[Mesa-dev] [RFC PATCH 08/26] glsl: select bindless sampler/image types on the fly

[Timothy Arceri]

On 12/04/17 02:48, Samuel Pitoiset wrote:
> At this point, there is enough information to take the decision
> to replace a sampler/image type by the corresponding bindless one.
>
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>  src/compiler/glsl/ast.h          | 10 ++++-
>  src/compiler/glsl/ast_to_hir.cpp | 93 ++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 98 insertions(+), 5 deletions(-)
>
> diff --git a/src/compiler/glsl/ast.h b/src/compiler/glsl/ast.h
> index 9327e03979..2a2dd4bcd9 100644
> --- a/src/compiler/glsl/ast.h
> +++ b/src/compiler/glsl/ast.h
> @@ -894,8 +894,14 @@ public:
>     }
>
>     const struct glsl_type *glsl_type(const char **name,
> -				     struct _mesa_glsl_parse_state *state)
> -      const;
> +                                     struct _mesa_glsl_parse_state *state,
> +                                     bool is_interface_block = false) const;
> +
> +   bool is_temporary_storage() const;
> +
> +   bool is_bindless_type(const struct glsl_type *type,
> +                         struct _mesa_glsl_parse_state *state,
> +                         bool is_interface_block) const;
>
>     ast_type_qualifier qualifier;
>     ast_type_specifier *specifier;
> diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
> index 5043d6a574..4a0f3fe315 100644
> --- a/src/compiler/glsl/ast_to_hir.cpp
> +++ b/src/compiler/glsl/ast_to_hir.cpp
> @@ -2646,9 +2646,96 @@ select_gles_precision(unsigned qual_precision,
>
>  const glsl_type *
>  ast_fully_specified_type::glsl_type(const char **name,
> -                                    struct _mesa_glsl_parse_state *state) const
> +                                    struct _mesa_glsl_parse_state *state,
> +                                    bool is_interface_block) const
>  {
> -   return this->specifier->glsl_type(name, state);
> +   const struct glsl_type *type;
> +
> +   type = this->specifier->glsl_type(name, state);
> +   if (!type)
> +      return NULL;
> +
> +   /* Bindless sampler/image types are replaced on-the-fly if needed as
> +    * specified by ARB_bindless_texture. */
> +   if (state->has_bindless()) {

Can we simplify this to:

if (state->has_bindless() &&
     is_bindless_type(type, state, is_interface_block)) {

And drop the two calls below. By now we should have already thrown an 
error if the bindless qualifiers were not applied to an image/sampler right?

> +      if (type->is_sampler()) {
> +         if (is_bindless_type(type, state, is_interface_block)) {
> +            type = glsl_type::get_sampler_instance(
> +                     (glsl_sampler_dim)type->sampler_dimensionality,
> +                     type->sampler_shadow,
> +                     type->sampler_array,
> +                     (glsl_base_type)type->sampled_type,
> +                     true);
> +         }
> +      }
> +      if (type->is_image()) {
> +         if (is_bindless_type(type, state, is_interface_block)) {
> +            type = glsl_type::get_image_instance(
> +                     (glsl_sampler_dim)type->sampler_dimensionality,
> +                     type->sampler_array,
> +                     (glsl_base_type)type->sampled_type,
> +                     true);
> +         }
> +      }
> +   }
> +
> +   return type;
> +}
> +
> +bool
> +ast_fully_specified_type::is_temporary_storage() const
> +{
> +   return (!qualifier.flags.q.in &&
> +           !qualifier.flags.q.out &&
> +           !qualifier.flags.q.attribute &&
> +           !qualifier.flags.q.varying &&
> +           !qualifier.flags.q.uniform &&
> +           !qualifier.flags.q.buffer &&
> +           !qualifier.flags.q.shared_storage);
> +}
> +
> +bool
> +ast_fully_specified_type::is_bindless_type(const struct glsl_type *type,
> +                                           struct _mesa_glsl_parse_state *state,
> +                                           bool is_interface_block) const
> +{
> +   /* The bindless_sampler (and respectively bindless_image) layout qualifiers
> +    * can be set as local scope, as well as at global scope. */
> +   if (qualifier.flags.q.bindless_sampler ||
> +       qualifier.flags.q.bindless_image ||
> +       state->bindless_sampler_specified ||
> +       state->bindless_image_specified)
> +      return true;
> +
> +   /* The ARB_bindless_texture spec says:
> +    *
> +    * "Modify Section 4.3.7, Interface Blocks, p. 38"
> +    *
> +    * "(remove the following bullet from the last list on p. 39, thereby
> +    *  permitting sampler types in interface blocks; image types are also
> +    *  permitted in blocks by this extension)"
> +    *
> +    *    * sampler types are not allowed
> +    */
> +   if (is_interface_block)
> +      return true;
> +
> +   /* The ARB_bindless_texture spec says:
> +    *
> +    * "Replace Section 4.1.7 (Samplers), p. 25"
> +    *
> +    * "Samplers may be declared as shader inputs and outputs, as uniform
> +    *  variables, as temporary variables, and as function parameters"
> +    *
> +    * "Replace Section 4.1.X, (Images)"
> +    *
> +    * "Images may be declared as shader inputs and outputs, as uniform
> +    *  variables, as temporary variables, and as function parameters."
> +    */
> +   if (qualifier.flags.q.in || qualifier.flags.q.out || is_temporary_storage())
> +      return true;
> +
> +   return false;
>  }
>
>  /**
> @@ -6844,7 +6931,7 @@ ast_process_struct_or_iface_block_members(exec_list *instructions,
>                            "embedded structure declarations are not allowed");
>
>        const glsl_type *decl_type =
> -         decl_list->type->glsl_type(& type_name, state);
> +         decl_list->type->glsl_type(& type_name, state, is_interface);

This looks like it should be a separate change?

>
>        const struct ast_type_qualifier *const qual =
>           &decl_list->type->qualifier;
>