6 #include "heuristical.h"
8 #include "html_dumper.h"
12 #include "pbqp_edge.h"
13 #include "pbqp_edge_t.h"
14 #include "pbqp_node.h"
15 #include "pbqp_node_t.h"
18 static pbqp_edge **edge_bucket;
19 static pbqp_node **node_buckets[4];
20 static pbqp_node **reduced_bucket = NULL;
21 static int buckets_filled = 0;
27 /* Forward declarations. */
28 static void apply_Brute_Force(pbqp *pbqp);
30 static void insert_into_edge_bucket(pbqp_edge *edge)
32 if (edge_bucket_contains(edge_bucket, edge)) {
33 /* Edge is already inserted. */
37 edge_bucket_insert(&edge_bucket, edge);
40 static void init_buckets(void)
44 edge_bucket_init(&edge_bucket);
45 node_bucket_init(&reduced_bucket);
47 for (i = 0; i < 4; ++i) {
48 node_bucket_init(&node_buckets[i]);
52 static void free_buckets(void)
56 for (i = 0; i < 4; ++i) {
57 node_bucket_free(&node_buckets[i]);
60 edge_bucket_free(&edge_bucket);
61 node_bucket_free(&reduced_bucket);
66 static void fill_node_buckets(pbqp *pbqp)
72 node_len = pbqp->num_nodes;
74 for (node_index = 0; node_index < node_len; ++node_index) {
76 pbqp_node *node = get_node(pbqp, node_index);
80 degree = pbqp_node_get_degree(node);
82 /* We have only one bucket for nodes with arity >= 3. */
87 node_bucket_insert(&node_buckets[degree], node);
93 static void normalize_towards_source(pbqp *pbqp, pbqp_edge *edge)
107 src_node = edge->src;
108 tgt_node = edge->tgt;
112 src_vec = src_node->costs;
113 tgt_vec = tgt_node->costs;
117 src_len = src_vec->len;
118 tgt_len = tgt_vec->len;
125 /* Normalize towards source node. */
126 for (src_index = 0; src_index < src_len; ++src_index) {
127 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
130 if (src_vec->entries[src_index].data == INF_COSTS) {
131 pbqp_matrix_set_row_value(mat, src_index, 0);
133 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
135 src_vec->entries[src_index].data = pbqp_add(
136 src_vec->entries[src_index].data, min);
138 if (min == INF_COSTS) {
140 unsigned edge_len = pbqp_node_get_degree(src_node);
142 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
143 pbqp_edge *edge_candidate = src_node->edges[edge_index];
144 if (edge_candidate != edge) {
145 insert_into_edge_bucket(edge_candidate);
153 static void normalize_towards_target(pbqp *pbqp, pbqp_edge *edge)
167 src_node = edge->src;
168 tgt_node = edge->tgt;
172 src_vec = src_node->costs;
173 tgt_vec = tgt_node->costs;
177 src_len = src_vec->len;
178 tgt_len = tgt_vec->len;
185 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
186 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
189 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
190 pbqp_matrix_set_col_value(mat, tgt_index, 0);
192 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
194 tgt_vec->entries[tgt_index].data = pbqp_add(
195 tgt_vec->entries[tgt_index].data, min);
197 if (min == INF_COSTS) {
199 unsigned edge_len = pbqp_node_get_degree(tgt_node);
201 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
202 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
203 if (edge_candidate != edge) {
204 insert_into_edge_bucket(edge_candidate);
212 static void reorder_node(pbqp_node *node)
214 unsigned degree = pbqp_node_get_degree(node);
215 /* Assume node lost one incident edge. */
216 unsigned old_degree = degree + 1;
218 if (!buckets_filled) return;
220 /* Same bucket as before */
221 if (degree > 2) return;
223 if (!node_bucket_contains(node_buckets[old_degree], node)) {
224 /* Old arity is new arity, so we have nothing to do. */
