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 Optimal reductions and helper functions.
24 * @author Sebastian Buchwald
29 #include "adt/array.h"
35 #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"
49 pbqp_edge **edge_bucket;
50 pbqp_edge **rm_bucket;
51 pbqp_node **node_buckets[4];
52 pbqp_node **reduced_bucket = NULL;
53 static int buckets_filled = 0;
55 static void insert_into_edge_bucket(pbqp_edge *edge)
57 if (edge_bucket_contains(edge_bucket, edge)) {
58 /* Edge is already inserted. */
62 edge_bucket_insert(&edge_bucket, edge);
65 static void insert_into_rm_bucket(pbqp_edge *edge)
67 if (edge_bucket_contains(rm_bucket, edge)) {
68 /* Edge is already inserted. */
72 edge_bucket_insert(&rm_bucket, edge);
75 static void init_buckets(void)
79 edge_bucket_init(&edge_bucket);
80 edge_bucket_init(&rm_bucket);
81 node_bucket_init(&reduced_bucket);
83 for (i = 0; i < 4; ++i) {
84 node_bucket_init(&node_buckets[i]);
88 void free_buckets(void)
92 for (i = 0; i < 4; ++i) {
93 node_bucket_free(&node_buckets[i]);
96 edge_bucket_free(&edge_bucket);
97 edge_bucket_free(&rm_bucket);
98 node_bucket_free(&reduced_bucket);
103 void fill_node_buckets(pbqp *pbqp)
109 node_len = pbqp->num_nodes;
112 ir_timer_t *t_fill_buckets = ir_timer_new();
113 ir_timer_start(t_fill_buckets);
116 for (node_index = 0; node_index < node_len; ++node_index) {
118 pbqp_node *node = get_node(pbqp, node_index);
122 degree = pbqp_node_get_degree(node);
124 /* We have only one bucket for nodes with arity >= 3. */
129 node_bucket_insert(&node_buckets[degree], node);
135 ir_timer_stop(t_fill_buckets);
136 printf("PBQP Fill Nodes into buckets: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_fill_buckets) / 1000.0);
140 static void normalize_towards_source(pbqp_edge *edge)
153 src_node = edge->src;
154 tgt_node = edge->tgt;
158 src_vec = src_node->costs;
159 tgt_vec = tgt_node->costs;
163 src_len = src_vec->len;
164 tgt_len = tgt_vec->len;
171 /* Normalize towards source node. */
172 for (src_index = 0; src_index < src_len; ++src_index) {
173 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
176 if (src_vec->entries[src_index].data == INF_COSTS) {
177 pbqp_matrix_set_row_value(mat, src_index, 0);
179 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
181 src_vec->entries[src_index].data = pbqp_add(
182 src_vec->entries[src_index].data, min);
184 if (min == INF_COSTS) {
186 unsigned edge_len = pbqp_node_get_degree(src_node);
188 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
189 pbqp_edge *edge_candidate = src_node->edges[edge_index];
190 if (edge_candidate != edge) {
191 insert_into_edge_bucket(edge_candidate);
199 static void normalize_towards_target(pbqp_edge *edge)
212 src_node = edge->src;
213 tgt_node = edge->tgt;
217 src_vec = src_node->costs;
218 tgt_vec = tgt_node->costs;
222 src_len = src_vec->len;
223 tgt_len = tgt_vec->len;
230 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
231 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
234 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
235 pbqp_matrix_set_col_value(mat, tgt_index, 0);
237 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
239 tgt_vec->entries[tgt_index].data = pbqp_add(
240 tgt_vec->entries[tgt_index].data, min);
242 if (min == INF_COSTS) {
244 unsigned edge_len = pbqp_node_get_degree(tgt_node);
246 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
247 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
248 if (edge_candidate != edge) {
249 insert_into_edge_bucket(edge_candidate);
258 * Tries to apply RM for the source node of the given edge.
260 * Checks whether the source node of edge can be merged into the target node of
261 * edge, and performs the merge, if possible.
