+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;
+}
+
+/* parse computed goto sides */
+static ast_expression *parse_goto_computed(parser_t *parser, ast_expression **side) {
+ ast_expression *on_true;
+ ast_expression *on_false;
+ ast_expression *cond;
+
+ if (!*side)
+ return NULL;
+
+ if (ast_istype(*side, ast_ternary)) {
+ ast_ternary *tern = (ast_ternary*)*side;
+ on_true = parse_goto_computed(parser, &tern->on_true);
+ on_false = parse_goto_computed(parser, &tern->on_false);
+
+ if (!on_true || !on_false) {
+ parseerror(parser, "expected label or expression in ternary");
+ if (on_true) ast_unref(on_true);
+ if (on_false) ast_unref(on_false);
+ return NULL;
+ }
+
+ cond = tern->cond;
+ tern->cond = NULL;
+ ast_delete(tern);
+ *side = NULL;
+ return (ast_expression*)ast_ifthen_new(parser_ctx(parser), cond, on_true, on_false);
+ } else if (ast_istype(*side, ast_label)) {
+ ast_goto *gt = ast_goto_new(parser_ctx(parser), ((ast_label*)*side)->name);
+ ast_goto_set_label(gt, ((ast_label*)*side));
+ *side = NULL;
+ return (ast_expression*)gt;
+ }
+ return NULL;
+}
+