[Mesa-dev] [PATCH 28/32] glsl: Add link_uniform_blocks to calculate all UBO data at link-time

Jordan Justen jljusten at gmail.com
Fri Jan 25 02:00:41 PST 2013


On Tue, Jan 22, 2013 at 12:52 AM, Ian Romanick <idr at freedesktop.org> wrote:
> From: Ian Romanick <ian.d.romanick at intel.com>
>
> Calculate all of the block member offsets, the IndexNames, and
> everything else to do with every UBO.
>
> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> ---
>  src/glsl/link_uniform_blocks.cpp | 248 +++++++++++++++++++++++++++++++++++++++
>  src/glsl/linker.h                |   7 ++
>  2 files changed, 255 insertions(+)
>
> diff --git a/src/glsl/link_uniform_blocks.cpp b/src/glsl/link_uniform_blocks.cpp
> index c9cbde9..74fe1e2 100644
> --- a/src/glsl/link_uniform_blocks.cpp
> +++ b/src/glsl/link_uniform_blocks.cpp
> @@ -25,8 +25,256 @@
>  #include "ir.h"
>  #include "linker.h"
>  #include "ir_uniform.h"
> +#include "link_uniform_block_active_visitor.h"
> +#include "main/hash_table.h"
>  #include "program.h"
>
> +class ubo_visitor : public uniform_field_visitor {
> +public:
> +   ubo_visitor(void *mem_ctx, gl_uniform_buffer_variable *variables,
> +               unsigned num_variables)
> +      : index(0), offset(0), buffer_size(0), variables(variables),
> +        num_variables(num_variables), mem_ctx(mem_ctx), is_array_instance(false)
> +   {
> +      /* empty */
> +   }
> +
> +   void process(const glsl_type *type, const char *name)
> +   {
> +      this->offset = 0;
> +      this->buffer_size = 0;
> +      this->is_array_instance = strchr(name, ']') != NULL;
> +      this->uniform_field_visitor::process(type, name);
> +   }
> +
> +   unsigned index;
> +   unsigned offset;
> +   unsigned buffer_size;
> +   gl_uniform_buffer_variable *variables;
> +   unsigned num_variables;
> +   void *mem_ctx;
> +   bool is_array_instance;
> +
> +private:
> +   virtual void visit_field(const glsl_type *type, const char *name,
> +                            bool row_major)
> +   {
> +      assert(this->index < this->num_variables);
> +
> +      gl_uniform_buffer_variable *v = &this->variables[this->index++];
> +
> +      v->Name = ralloc_strdup(mem_ctx, name);
> +      v->Type = type;
> +      v->RowMajor = row_major;
> +
> +      if (this->is_array_instance) {
> +         v->IndexName = ralloc_strdup(mem_ctx, name);
> +
> +         char *open_bracket = strchr(v->IndexName, '[');
> +         assert(open_bracket != NULL);
> +
> +         char *close_bracket = strchr(open_bracket, ']');
> +         assert(close_bracket != NULL);
> +
> +         /* Length of the tail without the ']' but with the NUL.
> +          */
> +         unsigned len = strlen(close_bracket + 1) + 1;
> +
> +         memmove(open_bracket, close_bracket + 1, len);
> +     } else {

Missing a space of indentation.

