[Mesa-dev] [PATCH V3 2/6] glsl: assign hidden uniforms their slot id earlier

[Timothy Arceri]

This is required so that the next patch can safely assign the slot id
to the var.

The ids are now assigned in the order we want before allocating storage
so there is no need to sort the storage array and move things around.
---
 src/glsl/link_uniforms.cpp | 90 +++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 49 deletions(-)

diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 5402c99..da8f2f7 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -300,11 +300,12 @@ namespace {
  */
 class count_uniform_size : public program_resource_visitor {
 public:
-   count_uniform_size(struct string_to_uint_map *map)
-      : num_active_uniforms(0), num_values(0), num_shader_samplers(0),
-        num_shader_images(0), num_shader_uniform_components(0),
-        num_shader_subroutines(0),
-        is_ubo_var(false), map(map)
+   count_uniform_size(struct string_to_uint_map *map,
+                      struct string_to_uint_map *hidden_map)
+      : num_active_uniforms(0), num_hidden_uniforms(0), num_values(0),
+        num_shader_samplers(0), num_shader_images(0),
+        num_shader_uniform_components(0), num_shader_subroutines(0),
+        is_ubo_var(false), map(map), hidden_map(hidden_map)
    {
       /* empty */
    }
@@ -319,6 +320,7 @@ public:
 
    void process(ir_variable *var)
    {
+      this->current_var = var;
       this->is_ubo_var = var->is_in_buffer_block();
       if (var->is_interface_instance())
          program_resource_visitor::process(var->get_interface_type(),
@@ -332,6 +334,8 @@ public:
     */
    unsigned num_active_uniforms;
 
+   unsigned num_hidden_uniforms;
+
    /**
     * Number of data values required to back the storage for the active uniforms
     */
@@ -359,6 +363,8 @@ public:
 
    bool is_ubo_var;
 
+   struct string_to_uint_map *map;
+
 private:
    virtual void visit_field(const glsl_type *type, const char *name,
                             bool row_major)
@@ -402,7 +408,13 @@ private:
       if (this->map->get(id, name))
 	 return;
 
-      this->map->put(this->num_active_uniforms, name);
+      if (this->current_var->data.how_declared == ir_var_hidden) {
+         this->hidden_map->put(this->num_hidden_uniforms, name);
+         this->num_hidden_uniforms++;
+      } else {
+         this->map->put(this->num_active_uniforms - this->num_hidden_uniforms,
+                        name);
+      }
 
       /* Each leaf uniform occupies one entry in the list of active
        * uniforms.
@@ -411,7 +423,12 @@ private:
       this->num_values += values;
    }
 
-   struct string_to_uint_map *map;
+   struct string_to_uint_map *hidden_map;
+
+   /**
+    * Current variable being processed.
+    */
+   ir_variable *current_var;
 };
 
 } /* anonymous namespace */
@@ -961,47 +978,19 @@ link_set_image_access_qualifiers(struct gl_shader_program *prog)
 }
 
 /**
- * Sort the array of uniform storage so that the non-hidden uniforms are first
- *
- * This function sorts the list "in place."  This is important because some of
- * the storage accessible from \c uniforms has \c uniforms as its \c ralloc
- * context.  If \c uniforms is freed, some other storage will also be freed.
+ * Combine the hidden uniform hash map with the uniform hash map so that the
+ * hidden uniforms will be given indicies at the end of the uniform storage
+ * array.
  */
-static unsigned
-move_hidden_uniforms_to_end(struct gl_shader_program *prog,
-                            struct gl_uniform_storage *uniforms,
-                            unsigned num_elements)
+static void
+assign_hidden_uniform_slot_id(const char *name, unsigned hidden_id,
+                              void *closure)
 {
-   struct gl_uniform_storage *sorted_uniforms =
-      ralloc_array(prog, struct gl_uniform_storage, num_elements);
-   unsigned hidden_uniforms = 0;
-   unsigned j = 0;
-
-   /* Add the non-hidden uniforms. */
-   for (unsigned i = 0; i < num_elements; i++) {
-      if (!uniforms[i].hidden)
-         sorted_uniforms[j++] = uniforms[i];
-   }
-
-   /* Add and count the hidden uniforms. */
-   for (unsigned i = 0; i < num_elements; i++) {
-      if (uniforms[i].hidden) {
-         sorted_uniforms[j++] = uniforms[i];
-         hidden_uniforms++;
-      }
-   }
+   count_uniform_size *uniform_size = (count_uniform_size *) closure;
+   unsigned hidden_slot_id = uniform_size->num_active_uniforms -
+      uniform_size->num_hidden_uniforms + hidden_id;
 
-   assert(prog->UniformHash != NULL);
-   prog->UniformHash->clear();
-   for (unsigned i = 0; i < num_elements; i++) {
-      if (sorted_uniforms[i].name != NULL)
-         prog->UniformHash->put(i, sorted_uniforms[i].name);
-   }
-
-   memcpy(uniforms, sorted_uniforms, sizeof(uniforms[0]) * num_elements);
-   ralloc_free(sorted_uniforms);
-
-   return hidden_uniforms;
+   uniform_size->map->put(hidden_slot_id, name);
 }
 
 void
@@ -1025,7 +1014,8 @@ link_assign_uniform_locations(struct gl_shader_program *prog,
     * Note: this is *NOT* the index that is returned to the application by
     * glGetUniformLocation.
     */
-   count_uniform_size uniform_size(prog->UniformHash);
+   struct string_to_uint_map *hiddenUniforms = new string_to_uint_map;
+   count_uniform_size uniform_size(prog->UniformHash, hiddenUniforms);
    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
       struct gl_shader *sh = prog->_LinkedShaders[i];
 
@@ -1073,12 +1063,17 @@ link_assign_uniform_locations(struct gl_shader_program *prog,
 
    const unsigned num_uniforms = uniform_size.num_active_uniforms;
    const unsigned num_data_slots = uniform_size.num_values;
+   const unsigned hidden_uniforms = uniform_size.num_hidden_uniforms;
 
    /* On the outside chance that there were no uniforms, bail out.
     */
    if (num_uniforms == 0)
       return;
 
+   /* assign hidden uniforms a slot id */
+   hiddenUniforms->iterate(assign_hidden_uniform_slot_id, &uniform_size);
+   delete hiddenUniforms;
+
    struct gl_uniform_storage *uniforms =
       rzalloc_array(prog, struct gl_uniform_storage, num_uniforms);
    union gl_constant_value *data =
@@ -1112,9 +1107,6 @@ link_assign_uniform_locations(struct gl_shader_program *prog,
              sizeof(prog->_LinkedShaders[i]->SamplerTargets));
    }
 
-   const unsigned hidden_uniforms =
-      move_hidden_uniforms_to_end(prog, uniforms, num_uniforms);
-
    /* Reserve all the explicit locations of the active uniforms. */
    for (unsigned i = 0; i < num_uniforms; i++) {
       if (uniforms[i].type->is_subroutine())
-- 
2.4.3