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 pbqp_node *merged_node = NULL;
54 static int buckets_filled = 0;
56 static void insert_into_edge_bucket(pbqp_edge *edge)
58 if (edge_bucket_contains(edge_bucket, edge)) {
59 /* Edge is already inserted. */
63 edge_bucket_insert(&edge_bucket, edge);
66 static void insert_into_rm_bucket(pbqp_edge *edge)
68 if (edge_bucket_contains(rm_bucket, edge)) {
69 /* Edge is already inserted. */
73 edge_bucket_insert(&rm_bucket, edge);
76 static void init_buckets(void)
80 edge_bucket_init(&edge_bucket);
81 edge_bucket_init(&rm_bucket);
82 node_bucket_init(&reduced_bucket);
84 for (i = 0; i < 4; ++i) {
85 node_bucket_init(&node_buckets[i]);
89 void free_buckets(void)
93 for (i = 0; i < 4; ++i) {
94 node_bucket_free(&node_buckets[i]);
97 edge_bucket_free(&edge_bucket);
98 edge_bucket_free(&rm_bucket);
99 node_bucket_free(&reduced_bucket);
104 void fill_node_buckets(pbqp *pbqp)
110 node_len = pbqp->num_nodes;
113 ir_timer_t *t_fill_buckets = ir_timer_new();
114 ir_timer_start(t_fill_buckets);
117 for (node_index = 0; node_index < node_len; ++node_index) {
119 pbqp_node *node = get_node(pbqp, node_index);
123 degree = pbqp_node_get_degree(node);
125 /* We have only one bucket for nodes with arity >= 3. */
130 node_bucket_insert(&node_buckets[degree], node);
136 ir_timer_stop(t_fill_buckets);
137 printf("PBQP Fill Nodes into buckets: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_fill_buckets) / 1000.0);
141 static void normalize_towards_source(pbqp_edge *edge)
151 unsigned new_infinity = 0;
155 src_node = edge->src;
156 tgt_node = edge->tgt;
160 src_vec = src_node->costs;
161 tgt_vec = tgt_node->costs;
165 src_len = src_vec->len;
166 tgt_len = tgt_vec->len;
173 /* Normalize towards source node. */
174 for (src_index = 0; src_index < src_len; ++src_index) {
175 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
178 if (src_vec->entries[src_index].data == INF_COSTS) {
179 pbqp_matrix_set_row_value(mat, src_index, 0);
183 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
184 src_vec->entries[src_index].data = pbqp_add(
185 src_vec->entries[src_index].data, min);
187 if (min == INF_COSTS) {
195 unsigned edge_len = pbqp_node_get_degree(src_node);
197 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
198 pbqp_edge *edge_candidate = src_node->edges[edge_index];
200 if (edge_candidate != edge) {
201 insert_into_edge_bucket(edge_candidate);
207 static void normalize_towards_target(pbqp_edge *edge)
217 unsigned new_infinity = 0;
221 src_node = edge->src;
222 tgt_node = edge->tgt;
226 src_vec = src_node->costs;
227 tgt_vec = tgt_node->costs;
231 src_len = src_vec->len;
232 tgt_len = tgt_vec->len;
239 /* Normalize towards target node. */
240 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
241 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
244 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
245 pbqp_matrix_set_col_value(mat, tgt_index, 0);
249 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
250 tgt_vec->entries[tgt_index].data = pbqp_add(
251 tgt_vec->entries[tgt_index].data, min);
253 if (min == INF_COSTS) {
261 unsigned edge_len = pbqp_node_get_degree(tgt_node);
263 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
264 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
266 if (edge_candidate != edge) {
267 insert_into_edge_bucket(edge_candidate);
274 * Tries to apply RM for the source node of the given edge.
276 * Checks whether the source node of edge can be merged into the target node of
277 * edge, and performs the merge, if possible.
