glsl: Calcluate Mesa state slots in front-end instead of back-end

This should be the last bit of infrastructure changes before
generating GLSL IR for assembly shaders.

This commit leaves some odd code formatting in ir_to_mesa and brw_fs.
This was done to minimize whitespace changes / reindentation in some
loops.  The following commit will restore formatting sanity.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Chad Versace <[email protected]>

4 files changed, 94 insertions, 3 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 39d4ebc7107..a41984310b3 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -253,6 +253,16 @@ enum ir_depth_layout {
 const char*
 depth_layout_string(ir_depth_layout layout);
 
+/**
+ * Description of built-in state associated with a uniform
+ *
+ * \sa ir_variable::state_slots
+ */
+struct ir_state_slot {
+   int tokens[5];
+   int swizzle;
+};
+
 class ir_variable : public ir_instruction {
 public:
    ir_variable(const struct glsl_type *, const char *, ir_variable_mode);
@@ -386,6 +396,22 @@ public:
    int location;
 
    /**
+    * Built-in state that backs this uniform
+    *
+    * Once set at variable creation, \c state_slots must remain invariant.
+    * This is because, ideally, this array would be shared by all clones of
+    * this variable in the IR tree.  In other words, we'd really like for it
+    * to be a fly-weight.
+    *
+    * If the variable is not a uniform, \c num_state_slots will be zero and
+    * \c state_slots will be \c NULL.
+    */
+   /*@{*/
+   unsigned num_state_slots;    /**< Number of state slots used */
+   ir_state_slot *state_slots;  /**< State descriptors. */
+   /*@}*/
+
+   /**
     * Emit a warning if this variable is accessed.
     */
    const char *warn_extension;
diff --git a/src/glsl/ir_clone.cpp b/src/glsl/ir_clone.cpp
index 2c0574dc6bf..069bb85e8de 100644
--- a/src/glsl/ir_clone.cpp
+++ b/src/glsl/ir_clone.cpp
@@ -53,6 +53,18 @@ ir_variable::clone(void *mem_ctx, struct hash_table *ht) const
    var->origin_upper_left = this->origin_upper_left;
    var->pixel_center_integer = this->pixel_center_integer;
    var->explicit_location = this->explicit_location;
+
+   var->num_state_slots = this->num_state_slots;
+   if (this->state_slots) {
+      /* FINISHME: This really wants to use something like talloc_reference, but
+       * FINISHME: ralloc doesn't have any similar function.
+       */
+      var->state_slots = ralloc_array(var, ir_state_slot,
+				      this->num_state_slots);
+      memcpy(var->state_slots, this->state_slots,
+	     sizeof(this->state_slots[0]) * var->num_state_slots);
+   }
+
    if (this->explicit_location)
       var->location = this->location;
 
diff --git a/src/glsl/ir_variable.cpp b/src/glsl/ir_variable.cpp
index c2715254a59..f3577175691 100644
--- a/src/glsl/ir_variable.cpp
+++ b/src/glsl/ir_variable.cpp
@@ -327,7 +327,43 @@ static ir_variable *
 add_uniform(exec_list *instructions, glsl_symbol_table *symtab,
 	    const char *name, const glsl_type *type)
 {
-   return add_variable(instructions, symtab, name, type, ir_var_uniform, -1);
+   ir_variable *const uni =
+      add_variable(instructions, symtab, name, type, ir_var_uniform, -1);
+
+   unsigned i;
+   for (i = 0; _mesa_builtin_uniform_desc[i].name != NULL; i++) {
+      if (strcmp(_mesa_builtin_uniform_desc[i].name, name) == 0) {
+	 break;
+      }
+   }
+
+   assert(_mesa_builtin_uniform_desc[i].name != NULL);
+   const struct gl_builtin_uniform_desc* const statevar =
+      &_mesa_builtin_uniform_desc[i];
+
+   const unsigned array_count = type->is_array() ? type->length : 1;
+   uni->num_state_slots = array_count * statevar->num_elements;
+
+   ir_state_slot *slots =
+      ralloc_array(uni, ir_state_slot, uni->num_state_slots);
+
+   uni->state_slots = slots;
+
+   for (unsigned a = 0; a < array_count; a++) {
+      for (unsigned j = 0; j < statevar->num_elements; j++) {
+	 struct gl_builtin_uniform_element *element = &statevar->elements[j];
+
+	 memcpy(slots->tokens, element->tokens, sizeof(element->tokens));
+	 if (type->is_array()) {
+	    slots->tokens[1] = a;
+	 }
+
+	 slots->swizzle = element->swizzle;
+	 slots++;
+      }
+   }
+
+   return uni;
 }
 
 static void
@@ -341,8 +377,12 @@ add_builtin_variable(exec_list *instructions, glsl_symbol_table *symtab,
 
    assert(type != NULL);
 
-   add_variable(instructions, symtab, proto->name, type, proto->mode,
-		proto->slot);
+   if (proto->mode == ir_var_uniform) {
+      add_uniform(instructions, symtab, proto->name, type);
+   } else {
+      add_variable(instructions, symtab, proto->name, type, proto->mode,
+		   proto->slot);
+   }
 }
 
 static void
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 7db5c5e8d53..17492357f2d 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -994,6 +994,19 @@ update_array_sizes(struct gl_shader_program *prog)
 	 }
 
 	 if (size + 1 != var->type->fields.array->length) {
+	    /* If this is a built-in uniform (i.e., it's backed by some
+	     * fixed-function state), adjust the number of state slots to
+	     * match the new array size.  The number of slots per array entry
+	     * is not known.  It seems saft to assume that the total number of
+	     * slots is an integer multiple of the number of array elements.
+	     * Determine the number of slots per array element by dividing by
+	     * the old (total) size.
+	     */
+	    if (var->num_state_slots > 0) {
+	       var->num_state_slots = (size + 1)
+		  * (var->num_state_slots / var->type->length);
+	    }
+
 	    var->type = glsl_type::get_array_instance(var->type->fields.array,
 						      size + 1);
 	    /* FINISHME: We should update the types of array