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.
24 * @author Sebastian Buchwald
28 #include "adt/array.h"
33 #include "heuristical.h"
36 #include "html_dumper.h"
40 #include "pbqp_edge.h"
41 #include "pbqp_edge_t.h"
42 #include "pbqp_node.h"
43 #include "pbqp_node_t.h"
48 static void apply_RN(pbqp_t *pbqp)
50 pbqp_node_t *node = NULL;
51 unsigned min_index = 0;
55 /* We want to reduce a node with maximum degree. */
56 node = get_node_with_max_degree();
57 assert(pbqp_node_get_degree(node) > 2);
60 if (pbqp->dump_file) {
62 sprintf(txt, "RN-Reduction of Node n%d", node->index);
63 pbqp_dump_section(pbqp->dump_file, 2, txt);
64 pbqp_dump_graph(pbqp);
68 min_index = get_local_minimal_alternative(pbqp, node);
71 if (pbqp->dump_file) {
72 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
73 node->index, min_index);
78 FILE *fh = fopen("solutions.pb", "a");
79 fprintf(fh, "[%u]", min_index);
84 /* Now that we found the local minimum set all other costs to infinity. */
85 select_alternative(node, min_index);
88 static void apply_heuristic_reductions(pbqp_t *pbqp)
91 if (edge_bucket_get_length(edge_bucket) > 0) {
93 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
95 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
97 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
105 void solve_pbqp_heuristical(pbqp_t *pbqp)
107 /* Reduce nodes degree ... */
108 initial_simplify_edges(pbqp);
110 /* ... and put node into bucket representing their degree. */
111 fill_node_buckets(pbqp);
114 FILE *fh = fopen("solutions.pb", "a");
115 fprintf(fh, "Solution");
119 apply_heuristic_reductions(pbqp);
121 pbqp->solution = determine_solution(pbqp);
124 fh = fopen("solutions.pb", "a");
125 #if KAPS_USE_UNSIGNED
126 fprintf(fh, ": %u RE:%u R0:%u R1:%u R2:%u RM:%u RN/BF:%u\n", pbqp->solution,
127 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
128 pbqp->num_rm, pbqp->num_rn);
130 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RM:%u RN/BF:%u\n", pbqp->solution,
131 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
132 pbqp->num_rm, pbqp->num_rn);
137 /* Solve reduced nodes. */
138 back_propagate(pbqp);