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_register("be_pbqp_fill_buckets", "PBQP Fill Nodes into buckets");
113 ir_timer_reset_and_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("%-20s: %8.3lf msec\n", ir_timer_get_description(t_fill_buckets), (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 = edge->src;
357 other_len = old_matrix->rows;
360 other_node = 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 disconnect_edge(src_node, old_edge);
404 disconnect_edge(other_node, old_edge);
406 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
407 insert_into_rm_bucket(new_edge);
410 /* Reduce the remaining source node via RI. */
415 * Tries to apply RM for the target node of the given edge.
417 * Checks whether the target node of edge can be merged into the source node of
418 * edge, and performs the merge, if possible.
420 static void merge_target_into_source(pbqp *pbqp, pbqp_edge *edge)
438 src_node = edge->src;
439 tgt_node = edge->tgt;
443 src_vec = src_node->costs;
444 tgt_vec = tgt_node->costs;
448 src_len = src_vec->len;
449 tgt_len = tgt_vec->len;
451 /* Matrizes are normalized. */
458 mapping = NEW_ARR_F(unsigned, src_len);
460 /* Check that each row has at most one zero entry. */
461 for (src_index = 0; src_index < src_len; ++src_index) {
462 unsigned onlyOneZero = 0;
464 if (src_vec->entries[src_index].data == INF_COSTS)
467 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
468 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
471 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
474 /* Matrix entry is finite. */
481 mapping[src_index] = tgt_index;
485 /* We know that we can merge the target node into the source node. */
486 edge_len = pbqp_node_get_degree(tgt_node);
492 /* Reconnect the target's edges with the source node. */
493 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
494 pbqp_edge *old_edge = tgt_node->edges[edge_index];
496 pbqp_matrix *old_matrix;
497 pbqp_matrix *new_matrix;
498 pbqp_node *other_node;
501 unsigned other_index;
506 if (old_edge == edge)
509 old_matrix = old_edge->costs;
512 if (old_edge->tgt == tgt_node) {
513 other_node = edge->src;
514 other_len = old_matrix->rows;
517 other_node = edge->tgt;
518 other_len = old_matrix->cols;
521 other_vec = other_node->costs;
523 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
525 /* Target node selects the column of the old_matrix. */
526 if (old_edge->tgt == tgt_node) {
527 for (src_index = 0; src_index < src_len; ++src_index) {
528 unsigned tgt_index = mapping[src_index];
530 if (src_vec->entries[src_index].data == INF_COSTS)
533 for (other_index = 0; other_index < other_len; ++other_index) {
534 if (other_vec->entries[other_index].data == INF_COSTS)
537 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
541 /* Source node selects the row of the old_matrix. */
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[tgt_index*other_len+other_index];
558 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
560 disconnect_edge(tgt_node, old_edge);
561 disconnect_edge(other_node, old_edge);
563 new_edge = get_edge(pbqp, src_node->index, other_node->index);
564 insert_into_rm_bucket(new_edge);
567 /* Reduce the remaining source node via RI. */
572 * Merge neighbors into the given node.
