-ast_expression *parser_builtin_pow(parser_t *parser) {
- /*
- * float __builtin_pow(float x, float y) {
- * float value = 1.0f;
- * while (y > 0) {
- * while (!(y&1)) {
- * y *= 2;
- * x *= x;
- * }
- * y = y - 1;
- * value = x * value;
- * }
- * return value;
- * }
- */
- static ast_function *pow_func = NULL;
- static ast_value *pow_func_val = NULL;
- if (!pow_func) {
- ast_value *pow_arguments[2];
- ast_value *pow_value = ast_value_new (parser_ctx(parser), "value", TYPE_FLOAT);
- ast_block *pow_body = ast_block_new (parser_ctx(parser));
- ast_block *pow_loop_body = ast_block_new (parser_ctx(parser));
- ast_block *pow_loop_nest_body = ast_block_new (parser_ctx(parser));
- ast_loop *pow_loop = NULL;
- ast_loop *pow_loop_nest = NULL;
-
- pow_arguments[0] = ast_value_new (parser_ctx(parser), "x", TYPE_FLOAT);
- pow_arguments[1] = ast_value_new (parser_ctx(parser), "x", TYPE_FLOAT);
- pow_func_val = ast_value_new (parser_ctx(parser), "__builtin_pow", TYPE_FUNCTION);
- pow_func_val->expression.next = (ast_expression*)ast_value_new(parser_ctx(parser), "<float>", TYPE_FLOAT);
-
- vec_push(pow_func_val->expression.params, pow_arguments[0]);
- vec_push(pow_func_val->expression.params, pow_arguments[1]);
-
- pow_func = ast_function_new(parser_ctx(parser), "__builtin_pow", pow_func_val);
-
- /* float value; */
- vec_push(pow_body->locals, pow_value);
- /* value = 1.0f; */
- vec_push(pow_body->exprs,
- (ast_expression*)ast_store_new(
- parser_ctx(parser),
- INSTR_STORE_F,
- (ast_expression*)pow_value,
- (ast_expression*)parser_const_float_1(parser)
- )
- );
-
- /* y >>= 2 */
- vec_push(pow_loop_nest_body->exprs,
- (ast_expression*)ast_binstore_new(
- parser_ctx(parser),
- INSTR_STORE_F,
- INSTR_MUL_F,
- (ast_expression*)pow_arguments[1],
- (ast_expression*)parser_const_float(parser, 0.25f)
- )
- );
- vec_push(pow_loop_nest_body->exprs,
- (ast_expression*)ast_binstore_new(
- parser_ctx(parser),
- INSTR_STORE_F,
- INSTR_MUL_F,
- (ast_expression*)pow_arguments[0],
- (ast_expression*)pow_arguments[0]
- )
- );
-
- /* while (!(y&1)) */
- pow_loop_nest = ast_loop_new (
- parser_ctx(parser),
- NULL,
- (ast_expression*)ast_binary_new(
- parser_ctx(parser),
- INSTR_AND,
- (ast_expression*)pow_arguments[1],
- (ast_expression*)parser_const_float_1(parser)
- ),
- true,
- NULL,
- false,
- NULL,
- (ast_expression*)pow_loop_nest_body
- );
-
- vec_push(pow_loop_body->exprs, (ast_expression*)pow_loop_nest);
- vec_push(pow_loop_body->exprs,
- (ast_expression*)ast_binstore_new(
- parser_ctx(parser),
- INSTR_STORE_F,
- INSTR_SUB_F,
- (ast_expression*)pow_arguments[1],
- (ast_expression*)parser_const_float_1(parser)
- )
- );
- vec_push(pow_loop_body->exprs,
- (ast_expression*)ast_binstore_new(
- parser_ctx(parser),
- INSTR_STORE_F,
- INSTR_MUL_F,
- (ast_expression*)pow_value,
- (ast_expression*)pow_arguments[0]
- )
- );
-
- /* while (y > 0) { */
- pow_loop = ast_loop_new(
- parser_ctx(parser),
- NULL,
- (ast_expression*)ast_binary_new(
- parser_ctx(parser),
- INSTR_GT,
- (ast_expression*)pow_arguments[1],
- (ast_expression*)parser_const_float_0(parser)
- ),
- false,
- NULL,
- false,
- NULL,
- (ast_expression*)pow_loop_body
- );
- /* } */
- vec_push(pow_body->exprs, (ast_expression*)pow_loop);
- /* return value; */
- vec_push(pow_body->exprs,
- (ast_expression*)ast_return_new(
- parser_ctx(parser),
- (ast_expression*)pow_value
- )
- );
-
- vec_push(pow_func->blocks, pow_body);
- vec_push(parser->globals, (ast_expression*)pow_func_val);
- vec_push(parser->functions, pow_func);
- }
-
- return (ast_expression*)pow_func_val;
-}
-