279 static void merge_source_into_target(pbqp *pbqp, pbqp_edge *edge)
297 src_node = edge->src;
298 tgt_node = edge->tgt;
302 src_vec = src_node->costs;
303 tgt_vec = tgt_node->costs;
307 src_len = src_vec->len;
308 tgt_len = tgt_vec->len;
310 /* Matrizes are normalized. */
317 mapping = NEW_ARR_F(unsigned, tgt_len);
319 /* Check that each column has at most one zero entry. */
320 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
321 unsigned onlyOneZero = 0;
323 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
326 for (src_index = 0; src_index < src_len; ++src_index) {
327 if (src_vec->entries[src_index].data == INF_COSTS)
330 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
333 /* Matrix entry is finite. */
340 mapping[tgt_index] = src_index;
344 /* We know that we can merge the source node into the target node. */
345 edge_len = pbqp_node_get_degree(src_node);
351 /* Reconnect the source's edges with the target node. */
352 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
353 pbqp_edge *old_edge = src_node->edges[edge_index];
355 pbqp_matrix *old_matrix;
356 pbqp_matrix *new_matrix;
357 pbqp_node *other_node;
360 unsigned other_index;
365 if (old_edge == edge)
368 old_matrix = old_edge->costs;
371 if (old_edge->tgt == src_node) {
372 other_node = old_edge->src;
373 other_len = old_matrix->rows;
376 other_node = old_edge->tgt;
377 other_len = old_matrix->cols;
380 other_vec = other_node->costs;
382 new_matrix = pbqp_matrix_alloc(pbqp, tgt_len, other_len);
384 /* Source node selects the column of the old_matrix. */
385 if (old_edge->tgt == src_node) {
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[other_index*src_len+src_index];
400 /* Source node selects the row of the old_matrix. */
402 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
403 unsigned src_index = mapping[tgt_index];
405 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
408 for (other_index = 0; other_index < other_len; ++other_index) {
409 if (other_vec->entries[other_index].data == INF_COSTS)
412 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[src_index*other_len+other_index];
417 add_edge_costs(pbqp, tgt_node->index, other_node->index, new_matrix);
419 delete_edge(old_edge);
421 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
422 insert_into_rm_bucket(new_edge);
431 * Tries to apply RM for the target node of the given edge.
433 * Checks whether the target node of edge can be merged into the source node of
434 * edge, and performs the merge, if possible.
436 static void merge_target_into_source(pbqp *pbqp, pbqp_edge *edge)
454 src_node = edge->src;
455 tgt_node = edge->tgt;
459 src_vec = src_node->costs;
460 tgt_vec = tgt_node->costs;
464 src_len = src_vec->len;
465 tgt_len = tgt_vec->len;
467 /* Matrizes are normalized. */
474 mapping = NEW_ARR_F(unsigned, src_len);
476 /* Check that each row has at most one zero entry. */
477 for (src_index = 0; src_index < src_len; ++src_index) {
478 unsigned onlyOneZero = 0;
480 if (src_vec->entries[src_index].data == INF_COSTS)
483 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
484 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
487 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
490 /* Matrix entry is finite. */
497 mapping[src_index] = tgt_index;
501 /* We know that we can merge the target node into the source node. */
502 edge_len = pbqp_node_get_degree(tgt_node);
508 /* Reconnect the target's edges with the source node. */
509 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
510 pbqp_edge *old_edge = tgt_node->edges[edge_index];
512 pbqp_matrix *old_matrix;
513 pbqp_matrix *new_matrix;
514 pbqp_node *other_node;
517 unsigned other_index;
522 if (old_edge == edge)
525 old_matrix = old_edge->costs;
528 if (old_edge->tgt == tgt_node) {
529 other_node = old_edge->src;
530 other_len = old_matrix->rows;
533 other_node = old_edge->tgt;
534 other_len = old_matrix->cols;
537 other_vec = other_node->costs;
539 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
541 /* Target node selects the column of the old_matrix. */
542 if (old_edge->tgt == tgt_node) {
543 for (src_index = 0; src_index < src_len; ++src_index) {
544 unsigned tgt_index = mapping[src_index];
546 if (src_vec->entries[src_index].data == INF_COSTS)
549 for (other_index = 0; other_index < other_len; ++other_index) {
550 if (other_vec->entries[other_index].data == INF_COSTS)
553 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
557 /* Source node selects the row of the old_matrix. */
559 for (src_index = 0; src_index < src_len; ++src_index) {
560 unsigned tgt_index = mapping[src_index];
562 if (src_vec->entries[src_index].data == INF_COSTS)
565 for (other_index = 0; other_index < other_len; ++other_index) {
566 if (other_vec->entries[other_index].data == INF_COSTS)
569 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
574 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
576 delete_edge(old_edge);
578 new_edge = get_edge(pbqp, src_node->index, other_node->index);
579 insert_into_rm_bucket(new_edge);
588 * Merge neighbors into the given node.
