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_node **node_buckets[4];
51 pbqp_node **reduced_bucket = NULL;
52 static int buckets_filled = 0;
54 static void insert_into_edge_bucket(pbqp_edge *edge)
56 if (edge_bucket_contains(edge_bucket, edge)) {
57 /* Edge is already inserted. */
61 edge_bucket_insert(&edge_bucket, edge);
64 static void init_buckets(void)
68 edge_bucket_init(&edge_bucket);
69 node_bucket_init(&reduced_bucket);
71 for (i = 0; i < 4; ++i) {
72 node_bucket_init(&node_buckets[i]);
76 void free_buckets(void)
80 for (i = 0; i < 4; ++i) {
81 node_bucket_free(&node_buckets[i]);
84 edge_bucket_free(&edge_bucket);
85 node_bucket_free(&reduced_bucket);
90 void fill_node_buckets(pbqp *pbqp)
96 node_len = pbqp->num_nodes;
99 ir_timer_t *t_fill_buckets = ir_timer_register("be_pbqp_fill_buckets", "PBQP Fill Nodes into buckets");
100 ir_timer_reset_and_start(t_fill_buckets);
103 for (node_index = 0; node_index < node_len; ++node_index) {
105 pbqp_node *node = get_node(pbqp, node_index);
109 degree = pbqp_node_get_degree(node);
111 /* We have only one bucket for nodes with arity >= 3. */
116 node_bucket_insert(&node_buckets[degree], node);
122 ir_timer_stop(t_fill_buckets);
123 printf("%-20s: %8.3lf msec\n", ir_timer_get_description(t_fill_buckets), (double)ir_timer_elapsed_usec(t_fill_buckets) / 1000.0);
127 static void normalize_towards_source(pbqp_edge *edge)
140 src_node = edge->src;
141 tgt_node = edge->tgt;
145 src_vec = src_node->costs;
146 tgt_vec = tgt_node->costs;
150 src_len = src_vec->len;
151 tgt_len = tgt_vec->len;
158 /* Normalize towards source node. */
159 for (src_index = 0; src_index < src_len; ++src_index) {
160 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
163 if (src_vec->entries[src_index].data == INF_COSTS) {
164 pbqp_matrix_set_row_value(mat, src_index, 0);
166 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
168 src_vec->entries[src_index].data = pbqp_add(
169 src_vec->entries[src_index].data, min);
171 if (min == INF_COSTS) {
173 unsigned edge_len = pbqp_node_get_degree(src_node);
175 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
176 pbqp_edge *edge_candidate = src_node->edges[edge_index];
177 if (edge_candidate != edge) {
178 insert_into_edge_bucket(edge_candidate);
186 static void normalize_towards_target(pbqp_edge *edge)
199 src_node = edge->src;
200 tgt_node = edge->tgt;
204 src_vec = src_node->costs;
205 tgt_vec = tgt_node->costs;
209 src_len = src_vec->len;
210 tgt_len = tgt_vec->len;
217 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
218 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
221 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
222 pbqp_matrix_set_col_value(mat, tgt_index, 0);
224 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
226 tgt_vec->entries[tgt_index].data = pbqp_add(
227 tgt_vec->entries[tgt_index].data, min);
229 if (min == INF_COSTS) {
231 unsigned edge_len = pbqp_node_get_degree(tgt_node);
233 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
234 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
235 if (edge_candidate != edge) {
236 insert_into_edge_bucket(edge_candidate);
245 * Tries to apply RM for the source node of the given edge.
247 * Checks whether the source node of edge can be merged into the target node of
248 * edge, and performs the merge, if possible.
