[Mesa-dev] [PATCH 4/6] mesa: generalize sso stage interleaving check

[Brian Paul]

On 06/14/2015 12:22 PM, Marek Olšák wrote:
> From: Chris Forbes <chrisf at ijw.co.nz>
>
> For tessellation.
>
> v2: cleanup by Marek Olšák
> ---
>   src/mesa/main/pipelineobj.c | 55 +++++++++++++++++++++++++++++++--------------
>   1 file changed, 38 insertions(+), 17 deletions(-)
>
> diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
> index 0fefa7d..22500b5 100644
> --- a/src/mesa/main/pipelineobj.c
> +++ b/src/mesa/main/pipelineobj.c
> @@ -673,6 +673,38 @@ program_stages_all_active(struct gl_pipeline_object *pipe,
>      return status;
>   }
>
> +static bool
> +program_stages_interleaved_illegally(struct gl_pipeline_object *pipe)

Could const-qualify that param.

Otherwise, for the series,
Reviewed-by: Brian Paul <brianp at vmware.com>


> +{
> +   struct gl_shader_program *prev = NULL;
> +   unsigned i, j;
> +
> +   /* Look for programs bound to stages: A -> B -> A, with any intervening
> +    * sequence of unrelated programs or empty stages.
> +    */
> +   for (i = 0; i < MESA_SHADER_STAGES; i++) {
> +      struct gl_shader_program *cur = pipe->CurrentProgram[i];
> +
> +      /* Empty stages anywhere in the pipe are OK */
> +      if (!cur || cur == prev)
> +         continue;
> +
> +      if (prev) {
> +         /* We've seen an A -> B transition; look at the rest of the pipe
> +          * to see if we ever see A again.
> +          */
> +         for (j = i + 1; j < MESA_SHADER_STAGES; j++) {
> +            if (pipe->CurrentProgram[j] == prev)
> +               return true;
> +         }
> +      }
> +
> +      prev = cur;
> +   }
> +
> +   return false;
> +}
> +
>   extern GLboolean
>   _mesa_validate_program_pipeline(struct gl_context* ctx,
>                                   struct gl_pipeline_object *pipe,
> @@ -721,24 +753,13 @@ _mesa_validate_program_pipeline(struct gl_context* ctx,
>       *         - One program object is active for at least two shader stages
>       *           and a second program is active for a shader stage between two
>       *           stages for which the first program was active."
> -    *
> -    * Without Tesselation, the only case where this can occur is the geometry
> -    * shader between the fragment shader and vertex shader.
>       */
> -   if (pipe->CurrentProgram[MESA_SHADER_GEOMETRY]
> -       && pipe->CurrentProgram[MESA_SHADER_FRAGMENT]
> -       && pipe->CurrentProgram[MESA_SHADER_VERTEX]) {
> -      if (pipe->CurrentProgram[MESA_SHADER_VERTEX]->Name == pipe->CurrentProgram[MESA_SHADER_FRAGMENT]->Name &&
> -          pipe->CurrentProgram[MESA_SHADER_GEOMETRY]->Name != pipe->CurrentProgram[MESA_SHADER_VERTEX]->Name) {
> -         pipe->InfoLog =
> -            ralloc_asprintf(pipe,
> -                            "Program %d is active for geometry stage between "
> -                            "two stages for which another program %d is "
> -                            "active",
> -                            pipe->CurrentProgram[MESA_SHADER_GEOMETRY]->Name,
> -                            pipe->CurrentProgram[MESA_SHADER_VERTEX]->Name);
> -         goto err;
> -      }
> +   if (program_stages_interleaved_illegally(pipe)) {
> +      pipe->InfoLog =
> +         ralloc_strdup(pipe,
> +                       "Program is active for multiple shader stages with an "
> +                       "intervening stage provided by another program");
> +      goto err;
>      }
>
>      /* Section 2.11.11 (Shader Execution), subheading "Validation," of the
>