263 static void merge_source_into_target(pbqp *pbqp, pbqp_edge *edge)
281 src_node = edge->src;
282 tgt_node = edge->tgt;
286 src_vec = src_node->costs;
287 tgt_vec = tgt_node->costs;
291 src_len = src_vec->len;
292 tgt_len = tgt_vec->len;
294 /* Matrizes are normalized. */
301 mapping = NEW_ARR_F(unsigned, tgt_len);
303 /* Check that each column has at most one zero entry. */
304 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
305 unsigned onlyOneZero = 0;
307 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
310 for (src_index = 0; src_index < src_len; ++src_index) {
311 if (src_vec->entries[src_index].data == INF_COSTS)
314 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
317 /* Matrix entry is finite. */
324 mapping[tgt_index] = src_index;
328 /* We know that we can merge the source node into the target node. */
329 edge_len = pbqp_node_get_degree(src_node);
335 /* Reconnect the source's edges with the target node. */
336 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
337 pbqp_edge *old_edge = src_node->edges[edge_index];
339 pbqp_matrix *old_matrix;
340 pbqp_matrix *new_matrix;
341 pbqp_node *other_node;
344 unsigned other_index;
349 if (old_edge == edge)
352 old_matrix = old_edge->costs;
355 if (old_edge->tgt == src_node) {
356 other_node = old_edge->src;
357 other_len = old_matrix->rows;
360 other_node = old_edge->tgt;
361 other_len = old_matrix->cols;
364 other_vec = other_node->costs;
366 new_matrix = pbqp_matrix_alloc(pbqp, tgt_len, other_len);
368 /* Source node selects the column of the old_matrix. */
369 if (old_edge->tgt == src_node) {
370 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
371 unsigned src_index = mapping[tgt_index];
373 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
376 for (other_index = 0; other_index < other_len; ++other_index) {
377 if (other_vec->entries[other_index].data == INF_COSTS)
380 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[other_index*src_len+src_index];
384 /* Source node selects the row of the old_matrix. */
386 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
387 unsigned src_index = mapping[tgt_index];
389 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
392 for (other_index = 0; other_index < other_len; ++other_index) {
393 if (other_vec->entries[other_index].data == INF_COSTS)
396 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[src_index*other_len+other_index];
401 add_edge_costs(pbqp, tgt_node->index, other_node->index, new_matrix);
403 delete_edge(old_edge);
404 reorder_node(src_node);
405 reorder_node(other_node);
407 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
408 insert_into_rm_bucket(new_edge);
411 /* Reduce the remaining source node via RI. */
416 * Tries to apply RM for the target node of the given edge.
418 * Checks whether the target node of edge can be merged into the source node of
419 * edge, and performs the merge, if possible.
421 static void merge_target_into_source(pbqp *pbqp, pbqp_edge *edge)
439 src_node = edge->src;
440 tgt_node = edge->tgt;
444 src_vec = src_node->costs;
445 tgt_vec = tgt_node->costs;
449 src_len = src_vec->len;
450 tgt_len = tgt_vec->len;
452 /* Matrizes are normalized. */
459 mapping = NEW_ARR_F(unsigned, src_len);
461 /* Check that each row has at most one zero entry. */
462 for (src_index = 0; src_index < src_len; ++src_index) {
463 unsigned onlyOneZero = 0;
465 if (src_vec->entries[src_index].data == INF_COSTS)
468 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
469 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
472 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
475 /* Matrix entry is finite. */
482 mapping[src_index] = tgt_index;
486 /* We know that we can merge the target node into the source node. */
487 edge_len = pbqp_node_get_degree(tgt_node);
493 /* Reconnect the target's edges with the source node. */
494 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
495 pbqp_edge *old_edge = tgt_node->edges[edge_index];
497 pbqp_matrix *old_matrix;
498 pbqp_matrix *new_matrix;
499 pbqp_node *other_node;
502 unsigned other_index;
507 if (old_edge == edge)
510 old_matrix = old_edge->costs;
513 if (old_edge->tgt == tgt_node) {
514 other_node = old_edge->src;
515 other_len = old_matrix->rows;
518 other_node = old_edge->tgt;
519 other_len = old_matrix->cols;
522 other_vec = other_node->costs;
524 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
526 /* Target node selects the column of the old_matrix. */
527 if (old_edge->tgt == tgt_node) {
528 for (src_index = 0; src_index < src_len; ++src_index) {
529 unsigned tgt_index = mapping[src_index];
531 if (src_vec->entries[src_index].data == INF_COSTS)
534 for (other_index = 0; other_index < other_len; ++other_index) {
535 if (other_vec->entries[other_index].data == INF_COSTS)
538 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
542 /* Source node selects the row of the old_matrix. */
544 for (src_index = 0; src_index < src_len; ++src_index) {
545 unsigned tgt_index = mapping[src_index];
547 if (src_vec->entries[src_index].data == INF_COSTS)
550 for (other_index = 0; other_index < other_len; ++other_index) {
551 if (other_vec->entries[other_index].data == INF_COSTS)
554 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
559 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
561 delete_edge(old_edge);
562 reorder_node(tgt_node);
563 reorder_node(other_node);
565 new_edge = get_edge(pbqp, src_node->index, other_node->index);
566 insert_into_rm_bucket(new_edge);
569 /* Reduce the remaining source node via RI. */
574 * Merge neighbors into the given node.
