[Mesa-dev] [PATCH V2 19/28] glsl: add support for explicit components to frag outputs

[Anuj Phogat]

On Wed, Jan 13, 2016 at 1:19 AM, Timothy Arceri
<timothy.arceri at collabora.com> wrote:
> V2: fix error checking for arrays and components. V1 was
> only taking into account all the array elements and all the
> components of one of the varyings during the comparision
> and treating the other as a single slot/component.
>
> Cc: Anuj Phogat <anuj.phogat at gmail.com>
> ---
>  src/glsl/linker.cpp | 72 +++++++++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 62 insertions(+), 10 deletions(-)
>
> diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
> index b81bfba..c66dcc4 100644
> --- a/src/glsl/linker.cpp
> +++ b/src/glsl/linker.cpp
> @@ -2411,7 +2411,12 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
>        }
>     } to_assign[16];
>
> +   /* Temporary array for the set of attributes that have locations assigned.
> +    */
> +   ir_variable *assigned[16];
> +
>     unsigned num_attr = 0;
> +   unsigned assigned_attr = 0;
>
>     foreach_in_list(ir_instruction, node, sh->ir) {
>        ir_variable *const var = node->as_variable();
> @@ -2573,18 +2578,62 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
>              * attribute overlaps any previously allocated bits.
>              */
>             if ((~(use_mask << attr) & used_locations) != used_locations) {
> -               if (target_index == MESA_SHADER_FRAGMENT ||
> -                   (prog->IsES && prog->Version >= 300)) {
> -                  linker_error(prog,
> -                               "overlapping location is assigned "
> -                               "to %s `%s' %d %d %d\n", string,
> -                               var->name, used_locations, use_mask, attr);
> +               if (target_index == MESA_SHADER_FRAGMENT && !prog->IsES) {
> +                  /* From section 4.4.2 (Output Layout Qualifiers) of the GLSL
> +                   * 4.40 spec:
> +                   *
> +                   *    "Additionally, for fragment shader outputs, if two
> +                   *    variables are placed within the same location, they
> +                   *    must have the same underlying type (floating-point or
> +                   *    integer). No component aliasing of output variables or
> +                   *    members is allowed.
> +                   */
> +                  for (unsigned i = 0; i < assigned_attr; i++) {
> +                     unsigned assigned_slots =
> +                        assigned[i]->type->count_attribute_slots(false);
> +                    unsigned assig_attr =
> +                        assigned[i]->data.location - generic_base;
> +                    unsigned assigned_use_mask = (1 << assigned_slots) - 1;
> +
> +                     if ((assigned_use_mask << assig_attr) &
> +                         (use_mask << attr)) {
> +
> +                        const glsl_type *assigned_type =
> +                           assigned[i]->type->without_array();
> +                        const glsl_type *type = var->type->without_array();
> +                        if (assigned_type->base_type != type->base_type) {
> +                           linker_error(prog, "types do not match for aliased"
> +                                        " %ss %s and %s\n", string,
> +                                        assigned[i]->name, var->name);
> +                           return false;
> +                        }
> +
> +                        unsigned assigned_component_mask =
> +                           ((1 << assigned_type->vector_elements) - 1) <<
> +                           assigned[i]->data.location_frac;
> +                        unsigned component_mask =
> +                           ((1 << type->vector_elements) - 1) <<
> +                           var->data.location_frac;
> +                        if (assigned_component_mask & component_mask) {
> +                           linker_error(prog, "overlapping component is "
> +                                        "assigned to %ss %s and %s "
> +                                        "(component=%d)\n",
> +                                        string, assigned[i]->name, var->name,
> +                                        var->data.location_frac);
> +                           return false;
> +                        }
> +                     }
> +                  }
> +               } else if (target_index == MESA_SHADER_FRAGMENT ||
> +                          (prog->IsES && prog->Version >= 300)) {
> +                  linker_error(prog, "overlapping location is assigned "
> +                               "to %s `%s' %d %d %d\n", string, var->name,
> +                               used_locations, use_mask, attr);
>                    return false;
>                 } else {
> -                  linker_warning(prog,
> -                                 "overlapping location is assigned "
> -                                 "to %s `%s' %d %d %d\n", string,
> -                                 var->name, used_locations, use_mask, attr);
> +                  linker_warning(prog, "overlapping location is assigned "
> +                                 "to %s `%s' %d %d %d\n", string, var->name,
> +                                 used_locations, use_mask, attr);
>                 }
>             }
>
> @@ -2614,6 +2663,9 @@ assign_attribute_or_color_locations(gl_shader_program *prog,
>                 double_storage_locations |= (use_mask << attr);
>          }
>
> +         assigned[assigned_attr] = var;
> +         assigned_attr++;
> +
>          continue;
>        }
>
> --
> 2.4.3
>

Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>