574 void apply_RM(pbqp *pbqp, pbqp_node *node)
584 edge_len = pbqp_node_get_degree(node);
586 /* Check all incident edges. */
587 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
588 pbqp_edge *edge = edges[edge_index];
590 insert_into_rm_bucket(edge);
593 /* ALAP: Merge neighbors into given node. */
594 while(edge_bucket_get_length(rm_bucket) > 0) {
595 pbqp_edge *edge = edge_bucket_pop(&rm_bucket);
598 if (edge->src == node)
599 merge_target_into_source(pbqp, edge);
601 merge_source_into_target(pbqp, edge);
605 void reorder_node(pbqp_node *node)
607 unsigned degree = pbqp_node_get_degree(node);
608 /* Assume node lost one incident edge. */
609 unsigned old_degree = degree + 1;
611 if (!buckets_filled) return;
613 /* Same bucket as before */
614 if (degree > 2) return;
616 if (!node_bucket_contains(node_buckets[old_degree], node)) {
617 /* Old arity is new arity, so we have nothing to do. */
618 assert(node_bucket_contains(node_buckets[degree], node));
622 /* Delete node from old bucket... */
623 node_bucket_remove(&node_buckets[old_degree], node);
625 /* ..and add to new one. */
626 node_bucket_insert(&node_buckets[degree], node);
629 void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
642 src_node = edge->src;
643 tgt_node = edge->tgt;
647 /* If edge are already deleted, we have nothing to do. */
648 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
652 if (pbqp->dump_file) {
654 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
655 dump_section(pbqp->dump_file, 3, txt);
659 src_vec = src_node->costs;
660 tgt_vec = tgt_node->costs;
664 src_len = src_vec->len;
665 tgt_len = tgt_vec->len;
673 if (pbqp->dump_file) {
674 fputs("Input:<br>\n", pbqp->dump_file);
675 dump_simplifyedge(pbqp, edge);
679 normalize_towards_source(edge);
680 normalize_towards_target(edge);
683 if (pbqp->dump_file) {
684 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
685 dump_simplifyedge(pbqp, edge);
689 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
691 if (pbqp->dump_file) {
692 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
701 reorder_node(src_node);
702 reorder_node(tgt_node);
706 void initial_simplify_edges(pbqp *pbqp)
714 ir_timer_t *t_int_simpl = ir_timer_register("be_pbqp_init_simp", "PBQP Initial simplify edges");
715 ir_timer_reset_and_start(t_int_simpl);
719 if (pbqp->dump_file) {
720 pbqp_dump_input(pbqp);
721 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
725 node_len = pbqp->num_nodes;
729 /* First simplify all edges. */
730 for (node_index = 0; node_index < node_len; ++node_index) {
732 pbqp_node *node = get_node(pbqp, node_index);
739 edge_len = pbqp_node_get_degree(node);
741 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
742 pbqp_edge *edge = edges[edge_index];
744 /* Simplify only once per edge. */
745 if (node != edge->src) continue;
747 simplify_edge(pbqp, edge);
752 ir_timer_stop(t_int_simpl);
753 printf("%-20s: %8.3lf msec\n", ir_timer_get_description(t_int_simpl), (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
757 num determine_solution(pbqp *pbqp)
764 ir_timer_t *t_det_solution = ir_timer_register("be_det_solution", "PBQP Determine Solution");
765 ir_timer_reset_and_start(t_det_solution);
775 file = pbqp->dump_file;
778 dump_section(file, 1, "4. Determine Solution/Minimum");
779 dump_section(file, 2, "4.1. Trivial Solution");
783 /* Solve trivial nodes and calculate solution. */
784 node_len = node_bucket_get_length(node_buckets[0]);
787 pbqp->num_r0 = node_len;
790 for (node_index = 0; node_index < node_len; ++node_index) {
791 pbqp_node *node = node_buckets[0][node_index];
794 node->solution = vector_get_min_index(node->costs);
795 solution = pbqp_add(solution,
796 node->costs->entries[node->solution].data);
800 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
801 dump_node(file, node);
808 dump_section(file, 2, "Minimum");
809 #if KAPS_USE_UNSIGNED
810 fprintf(file, "Minimum is equal to %u.", solution);
812 fprintf(file, "Minimum is equal to %lld.", solution);
818 ir_timer_stop(t_det_solution);
819 printf("%-20s: %8.3lf msec\n", ir_timer_get_description(t_det_solution), (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