250 static void merge_source_into_target(pbqp *pbqp, pbqp_edge *edge)
268 src_node = edge->src;
269 tgt_node = edge->tgt;
273 src_vec = src_node->costs;
274 tgt_vec = tgt_node->costs;
278 src_len = src_vec->len;
279 tgt_len = tgt_vec->len;
281 /* Matrizes are normalized. */
288 mapping = NEW_ARR_F(unsigned, tgt_len);
290 /* Check that each column has at most one zero entry. */
291 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
292 unsigned onlyOneZero = 0;
294 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
297 for (src_index = 0; src_index < src_len; ++src_index) {
298 if (src_vec->entries[src_index].data == INF_COSTS)
301 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
304 /* Matrix entry is finite. */
311 mapping[tgt_index] = src_index;
315 /* We know that we can merge the source node into the target node. */
316 edge_len = pbqp_node_get_degree(src_node);
322 /* Reconnect the source's edges with the target node. */
323 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
324 pbqp_edge *old_edge = src_node->edges[edge_index];
325 pbqp_matrix *old_matrix;
326 pbqp_matrix *new_matrix;
327 pbqp_node *other_node;
329 unsigned other_index;
334 if (old_edge == edge)
337 old_matrix = old_edge->costs;
340 if (old_edge->tgt == src_node) {
341 other_node = edge->src;
342 other_len = old_matrix->rows;
345 other_node = edge->tgt;
346 other_len = old_matrix->cols;
350 new_matrix = pbqp_matrix_alloc(pbqp, tgt_len, other_len);
352 /* Source node selects the column of the old_matrix. */
353 if (old_edge->tgt == src_node) {
354 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
355 unsigned src_index = mapping[tgt_index];
357 for (other_index = 0; other_index < other_len; ++other_index) {
358 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[other_index*src_len+src_index];
362 /* Source node selects the row of the old_matrix. */
364 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
365 unsigned src_index = mapping[tgt_index];
367 for (other_index = 0; other_index < other_len; ++other_index) {
368 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[src_index*other_len+other_index];
373 add_edge_costs(pbqp, tgt_node->index, other_node->index, new_matrix);
375 disconnect_edge(src_node, old_edge);
376 disconnect_edge(other_node, old_edge);
379 /* Reduce the remaining source node via RI. */
384 * Tries to apply RM for the target node of the given edge.
386 * Checks whether the target node of edge can be merged into the source node of
387 * edge, and performs the merge, if possible.
389 static void merge_target_into_source(pbqp *pbqp, pbqp_edge *edge)
407 src_node = edge->src;
408 tgt_node = edge->tgt;
412 src_vec = src_node->costs;
413 tgt_vec = tgt_node->costs;
417 src_len = src_vec->len;
418 tgt_len = tgt_vec->len;
420 /* Matrizes are normalized. */
427 mapping = NEW_ARR_F(unsigned, src_len);
429 /* Check that each row has at most one zero entry. */
430 for (src_index = 0; src_index < src_len; ++src_index) {
431 unsigned onlyOneZero = 0;
433 if (src_vec->entries[src_index].data == INF_COSTS)
436 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
437 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
440 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
443 /* Matrix entry is finite. */
449 mapping[src_index] = tgt_index;
453 /* We know that we can merge the target node into the source node. */
454 edge_len = pbqp_node_get_degree(tgt_node);
460 /* Reconnect the target's edges with the source node. */
461 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
462 pbqp_edge *old_edge = tgt_node->edges[edge_index];
463 pbqp_matrix *old_matrix;
464 pbqp_matrix *new_matrix;
465 pbqp_node *other_node;
467 unsigned other_index;
472 if (old_edge == edge)
475 old_matrix = old_edge->costs;
478 if (old_edge->tgt == tgt_node) {
479 other_node = edge->src;
480 other_len = old_matrix->rows;
483 other_node = edge->tgt;
484 other_len = old_matrix->cols;
488 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
490 /* Target node selects the column of the old_matrix. */
491 if (old_edge->tgt == tgt_node) {
492 for (src_index = 0; src_index < src_len; ++src_index) {
493 unsigned tgt_index = mapping[src_index];
495 for (other_index = 0; other_index < other_len; ++other_index) {
496 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
500 /* Source node selects the row of the old_matrix. */
502 for (src_index = 0; src_index < src_len; ++src_index) {
503 unsigned tgt_index = mapping[src_index];
