Add functions to generate constructors for built-in types.

Currently only vector and matrix types are supported.  Structure types will be
added later.

glsl_types.cpp

@@ -111,6 +111,376 @@ const glsl_type *glsl_type::get_base_type() const
 }
 
 
+/**
+ * Generate the function intro for a constructor
+ *
+ * \param type         Data type to be constructed
+ * \param count        Number of parameters to this concrete constructor.  Most
+ *                     types have at least two constructors.  One will take a
+ *                     single scalar parameter and the other will take "N"
+ *                     scalar parameters.
+ * \param parameters   Storage for the list of parameters.  These are
+ *                     typically stored in an \c ir_function_signature.
+ * \param instructions Storage for the preamble and body of the function.
+ * \param declarations Pointers to the variable declarations for the function
+ *                     parameters.  These are used later to avoid having to use
+ *                     the symbol table.
+ */
+static void
+generate_constructor_intro(const glsl_type *type, unsigned parameter_count,
+			   exec_list *parameters, exec_list *instructions,
+			   ir_variable **declarations)
+{
+   /* Names of parameters used in vector and matrix constructors
+    */
+   static const char *const names[] = {
+      "a", "b", "c", "d", "e", "f", "g", "h",
+      "i", "j", "k", "l", "m", "n", "o", "p",
+   };
+
+   assert(parameter_count <= Elements(names));
+
+   const glsl_type *const parameter_type = type->get_base_type();
+
+   ir_label *const label = new ir_label(type->name);
+   instructions->push_tail(label);
+
+   for (unsigned i = 0; i < parameter_count; i++) {
+      ir_variable *var = new ir_variable(parameter_type, names[i]);
+
+      var->mode = ir_var_in;
+      parameters->push_tail(var);
+
+      var = new ir_variable(parameter_type, names[i]);
+
+      var->mode = ir_var_in;
+      instructions->push_tail(var);
+
+      declarations[i] = var;
+   }
+
+   ir_variable *retval = new ir_variable(type, "__retval");
+   instructions->push_tail(retval);
+
+   declarations[16] = retval;
+}
+
+
+/**
+ * Generate the body of a vector constructor that takes a single scalar
+ */
+static void
+generate_vec_body_from_scalar(exec_list *instructions,
+			      ir_variable **declarations)
+{
+   ir_instruction *inst;
+
+   /* Generate a single assignment of the parameter to __retval.x and return
+    * __retval.xxxx for however many vector components there are.
+    */
+   ir_dereference *const lhs = new ir_dereference(declarations[16]);
+   ir_dereference *const rhs = new ir_dereference(declarations[0]);
+
+   lhs->set_swizzle(0, 0, 0, 0, 1);
+
+   inst = new ir_assignment(lhs, rhs, NULL);
+   instructions->push_tail(inst);
+
+   ir_dereference *const retval = new ir_dereference(declarations[16]);
+
+   retval->set_swizzle(0, 0, 0, 0, declarations[16]->type->vector_elements);
+
+   inst = new ir_return((ir_expression *) retval);
+   instructions->push_tail(inst);
+}
+
+
+/**
+ * Generate the body of a vector constructor that takes multiple scalars
+ */
+static void
+generate_vec_body_from_N_scalars(exec_list *instructions,
+				 ir_variable **declarations)
+{
+   ir_instruction *inst;
+   const glsl_type *const vec_type = declarations[16]->type;
+
+
+   /* Generate an assignment of each parameter to a single component of
+    * __retval.x and return __retval.
+    */
+   for (unsigned i = 0; i < vec_type->vector_elements; i++) {
+      ir_dereference *const lhs = new ir_dereference(declarations[16]);
+      ir_dereference *const rhs = new ir_dereference(declarations[i]);
+
+      lhs->selector.swizzle.x = i;
+      lhs->selector.swizzle.num_components = 1;
+
+      inst = new ir_assignment(lhs, rhs, NULL);
+      instructions->push_tail(inst);
+   }
+
+   ir_dereference *retval = new ir_dereference(declarations[16]);
+
+   inst = new ir_return((ir_expression *) retval);
+   instructions->push_tail(inst);
+}
+
+
+/**
+ * Generate the body of a matrix constructor that takes a single scalar
+ */
+static void
+generate_mat_body_from_scalar(exec_list *instructions,
+			      ir_variable **declarations)
