[Mesa-dev] [PATCH 1/4] radv: move emitting VGT_GS_MODE into the HW VS path

[Bas Nieuwenhuizen]

On Thu, Jul 18, 2019 at 2:05 AM Bas Nieuwenhuizen
<bas at basnieuwenhuizen.nl> wrote:
>
> On Wed, Jul 17, 2019 at 3:44 PM Samuel Pitoiset
> <samuel.pitoiset at gmail.com> wrote:
> >
> > It's useless for NGG anyways.
> >
> > Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> > ---
> >  src/amd/vulkan/radv_pipeline.c | 43 ++++++++++++++++++++++++++--------
> >  1 file changed, 33 insertions(+), 10 deletions(-)
> >
> > diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
> > index fdeb31c453e..686fd371f0f 100644
> > --- a/src/amd/vulkan/radv_pipeline.c
> > +++ b/src/amd/vulkan/radv_pipeline.c
> > @@ -3272,27 +3272,18 @@ radv_pipeline_generate_vgt_gs_mode(struct radeon_cmdbuf *ctx_cs,
>
> Can you rename the function?

Actually now that I see your later patches, how about we keep this
function, return immediately if ngg, and then move the primitive id
stuff for ngg to ngg?


>
>
> >                 pipeline->shaders[MESA_SHADER_TESS_EVAL] :
> >                 pipeline->shaders[MESA_SHADER_VERTEX];
> >         unsigned vgt_primitiveid_en = 0;
> > -       uint32_t vgt_gs_mode = 0;
> >
> > -       if (radv_pipeline_has_gs(pipeline)) {
> > -               const struct radv_shader_variant *gs =
> > -                       pipeline->shaders[MESA_SHADER_GEOMETRY];
> > -
> > -               vgt_gs_mode = ac_vgt_gs_mode(gs->info.gs.vertices_out,
> > -                                            pipeline->device->physical_device->rad_info.chip_class);
> > -       } else if (radv_pipeline_has_ngg(pipeline)) {
> > +       if (radv_pipeline_has_ngg(pipeline)) {
> >                 bool enable_prim_id =
> >                         outinfo->export_prim_id || vs->info.info.uses_prim_id;
> >
> >                 vgt_primitiveid_en |= S_028A84_PRIMITIVEID_EN(enable_prim_id) |
> >                                       S_028A84_NGG_DISABLE_PROVOK_REUSE(enable_prim_id);
> >         } else if (outinfo->export_prim_id || vs->info.info.uses_prim_id) {
> > -               vgt_gs_mode = S_028A40_MODE(V_028A40_GS_SCENARIO_A);
> >                 vgt_primitiveid_en |= S_028A84_PRIMITIVEID_EN(1);
> >         }
> >
> >         radeon_set_context_reg(ctx_cs, R_028A84_VGT_PRIMITIVEID_EN, vgt_primitiveid_en);
> > -       radeon_set_context_reg(ctx_cs, R_028A40_VGT_GS_MODE, vgt_gs_mode);
> >  }
> >
> >  static void
> > @@ -3370,6 +3361,38 @@ radv_pipeline_generate_hw_vs(struct radeon_cmdbuf *ctx_cs,
> >                                cull_dist_mask << 8 |
> >                                clip_dist_mask);
> >
> > +       /* We always write VGT_GS_MODE in the VS state, because every switch
> > +        * between different shader pipelines involving a different GS or no GS
> > +        * at all involves a switch of the VS (different GS use different copy
> > +        * shaders). On the other hand, when the API switches from a GS to no
> > +        * GS and then back to the same GS used originally, the GS state is not
> > +        * sent again.
> > +        */
> > +       unsigned vgt_gs_mode;
> > +       if (!radv_pipeline_has_gs(pipeline)) {
> > +               const struct radv_vs_output_info *outinfo =
> > +                       get_vs_output_info(pipeline);
> > +               const struct radv_shader_variant *vs =
> > +                       pipeline->shaders[MESA_SHADER_TESS_EVAL] ?
> > +                       pipeline->shaders[MESA_SHADER_TESS_EVAL] :
> > +                       pipeline->shaders[MESA_SHADER_VERTEX];
> > +               unsigned mode = V_028A40_GS_OFF;
> > +
> > +               /* PrimID needs GS scenario A. */
> > +               if (outinfo->export_prim_id || vs->info.info.uses_prim_id)
> > +                       mode = V_028A40_GS_SCENARIO_A;
> > +
> > +               vgt_gs_mode = S_028A40_MODE(mode);
> > +       } else {
> > +               const struct radv_shader_variant *gs =
> > +                       pipeline->shaders[MESA_SHADER_GEOMETRY];
> > +
> > +               vgt_gs_mode = ac_vgt_gs_mode(gs->info.gs.vertices_out,
> > +                                            pipeline->device->physical_device->rad_info.chip_class);
> > +       }
> > +
> > +       radeon_set_context_reg(ctx_cs, R_028A40_VGT_GS_MODE, vgt_gs_mode);
> > +
>
> Can you keep this in a separate function (possibly with the name
> radv_pipeline_generate_vgt_gs_mode)?
> >         if (pipeline->device->physical_device->rad_info.chip_class <= GFX8)
> >                 radeon_set_context_reg(ctx_cs, R_028AB4_VGT_REUSE_OFF,
> >                                        outinfo->writes_viewport_index);
> > --
> > 2.22.0
> >
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