505 for (other_index = 0; other_index < other_len; ++other_index) {
506 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
511 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
513 disconnect_edge(tgt_node, old_edge);
514 disconnect_edge(other_node, old_edge);
517 /* Reduce the remaining source node via RI. */
521 void reorder_node(pbqp_node *node)
523 unsigned degree = pbqp_node_get_degree(node);
524 /* Assume node lost one incident edge. */
525 unsigned old_degree = degree + 1;
527 if (!buckets_filled) return;
529 /* Same bucket as before */
530 if (degree > 2) return;
532 if (!node_bucket_contains(node_buckets[old_degree], node)) {
533 /* Old arity is new arity, so we have nothing to do. */
534 assert(node_bucket_contains(node_buckets[degree], node));
538 /* Delete node from old bucket... */
539 node_bucket_remove(&node_buckets[old_degree], node);
541 /* ..and add to new one. */
542 node_bucket_insert(&node_buckets[degree], node);
546 void check_melting_possibility(pbqp *pbqp, pbqp_edge *edge)
561 src_node = edge->src;
562 tgt_node = edge->tgt;
566 src_vec = src_node->costs;
567 tgt_vec = tgt_node->costs;
571 src_len = src_vec->len;
572 tgt_len = tgt_vec->len;
579 if (src_len == 1 && tgt_len == 1) {
580 //panic("Something is wrong");
584 for (src_index = 0; src_index < src_len; ++src_index) {
586 if (src_vec->entries[src_index].data == INF_COSTS) {
589 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
590 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
593 if (mat->entries[src_index * tgt_len + tgt_index] == 0) {
602 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS) {
608 allRowsOk &= onlyOneZero;
612 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
614 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
617 for (src_index = 0; src_index < src_len; ++src_index) {
618 if (src_vec->entries[src_index].data == INF_COSTS) {
621 if (mat->entries[src_index * tgt_len + tgt_index] == 0) {
630 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS) {
636 allColsOk &= onlyOneZero;
639 if (allRowsOk || allColsOk) {
645 void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
658 src_node = edge->src;
659 tgt_node = edge->tgt;
663 /* If edge are already deleted, we have nothing to do. */
664 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
668 if (pbqp->dump_file) {
670 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
671 dump_section(pbqp->dump_file, 3, txt);
675 src_vec = src_node->costs;
676 tgt_vec = tgt_node->costs;
680 src_len = src_vec->len;
681 tgt_len = tgt_vec->len;
689 if (pbqp->dump_file) {
690 fputs("Input:<br>\n", pbqp->dump_file);
691 dump_simplifyedge(pbqp, edge);
695 normalize_towards_source(edge);
696 normalize_towards_target(edge);
699 if (pbqp->dump_file) {
700 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
701 dump_simplifyedge(pbqp, edge);
705 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
707 if (pbqp->dump_file) {
708 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
717 reorder_node(src_node);
718 reorder_node(tgt_node);
722 void initial_simplify_edges(pbqp *pbqp)
730 ir_timer_t *t_int_simpl = ir_timer_register("be_pbqp_init_simp", "PBQP Initial simplify edges");
731 ir_timer_reset_and_start(t_int_simpl);
735 if (pbqp->dump_file) {
736 pbqp_dump_input(pbqp);
737 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
741 node_len = pbqp->num_nodes;
745 /* First simplify all edges. */
746 for (node_index = 0; node_index < node_len; ++node_index) {
748 pbqp_node *node = get_node(pbqp, node_index);
755 edge_len = pbqp_node_get_degree(node);
757 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
758 pbqp_edge *edge = edges[edge_index];
760 /* Simplify only once per edge. */
761 if (node != edge->src) continue;
763 simplify_edge(pbqp, edge);
768 ir_timer_stop(t_int_simpl);
769 printf("%-20s: %8.3lf msec\n", ir_timer_get_description(t_int_simpl), (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
773 num determine_solution(pbqp *pbqp)
780 ir_timer_t *t_det_solution = ir_timer_register("be_det_solution", "PBQP Determine Solution");
781 ir_timer_reset_and_start(t_det_solution);
791 file = pbqp->dump_file;
794 dump_section(file, 1, "4. Determine Solution/Minimum");
795 dump_section(file, 2, "4.1. Trivial Solution");
799 /* Solve trivial nodes and calculate solution. */
800 node_len = node_bucket_get_length(node_buckets[0]);
803 pbqp->num_r0 = node_len;
806 for (node_index = 0; node_index < node_len; ++node_index) {