225 assert(node_bucket_contains(node_buckets[degree], node));
229 /* Delete node from old bucket... */
230 node_bucket_remove(&node_buckets[old_degree], node);
232 /* ..and add to new one. */
233 node_bucket_insert(&node_buckets[degree], node);
237 static void check_melting_possibility(pbqp *pbqp, pbqp_edge *edge)
252 src_node = edge->src;
253 tgt_node = edge->tgt;
257 src_vec = src_node->costs;
258 tgt_vec = tgt_node->costs;
262 src_len = src_vec->len;
263 tgt_len = tgt_vec->len;
270 if (src_len == 1 && tgt_len == 1) {
271 //panic("Something is wrong");
275 for (src_index = 0; src_index < src_len; ++src_index) {
277 if (src_vec->entries[src_index].data == INF_COSTS) {
280 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
281 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
284 if (mat->entries[src_index * tgt_len + tgt_index] == 0) {
293 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS) {
299 allRowsOk &= onlyOneZero;
303 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
305 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
308 for (src_index = 0; src_index < src_len; ++src_index) {
309 if (src_vec->entries[src_index].data == INF_COSTS) {
312 if (mat->entries[src_index * tgt_len + tgt_index] == 0) {
321 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS) {
327 allColsOk &= onlyOneZero;
330 if (allRowsOk && allColsOk) {
336 static void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
349 src_node = edge->src;
350 tgt_node = edge->tgt;
354 /* If edge are already deleted, we have nothing to do. */
355 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
359 if (pbqp->dump_file) {
361 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
362 dump_section(pbqp->dump_file, 3, txt);
366 src_vec = src_node->costs;
367 tgt_vec = tgt_node->costs;
371 src_len = src_vec->len;
372 tgt_len = tgt_vec->len;
380 if (pbqp->dump_file) {
381 fputs("Input:<br>\n", pbqp->dump_file);
382 dump_simplifyedge(pbqp, edge);
386 normalize_towards_source(pbqp, edge);
387 normalize_towards_target(pbqp, edge);
390 if (pbqp->dump_file) {
391 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
392 dump_simplifyedge(pbqp, edge);
396 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
398 if (pbqp->dump_file) {
399 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
410 reorder_node(src_node);
411 reorder_node(tgt_node);
415 static void initial_simplify_edges(pbqp *pbqp)
423 if (pbqp->dump_file) {
424 pbqp_dump_input(pbqp);
425 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
429 node_len = pbqp->num_nodes;
433 /* First simplify all edges. */
434 for (node_index = 0; node_index < node_len; ++node_index) {
436 pbqp_node *node = get_node(pbqp, node_index);
443 edge_len = pbqp_node_get_degree(node);
445 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
446 pbqp_edge *edge = edges[edge_index];
448 /* Simplify only once per edge. */
449 if (node != edge->src) continue;
451 simplify_edge(pbqp, edge);
456 static num determine_solution(pbqp *pbqp)
468 file = pbqp->dump_file;
471 dump_section(file, 1, "4. Determine Solution/Minimum");
472 dump_section(file, 2, "4.1. Trivial Solution");
476 /* Solve trivial nodes and calculate solution. */
477 node_len = node_bucket_get_length(node_buckets[0]);
481 pbqp->num_r0 = node_len;
485 for (node_index = 0; node_index < node_len; ++node_index) {
486 pbqp_node *node = node_buckets[0][node_index];
489 node->solution = vector_get_min_index(node->costs);
490 solution = pbqp_add(solution,
