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 Heuristic PBQP solver for SSA-based register allocation.
24 * @author Thomas Bersch
29 #include "adt/array.h"
34 #include "heuristical_co.h"
37 #include "html_dumper.h"
41 #include "pbqp_edge.h"
42 #include "pbqp_edge_t.h"
43 #include "pbqp_node.h"
44 #include "pbqp_node_t.h"
50 static void merge_into_RN_node(pbqp *pbqp, plist_t *rpeo)
52 pbqp_node *node = NULL;
56 /* We want to reduce the first node in reverse perfect elimination order. */
58 /* get first element from reverse perfect elimination order */
59 node = plist_first(rpeo)->data;
60 /* remove element from reverse perfect elimination order */
61 plist_erase(rpeo, plist_first(rpeo));
62 /* insert node at the end of rpeo so the rpeo already exits after pbqp solving */
63 plist_insert_back(rpeo, node);
64 } while(node_is_reduced(node));
67 assert(pbqp_node_get_degree(node) > 2);
69 /* Check whether we can merge a neighbor into the current node. */
73 static void apply_RN_co(pbqp *pbqp)
75 pbqp_node *node = NULL;
76 unsigned min_index = 0;
84 if (node_is_reduced(node))
88 if (pbqp->dump_file) {
90 sprintf(txt, "RN-Reduction of Node n%d", node->index);
91 dump_section(pbqp->dump_file, 2, txt);
92 pbqp_dump_graph(pbqp);
96 min_index = get_local_minimal_alternative(pbqp, node);
99 if (pbqp->dump_file) {
100 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
101 node->index, min_index);
106 FILE *fh = fopen("solutions.pb", "a");
107 fprintf(fh, "[%u]", min_index);
112 /* Now that we found the local minimum set all other costs to infinity. */
113 select_alternative(node, min_index);
116 static void apply_heuristic_reductions_co(pbqp *pbqp, plist_t *rpeo)
120 ir_timer_t *t_edge = ir_timer_new();
121 ir_timer_t *t_r1 = ir_timer_new();
122 ir_timer_t *t_r2 = ir_timer_new();
123 ir_timer_t *t_rn = ir_timer_new();
127 if (edge_bucket_get_length(edge_bucket) > 0) {
129 ir_timer_start(t_edge);
135 ir_timer_stop(t_edge);
137 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
139 ir_timer_start(t_r1);
147 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
149 ir_timer_start(t_r2);
157 } else if (merged_node != NULL) {
159 ir_timer_start(t_rn);
167 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
169 ir_timer_start(t_rn);
172 merge_into_RN_node(pbqp, rpeo);
179 printf("PBQP RE reductions: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_edge) / 1000.0);
180 printf("PBQP R1 reductions: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_r1) / 1000.0);
181 printf("PBQP R2 reductions: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_r2) / 1000.0);
182 printf("PBQP RN reductions: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_rn) / 1000.0);
190 void solve_pbqp_heuristical_co(pbqp *pbqp, plist_t *rpeo)
192 /* Reduce nodes degree ... */
193 initial_simplify_edges(pbqp);
195 /* ... and put node into bucket representing their degree. */
196 fill_node_buckets(pbqp);
199 FILE *fh = fopen("solutions.pb", "a");
200 fprintf(fh, "Solution");
204 apply_heuristic_reductions_co(pbqp, rpeo);
206 pbqp->solution = determine_solution(pbqp);
209 fh = fopen("solutions.pb", "a");
210 #if KAPS_USE_UNSIGNED
211 fprintf(fh, ": %u RE:%u R0:%u R1:%u R2:%u RM:%u RN/BF:%u\n", pbqp->solution,
212 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
213 pbqp->num_rm, pbqp->num_rn);
215 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RM:%u RN/BF:%u\n", pbqp->solution,
216 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
221 /* Solve reduced nodes. */
222 back_propagate(pbqp);