the way we use it for texturing.

Ok. That makes sense.