491 node->costs->entries[node->solution].data);
495 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
496 dump_node(file, node);
503 dump_section(file, 2, "Minimum");
504 fprintf(file, "Minimum is equal to %lld.", solution);
511 static void back_propagate(pbqp *pbqp)
514 unsigned node_len = node_bucket_get_length(reduced_bucket);
519 if (pbqp->dump_file) {
520 dump_section(pbqp->dump_file, 2, "Back Propagation");
524 for (node_index = node_len; node_index > 0; --node_index) {
525 pbqp_node *node = reduced_bucket[node_index - 1];
527 switch (pbqp_node_get_degree(node)) {
529 back_propagate_RI(pbqp, node);
532 back_propagate_RII(pbqp, node);
535 panic("Only nodes with degree one or two should be in this bucket");
541 static void apply_heuristic_reductions(pbqp *pbqp)
544 if (edge_bucket_get_length(edge_bucket) > 0) {
546 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
548 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
550 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
558 void solve_pbqp_heuristical(pbqp *pbqp)
560 /* Reduce nodes degree ... */
561 initial_simplify_edges(pbqp);
563 /* ... and put node into bucket representing their degree. */
564 fill_node_buckets(pbqp);
567 FILE *fh = fopen("solutions.pb", "a");
568 fprintf(fh, "Solution");
572 apply_heuristic_reductions(pbqp);
574 pbqp->solution = determine_solution(pbqp);
577 fh = fopen("solutions.pb", "a");
578 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
579 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
584 /* Solve reduced nodes. */
585 back_propagate(pbqp);
590 void apply_edge(pbqp *pbqp)
592 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
594 simplify_edge(pbqp, edge);
597 void apply_RI(pbqp *pbqp)
599 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
600 pbqp_edge *edge = node->edges[0];
601 pbqp_matrix *mat = edge->costs;
602 int is_src = edge->src == node;
603 pbqp_node *other_node;
605 assert(pbqp_node_get_degree(node) == 1);
608 other_node = edge->tgt;
610 other_node = edge->src;
614 if (pbqp->dump_file) {
616 sprintf(txt, "RI-Reduction of Node n%d", node->index);
617 dump_section(pbqp->dump_file, 2, txt);
618 pbqp_dump_graph(pbqp);
619 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
620 dump_node(pbqp->dump_file, node);
621 dump_node(pbqp->dump_file, other_node);
622 dump_edge(pbqp->dump_file, edge);
627 pbqp_matrix_add_to_all_cols(mat, node->costs);
628 normalize_towards_target(pbqp, edge);
630 pbqp_matrix_add_to_all_rows(mat, node->costs);
631 normalize_towards_source(pbqp, edge);
633 disconnect_edge(other_node, edge);
636 if (pbqp->dump_file) {
637 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
638 dump_node(pbqp->dump_file, other_node);
642 reorder_node(other_node);
650 /* Add node to back propagation list. */
651 node_bucket_insert(&reduced_bucket, node);
654 void apply_RII(pbqp *pbqp)
656 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
657 pbqp_edge *src_edge = node->edges[0];
658 pbqp_edge *tgt_edge = node->edges[1];
659 int src_is_src = src_edge->src == node;
660 int tgt_is_src = tgt_edge->src == node;
661 pbqp_matrix *src_mat;
662 pbqp_matrix *tgt_mat;
677 assert(pbqp_node_get_degree(node) == 2);
680 src_node = src_edge->tgt;
682 src_node = src_edge->src;
686 tgt_node = tgt_edge->tgt;
688 tgt_node = tgt_edge->src;
691 /* Swap nodes if necessary. */
692 if (tgt_node->index < src_node->index) {
704 src_is_src = src_edge->src == node;
705 tgt_is_src = tgt_edge->src == node;
709 if (pbqp->dump_file) {