807 pbqp_node *node = node_buckets[0][node_index];
810 node->solution = vector_get_min_index(node->costs);
811 solution = pbqp_add(solution,
812 node->costs->entries[node->solution].data);
816 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
817 dump_node(file, node);
824 dump_section(file, 2, "Minimum");
825 #if KAPS_USE_UNSIGNED
826 fprintf(file, "Minimum is equal to %u.", solution);
828 fprintf(file, "Minimum is equal to %lld.", solution);
834 ir_timer_stop(t_det_solution);
835 printf("%-20s: %8.3lf msec\n", ir_timer_get_description(t_det_solution), (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
841 static void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
852 edge = node->edges[0];
854 is_src = edge->src == node;
861 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
866 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
870 if (pbqp->dump_file) {
871 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
876 static void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
878 pbqp_edge *src_edge = node->edges[0];
879 pbqp_edge *tgt_edge = node->edges[1];
880 int src_is_src = src_edge->src == node;
881 int tgt_is_src = tgt_edge->src == node;
882 pbqp_matrix *src_mat;
883 pbqp_matrix *tgt_mat;
894 src_node = src_edge->tgt;
896 src_node = src_edge->src;
900 tgt_node = tgt_edge->tgt;
902 tgt_node = tgt_edge->src;
905 /* Swap nodes if necessary. */
906 if (tgt_node->index < src_node->index) {
918 src_is_src = src_edge->src == node;
919 tgt_is_src = tgt_edge->src == node;
922 src_mat = src_edge->costs;
923 tgt_mat = tgt_edge->costs;
925 node_vec = node->costs;
927 row_index = src_node->solution;
928 col_index = tgt_node->solution;
930 vec = vector_copy(pbqp, node_vec);
933 vector_add_matrix_col(vec, src_mat, row_index);
935 vector_add_matrix_row(vec, src_mat, row_index);
939 vector_add_matrix_col(vec, tgt_mat, col_index);
941 vector_add_matrix_row(vec, tgt_mat, col_index);
944 node->solution = vector_get_min_index(vec);
947 if (pbqp->dump_file) {
948 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
952 obstack_free(&pbqp->obstack, vec);
955 void back_propagate(pbqp *pbqp)
958 unsigned node_len = node_bucket_get_length(reduced_bucket);
963 if (pbqp->dump_file) {
964 dump_section(pbqp->dump_file, 2, "Back Propagation");
968 for (node_index = node_len; node_index > 0; --node_index) {
969 pbqp_node *node = reduced_bucket[node_index - 1];
971 switch (pbqp_node_get_degree(node)) {
973 back_propagate_RI(pbqp, node);
976 back_propagate_RII(pbqp, node);
979 panic("Only nodes with degree one or two should be in this bucket");
985 void apply_edge(pbqp *pbqp)
987 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
989 simplify_edge(pbqp, edge);
992 void apply_RI(pbqp *pbqp)
994 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
995 pbqp_edge *edge = node->edges[0];
996 pbqp_matrix *mat = edge->costs;
997 int is_src = edge->src == node;
998 pbqp_node *other_node;
1001 assert(pbqp_node_get_degree(node) == 1);
1004 other_node = edge->tgt;
1006 other_node = edge->src;
1010 if (pbqp->dump_file) {
1012 sprintf(txt, "RI-Reduction of Node n%d", node->index);
1013 dump_section(pbqp->dump_file, 2, txt);
1014 pbqp_dump_graph(pbqp);
1015 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1016 dump_node(pbqp->dump_file, node);
1017 dump_node(pbqp->dump_file, other_node);
1018 dump_edge(pbqp->dump_file, edge);
1023 pbqp_matrix_add_to_all_cols(mat, node->costs);
1024 normalize_towards_target(edge);
1026 pbqp_matrix_add_to_all_rows(mat, node->costs);
1027 normalize_towards_source(edge);
1029 disconnect_edge(other_node, edge);
1032 if (pbqp->dump_file) {
1033 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1034 dump_node(pbqp->dump_file, other_node);
1038 reorder_node(other_node);
1044 /* Add node to back propagation list. */
1045 node_bucket_insert(&reduced_bucket, node);
1048 void apply_RII(pbqp *pbqp)
1050 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
1051 pbqp_edge *src_edge = node->edges[0];
1052 pbqp_edge *tgt_edge = node->edges[1];
1053 int src_is_src = src_edge->src == node;
1054 int tgt_is_src = tgt_edge->src == node;
1055 pbqp_matrix *src_mat;
1056 pbqp_matrix *tgt_mat;
1057 pbqp_node *src_node;
1058 pbqp_node *tgt_node;
1071 assert(pbqp_node_get_degree(node) == 2);
1074 src_node = src_edge->tgt;
1076 src_node = src_edge->src;
1080 tgt_node = tgt_edge->tgt;
1082 tgt_node = tgt_edge->src;
1085 /* Swap nodes if necessary. */
