2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Random node selector.
23 * @author Matthias Braun
32 #include "belistsched.h"
36 * The random selector:
37 * Just assure that branches are executed last, otherwise select a random node
39 static ir_node *random_select(void *block_env, ir_nodeset_t *ready_set,
40 ir_nodeset_t *live_set)
42 ir_nodeset_iterator_t iter;
44 int only_branches_left = 1;
48 /* assure that branches and constants are executed last */
49 ir_nodeset_iterator_init(&iter, ready_set);
50 while ( (irn = ir_nodeset_iterator_next(&iter)) != NULL) {
52 only_branches_left = 0;
57 if (only_branches_left) {
58 /* at last: schedule branches */
59 ir_nodeset_iterator_init(&iter, ready_set);
60 irn = ir_nodeset_iterator_next(&iter);
63 /* take 1 random node */
64 int n = rand() % ir_nodeset_size(ready_set);
66 ir_nodeset_iterator_init(&iter, ready_set);
67 while ((irn = ir_nodeset_iterator_next(&iter)) != NULL) {
73 } while (is_cfop(irn));
79 static void *random_init_graph(ir_graph *irg)
82 /* TODO: add commandline option for the seed */
87 static void *random_init_block(void *graph_env, ir_node *block)
94 static void sched_random(ir_graph *irg)
96 static const list_sched_selector_t random_selector = {
100 NULL, /* node_ready */
101 NULL, /* node_selected */
102 NULL, /* finish_block */
103 NULL /* finish_graph */
105 be_list_sched_graph(irg, &random_selector);
108 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_sched_rand);
109 void be_init_sched_rand(void)
111 be_register_scheduler("random", sched_random);