711 sprintf(txt, "RII-Reduction of Node n%d", node->index);
712 dump_section(pbqp->dump_file, 2, txt);
713 pbqp_dump_graph(pbqp);
714 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
715 dump_node(pbqp->dump_file, src_node);
716 dump_edge(pbqp->dump_file, src_edge);
717 dump_node(pbqp->dump_file, node);
718 dump_edge(pbqp->dump_file, tgt_edge);
719 dump_node(pbqp->dump_file, tgt_node);
723 src_mat = src_edge->costs;
724 tgt_mat = tgt_edge->costs;
726 src_vec = src_node->costs;
727 tgt_vec = tgt_node->costs;
728 node_vec = node->costs;
730 row_len = src_vec->len;
731 col_len = tgt_vec->len;
732 node_len = node_vec->len;
734 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
736 for (row_index = 0; row_index < row_len; ++row_index) {
737 for (col_index = 0; col_index < col_len; ++col_index) {
738 vec = vector_copy(pbqp, node_vec);
741 vector_add_matrix_col(vec, src_mat, row_index);
743 vector_add_matrix_row(vec, src_mat, row_index);
747 vector_add_matrix_col(vec, tgt_mat, col_index);
749 vector_add_matrix_row(vec, tgt_mat, col_index);
752 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
754 obstack_free(&pbqp->obstack, vec);
758 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
760 /* Disconnect node. */
761 disconnect_edge(src_node, src_edge);
762 disconnect_edge(tgt_node, tgt_edge);
770 /* Add node to back propagation list. */
771 node_bucket_insert(&reduced_bucket, node);
774 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
776 pbqp_matrix_add(edge->costs, mat);
778 /* Free local matrix. */
779 obstack_free(&pbqp->obstack, mat);
781 reorder_node(src_node);
782 reorder_node(tgt_node);
786 if (pbqp->dump_file) {
787 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
788 dump_edge(pbqp->dump_file, edge);
792 /* Edge has changed so we simplify it. */
793 simplify_edge(pbqp, edge);
796 static void select_alternative(pbqp_node *node, unsigned selected_index)
802 unsigned max_degree = pbqp_node_get_degree(node);
805 node->solution = selected_index;
806 node_vec = node->costs;
807 node_len = node_vec->len;
808 assert(selected_index < node_len);
810 /* Set all other costs to infinity. */
811 for (node_index = 0; node_index < node_len; ++node_index) {
812 if (node_index != selected_index) {
813 node_vec->entries[node_index].data = INF_COSTS;
817 /* Add all incident edges to edge bucket, since they are now independent. */
818 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
819 insert_into_edge_bucket(node->edges[edge_index]);
823 static pbqp_node *get_node_with_max_degree(void)
825 pbqp_node **bucket = node_buckets[3];
826 unsigned bucket_len = node_bucket_get_length(bucket);
827 unsigned bucket_index;
828 unsigned max_degree = 0;
829 pbqp_node *result = NULL;
831 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
832 pbqp_node *candidate = bucket[bucket_index];
833 unsigned degree = pbqp_node_get_degree(candidate);
835 if (degree > max_degree) {
844 static unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
851 unsigned max_degree = 0;
854 unsigned min_index = 0;
860 node_vec = node->costs;
861 node_len = node_vec->len;
863 for (node_index = 0; node_index < node_len; ++node_index) {
864 num value = node_vec->entries[node_index].data;
866 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
867 edge = node->edges[edge_index];
869 is_src = edge->src == node;
872 vec = vector_copy(pbqp, edge->tgt->costs);
873 vector_add_matrix_row(vec, mat, node_index);
875 vec = vector_copy(pbqp, edge->src->costs);