590 void apply_RM(pbqp *pbqp, pbqp_node *node)
600 edge_len = pbqp_node_get_degree(node);
602 /* Check all incident edges. */
603 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
604 pbqp_edge *edge = edges[edge_index];
606 insert_into_rm_bucket(edge);
609 /* ALAP: Merge neighbors into given node. */
610 while(edge_bucket_get_length(rm_bucket) > 0) {
611 pbqp_edge *edge = edge_bucket_pop(&rm_bucket);
614 if (edge->src == node)
615 merge_target_into_source(pbqp, edge);
617 merge_source_into_target(pbqp, edge);
623 void reorder_node(pbqp_node *node)
625 unsigned degree = pbqp_node_get_degree(node);
626 /* Assume node lost one incident edge. */
627 unsigned old_degree = degree + 1;
629 if (!buckets_filled) return;
631 /* Same bucket as before */
632 if (degree > 2) return;
634 if (!node_bucket_contains(node_buckets[old_degree], node)) {
635 /* Old arity is new arity, so we have nothing to do. */
636 assert(node_bucket_contains(node_buckets[degree], node));
640 /* Delete node from old bucket... */
641 node_bucket_remove(&node_buckets[old_degree], node);
643 /* ..and add to new one. */
644 node_bucket_insert(&node_buckets[degree], node);
647 void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
662 src_node = edge->src;
663 tgt_node = edge->tgt;
667 /* If edge are already deleted, we have nothing to do. */
668 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
672 if (pbqp->dump_file) {
674 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
675 dump_section(pbqp->dump_file, 3, txt);
679 src_vec = src_node->costs;
680 tgt_vec = tgt_node->costs;
684 src_len = src_vec->len;
685 tgt_len = tgt_vec->len;
693 if (pbqp->dump_file) {
694 fputs("Input:<br>\n", pbqp->dump_file);
695 dump_simplifyedge(pbqp, edge);
699 normalize_towards_source(edge);
700 normalize_towards_target(edge);
703 if (pbqp->dump_file) {
704 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
705 dump_simplifyedge(pbqp, edge);
709 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
711 if (pbqp->dump_file) {
712 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
724 void initial_simplify_edges(pbqp *pbqp)
732 ir_timer_t *t_int_simpl = ir_timer_new();
733 ir_timer_start(t_int_simpl);
737 if (pbqp->dump_file) {
738 pbqp_dump_input(pbqp);
739 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
743 node_len = pbqp->num_nodes;
747 /* First simplify all edges. */
748 for (node_index = 0; node_index < node_len; ++node_index) {
750 pbqp_node *node = get_node(pbqp, node_index);
757 edge_len = pbqp_node_get_degree(node);
759 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
760 pbqp_edge *edge = edges[edge_index];
762 /* Simplify only once per edge. */
763 if (node != edge->src) continue;
765 simplify_edge(pbqp, edge);
770 ir_timer_stop(t_int_simpl);
771 printf("PBQP Initial simplify edges: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
775 num determine_solution(pbqp *pbqp)
782 ir_timer_t *t_det_solution = ir_timer_new();
783 ir_timer_reset_and_start(t_det_solution);
795 file = pbqp->dump_file;
798 dump_section(file, 1, "4. Determine Solution/Minimum");
799 dump_section(file, 2, "4.1. Trivial Solution");
803 /* Solve trivial nodes and calculate solution. */
804 node_len = node_bucket_get_length(node_buckets[0]);
807 pbqp->num_r0 = node_len;
810 for (node_index = 0; node_index < node_len; ++node_index) {
811 pbqp_node *node = node_buckets[0][node_index];
814 node->solution = vector_get_min_index(node->costs);
815 solution = pbqp_add(solution,
816 node->costs->entries[node->solution].data);