825 static void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
836 edge = node->edges[0];
838 is_src = edge->src == node;
845 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
850 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
854 if (pbqp->dump_file) {
855 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
860 static void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
862 pbqp_edge *src_edge = node->edges[0];
863 pbqp_edge *tgt_edge = node->edges[1];
864 int src_is_src = src_edge->src == node;
865 int tgt_is_src = tgt_edge->src == node;
866 pbqp_matrix *src_mat;
867 pbqp_matrix *tgt_mat;
878 src_node = src_edge->tgt;
880 src_node = src_edge->src;
884 tgt_node = tgt_edge->tgt;
886 tgt_node = tgt_edge->src;
889 /* Swap nodes if necessary. */
890 if (tgt_node->index < src_node->index) {
902 src_is_src = src_edge->src == node;
903 tgt_is_src = tgt_edge->src == node;
906 src_mat = src_edge->costs;
907 tgt_mat = tgt_edge->costs;
909 node_vec = node->costs;
911 row_index = src_node->solution;
912 col_index = tgt_node->solution;
914 vec = vector_copy(pbqp, node_vec);
917 vector_add_matrix_col(vec, src_mat, row_index);
919 vector_add_matrix_row(vec, src_mat, row_index);
923 vector_add_matrix_col(vec, tgt_mat, col_index);
925 vector_add_matrix_row(vec, tgt_mat, col_index);
928 node->solution = vector_get_min_index(vec);
931 if (pbqp->dump_file) {
932 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
936 obstack_free(&pbqp->obstack, vec);
939 void back_propagate(pbqp *pbqp)
942 unsigned node_len = node_bucket_get_length(reduced_bucket);
947 if (pbqp->dump_file) {
948 dump_section(pbqp->dump_file, 2, "Back Propagation");
952 for (node_index = node_len; node_index > 0; --node_index) {
953 pbqp_node *node = reduced_bucket[node_index - 1];
955 switch (pbqp_node_get_degree(node)) {
957 back_propagate_RI(pbqp, node);
960 back_propagate_RII(pbqp, node);
963 panic("Only nodes with degree one or two should be in this bucket");
969 void apply_edge(pbqp *pbqp)
971 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
973 simplify_edge(pbqp, edge);
976 void apply_RI(pbqp *pbqp)
978 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
979 pbqp_edge *edge = node->edges[0];
980 pbqp_matrix *mat = edge->costs;
981 int is_src = edge->src == node;
982 pbqp_node *other_node;
985 assert(pbqp_node_get_degree(node) == 1);
988 other_node = edge->tgt;
990 other_node = edge->src;
994 if (pbqp->dump_file) {
996 sprintf(txt, "RI-Reduction of Node n%d", node->index);
997 dump_section(pbqp->dump_file, 2, txt);
998 pbqp_dump_graph(pbqp);
999 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1000 dump_node(pbqp->dump_file, node);
1001 dump_node(pbqp->dump_file, other_node);
1002 dump_edge(pbqp->dump_file, edge);
1007 pbqp_matrix_add_to_all_cols(mat, node->costs);
1008 normalize_towards_target(edge);
1010 pbqp_matrix_add_to_all_rows(mat, node->costs);
1011 normalize_towards_source(edge);
1013 disconnect_edge(other_node, edge);
1016 if (pbqp->dump_file) {
1017 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1018 dump_node(pbqp->dump_file, other_node);
1022 reorder_node(other_node);
1028 /* Add node to back propagation list. */
1029 node_bucket_insert(&reduced_bucket, node);
1032 void apply_RII(pbqp *pbqp)
1034 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
1035 pbqp_edge *src_edge = node->edges[0];
1036 pbqp_edge *tgt_edge = node->edges[1];
1037 int src_is_src = src_edge->src == node;
1038 int tgt_is_src = tgt_edge->src == node;
1039 pbqp_matrix *src_mat;
1040 pbqp_matrix *tgt_mat;
1041 pbqp_node *src_node;
1042 pbqp_node *tgt_node;
1055 assert(pbqp_node_get_degree(node) == 2);
1058 src_node = src_edge->tgt;
1060 src_node = src_edge->src;
1064 tgt_node = tgt_edge->tgt;
1066 tgt_node = tgt_edge->src;
1069 /* Swap nodes if necessary. */
1070 if (tgt_node->index < src_node->index) {
1071 pbqp_node *tmp_node;
1072 pbqp_edge *tmp_edge;
1074 tmp_node = src_node;
1075 src_node = tgt_node;
1076 tgt_node = tmp_node;
1078 tmp_edge = src_edge;
1079 src_edge = tgt_edge;
1080 tgt_edge = tmp_edge;
1082 src_is_src = src_edge->src == node;
