[Mesa-dev] [PATCH 1/6] i965/fs: Log a performance warning if skipping 16-wide due to pulls.

[Matt Turner]

On Mon, Aug 5, 2013 at 6:28 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> Usually, the driver creates both 8-wide and 16-wide variants of every
> fragment shader.  When 16-wide compilation fails, it logs a performance
> warning explaining why only an 8-wide program exists.
>
> However, when there are pull parameters, the driver won't even bother
> trying the 16-wide compile (since it would fail).  In this case, it
> failed to emit a performance warning, leaving no explanation for the
> missing 16-wide program.
>
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/mesa/drivers/dri/i965/brw_fs.cpp | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
> index a81e97f..a953310 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> @@ -3058,14 +3058,18 @@ brw_wm_fs_emit(struct brw_context *brw, struct brw_wm_compile *c,
>
>     exec_list *simd16_instructions = NULL;
>     fs_visitor v2(brw, c, prog, fp, 16);
> -   bool no16 = INTEL_DEBUG & DEBUG_NO16;
> -   if (brw->gen >= 5 && c->prog_data.nr_pull_params == 0 && likely(!no16)) {
> -      v2.import_uniforms(&v);
> -      if (!v2.run()) {
> -         perf_debug("16-wide shader failed to compile, falling back to "
> -                    "8-wide at a 10-20%% performance cost: %s", v2.fail_msg);
> +   if (brw->gen >= 5 && likely(!(INTEL_DEBUG & DEBUG_NO16))) {
> +      if (c->prog_data.nr_pull_params == 0) {
> +         /* Try a 16-wide compile */
> +         v2.import_uniforms(&v);
> +         if (!v2.run()) {
> +            perf_debug("16-wide shader failed to compile, falling back to "
> +                       "8-wide at a 10-20%% performance cost: %s", v2.fail_msg);
> +         } else {
> +            simd16_instructions = &v2.instructions;
> +         }
>        } else {
> -         simd16_instructions = &v2.instructions;
> +         perf_debug("Skipping 16-wide due to pull parameters.\n");
>        }
>     }
>
> --
> 1.8.3.4

Series is
Reviewed-by: Matt Turner <mattst88 at gmail.com>