[Mesa-dev] [PATCH 1/3 v2] r600g: skip repeating vs, gs, and tes shader binds

[Marek Olšák]

On Sun, Apr 9, 2017 at 11:09 PM, Constantine Kharlamov
<Hi-Angel at yandex.ru> wrote:
> The idea is taken from radeonsi. The code lacks some checks for null vs,
> and I'm unsure about some changes against that, so I left it in place.
>
> Some statistics for GTAⅣ:
> Average tesselation bind skip per frame: ≈350
> Average geometric shaders bind skip per frame: ≈260
> Skip of binding vertex ones occurs rarely enough to not get into per-frame
> counter at all, so I just gonna say: it happens.
>
> v2: I've occasionally removed an empty line, don't do this.
>
> Signed-off-by: Constantine Kharlamov <Hi-Angel at yandex.ru>
> ---
>  src/gallium/drivers/r600/r600_state_common.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/src/gallium/drivers/r600/r600_state_common.c b/src/gallium/drivers/r600/r600_state_common.c
> index 4de2a7344b..94f85e6dd3 100644
> --- a/src/gallium/drivers/r600/r600_state_common.c
> +++ b/src/gallium/drivers/r600/r600_state_common.c
> @@ -931,7 +931,7 @@ static void r600_bind_vs_state(struct pipe_context *ctx, void *state)
>  {
>         struct r600_context *rctx = (struct r600_context *)ctx;
>
> -       if (!state)
> +       if (!state || rctx->vs_shader == state)
>                 return;
>
>         rctx->vs_shader = (struct r600_pipe_shader_selector *)state;
> @@ -943,11 +943,12 @@ static void r600_bind_gs_state(struct pipe_context *ctx, void *state)
>  {
>         struct r600_context *rctx = (struct r600_context *)ctx;
>
> +       if (state == rctx->gs_shader)
> +               return;
> +
>         rctx->gs_shader = (struct r600_pipe_shader_selector *)state;
>         r600_update_vs_writes_viewport_index(&rctx->b, r600_get_vs_info(rctx));
>
> -       if (!state)
> -               return;
>         rctx->b.streamout.stride_in_dw = rctx->gs_shader->so.stride;

This will crash if states == NULL.

>  }
>
> @@ -962,11 +963,12 @@ static void r600_bind_tes_state(struct pipe_context *ctx, void *state)
>  {
>         struct r600_context *rctx = (struct r600_context *)ctx;
>
> +       if (state == rctx->tes_shader)
> +               return;
> +
>         rctx->tes_shader = (struct r600_pipe_shader_selector *)state;
>         r600_update_vs_writes_viewport_index(&rctx->b, r600_get_vs_info(rctx));
>
> -       if (!state)
> -               return;
>         rctx->b.streamout.stride_in_dw = rctx->tes_shader->so.stride;

Same here.

Marek