1083 tgt_is_src = tgt_edge->src == node;
1087 if (pbqp->dump_file) {
1089 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1090 dump_section(pbqp->dump_file, 2, txt);
1091 pbqp_dump_graph(pbqp);
1092 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1093 dump_node(pbqp->dump_file, src_node);
1094 dump_edge(pbqp->dump_file, src_edge);
1095 dump_node(pbqp->dump_file, node);
1096 dump_edge(pbqp->dump_file, tgt_edge);
1097 dump_node(pbqp->dump_file, tgt_node);
1101 src_mat = src_edge->costs;
1102 tgt_mat = tgt_edge->costs;
1104 src_vec = src_node->costs;
1105 tgt_vec = tgt_node->costs;
1106 node_vec = node->costs;
1108 row_len = src_vec->len;
1109 col_len = tgt_vec->len;
1110 node_len = node_vec->len;
1112 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1114 for (row_index = 0; row_index < row_len; ++row_index) {
1115 for (col_index = 0; col_index < col_len; ++col_index) {
1116 vec = vector_copy(pbqp, node_vec);
1119 vector_add_matrix_col(vec, src_mat, row_index);
1121 vector_add_matrix_row(vec, src_mat, row_index);
1125 vector_add_matrix_col(vec, tgt_mat, col_index);
1127 vector_add_matrix_row(vec, tgt_mat, col_index);
1130 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1132 obstack_free(&pbqp->obstack, vec);
1136 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
1138 /* Disconnect node. */
1139 disconnect_edge(src_node, src_edge);
1140 disconnect_edge(tgt_node, tgt_edge);
1146 /* Add node to back propagation list. */
1147 node_bucket_insert(&reduced_bucket, node);
1150 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1153 pbqp_matrix_add(edge->costs, mat);
1155 /* Free local matrix. */
1156 obstack_free(&pbqp->obstack, mat);
1158 reorder_node(src_node);
1159 reorder_node(tgt_node);
1163 if (pbqp->dump_file) {
1164 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1165 dump_edge(pbqp->dump_file, edge);
1169 /* Edge has changed so we simplify it. */
1170 simplify_edge(pbqp, edge);
1173 void select_alternative(pbqp_node *node, unsigned selected_index)
1175 unsigned edge_index;
1176 unsigned node_index;
1179 unsigned max_degree = pbqp_node_get_degree(node);
1182 node->solution = selected_index;
1183 node_vec = node->costs;
1184 node_len = node_vec->len;
1185 assert(selected_index < node_len);
1187 /* Set all other costs to infinity. */
1188 for (node_index = 0; node_index < node_len; ++node_index) {
1189 if (node_index != selected_index) {
1190 node_vec->entries[node_index].data = INF_COSTS;
1194 /* Add all incident edges to edge bucket, since they are now independent. */
1195 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1196 insert_into_edge_bucket(node->edges[edge_index]);
1200 pbqp_node *get_node_with_max_degree(void)
1202 pbqp_node **bucket = node_buckets[3];
1203 unsigned bucket_len = node_bucket_get_length(bucket);
1204 unsigned bucket_index;
1205 unsigned max_degree = 0;
1206 pbqp_node *result = NULL;
1208 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1209 pbqp_node *candidate = bucket[bucket_index];
1210 unsigned degree = pbqp_node_get_degree(candidate);
1212 if (degree > max_degree) {
1214 max_degree = degree;
1221 unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
1227 unsigned edge_index;
1228 unsigned max_degree;
1229 unsigned node_index;
1231 unsigned min_index = 0;
1232 num min = INF_COSTS;
1237 node_vec = node->costs;
1238 node_len = node_vec->len;
1239 max_degree = pbqp_node_get_degree(node);
1241 for (node_index = 0; node_index < node_len; ++node_index) {
1242 num value = node_vec->entries[node_index].data;
1244 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1245 edge = node->edges[edge_index];
1247 is_src = edge->src == node;
1250 vec = vector_copy(pbqp, edge->tgt->costs);
1251 vector_add_matrix_row(vec, mat, node_index);
1253 vec = vector_copy(pbqp, edge->src->costs);
1254 vector_add_matrix_col(vec, mat, node_index);
1257 value = pbqp_add(value, vector_get_min(vec));
1259 obstack_free(&pbqp->obstack, vec);
1264 min_index = node_index;
1271 int node_is_reduced(pbqp_node *node)
1273 if (!reduced_bucket) return 0;
1275 if (pbqp_node_get_degree(node) == 0) return 1;
1277 return node_bucket_contains(reduced_bucket, node);