[Mesa-dev] [v2 3/7] i965/gen4: Remove redundant check for depth when rebasing stencil

[Jason Ekstrand]

On Thu, Jun 15, 2017 at 9:36 AM, Jason Ekstrand <jason at jlekstrand.net>
wrote:

> This patch makes the assumption that, if stencil_irb != NULL then
> depth_irb != NULL.  I did a bunch of digging and I am now convinced that
> this is a fine assumption.  Specifically, in intel_renderbuffer_format() in
> intel_fbo.c, we map all STENCIL_INDEX internal formats to Z24_UNORM_S8_UINT
> on gen4-5.
>

Except that patch 1 only makes a difference if (stencil_irb && !depth_irb)
can be true.  Now I'm very confused...


> On Mon, May 22, 2017 at 12:12 PM, Topi Pohjolainen <
> topi.pohjolainen at gmail.com> wrote:
>
>> In case of gen < 6 stencil (if present) is always combined with
>> depth. Both stencil and depth attachments point to the same
>> physical surface.
>> Alignment workaround starts by considering depth and updates
>> stencil accordingly. Current logic continues with stencil and
>> in vain considers the case where depth would refer to different
>> surface than stencil.
>>
>> Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
>> ---
>>  src/mesa/drivers/dri/i965/brw_misc_state.c | 63
>> ++++++------------------------
>>  1 file changed, 12 insertions(+), 51 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/brw_misc_state.c
>> b/src/mesa/drivers/dri/i965/brw_misc_state.c
>> index 6ea1fb0..9fe3655 100644
>> --- a/src/mesa/drivers/dri/i965/brw_misc_state.c
>> +++ b/src/mesa/drivers/dri/i965/brw_misc_state.c
>> @@ -295,28 +295,14 @@ brw_workaround_depthstencil_alignment(struct
>> brw_context *brw,
>>        }
>>
>>        if (stencil_irb) {
>> -         stencil_mt = get_stencil_miptree(stencil_irb);
>> -         intel_miptree_get_image_offset(stencil_mt,
>> -                                        stencil_irb->mt_level,
>> -                                        stencil_irb->mt_layer,
>> -                                        &stencil_draw_x,
>> &stencil_draw_y);
>> -         int stencil_tile_x = stencil_draw_x & tile_mask_x;
>> -         int stencil_tile_y = stencil_draw_y & tile_mask_y;
>> -
>> -         /* If stencil doesn't match depth, then we'll need to rebase
>> stencil
>> -          * as well.  (if we hadn't decided to rebase stencil before, the
>> -          * post-stencil depth test will also rebase depth to try to
>> match it
>> -          * up).
>> -          */
>> -         if (tile_x != stencil_tile_x ||
>> -             tile_y != stencil_tile_y) {
>> -            rebase_stencil = true;
>> -         }
>> +         assert(stencil_irb->mt == depth_irb->mt);
>> +         assert(stencil_irb->mt_level == depth_irb->mt_level);
>> +         assert(stencil_irb->mt_layer == depth_irb->mt_layer);
>>        }
>>     }
>>
>>     /* If we have (just) stencil, check it for ignored low bits as well */
>> -   if (stencil_irb) {
>> +   if (!depth_irb && stencil_irb) {
>>        intel_miptree_get_image_offset(stencil_mt,
>>                                       stencil_irb->mt_level,
>>                                       stencil_irb->mt_layer,
>> @@ -334,6 +320,14 @@ brw_workaround_depthstencil_alignment(struct
>> brw_context *brw,
>>     }
>>
>>     if (rebase_stencil) {
>> +      /* If stencil needs rebase, there isn't a depth attachment and the
>> +       * combined depth-stencil is used for stencil only. Otherwise in
>> case
>> +       * depth attachment is present both stencil and depth point to the
>> same
>> +       * miptree. Rebase of depth is considered first updating stencil
>> +       * attachment accordingly - hence stencil is rebased only if there
>> is no
>> +       * depth attachment.
>> +       */
>> +      assert(!depth_irb);
>>        perf_debug("HW workaround: blitting stencil level %d to a
>> temporary "
>>                   "to fix alignment (stencil tile offset %d,%d)\n",
>>                   stencil_irb->mt_level, stencil_tile_x, stencil_tile_y);
>> @@ -347,39 +341,6 @@ brw_workaround_depthstencil_alignment(struct
>> brw_context *brw,
>>                                       &stencil_draw_x, &stencil_draw_y);
>>        stencil_tile_x = stencil_draw_x & tile_mask_x;
>>        stencil_tile_y = stencil_draw_y & tile_mask_y;
>> -
>> -      if (depth_irb && depth_irb->mt == stencil_irb->mt) {
>> -         intel_miptree_reference(&depth_irb->mt, stencil_irb->mt);
>> -         intel_renderbuffer_set_draw_offset(depth_irb);
>> -      } else if (depth_irb && !rebase_depth) {
>> -         if (tile_x != stencil_tile_x ||
>> -             tile_y != stencil_tile_y) {
>> -            perf_debug("HW workaround: blitting depth level %d to a
>> temporary "
>> -                       "to match stencil level %d alignment (depth tile
>> offset "
>> -                       "%d,%d, stencil offset %d,%d)\n",
>> -                       depth_irb->mt_level,
>> -                       stencil_irb->mt_level,
>> -                       tile_x, tile_y,
>> -                       stencil_tile_x, stencil_tile_y);
>> -
>> -            intel_renderbuffer_move_to_temp(brw, depth_irb,
>> invalidate_depth);
>> -
>> -            tile_x = depth_irb->draw_x & tile_mask_x;
>> -            tile_y = depth_irb->draw_y & tile_mask_y;
>> -
>> -            if (stencil_irb && stencil_irb->mt == depth_mt) {
>> -               intel_miptree_reference(&stencil_irb->mt, depth_irb->mt);
>> -               intel_renderbuffer_set_draw_offset(stencil_irb);
>> -            }
>> -
>> -            WARN_ONCE(stencil_tile_x != tile_x ||
>> -                      stencil_tile_y != tile_y,
>> -                      "Rebased stencil tile offset (%d,%d) doesn't match
>> depth "
>> -                      "tile offset (%d,%d).\n",
>> -                      stencil_tile_x, stencil_tile_y,
>> -                      tile_x, tile_y);
>> -         }
>> -      }
>>     }
>>
>>     if (!depth_irb) {
>> --
>> 2.9.3
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20170615/5c350912/attachment.html>