fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-27 12:40:09 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

broadcom/compiler: clarify PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR setting

Browse source 
We enabled this in the past to fix some register allocation issues we
faced with geometry shaders but we didn't document why it is safe for
us to do this, which is not immediately obvious.

Reviewed-by: Juan A. Suarez <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10745>
This commit is contained in:
Iago Toral Quiroga 2021-05-11 11:59:56 +02:00
parent 370495abd1
commit 6f93354bae
2 changed files with 19 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
src/broadcom/compiler/nir_to_vir.c
View file

@ -2359,8 +2359,16 @@ ntq_emit_load_uniform(struct v3d_compile *c, nir_intrinsic_instr *instr)
static void
ntq_emit_load_input(struct v3d_compile *c, nir_intrinsic_instr *instr)
{
/* XXX: Use ldvpmv (uniform offset) or ldvpmd (non-uniform offset)
* and enable PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR.
/* XXX: Use ldvpmv (uniform offset) or ldvpmd (non-uniform offset).
*
* Right now the driver sets PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR even
* if we don't support non-uniform offsets because we also set the
* lower_all_io_to_temps option in the NIR compiler. This ensures that
* any indirect indexing on in/out variables is turned into indirect
* indexing on temporary variables instead, that we handle by lowering
* to scratch. If we implement non-uniform offset here we might be able
* to avoid the temp and scratch lowering, which involves copying from
* the input to the temp variable, possibly making code more optimal.
*/
unsigned offset =
nir_intrinsic_base(instr) + nir_src_as_uint(instr->src[0]);

9
src/gallium/drivers/v3d/v3d_screen.c
View file

@ -368,6 +368,15 @@ v3d_screen_get_shader_param(struct pipe_screen *pscreen, unsigned shader,
case PIPE_SHADER_CAP_TGSI_CONT_SUPPORTED:
return 0;
case PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR:
/* We don't currently support this in the backend, but that is
* okay because our NIR compiler sets the option
* lower_all_io_to_temps, which will eliminate indirect
* indexing on all input/output variables by translating it to
* indirect indexing on temporary variables instead, which we
* will then lower to scratch. We prefer this over setting this
* to 0, which would cause if-ladder injection to eliminate
* indirect indexing on inputs.
*/
return 1;
case PIPE_SHADER_CAP_INDIRECT_OUTPUT_ADDR:
return 1;