+{
+   ir_instruction *inst;
+
+   /* Generate an assignment of the parameter to the X component of a
+    * temporary vector.  Set the remaining fields of the vector to 0.  The
+    * size of the vector is equal to the number of rows of the matrix.
+    *
+    * Set each column of the matrix to a successive "rotation" of the
+    * temporary vector.  This fills the matrix with 0s, but writes the single
+    * scalar along the matrix's diagonal.
+    *
+    * For a mat4x3, this is equivalent to:
+    *
+    *   vec3 tmp;
+    *   mat4x3 __retval;
+    *   tmp.x = a;
+    *   tmp.y = 0.0;
+    *   tmp.z = 0.0;
+    *   __retval[0] = tmp.xyy;
+    *   __retval[1] = tmp.yxy;
+    *   __retval[2] = tmp.yyx;
+    *   __retval[3] = tmp.yyy;
+    */
+   const glsl_type *const column_type = declarations[16]->type->column_type();
+   const glsl_type *const row_type = declarations[16]->type->row_type();
+   ir_variable *const column = new ir_variable(column_type, "v");
+
+   instructions->push_tail(column);
+
+   ir_dereference *const lhs = new ir_dereference(column);
+   ir_dereference *const rhs = new ir_dereference(declarations[0]);
+
+   lhs->set_swizzle(0, 0, 0, 0, 1);
+
+   inst = new ir_assignment(lhs, rhs, NULL);
+   instructions->push_tail(inst);
+
+   const float z = 0.0f;
+   ir_constant *const zero = new ir_constant(glsl_float_type, &z);
+
+   for (unsigned i = 1; i < column_type->vector_elements; i++) {
+      ir_dereference *const lhs = new ir_dereference(column);
+
+      lhs->set_swizzle(i, 0, 0, 0, 1);
+
+      inst = new ir_assignment(lhs, zero, NULL);
+      instructions->push_tail(inst);
+   }
+
+
+   for (unsigned i = 0; i < row_type->vector_elements; i++) {
+      static const unsigned swiz[] = { 1, 1, 1, 0, 1, 1, 1 };
+      ir_dereference *const rhs = new ir_dereference(column);
+
+      /* This will be .xyyy when i=0, .yxyy when i=1, etc.
+       */
+      rhs->set_swizzle(swiz[3 - i], swiz[4 - i], swiz[5 - i], swiz[6 - i],
+		       column_type->vector_elements);
+
+      ir_constant *const idx = new ir_constant(glsl_int_type, &i);
+      ir_dereference *const lhs = new ir_dereference(declarations[16], idx);
+
+      inst = new ir_assignment(lhs, rhs, NULL);
+      instructions->push_tail(inst);
+   }
+
+   ir_dereference *const retval = new ir_dereference(declarations[16]);
+   inst = new ir_return((ir_expression *) retval);
+   instructions->push_tail(inst);
+}
+
+
+/**
+ * Generate the body of a vector constructor that takes multiple scalars
+ */
+static void
+generate_mat_body_from_N_scalars(exec_list *instructions,
+				 ir_variable **declarations)
+{
+   ir_instruction *inst;
+   const glsl_type *const row_type = declarations[16]->type->row_type();
+   const glsl_type *const column_type = declarations[16]->type->column_type();
+
+
+   /* Generate an assignment of each parameter to a single component of
+    * of a particular column of __retval and return __retval.
+    */
+   for (unsigned i = 0; i < column_type->vector_elements; i++) {
+      for (unsigned j = 0; j < row_type->vector_elements; j++) {
+	 ir_constant *row_index = new ir_constant(glsl_int_type, &i);
+	 ir_dereference *const row_access =
+	    new ir_dereference(declarations[16], row_index);
+
+	 ir_dereference *const component_access =
+	    new ir_dereference(row_access);
+
+	 component_access->selector.swizzle.x = j;
+	 component_access->selector.swizzle.num_components = 1;
+
+	 const unsigned param = (i * row_type->vector_elements) + j;
+	 ir_dereference *const rhs = new ir_dereference(declarations[param]);
+
+	 inst = new ir_assignment(component_access, rhs, NULL);
+	 instructions->push_tail(inst);
+      }
+   }
+
+   ir_dereference *retval = new ir_dereference(declarations[16]);
+
+   inst = new ir_return((ir_expression *) retval);
+   instructions->push_tail(inst);
+}
+
+
+/**
+ * Generate the constructors for a set of GLSL types
+ *
+ * Constructor implementations are added to \c instructions, and the symbols
+ * are added to \c symtab.
+ */
+static void
+generate_constructor(glsl_symbol_table *symtab, const struct glsl_type *types,
+		     unsigned num_types, exec_list *instructions)
+{