1086 if (tgt_node->index < src_node->index) {
1087 pbqp_node *tmp_node;
1088 pbqp_edge *tmp_edge;
1090 tmp_node = src_node;
1091 src_node = tgt_node;
1092 tgt_node = tmp_node;
1094 tmp_edge = src_edge;
1095 src_edge = tgt_edge;
1096 tgt_edge = tmp_edge;
1098 src_is_src = src_edge->src == node;
1099 tgt_is_src = tgt_edge->src == node;
1103 if (pbqp->dump_file) {
1105 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1106 dump_section(pbqp->dump_file, 2, txt);
1107 pbqp_dump_graph(pbqp);
1108 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1109 dump_node(pbqp->dump_file, src_node);
1110 dump_edge(pbqp->dump_file, src_edge);
1111 dump_node(pbqp->dump_file, node);
1112 dump_edge(pbqp->dump_file, tgt_edge);
1113 dump_node(pbqp->dump_file, tgt_node);
1117 src_mat = src_edge->costs;
1118 tgt_mat = tgt_edge->costs;
1120 src_vec = src_node->costs;
1121 tgt_vec = tgt_node->costs;
1122 node_vec = node->costs;
1124 row_len = src_vec->len;
1125 col_len = tgt_vec->len;
1126 node_len = node_vec->len;
1128 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1130 for (row_index = 0; row_index < row_len; ++row_index) {
1131 for (col_index = 0; col_index < col_len; ++col_index) {
1132 vec = vector_copy(pbqp, node_vec);
1135 vector_add_matrix_col(vec, src_mat, row_index);
1137 vector_add_matrix_row(vec, src_mat, row_index);
1141 vector_add_matrix_col(vec, tgt_mat, col_index);
1143 vector_add_matrix_row(vec, tgt_mat, col_index);
1146 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1148 obstack_free(&pbqp->obstack, vec);
1152 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
1154 /* Disconnect node. */
1155 disconnect_edge(src_node, src_edge);
1156 disconnect_edge(tgt_node, tgt_edge);
1162 /* Add node to back propagation list. */
1163 node_bucket_insert(&reduced_bucket, node);
1166 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1169 pbqp_matrix_add(edge->costs, mat);
1171 /* Free local matrix. */
1172 obstack_free(&pbqp->obstack, mat);
1174 reorder_node(src_node);
1175 reorder_node(tgt_node);
1179 if (pbqp->dump_file) {
1180 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1181 dump_edge(pbqp->dump_file, edge);
1185 /* Edge has changed so we simplify it. */
1186 simplify_edge(pbqp, edge);
1189 void select_alternative(pbqp_node *node, unsigned selected_index)
1191 unsigned edge_index;
1192 unsigned node_index;
1195 unsigned max_degree = pbqp_node_get_degree(node);
1198 node->solution = selected_index;
1199 node_vec = node->costs;
1200 node_len = node_vec->len;
1201 assert(selected_index < node_len);
1203 /* Set all other costs to infinity. */
1204 for (node_index = 0; node_index < node_len; ++node_index) {
1205 if (node_index != selected_index) {
1206 node_vec->entries[node_index].data = INF_COSTS;
1210 /* Add all incident edges to edge bucket, since they are now independent. */
1211 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1212 insert_into_edge_bucket(node->edges[edge_index]);
1216 pbqp_node *get_node_with_max_degree(void)
1218 pbqp_node **bucket = node_buckets[3];
1219 unsigned bucket_len = node_bucket_get_length(bucket);
1220 unsigned bucket_index;
1221 unsigned max_degree = 0;
1222 pbqp_node *result = NULL;
1224 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1225 pbqp_node *candidate = bucket[bucket_index];
1226 unsigned degree = pbqp_node_get_degree(candidate);
1228 if (degree > max_degree) {
1230 max_degree = degree;
1237 unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
1243 unsigned edge_index;
1244 unsigned max_degree;
1245 unsigned node_index;
1247 unsigned min_index = 0;
1248 num min = INF_COSTS;
1253 node_vec = node->costs;
1254 node_len = node_vec->len;
1255 max_degree = pbqp_node_get_degree(node);
1257 for (node_index = 0; node_index < node_len; ++node_index) {
1258 num value = node_vec->entries[node_index].data;
1260 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1261 edge = node->edges[edge_index];
1263 is_src = edge->src == node;
1266 vec = vector_copy(pbqp, edge->tgt->costs);
1267 vector_add_matrix_row(vec, mat, node_index);
1269 vec = vector_copy(pbqp, edge->src->costs);
1270 vector_add_matrix_col(vec, mat, node_index);
1273 value = pbqp_add(value, vector_get_min(vec));
1275 obstack_free(&pbqp->obstack, vec);
1280 min_index = node_index;
1287 int node_is_reduced(pbqp_node *node)
1289 if (!reduced_bucket) return 0;
1291 if (pbqp_node_get_degree(node) == 0) return 1;
1293 return node_bucket_contains(reduced_bucket, node);