576 void apply_RM(pbqp *pbqp, pbqp_node *node)
586 edge_len = pbqp_node_get_degree(node);
588 /* Check all incident edges. */
589 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
590 pbqp_edge *edge = edges[edge_index];
592 insert_into_rm_bucket(edge);
595 /* ALAP: Merge neighbors into given node. */
596 while(edge_bucket_get_length(rm_bucket) > 0) {
597 pbqp_edge *edge = edge_bucket_pop(&rm_bucket);
600 if (edge->src == node)
601 merge_target_into_source(pbqp, edge);
603 merge_source_into_target(pbqp, edge);
607 void reorder_node(pbqp_node *node)
609 unsigned degree = pbqp_node_get_degree(node);
610 /* Assume node lost one incident edge. */
611 unsigned old_degree = degree + 1;
613 if (!buckets_filled) return;
615 /* Same bucket as before */
616 if (degree > 2) return;
618 if (!node_bucket_contains(node_buckets[old_degree], node)) {
619 /* Old arity is new arity, so we have nothing to do. */
620 assert(node_bucket_contains(node_buckets[degree], node));
624 /* Delete node from old bucket... */
625 node_bucket_remove(&node_buckets[old_degree], node);
627 /* ..and add to new one. */
628 node_bucket_insert(&node_buckets[degree], node);
631 void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
644 src_node = edge->src;
645 tgt_node = edge->tgt;
649 /* If edge are already deleted, we have nothing to do. */
650 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
654 if (pbqp->dump_file) {
656 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
657 dump_section(pbqp->dump_file, 3, txt);
661 src_vec = src_node->costs;
662 tgt_vec = tgt_node->costs;
666 src_len = src_vec->len;
667 tgt_len = tgt_vec->len;
675 if (pbqp->dump_file) {
676 fputs("Input:<br>\n", pbqp->dump_file);
677 dump_simplifyedge(pbqp, edge);
681 normalize_towards_source(edge);
682 normalize_towards_target(edge);
685 if (pbqp->dump_file) {
686 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
687 dump_simplifyedge(pbqp, edge);
691 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
693 if (pbqp->dump_file) {
694 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
703 reorder_node(src_node);
704 reorder_node(tgt_node);
708 void initial_simplify_edges(pbqp *pbqp)
716 ir_timer_t *t_int_simpl = ir_timer_new();
717 ir_timer_start(t_int_simpl);
721 if (pbqp->dump_file) {
722 pbqp_dump_input(pbqp);
723 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
727 node_len = pbqp->num_nodes;
731 /* First simplify all edges. */
732 for (node_index = 0; node_index < node_len; ++node_index) {
734 pbqp_node *node = get_node(pbqp, node_index);
741 edge_len = pbqp_node_get_degree(node);
743 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
744 pbqp_edge *edge = edges[edge_index];
746 /* Simplify only once per edge. */
747 if (node != edge->src) continue;
749 simplify_edge(pbqp, edge);
754 ir_timer_stop(t_int_simpl);
755 printf("PBQP Initial simplify edges: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
759 num determine_solution(pbqp *pbqp)
766 ir_timer_t *t_det_solution = ir_timer_new();
767 ir_timer_reset_and_start(t_det_solution);
777 file = pbqp->dump_file;
780 dump_section(file, 1, "4. Determine Solution/Minimum");
781 dump_section(file, 2, "4.1. Trivial Solution");
785 /* Solve trivial nodes and calculate solution. */
786 node_len = node_bucket_get_length(node_buckets[0]);
789 pbqp->num_r0 = node_len;
792 for (node_index = 0; node_index < node_len; ++node_index) {
793 pbqp_node *node = node_buckets[0][node_index];
796 node->solution = vector_get_min_index(node->costs);
797 solution = pbqp_add(solution,
798 node->costs->entries[node->solution].data);
802 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
803 dump_node(file, node);
810 dump_section(file, 2, "Minimum");
811 #if KAPS_USE_UNSIGNED
812 fprintf(file, "Minimum is equal to %u.", solution);
814 fprintf(file, "Minimum is equal to %lld.", solution);
820 ir_timer_stop(t_det_solution);
821 printf("PBQP Determine Solution: %8.3lf msec\n", (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
827 static void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
838 edge = node->edges[0];