820 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
821 dump_node(file, node);
828 dump_section(file, 2, "Minimum");
829 #if KAPS_USE_UNSIGNED
830 fprintf(file, "Minimum is equal to %u.", solution);
832 fprintf(file, "Minimum is equal to %lld.", solution);
838 ir_timer_stop(t_det_solution);
839 printf("PBQP Determine Solution: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
845 static void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
858 edge = node->edges[0];
860 is_src = edge->src == node;
867 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
872 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
876 if (pbqp->dump_file) {
877 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
882 static void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
884 pbqp_edge *src_edge = node->edges[0];
885 pbqp_edge *tgt_edge = node->edges[1];
886 int src_is_src = src_edge->src == node;
887 int tgt_is_src = tgt_edge->src == node;
888 pbqp_matrix *src_mat;
889 pbqp_matrix *tgt_mat;
900 src_node = src_edge->tgt;
902 src_node = src_edge->src;
906 tgt_node = tgt_edge->tgt;
908 tgt_node = tgt_edge->src;
911 /* Swap nodes if necessary. */
912 if (tgt_node->index < src_node->index) {
924 src_is_src = src_edge->src == node;
925 tgt_is_src = tgt_edge->src == node;
928 src_mat = src_edge->costs;
929 tgt_mat = tgt_edge->costs;
931 node_vec = node->costs;
933 row_index = src_node->solution;
934 col_index = tgt_node->solution;
936 vec = vector_copy(pbqp, node_vec);
939 vector_add_matrix_col(vec, src_mat, row_index);
941 vector_add_matrix_row(vec, src_mat, row_index);
945 vector_add_matrix_col(vec, tgt_mat, col_index);
947 vector_add_matrix_row(vec, tgt_mat, col_index);
950 node->solution = vector_get_min_index(vec);
953 if (pbqp->dump_file) {
954 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
958 obstack_free(&pbqp->obstack, vec);
961 void back_propagate(pbqp *pbqp)
964 unsigned node_len = node_bucket_get_length(reduced_bucket);
969 if (pbqp->dump_file) {
970 dump_section(pbqp->dump_file, 2, "Back Propagation");
974 for (node_index = node_len; node_index > 0; --node_index) {
975 pbqp_node *node = reduced_bucket[node_index - 1];
977 switch (pbqp_node_get_degree(node)) {
979 back_propagate_RI(pbqp, node);
982 back_propagate_RII(pbqp, node);
985 panic("Only nodes with degree one or two should be in this bucket");
991 void apply_edge(pbqp *pbqp)
993 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
995 simplify_edge(pbqp, edge);
998 void apply_RI(pbqp *pbqp)
1000 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
1001 pbqp_edge *edge = node->edges[0];
1002 pbqp_matrix *mat = edge->costs;
1003 int is_src = edge->src == node;
1004 pbqp_node *other_node;
1007 assert(pbqp_node_get_degree(node) == 1);
1010 other_node = edge->tgt;
1012 other_node = edge->src;
1016 if (pbqp->dump_file) {
1018 sprintf(txt, "RI-Reduction of Node n%d", node->index);
1019 dump_section(pbqp->dump_file, 2, txt);
1020 pbqp_dump_graph(pbqp);
1021 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1022 dump_node(pbqp->dump_file, node);
1023 dump_node(pbqp->dump_file, other_node);
1024 dump_edge(pbqp->dump_file, edge);
1029 pbqp_matrix_add_to_all_cols(mat, node->costs);
1030 normalize_towards_target(edge);
1032 pbqp_matrix_add_to_all_rows(mat, node->costs);
1033 normalize_towards_source(edge);
1035 disconnect_edge(other_node, edge);
1038 if (pbqp->dump_file) {
1039 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1040 dump_node(pbqp->dump_file, other_node);