+   ir_variable *declarations[17];
+
+   for (unsigned i = 0; i < num_types; i++) {
+      /* Only numeric and boolean vectors and matrices get constructors here.
+       * Structures need to be handled elsewhere.  It is expected that scalar
+       * constructors are never actually called, so they are not generated.
+       */
+      if (!types[i].is_numeric() && !types[i].is_boolean())
+	 continue;
+
+      if (types[i].is_scalar())
+	 continue;
+
+      /* Generate the function name and add it to the symbol table.
+       */
+      ir_function *const f = new ir_function(types[i].name);
+
+      bool added = symtab->add_function(types[i].name, f);
+      assert(added);
+
+
+      /* Each type has several basic constructors.  The total number of forms
+       * depends on the derived type.
+       *
+       * Vectors:  1 scalar, N scalars
+       * Matrices: 1 scalar, NxM scalars
+       *
+       * Several possible types of constructors are not included in this list.
+       *
+       * Scalar constructors are not included.  The expectation is that the
+       * IR generator won't actually generate these as constructor calls.  The
+       * expectation is that it will just generate the necessary type
+       * conversion.
+       *
+       * Matrix contructors from matrices are also not included.  The
+       * expectation is that the IR generator will generate a call to the
+       * appropriate from-scalars constructor.
+       */
+      ir_function_signature *const sig = new ir_function_signature(& types[i]);
+      f->signatures.push_tail(sig);
+
+      generate_constructor_intro(& types[i], 1, & sig->parameters,
+				 instructions, declarations);
+
+      if (types[i].is_vector()) {
+	 generate_vec_body_from_scalar(instructions, declarations);
+
+	 ir_function_signature *const vec_sig =
+	    new ir_function_signature(& types[i]);
+	 f->signatures.push_tail(vec_sig);
+
+	 generate_constructor_intro(& types[i], types[i].vector_elements,
+				    & vec_sig->parameters, instructions,
+				    declarations);
+	 generate_vec_body_from_N_scalars(instructions, declarations);
+      } else {
+	 assert(types[i].is_matrix());
+
+	 generate_mat_body_from_scalar(instructions, declarations);
+
+	 ir_function_signature *const mat_sig =
+	    new ir_function_signature(& types[i]);
+	 f->signatures.push_tail(mat_sig);
+
+	 generate_constructor_intro(& types[i],
+				    (types[i].vector_elements
+				     * types[i].matrix_columns),
+				    & mat_sig->parameters, instructions,
+				    declarations);
+	 generate_mat_body_from_N_scalars(instructions, declarations);
+      }
+   }
+}
+
+
+void
+generate_110_constructors(glsl_symbol_table *symtab, exec_list *instructions)
+{
+   generate_constructor(symtab, builtin_core_types,
+			Elements(builtin_core_types), instructions);
+}
+
+
+void
+generate_120_constructors(glsl_symbol_table *symtab, exec_list *instructions)
+{
+   generate_110_constructors(symtab, instructions);
+
+   generate_constructor(symtab, builtin_120_types,
+			Elements(builtin_120_types), instructions);
+}
+
+
+void
+generate_130_constructors(glsl_symbol_table *symtab, exec_list *instructions)
+{
+   generate_120_constructors(symtab, instructions);
+
+   generate_constructor(symtab, builtin_130_types,
+			Elements(builtin_130_types), instructions);
+}
+
+
+void
+_mesa_glsl_initialize_constructors(exec_list *instructions,
+				   struct _mesa_glsl_parse_state *state)
+{
+   switch (state->language_version) {
+   case 110:
+      generate_110_constructors(state->symbols, instructions);
+      break;
+   case 120:
+      generate_120_constructors(state->symbols, instructions);
+      break;
+   case 130:
+      generate_130_constructors(state->symbols, instructions);
+      break;
+   default:
+      /* error */
+      break;
+   }
+}
+
+
 const glsl_type *
 glsl_type::get_instance(unsigned base_type, unsigned rows, unsigned columns)
 {

glsl_types.h

@@ -288,6 +288,10 @@ extern "C" {
 extern void
 _mesa_glsl_initialize_types(struct _mesa_glsl_parse_state *state);
 
+extern void
+_mesa_glsl_initialize_constructors(struct exec_list *instructions,
+				   struct _mesa_glsl_parse_state *state);
+
 #ifdef __cplusplus
 }
 #endif