840 is_src = edge->src == node;
847 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
852 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
856 if (pbqp->dump_file) {
857 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
862 static void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
864 pbqp_edge *src_edge = node->edges[0];
865 pbqp_edge *tgt_edge = node->edges[1];
866 int src_is_src = src_edge->src == node;
867 int tgt_is_src = tgt_edge->src == node;
868 pbqp_matrix *src_mat;
869 pbqp_matrix *tgt_mat;
880 src_node = src_edge->tgt;
882 src_node = src_edge->src;
886 tgt_node = tgt_edge->tgt;
888 tgt_node = tgt_edge->src;
891 /* Swap nodes if necessary. */
892 if (tgt_node->index < src_node->index) {
904 src_is_src = src_edge->src == node;
905 tgt_is_src = tgt_edge->src == node;
908 src_mat = src_edge->costs;
909 tgt_mat = tgt_edge->costs;
911 node_vec = node->costs;
913 row_index = src_node->solution;
914 col_index = tgt_node->solution;
916 vec = vector_copy(pbqp, node_vec);
919 vector_add_matrix_col(vec, src_mat, row_index);
921 vector_add_matrix_row(vec, src_mat, row_index);
925 vector_add_matrix_col(vec, tgt_mat, col_index);
927 vector_add_matrix_row(vec, tgt_mat, col_index);
930 node->solution = vector_get_min_index(vec);
933 if (pbqp->dump_file) {
934 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
938 obstack_free(&pbqp->obstack, vec);
941 void back_propagate(pbqp *pbqp)
944 unsigned node_len = node_bucket_get_length(reduced_bucket);
949 if (pbqp->dump_file) {
950 dump_section(pbqp->dump_file, 2, "Back Propagation");
954 for (node_index = node_len; node_index > 0; --node_index) {
955 pbqp_node *node = reduced_bucket[node_index - 1];
957 switch (pbqp_node_get_degree(node)) {
959 back_propagate_RI(pbqp, node);
962 back_propagate_RII(pbqp, node);
965 panic("Only nodes with degree one or two should be in this bucket");
971 void apply_edge(pbqp *pbqp)
973 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
975 simplify_edge(pbqp, edge);
978 void apply_RI(pbqp *pbqp)
980 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
981 pbqp_edge *edge = node->edges[0];
982 pbqp_matrix *mat = edge->costs;
983 int is_src = edge->src == node;
984 pbqp_node *other_node;
987 assert(pbqp_node_get_degree(node) == 1);
990 other_node = edge->tgt;
992 other_node = edge->src;
996 if (pbqp->dump_file) {
998 sprintf(txt, "RI-Reduction of Node n%d", node->index);
999 dump_section(pbqp->dump_file, 2, txt);
1000 pbqp_dump_graph(pbqp);
1001 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1002 dump_node(pbqp->dump_file, node);
1003 dump_node(pbqp->dump_file, other_node);
1004 dump_edge(pbqp->dump_file, edge);
1009 pbqp_matrix_add_to_all_cols(mat, node->costs);
1010 normalize_towards_target(edge);
1012 pbqp_matrix_add_to_all_rows(mat, node->costs);
1013 normalize_towards_source(edge);
1015 disconnect_edge(other_node, edge);
1018 if (pbqp->dump_file) {
1019 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1020 dump_node(pbqp->dump_file, other_node);
1024 reorder_node(other_node);
1030 /* Add node to back propagation list. */
1031 node_bucket_insert(&reduced_bucket, node);
1034 void apply_RII(pbqp *pbqp)
1036 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
1037 pbqp_edge *src_edge = node->edges[0];
1038 pbqp_edge *tgt_edge = node->edges[1];
1039 int src_is_src = src_edge->src == node;
1040 int tgt_is_src = tgt_edge->src == node;
1041 pbqp_matrix *src_mat;
1042 pbqp_matrix *tgt_mat;
1043 pbqp_node *src_node;
1044 pbqp_node *tgt_node;
1057 assert(pbqp_node_get_degree(node) == 2);
1060 src_node = src_edge->tgt;
1062 src_node = src_edge->src;
1066 tgt_node = tgt_edge->tgt;
1068 tgt_node = tgt_edge->src;
1071 /* Swap nodes if necessary. */
1072 if (tgt_node->index < src_node->index) {
1073 pbqp_node *tmp_node;
1074 pbqp_edge *tmp_edge;
1076 tmp_node = src_node;
1077 src_node = tgt_node;
1078 tgt_node = tmp_node;
1080 tmp_edge = src_edge;
1081 src_edge = tgt_edge;
1082 tgt_edge = tmp_edge;
1084 src_is_src = src_edge->src == node;
1085 tgt_is_src = tgt_edge->src == node;
1089 if (pbqp->dump_file) {