1044 reorder_node(other_node);
1050 /* Add node to back propagation list. */
1051 node_bucket_insert(&reduced_bucket, node);
1054 void apply_RII(pbqp *pbqp)
1056 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
1057 pbqp_edge *src_edge = node->edges[0];
1058 pbqp_edge *tgt_edge = node->edges[1];
1059 int src_is_src = src_edge->src == node;
1060 int tgt_is_src = tgt_edge->src == node;
1061 pbqp_matrix *src_mat;
1062 pbqp_matrix *tgt_mat;
1063 pbqp_node *src_node;
1064 pbqp_node *tgt_node;
1077 assert(pbqp_node_get_degree(node) == 2);
1080 src_node = src_edge->tgt;
1082 src_node = src_edge->src;
1086 tgt_node = tgt_edge->tgt;
1088 tgt_node = tgt_edge->src;
1091 /* Swap nodes if necessary. */
1092 if (tgt_node->index < src_node->index) {
1093 pbqp_node *tmp_node;
1094 pbqp_edge *tmp_edge;
1096 tmp_node = src_node;
1097 src_node = tgt_node;
1098 tgt_node = tmp_node;
1100 tmp_edge = src_edge;
1101 src_edge = tgt_edge;
1102 tgt_edge = tmp_edge;
1104 src_is_src = src_edge->src == node;
1105 tgt_is_src = tgt_edge->src == node;
1109 if (pbqp->dump_file) {
1111 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1112 dump_section(pbqp->dump_file, 2, txt);
1113 pbqp_dump_graph(pbqp);
1114 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1115 dump_node(pbqp->dump_file, src_node);
1116 dump_edge(pbqp->dump_file, src_edge);
1117 dump_node(pbqp->dump_file, node);
1118 dump_edge(pbqp->dump_file, tgt_edge);
1119 dump_node(pbqp->dump_file, tgt_node);
1123 src_mat = src_edge->costs;
1124 tgt_mat = tgt_edge->costs;
1126 src_vec = src_node->costs;
1127 tgt_vec = tgt_node->costs;
1128 node_vec = node->costs;
1130 row_len = src_vec->len;
1131 col_len = tgt_vec->len;
1132 node_len = node_vec->len;
1134 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1136 for (row_index = 0; row_index < row_len; ++row_index) {
1137 for (col_index = 0; col_index < col_len; ++col_index) {
1138 vec = vector_copy(pbqp, node_vec);
1141 vector_add_matrix_col(vec, src_mat, row_index);
1143 vector_add_matrix_row(vec, src_mat, row_index);
1147 vector_add_matrix_col(vec, tgt_mat, col_index);
1149 vector_add_matrix_row(vec, tgt_mat, col_index);
1152 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1154 obstack_free(&pbqp->obstack, vec);
1158 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
1160 /* Disconnect node. */
1161 disconnect_edge(src_node, src_edge);
1162 disconnect_edge(tgt_node, tgt_edge);
1168 /* Add node to back propagation list. */
1169 node_bucket_insert(&reduced_bucket, node);
1172 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1175 pbqp_matrix_add(edge->costs, mat);
1177 /* Free local matrix. */
1178 obstack_free(&pbqp->obstack, mat);
1180 reorder_node(src_node);
1181 reorder_node(tgt_node);
1185 if (pbqp->dump_file) {
1186 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1187 dump_edge(pbqp->dump_file, edge);
1191 /* Edge has changed so we simplify it. */
1192 simplify_edge(pbqp, edge);
1195 static void select_column(pbqp_edge *edge, unsigned col_index)
1198 pbqp_node *src_node;
1199 pbqp_node *tgt_node;
1205 unsigned new_infinity = 0;
1209 src_node = edge->src;
1210 tgt_node = edge->tgt;
1214 src_vec = src_node->costs;
1215 tgt_vec = tgt_node->costs;
1219 src_len = src_vec->len;
1220 tgt_len = tgt_vec->len;
1221 assert(src_len > 0);
1222 assert(tgt_len > 0);
1227 for (src_index = 0; src_index < src_len; ++src_index) {
1228 num elem = mat->entries[src_index * tgt_len + col_index];
1231 if (elem == INF_COSTS && src_vec->entries[src_index].data != INF_COSTS)
