[Mesa-dev] [PATCH 05/11] glsl: reject compute shaders with fixed and variable local size

[Ian Romanick]

On 09/08/2016 01:31 PM, Samuel Pitoiset wrote:
> The ARB_compute_variable_group_size specification explains that
> when a compute shader includes both a fixed and a variable local
> size, a compile-time error occurs.

I probably would have squashed this in with the previous commit, but
it's fine either way.

> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>  src/compiler/glsl/ast_to_hir.cpp | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
> index 4fc4c5c..a53a82e 100644
> --- a/src/compiler/glsl/ast_to_hir.cpp
> +++ b/src/compiler/glsl/ast_to_hir.cpp
> @@ -8013,6 +8013,20 @@ ast_cs_input_layout::hir(exec_list *instructions,
>        }
>     }
>  
> +   /* From the ARB_compute_variable_group_size specification:

Same comment about spec quotes.

It's hard to tell from just the patch... is this check order dependent?
Does it correct handle all the cases:

// case 1
layout(local_size_variable, local_size_x = 32, local_size_y = 32);

// case 2
layout(local_size_x = 32, local_size_y = 32, local_size_variable);

// case 3
layout(local_size_variable);
layout(local_size_x = 32, local_size_y = 32);

// case 4
layout(local_size_x = 32, local_size_y = 32);
layout(local_size_variable);

> +    *
> +    *     If a compute shader including a *local_size_variable* qualifier also
> +    *     declares a fixed local group size using the *local_size_x*,
> +    *     *local_size_y*, or *local_size_z* qualifiers, a compile-time error
> +    *     results
> +    */
> +   if (state->cs_input_local_size_variable_specified) {
> +      _mesa_glsl_error(&loc, state,
> +                       "compute shader can't include both a variable and a "
> +                       "fixed local group size");
> +      return NULL;
> +   }
> +
>     state->cs_input_local_size_specified = true;
>     for (int i = 0; i < 3; i++)
>        state->cs_input_local_size[i] = qual_local_size[i];
>