1091 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1092 dump_section(pbqp->dump_file, 2, txt);
1093 pbqp_dump_graph(pbqp);
1094 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1095 dump_node(pbqp->dump_file, src_node);
1096 dump_edge(pbqp->dump_file, src_edge);
1097 dump_node(pbqp->dump_file, node);
1098 dump_edge(pbqp->dump_file, tgt_edge);
1099 dump_node(pbqp->dump_file, tgt_node);
1103 src_mat = src_edge->costs;
1104 tgt_mat = tgt_edge->costs;
1106 src_vec = src_node->costs;
1107 tgt_vec = tgt_node->costs;
1108 node_vec = node->costs;
1110 row_len = src_vec->len;
1111 col_len = tgt_vec->len;
1112 node_len = node_vec->len;
1114 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1116 for (row_index = 0; row_index < row_len; ++row_index) {
1117 for (col_index = 0; col_index < col_len; ++col_index) {
1118 vec = vector_copy(pbqp, node_vec);
1121 vector_add_matrix_col(vec, src_mat, row_index);
1123 vector_add_matrix_row(vec, src_mat, row_index);
1127 vector_add_matrix_col(vec, tgt_mat, col_index);
1129 vector_add_matrix_row(vec, tgt_mat, col_index);
1132 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1134 obstack_free(&pbqp->obstack, vec);
1138 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
1140 /* Disconnect node. */
1141 disconnect_edge(src_node, src_edge);
1142 disconnect_edge(tgt_node, tgt_edge);
1148 /* Add node to back propagation list. */
1149 node_bucket_insert(&reduced_bucket, node);
1152 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1155 pbqp_matrix_add(edge->costs, mat);
1157 /* Free local matrix. */
1158 obstack_free(&pbqp->obstack, mat);
1160 reorder_node(src_node);
1161 reorder_node(tgt_node);
1165 if (pbqp->dump_file) {
1166 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1167 dump_edge(pbqp->dump_file, edge);
1171 /* Edge has changed so we simplify it. */
1172 simplify_edge(pbqp, edge);
1175 void select_alternative(pbqp_node *node, unsigned selected_index)
1177 unsigned edge_index;
1178 unsigned node_index;
1181 unsigned max_degree = pbqp_node_get_degree(node);
1184 node->solution = selected_index;
1185 node_vec = node->costs;
1186 node_len = node_vec->len;
1187 assert(selected_index < node_len);
1189 /* Set all other costs to infinity. */
1190 for (node_index = 0; node_index < node_len; ++node_index) {
1191 if (node_index != selected_index) {
1192 node_vec->entries[node_index].data = INF_COSTS;
1196 /* Add all incident edges to edge bucket, since they are now independent. */
1197 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1198 insert_into_edge_bucket(node->edges[edge_index]);
1202 pbqp_node *get_node_with_max_degree(void)
1204 pbqp_node **bucket = node_buckets[3];
1205 unsigned bucket_len = node_bucket_get_length(bucket);
1206 unsigned bucket_index;
1207 unsigned max_degree = 0;
1208 pbqp_node *result = NULL;
1210 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1211 pbqp_node *candidate = bucket[bucket_index];
1212 unsigned degree = pbqp_node_get_degree(candidate);
1214 if (degree > max_degree) {
1216 max_degree = degree;
1223 unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
1229 unsigned edge_index;
1230 unsigned max_degree;
1231 unsigned node_index;
1233 unsigned min_index = 0;
1234 num min = INF_COSTS;
1239 node_vec = node->costs;
1240 node_len = node_vec->len;
1241 max_degree = pbqp_node_get_degree(node);
1243 for (node_index = 0; node_index < node_len; ++node_index) {
1244 num value = node_vec->entries[node_index].data;
1246 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1247 edge = node->edges[edge_index];
1249 is_src = edge->src == node;
1252 vec = vector_copy(pbqp, edge->tgt->costs);
1253 vector_add_matrix_row(vec, mat, node_index);
1255 vec = vector_copy(pbqp, edge->src->costs);
1256 vector_add_matrix_col(vec, mat, node_index);
1259 value = pbqp_add(value, vector_get_min(vec));
1261 obstack_free(&pbqp->obstack, vec);
1266 min_index = node_index;
1273 int node_is_reduced(pbqp_node *node)
1275 if (!reduced_bucket) return 0;
1277 if (pbqp_node_get_degree(node) == 0) return 1;
1279 return node_bucket_contains(reduced_bucket, node);