876 vector_add_matrix_col(vec, mat, node_index);
879 value = pbqp_add(value, vector_get_min(vec));
881 obstack_free(&pbqp->obstack, vec);
886 min_index = node_index;
893 void apply_RN(pbqp *pbqp)
895 pbqp_node *node = NULL;
896 unsigned min_index = 0;
900 /* We want to reduce a node with maximum degree. */
901 node = get_node_with_max_degree();
903 assert(pbqp_node_get_degree(node) > 2);
906 if (pbqp->dump_file) {
908 sprintf(txt, "RN-Reduction of Node n%d", node->index);
909 dump_section(pbqp->dump_file, 2, txt);
910 pbqp_dump_graph(pbqp);
914 min_index = get_local_minimal_alternative(pbqp, node);
917 if (pbqp->dump_file) {
918 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
919 node->index, min_index);
925 FILE *fh = fopen("solutions.pb", "a");
926 fprintf(fh, "[%u]", min_index);
932 /* Now that we found the local minimum set all other costs to infinity. */
933 select_alternative(node, min_index);
936 static void apply_brute_force_reductions(pbqp *pbqp)
939 if (edge_bucket_get_length(edge_bucket) > 0) {
941 } else if (node_bucket_get_length(node_buckets[1]) > 0) {
943 } else if (node_bucket_get_length(node_buckets[2]) > 0) {
945 } else if (node_bucket_get_length(node_buckets[3]) > 0) {
946 apply_Brute_Force(pbqp);
953 static unsigned get_minimal_alternative(pbqp *pbqp, pbqp_node *node)
958 unsigned min_index = 0;
960 unsigned bucket_index;
964 node_vec = node->costs;
965 node_len = node_vec->len;
966 bucket_index = node->bucket_index;
968 for (node_index = 0; node_index < node_len; ++node_index) {
969 pbqp_node_bucket bucket_deg3;
971 unsigned bucket_0_length;
972 unsigned bucket_red_length;
974 char *tmp = obstack_finish(&pbqp->obstack);
976 node_bucket_init(&bucket_deg3);
978 /* Some node buckets and the edge bucket should be empty. */
979 assert(node_bucket_get_length(node_buckets[1]) == 0);
980 assert(node_bucket_get_length(node_buckets[2]) == 0);
981 assert(edge_bucket_get_length(edge_bucket) == 0);
983 /* char *tmp = obstack_finish(&pbqp->obstack); */
985 /* Save current PBQP state. */
986 node_bucket_copy(&bucket_deg3, node_buckets[3]);
987 node_bucket_shrink(&node_buckets[3], 0);
988 node_bucket_deep_copy(pbqp, &node_buckets[3], bucket_deg3);
989 node_bucket_update(pbqp, node_buckets[3]);
990 bucket_0_length = node_bucket_get_length(node_buckets[0]);
991 bucket_red_length = node_bucket_get_length(reduced_bucket);
993 /* Select alternative and solve PBQP recursively. */
994 select_alternative(node_buckets[3][bucket_index], node_index);
995 apply_brute_force_reductions(pbqp);
997 value = determine_solution(pbqp);
1001 min_index = node_index;
1004 /* Some node buckets and the edge bucket should still be empty. */
1005 assert(node_bucket_get_length(node_buckets[1]) == 0);
1006 assert(node_bucket_get_length(node_buckets[2]) == 0);
1007 assert(edge_bucket_get_length(edge_bucket) == 0);
1009 /* Clear modified buckets... */
1010 node_bucket_shrink(&node_buckets[3], 0);
1012 /* ... and restore old PBQP state. */
1013 node_bucket_shrink(&node_buckets[0], bucket_0_length);
1014 node_bucket_shrink(&reduced_bucket, bucket_red_length);
1015 node_bucket_copy(&node_buckets[3], bucket_deg3);
1016 node_bucket_update(pbqp, node_buckets[3]);
1019 /* obstack_free(&pbqp->obstack, tmp); */
1020 node_bucket_free(&bucket_deg3);
1022 obstack_free(&pbqp->obstack, tmp);
1028 void apply_Brute_Force(pbqp *pbqp)
1030 pbqp_node *node = NULL;
1031 unsigned min_index = 0;
1035 /* We want to reduce a node with maximum degree. */
1036 node = get_node_with_max_degree();