1234 src_vec->entries[src_index].data = pbqp_add(
1235 src_vec->entries[src_index].data, elem);
1240 unsigned edge_index;
1241 unsigned edge_len = pbqp_node_get_degree(src_node);
1243 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1244 pbqp_edge *edge_candidate = src_node->edges[edge_index];
1246 if (edge_candidate != edge) {
1247 insert_into_edge_bucket(edge_candidate);
1255 static void select_row(pbqp_edge *edge, unsigned row_index)
1258 pbqp_node *src_node;
1259 pbqp_node *tgt_node;
1263 unsigned new_infinity = 0;
1267 src_node = edge->src;
1268 tgt_node = edge->tgt;
1271 tgt_vec = tgt_node->costs;
1274 tgt_len = tgt_vec->len;
1275 assert(tgt_len > 0);
1280 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
1281 num elem = mat->entries[row_index * tgt_len + tgt_index];
1284 if (elem == INF_COSTS && tgt_vec->entries[tgt_index].data != INF_COSTS)
1287 tgt_vec->entries[tgt_index].data = pbqp_add(
1288 tgt_vec->entries[tgt_index].data, elem);
1293 unsigned edge_index;
1294 unsigned edge_len = pbqp_node_get_degree(tgt_node);
1296 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1297 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
1299 if (edge_candidate != edge) {
1300 insert_into_edge_bucket(edge_candidate);
1308 void select_alternative(pbqp_node *node, unsigned selected_index)
1310 unsigned edge_index;
1311 unsigned node_index;
1314 unsigned max_degree = pbqp_node_get_degree(node);
1317 node->solution = selected_index;
1318 node_vec = node->costs;
1319 node_len = node_vec->len;
1320 assert(selected_index < node_len);
1322 /* Set all other costs to infinity. */
1323 for (node_index = 0; node_index < node_len; ++node_index) {
1324 if (node_index != selected_index) {
1325 node_vec->entries[node_index].data = INF_COSTS;
1329 /* Select corresponding row/column for incident edges. */
1330 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1331 pbqp_edge *edge = node->edges[edge_index];
1333 if (edge->src == node)
1334 select_row(edge, selected_index);
1336 select_column(edge, selected_index);
1340 pbqp_node *get_node_with_max_degree(void)
1342 pbqp_node **bucket = node_buckets[3];
1343 unsigned bucket_len = node_bucket_get_length(bucket);
1344 unsigned bucket_index;
1345 unsigned max_degree = 0;
1346 pbqp_node *result = NULL;
1348 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1349 pbqp_node *candidate = bucket[bucket_index];
1350 unsigned degree = pbqp_node_get_degree(candidate);
1352 if (degree > max_degree) {
1354 max_degree = degree;
1361 unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
1367 unsigned edge_index;
1368 unsigned max_degree;
1369 unsigned node_index;
1371 unsigned min_index = 0;
1372 num min = INF_COSTS;
1377 node_vec = node->costs;
1378 node_len = node_vec->len;
1379 max_degree = pbqp_node_get_degree(node);
1381 for (node_index = 0; node_index < node_len; ++node_index) {
1382 num value = node_vec->entries[node_index].data;
1384 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1385 edge = node->edges[edge_index];
1387 is_src = edge->src == node;
1390 vec = vector_copy(pbqp, edge->tgt->costs);
1391 vector_add_matrix_row(vec, mat, node_index);
1393 vec = vector_copy(pbqp, edge->src->costs);
1394 vector_add_matrix_col(vec, mat, node_index);
1397 value = pbqp_add(value, vector_get_min(vec));
1399 obstack_free(&pbqp->obstack, vec);
1404 min_index = node_index;
1411 int node_is_reduced(pbqp_node *node)
1413 if (!reduced_bucket) return 0;
1415 if (pbqp_node_get_degree(node) == 0) return 1;
1417 return node_bucket_contains(reduced_bucket, node);