[Mesa-dev] [PATCH 2/3] mesa: build up a mask of active shader stages in a pipeline

[Juha-Pekka Heikkila]

On 07.12.2015 11:29, Tapani Pälli wrote:
> This will be used for validating SSO pipeline where all active stages
> in linked programs should be in use when rendering.
>
> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
> ---
>   src/mesa/main/mtypes.h      |  2 ++
>   src/mesa/main/pipelineobj.c | 39 +++++++++++++++++++++++++++++++++++++++
>   2 files changed, 41 insertions(+)
>
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index fa7ead0..d5a22c9 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -2824,6 +2824,8 @@ struct gl_pipeline_object
>      GLboolean Validated;                 /**< Pipeline Validation status */
>
>      GLchar *InfoLog;
> +
> +   uint8_t ActiveStages;                /**< Stages used, (glUseProgramStages) */
>   };
>
>   /**
> diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
> index 6710d0d..c510ee8 100644
> --- a/src/mesa/main/pipelineobj.c
> +++ b/src/mesa/main/pipelineobj.c
> @@ -218,6 +218,43 @@ _mesa_reference_pipeline_object_(struct gl_context *ctx,
>      }
>   }
>
> +static GLenum
> +shader_bit_from_shader_stage(gl_shader_stage stage)
> +{
> +   switch (stage) {
> +   case MESA_SHADER_VERTEX:
> +      return GL_VERTEX_SHADER_BIT;
> +   case MESA_SHADER_FRAGMENT:
> +      return GL_FRAGMENT_SHADER_BIT;
> +   case MESA_SHADER_GEOMETRY:
> +      return GL_GEOMETRY_SHADER_BIT;
> +   case MESA_SHADER_TESS_CTRL:
> +      return GL_TESS_CONTROL_SHADER_BIT;
> +   case MESA_SHADER_TESS_EVAL:
> +      return GL_TESS_EVALUATION_SHADER_BIT;
> +   case MESA_SHADER_COMPUTE:
> +      return GL_COMPUTE_SHADER_BIT;
> +   default:
> +      unreachable("bad value in _mesa_shader_bit_from_shader_stage()");

maybe return value here just because it should?

> +   }
> +}
> +
> +static void
> +update_active_pipeline_stages(struct gl_pipeline_object *pipe,
> +                              struct gl_shader_program *shProg,
> +                              GLbitfield stages)
> +{
> +   unsigned i;
> +   for (i = 0; i < MESA_SHADER_STAGES; i++) {
> +      if ((stages & shader_bit_from_shader_stage(i)) != 0) {
> +         if (shProg && shProg->ActiveStages & (1 << i))
> +            pipe->ActiveStages |= (1 << i);
> +         else
> +            pipe->ActiveStages &= ~(1 << i);
> +      }
> +   }
> +}
> +
>   /**
>    * Bound program to severals stages of the pipeline
>    */
> @@ -311,6 +348,8 @@ _mesa_UseProgramStages(GLuint pipeline, GLbitfield stages, GLuint program)
>         }
>      }
>
> +   update_active_pipeline_stages(pipe, shProg, stages);
> +
>      /* Enable individual stages from the program as requested by the
>       * application.  If there is no shader for a requested stage in the
>       * program, _mesa_use_shader_program will enable fixed-function processing
>