1038 assert(pbqp_node_get_degree(node) > 2);
1041 if (pbqp->dump_file) {
1043 sprintf(txt, "BF-Reduction of Node n%d", node->index);
1044 dump_section(pbqp->dump_file, 2, txt);
1045 pbqp_dump_graph(pbqp);
1053 min_index = get_minimal_alternative(pbqp, node);
1054 node = pbqp->nodes[node->index];
1057 if (pbqp->dump_file) {
1058 fprintf(pbqp->dump_file, "node n%d is set to %d<br><br>\n",
1059 node->index, min_index);
1066 FILE *fh = fopen("solutions.pb", "a");
1067 fprintf(fh, "[%u]", min_index);
1073 /* Now that we found the minimum set all other costs to infinity. */
1074 select_alternative(node, min_index);
1077 void solve_pbqp_brute_force(pbqp *pbqp)
1079 /* Reduce nodes degree ... */
1080 initial_simplify_edges(pbqp);
1082 /* ... and put node into bucket representing their degree. */
1083 fill_node_buckets(pbqp);
1086 FILE *fh = fopen("solutions.pb", "a");
1087 fprintf(fh, "Solution");
1091 apply_brute_force_reductions(pbqp);
1093 pbqp->solution = determine_solution(pbqp);
1096 fh = fopen("solutions.pb", "a");
1097 fprintf(fh, ": %lld RE:%u R0:%u R1:%u R2:%u RN/BF:%u\n", pbqp->solution,
1098 pbqp->num_edges, pbqp->num_r0, pbqp->num_r1, pbqp->num_r2,
1103 /* Solve reduced nodes. */
1104 back_propagate(pbqp);
1109 void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
1120 edge = node->edges[0];
1122 is_src = edge->src == node;
1129 /* Update pointer for brute force solver. */
1130 other = pbqp->nodes[other->index];
1132 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
1137 /* Update pointer for brute force solver. */
1138 other = pbqp->nodes[other->index];
1140 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
1144 if (pbqp->dump_file) {
1145 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
1150 void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
1152 pbqp_edge *src_edge = node->edges[0];
1153 pbqp_edge *tgt_edge = node->edges[1];
1154 int src_is_src = src_edge->src == node;
1155 int tgt_is_src = tgt_edge->src == node;
1156 pbqp_matrix *src_mat;
1157 pbqp_matrix *tgt_mat;
1158 pbqp_node *src_node;
1159 pbqp_node *tgt_node;
1168 src_node = src_edge->tgt;
1170 src_node = src_edge->src;
1174 tgt_node = tgt_edge->tgt;
1176 tgt_node = tgt_edge->src;
1179 /* Swap nodes if necessary. */
1180 if (tgt_node->index < src_node->index) {
1181 pbqp_node *tmp_node;
1182 pbqp_edge *tmp_edge;
1184 tmp_node = src_node;
1185 src_node = tgt_node;
1186 tgt_node = tmp_node;
1188 tmp_edge = src_edge;
1189 src_edge = tgt_edge;
1190 tgt_edge = tmp_edge;
1192 src_is_src = src_edge->src == node;
1193 tgt_is_src = tgt_edge->src == node;
1196 /* Update pointer for brute force solver. */
1197 src_node = pbqp->nodes[src_node->index];
1198 tgt_node = pbqp->nodes[tgt_node->index];
1200 src_mat = src_edge->costs;
1201 tgt_mat = tgt_edge->costs;
1203 node_vec = node->costs;
1205 row_index = src_node->solution;
1206 col_index = tgt_node->solution;
1208 vec = vector_copy(pbqp, node_vec);
1211 vector_add_matrix_col(vec, src_mat, row_index);
1213 vector_add_matrix_row(vec, src_mat, row_index);
1217 vector_add_matrix_col(vec, tgt_mat, col_index);
1219 vector_add_matrix_row(vec, tgt_mat, col_index);
1222 node->solution = vector_get_min_index(vec);
1225 if (pbqp->dump_file) {
1226 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
1230 obstack_free(&pbqp->obstack, vec);
1233 int node_is_reduced(pbqp_node *node)
1235 if (!reduced_bucket) return 0;
1237 if (pbqp_node_get_degree(node) == 0) return 1;
1239 return node_bucket_contains(reduced_bucket, node);