[Mesa-dev] [PATCH 1/7] blorp: Handle the RGB workaround more like other workarounds

Jason Ekstrand jason at jlekstrand.net
Thu Jan 26 06:51:53 UTC 2017


On Wed, Jan 25, 2017 at 10:46 PM, Pohjolainen, Topi <
topi.pohjolainen at gmail.com> wrote:

> On Tue, Jan 24, 2017 at 03:45:48PM -0800, Jason Ekstrand wrote:
> > The previous version was sort-of strapped on in that it just adjusted
> > the blit rectangle and trusted in the fact that we would use texelFetch
> > and round to the nearest integer to ensure that the component positions
> > matched.  This new version, while slightly more complicated, is more
> > accurate because all three components end up with exactly the same
> > dst_pos and so they will get interpolated and sampled at the same
> > texture coordinate.  This makes the workaround suitable for using with
> > scaled blits.
> > ---
> >  src/intel/blorp/blorp_blit.c | 60 ++++++++++++++++++++++--------
> --------------
> >  1 file changed, 30 insertions(+), 30 deletions(-)
> >
> > diff --git a/src/intel/blorp/blorp_blit.c b/src/intel/blorp/blorp_blit.c
> > index 111f1c1..fc76fd4 100644
> > --- a/src/intel/blorp/blorp_blit.c
> > +++ b/src/intel/blorp/blorp_blit.c
> > @@ -1138,6 +1138,20 @@ brw_blorp_build_nir_shader(struct blorp_context
> *blorp, void *mem_ctx,
> >                                        key->dst_layout);
> >     }
> >
> > +   nir_ssa_def *comp = NULL;
> > +   if (key->dst_rgb) {
> > +      /* The destination image is bound as a red texture three times as
> wide
> > +       * as the actual image.  Our shader is effectively running one
> color
> > +       * component at a time.  We need to save off the component and
> adjust
> > +       * the destination position.
> > +       */
> > +      assert(dst_pos->num_components == 2);
> > +      nir_ssa_def *dst_x = nir_channel(&b, dst_pos, 0);
> > +      comp = nir_umod(&b, dst_x, nir_imm_int(&b, 3));
> > +      dst_pos = nir_vec2(&b, nir_idiv(&b, dst_x, nir_imm_int(&b, 3)),
> > +                             nir_channel(&b, dst_pos, 1));
>
> Just to check that I understood correctly, before we had this scale-factor
> of
> three in v_coord_transform. Now we have it here explicitly?
>

Yes, that's correct.


> > +   }
> > +
> >     /* Now (X, Y, S) = decode_msaa(dst_samples, detile(dst_tiling,
> offset)).
> >      *
> >      * That is: X, Y and S now contain the true coordinates and sample
> index of
> > @@ -1267,8 +1281,6 @@ brw_blorp_build_nir_shader(struct blorp_context
> *blorp, void *mem_ctx,
> >         * from the source color and write that to destination red.
> >         */
> >        assert(dst_pos->num_components == 2);
> > -      nir_ssa_def *comp =
> > -         nir_umod(&b, nir_channel(&b, dst_pos, 0), nir_imm_int(&b, 3));
> >
> >        nir_ssa_def *color_component =
> >           nir_bcsel(&b, nir_ieq(&b, comp, nir_imm_int(&b, 0)),
> > @@ -1543,15 +1555,12 @@ struct blt_coords {
> >
> >  static void
> >  surf_fake_rgb_with_red(const struct isl_device *isl_dev,
> > -                       struct brw_blorp_surface_info *info,
> > -                       uint32_t *x, uint32_t *width)
> > +                       struct brw_blorp_surface_info *info)
> >  {
> >     surf_convert_to_single_slice(isl_dev, info);
> >
> >     info->surf.logical_level0_px.width *= 3;
> >     info->surf.phys_level0_sa.width *= 3;
> > -   *x *= 3;
> > -   *width *= 3;
> >
> >     enum isl_format red_format;
> >     switch (info->view.format) {
> > @@ -1581,28 +1590,6 @@ surf_fake_rgb_with_red(const struct isl_device
> *isl_dev,
> >     info->surf.format = info->view.format = red_format;
> >  }
> >
> > -static void
> > -fake_dest_rgb_with_red(const struct isl_device *dev,
> > -                       struct blorp_params *params,
> > -                       struct brw_blorp_blit_prog_key *wm_prog_key,
> > -                       struct blt_coords *coords)
> > -{
> > -   /* Handle RGB destinations for blorp_copy */
> > -   const struct isl_format_layout *dst_fmtl =
> > -      isl_format_get_layout(params->dst.surf.format);
> > -
> > -   if (dst_fmtl->bpb % 3 == 0) {
> > -      uint32_t dst_x = coords->x.dst0;
> > -      uint32_t dst_width = coords->x.dst1 - dst_x;
> > -      surf_fake_rgb_with_red(dev, &params->dst,
> > -                             &dst_x, &dst_width);
> > -      coords->x.dst0 = dst_x;
> > -      coords->x.dst1 = dst_x + dst_width;
> > -      wm_prog_key->dst_rgb = true;
> > -      wm_prog_key->need_dst_offset = true;
> > -   }
> > -}
> > -
> >  enum blit_shrink_status {
> >     BLIT_NO_SHRINK = 0,
> >     BLIT_WIDTH_SHRINK = 1,
> > @@ -1621,8 +1608,6 @@ try_blorp_blit(struct blorp_batch *batch,
> >  {
> >     const struct gen_device_info *devinfo = batch->blorp->isl_dev->info;
> >
> > -   fake_dest_rgb_with_red(batch->blorp->isl_dev, params, wm_prog_key,
> coords);
> > -
> >     if (isl_format_has_sint_channel(params->src.view.format)) {
> >        wm_prog_key->texture_data_type = nir_type_int;
> >     } else if (isl_format_has_uint_channel(params->src.view.format)) {
> > @@ -1799,6 +1784,21 @@ try_blorp_blit(struct blorp_batch *batch,
> >
> >     params->num_samples = params->dst.surf.samples;
> >
> > +   if (isl_format_get_layout(params->dst.view.format)->bpb % 3 == 0) {
> > +      /* We can't render to  RGB formats natively because they aren't a
> > +       * power-of-two size.  Instead, we fake them by using a red format
> > +       * with the same channel type and size and emitting shader code to
> > +       * only write one channel at a time.
> > +       */
> > +      params->x0 *= 3;
> > +      params->x1 *= 3;
>
> It looks to me that we stop adjusting v_discard_rect as well. Before it
> was calculated against adjusted coords. Now we only adjust the vertices.
> This means blorp_nir_discard_if_outside_rect() isn't used for the
> rgb-trick -
> otherwise it would clip too much in the right hand side. Or am I missing
> something? If not, can we add?
>

Yes, that's correct.


>          assert(!wm_prog_key->use_kill);
>

i don't really see why it's needed but I'm happy to add it.


> > +
> > +      surf_fake_rgb_with_red(batch->blorp->isl_dev, &params->dst);
> > +
> > +      wm_prog_key->dst_rgb = true;
> > +      wm_prog_key->need_dst_offset = true;
> > +   }
> > +
> >     if (params->src.tile_x_sa || params->src.tile_y_sa) {
> >        assert(wm_prog_key->need_src_offset);
> >        surf_get_intratile_offset_px(&params->src,
> > --
> > 2.5.0.400.gff86faf
> >
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
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