-Jordan

> +         v->IndexName = v->Name;
> +      }
> +
> +      unsigned alignment = type->std140_base_alignment(v->RowMajor);
> +      unsigned size = type->std140_size(v->RowMajor);
> +
> +      this->offset = glsl_align(this->offset, alignment);
> +      v->Offset = this->offset;
> +      this->offset += size;
> +
> +      /* From the GL_ARB_uniform_buffer_object spec:
> +       *
> +       *     "For uniform blocks laid out according to [std140] rules, the
> +       *      minimum buffer object size returned by the
> +       *      UNIFORM_BLOCK_DATA_SIZE query is derived by taking the offset of
> +       *      the last basic machine unit consumed by the last uniform of the
> +       *      uniform block (including any end-of-array or end-of-structure
> +       *      padding), adding one, and rounding up to the next multiple of
> +       *      the base alignment required for a vec4."
> +       */
> +      this->buffer_size = glsl_align(this->offset, 16);
> +   }
> +
> +   virtual void visit_field(const glsl_struct_field *field)
> +   {
> +      this->offset = glsl_align(this->offset,
> +                                field->type->std140_base_alignment(false));
> +   }
> +};
> +
> +class count_block_size : public uniform_field_visitor {
> +public:
> +   count_block_size() : num_active_uniforms(0)
> +   {
> +      /* empty */
> +   }
> +
> +   unsigned num_active_uniforms;
> +
> +private:
> +   virtual void visit_field(const glsl_type *type, const char *name,
> +                            bool row_major)
> +   {
> +      (void) type;
> +      (void) name;
> +      (void) row_major;
> +      this->num_active_uniforms++;
> +   }
> +};
> +
> +struct block {
> +   const glsl_type *type;
> +   bool has_instance_name;
> +};
> +
> +int
> +link_uniform_blocks(void *mem_ctx,
> +                    struct gl_shader_program *prog,
> +                    struct gl_shader **shader_list,
> +                    unsigned num_shaders,
> +                    struct gl_uniform_block **blocks_ret)
> +{
> +   /* This hash table will track all of the uniform blocks that have been
> +    * encountered.  Since blocks with the same block-name must be the same,
> +    * the hash is organized by block-name.
> +    */
> +   struct hash_table *block_hash =
> +      _mesa_hash_table_create(mem_ctx, _mesa_key_string_equal);
> +
> +   /* Determine which uniform blocks are active.
> +    */
> +   link_uniform_block_active_visitor v(mem_ctx, block_hash, prog);
> +   for (unsigned i = 0; i < num_shaders; i++) {
> +      visit_list_elements(&v, shader_list[i]->ir);
> +   }
> +
> +   /* Count the number of active uniform blocks.  Count the total number of
> +    * active slots in those uniform blocks.
> +    */
> +   unsigned num_blocks = 0;
> +   unsigned num_variables = 0;
> +   count_block_size block_size;
> +   struct hash_entry *entry;
> +
> +   hash_table_foreach (block_hash, entry) {
> +      const struct link_uniform_block_active *const b =
> +         (const struct link_uniform_block_active *) entry->data;
> +
> +      const glsl_type *const block_type =
> +         b->type->is_array() ? b->type->fields.array : b->type;
> +
> +      assert((b->num_array_elements > 0) == b->type->is_array());
> +
> +      block_size.num_active_uniforms = 0;
> +      block_size.process(block_type, "");
> +
> +      if (b->num_array_elements > 0) {
> +         num_blocks += b->num_array_elements;
> +         num_variables += b->num_array_elements
> +            * block_size.num_active_uniforms;
> +      } else {
> +         num_blocks++;
> +         num_variables += block_size.num_active_uniforms;
> +      }
> +
> +   }
> +
> +   if (num_blocks == 0) {
> +      assert(num_variables == 0);
> +      _mesa_hash_table_destroy(block_hash, NULL);
> +      return 0;
> +   }
> +
> +   assert(num_variables != 0);
> +
> +   /* Allocate storage to hold all of the informatation related to uniform
> +    * blocks that can be queried through the API.
> +    */
> +   gl_uniform_block *blocks =
> +      ralloc_array(mem_ctx, gl_uniform_block, num_blocks);
> +   gl_uniform_buffer_variable *variables =
> +      ralloc_array(blocks, gl_uniform_buffer_variable, num_variables);
> +
> +   /* Add each variable from each uniform block to the API tracking
> +    * structures.
> +    */
> +   unsigned i = 0;
> +   ubo_visitor parcel(blocks, variables, num_variables);
> +
> +   STATIC_ASSERT(unsigned(GLSL_INTERFACE_PACKING_STD140)
> +                 == unsigned(ubo_packing_std140));
> +   STATIC_ASSERT(unsigned(GLSL_INTERFACE_PACKING_SHARED)
> +                 == unsigned(ubo_packing_shared));
> +   STATIC_ASSERT(unsigned(GLSL_INTERFACE_PACKING_PACKED)
> +                 == unsigned(ubo_packing_packed));
> +
> +
> +   hash_table_foreach (block_hash, entry) {
> +      const struct link_uniform_block_active *const b =
> +         (const struct link_uniform_block_active *) entry->data;
> +      const glsl_type *block_type = b->type;
> +
> +      if (b->num_array_elements > 0) {
> +         const char *const name = block_type->fields.array->name;
> +
> +         assert(b->has_instance_name);
> +         for (unsigned j = 0; j < b->num_array_elements; j++) {
> +            blocks[i].Name = ralloc_asprintf(blocks, "%s[%u]", name,
> +                                             b->array_elements[j]);
> +            blocks[i].Uniforms = &variables[parcel.index];
> +            blocks[i].Binding = 0;
> +            blocks[i].UniformBufferSize = 0;
> +            blocks[i]._Packing =
> +               gl_uniform_block_packing(block_type->interface_packing);
> +
> +            parcel.process(block_type->fields.array,
> +                           blocks[i].Name);
> +
> +            blocks[i].UniformBufferSize = parcel.buffer_size;
> +
> +            blocks[i].NumUniforms =
> +               (unsigned)(ptrdiff_t)(&variables[parcel.index] - blocks[i].Uniforms);
> +
> +            i++;
> +         }
> +      } else {
> +         blocks[i].Name = ralloc_strdup(blocks, block_type->name);
> +         blocks[i].Uniforms = &variables[parcel.index];
> +         blocks[i].Binding = 0;
> +         blocks[i].UniformBufferSize = 0;
> +         blocks[i]._Packing =
> +            gl_uniform_block_packing(block_type->interface_packing);
> +
> +         parcel.process(block_type,
> +                        b->has_instance_name ? block_type->name : "");
> +
> +         blocks[i].UniformBufferSize = parcel.buffer_size;
> +
> +         blocks[i].NumUniforms =
> +            (unsigned)(ptrdiff_t)(&variables[parcel.index] - blocks[i].Uniforms);
> +
> +         i++;
> +      }
> +   }
> +
> +   assert(parcel.index == num_variables);
> +
> +   _mesa_hash_table_destroy(block_hash, NULL);
> +
> +   *blocks_ret = blocks;
> +   return num_blocks;
> +}
> +
>  bool
>  link_uniform_blocks_are_compatible(const gl_uniform_block *a,
>                                    const gl_uniform_block *b)
> diff --git a/src/glsl/linker.h b/src/glsl/linker.h
> index 71586d0..6a080a2 100644
> --- a/src/glsl/linker.h
> +++ b/src/glsl/linker.h
> @@ -53,6 +53,13 @@ extern bool
>  link_uniform_blocks_are_compatible(const gl_uniform_block *a,
>                                    const gl_uniform_block *b);
>
> +extern int
> +link_uniform_blocks(void *mem_ctx,
> +                    struct gl_shader_program *prog,
> +                    struct gl_shader **shader_list,
> +                    unsigned num_shaders,
> +                    struct gl_uniform_block **blocks_ret);
> +
>  /**
>   * Class for processing all of the leaf fields of an uniform
>   *
> --
> 1.7.11.7
>
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