[Mesa-dev] [PATCH 02/13] i965: Only call brw_upload_tcs/tes_prog when using tessellation.

[eocallaghan at alterapraxis.com]

On 2015-12-22 21:20, Kenneth Graunke wrote:
> If there's no evaluation shader, tessellation is disabled.  The upload
> functions would just bail.  Instead, don't bother calling them.
> 
> This will simplify the optional-TCS case a bit, as brw_upload_tcs can
> assume that we're doing tessellation.
> 
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/mesa/drivers/dri/i965/brw_state_upload.c | 11 +++++++++--
>  src/mesa/drivers/dri/i965/brw_tcs.c          | 17 ++++-------------
>  src/mesa/drivers/dri/i965/brw_tes.c          |  9 ---------
>  3 files changed, 13 insertions(+), 24 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_state_upload.c
> b/src/mesa/drivers/dri/i965/brw_state_upload.c
> index 56962d5..af9fb5b 100644
> --- a/src/mesa/drivers/dri/i965/brw_state_upload.c
> +++ b/src/mesa/drivers/dri/i965/brw_state_upload.c
> @@ -678,8 +678,15 @@ brw_upload_programs(struct brw_context *brw,
>  {
>     if (pipeline == BRW_RENDER_PIPELINE) {
>        brw_upload_vs_prog(brw);
> -      brw_upload_tcs_prog(brw);
> -      brw_upload_tes_prog(brw);
> +      if (brw->tess_eval_program) {
> +         brw_upload_tcs_prog(brw);
> +         brw_upload_tes_prog(brw);
> +      } else {
> +         brw->tcs.prog_data = NULL;
> +         brw->tcs.base.prog_data = NULL;
> +         brw->tes.prog_data = NULL;
> +         brw->tes.base.prog_data = NULL;
> +      }
> 
>        if (brw->gen < 6)
>           brw_upload_ff_gs_prog(brw);
> diff --git a/src/mesa/drivers/dri/i965/brw_tcs.c
> b/src/mesa/drivers/dri/i965/brw_tcs.c
> index b5eb4cd..037a2da 100644
> --- a/src/mesa/drivers/dri/i965/brw_tcs.c
> +++ b/src/mesa/drivers/dri/i965/brw_tcs.c
> @@ -187,6 +187,10 @@ brw_upload_tcs_prog(struct brw_context *brw)
>     /* BRW_NEW_TESS_CTRL_PROGRAM */
>     struct brw_tess_ctrl_program *tcp =
>        (struct brw_tess_ctrl_program *) brw->tess_ctrl_program;
> +   /* BRW_NEW_TESS_EVAL_PROGRAM */
> +   struct brw_tess_eval_program *tep =
> +      (struct brw_tess_eval_program *) brw->tess_eval_program;
> +   assert(tcp && tep);
> 
>     if (!brw_state_dirty(brw,
>                          _NEW_TEXTURE,
> @@ -195,15 +199,6 @@ brw_upload_tcs_prog(struct brw_context *brw)
>                          BRW_NEW_TESS_EVAL_PROGRAM))
>        return;
> 
> -   if (tcp == NULL) {
> -      /* Other state atoms had better not try to access prog_data, 
> since
> -       * there's no HS program.
> -       */
> -      brw->tcs.prog_data = NULL;
> -      brw->tcs.base.prog_data = NULL;
> -      return;
> -   }
> -
>     struct gl_program *prog = &tcp->program.Base;
> 
>     memset(&key, 0, sizeof(key));
> @@ -216,13 +211,9 @@ brw_upload_tcs_prog(struct brw_context *brw)
>     brw_populate_sampler_prog_key_data(ctx, prog, 
> stage_state->sampler_count,
>                                        &key.tex);
> 
> -   /* BRW_NEW_TESS_EVAL_PROGRAM */
>     /* We need to specialize our code generation for tessellation 
> levels
>      * based on the domain the DS is expecting to tessellate.
>      */
> -   struct brw_tess_eval_program *tep =
> -      (struct brw_tess_eval_program *) brw->tess_eval_program;
> -   assert(tep);
>     key.tes_primitive_mode = tep->program.PrimitiveMode;

Does this compile? You've killed off *tep yet we still dereference it.

> 
>     if (!brw_search_cache(&brw->cache, BRW_CACHE_TCS_PROG,
> diff --git a/src/mesa/drivers/dri/i965/brw_tes.c
> b/src/mesa/drivers/dri/i965/brw_tes.c
> index 3c12706..4b2bf8c 100644
> --- a/src/mesa/drivers/dri/i965/brw_tes.c
> +++ b/src/mesa/drivers/dri/i965/brw_tes.c
> @@ -241,15 +241,6 @@ brw_upload_tes_prog(struct brw_context *brw)
>                          BRW_NEW_TESS_EVAL_PROGRAM))
>        return;
> 
> -   if (tep == NULL) {
> -      /* Other state atoms had better not try to access prog_data, 
> since
> -       * there's no TES program.
> -       */
> -      brw->tes.prog_data = NULL;
> -      brw->tes.base.prog_data = NULL;
> -      return;
> -   }
> -
>     struct gl_program *prog = &tep->program.Base;
> 
>     memset(&key, 0, sizeof(key));