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
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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
29 #include "adt/array.h"
34 #include "heuristical.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 apply_heuristic_reductions(pbqp *pbqp)
53 if (edge_bucket_get_length(edge_bucket) > 0) {
55 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
57 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
59 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
67 void solve_pbqp_heuristical(pbqp *pbqp)
69 /* Reduce nodes degree ... */
70 initial_simplify_edges(pbqp);
72 /* ... and put node into bucket representing their degree. */
73 fill_node_buckets(pbqp);
76 FILE *fh = fopen("solutions.pb", "a");
77 fprintf(fh, "Solution");
81 apply_heuristic_reductions(pbqp);
83 pbqp->solution = determine_solution(pbqp);
86 fh = fopen("solutions.pb", "a");
87 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
88 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
93 /* Solve reduced nodes. */
99 void apply_RN(pbqp *pbqp)
101 pbqp_node *node = NULL;
102 unsigned min_index = 0;
106 /* We want to reduce a node with maximum degree. */
107 node = get_node_with_max_degree();
109 assert(pbqp_node_get_degree(node) > 2);
112 if (pbqp->dump_file) {
114 sprintf(txt, "RN-Reduction of Node n%d", node->index);
115 dump_section(pbqp->dump_file, 2, txt);
116 pbqp_dump_graph(pbqp);
120 min_index = get_local_minimal_alternative(pbqp, node);
123 if (pbqp->dump_file) {
124 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
125 node->index, min_index);
131 FILE *fh = fopen("solutions.pb", "a");
132 fprintf(fh, "[%u]", min_index);
138 /* Now that we found the local minimum set all other costs to infinity. */
139 select_alternative(node, min_index);