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_t **edge_bucket;
50 static pbqp_edge_t **rm_bucket;
51 pbqp_node_t **node_buckets[4];
52 pbqp_node_t **reduced_bucket = NULL;
53 pbqp_node_t *merged_node = NULL;
54 static int buckets_filled = 0;
56 static void insert_into_edge_bucket(pbqp_edge_t *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_t *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_t *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_t *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: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_fill_buckets) / 1000.0);
140 static void normalize_towards_source(pbqp_edge_t *edge)
143 pbqp_node_t *src_node;
144 pbqp_node_t *tgt_node;
150 unsigned new_infinity = 0;
152 src_node = edge->src;
153 tgt_node = edge->tgt;
155 src_vec = src_node->costs;
156 tgt_vec = tgt_node->costs;
158 src_len = src_vec->len;
159 tgt_len = tgt_vec->len;
165 /* Normalize towards source node. */
166 for (src_index = 0; src_index < src_len; ++src_index) {
167 num min = pbqp_matrix_get_row_min(mat, src_index, tgt_vec);
170 if (src_vec->entries[src_index].data == INF_COSTS) {
171 pbqp_matrix_set_row_value(mat, src_index, 0);
175 pbqp_matrix_sub_row_value(mat, src_index, tgt_vec, min);
176 src_vec->entries[src_index].data = pbqp_add(
177 src_vec->entries[src_index].data, min);
179 if (min == INF_COSTS) {
187 unsigned edge_len = pbqp_node_get_degree(src_node);
189 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
190 pbqp_edge_t *edge_candidate = src_node->edges[edge_index];
192 if (edge_candidate != edge) {
193 insert_into_edge_bucket(edge_candidate);
199 static void normalize_towards_target(pbqp_edge_t *edge)
202 pbqp_node_t *src_node;
203 pbqp_node_t *tgt_node;
209 unsigned new_infinity = 0;
211 src_node = edge->src;
212 tgt_node = edge->tgt;
214 src_vec = src_node->costs;
215 tgt_vec = tgt_node->costs;
217 src_len = src_vec->len;
218 tgt_len = tgt_vec->len;
224 /* Normalize towards target node. */
225 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
226 num min = pbqp_matrix_get_col_min(mat, tgt_index, src_vec);
229 if (tgt_vec->entries[tgt_index].data == INF_COSTS) {
230 pbqp_matrix_set_col_value(mat, tgt_index, 0);
234 pbqp_matrix_sub_col_value(mat, tgt_index, src_vec, min);
235 tgt_vec->entries[tgt_index].data = pbqp_add(
236 tgt_vec->entries[tgt_index].data, min);
238 if (min == INF_COSTS) {
246 unsigned edge_len = pbqp_node_get_degree(tgt_node);
248 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
249 pbqp_edge_t *edge_candidate = tgt_node->edges[edge_index];
251 if (edge_candidate != edge) {
252 insert_into_edge_bucket(edge_candidate);
259 * Tries to apply RM for the source node of the given edge.
261 * Checks whether the source node of edge can be merged into the target node of
262 * edge, and performs the merge, if possible.
264 static void merge_source_into_target(pbqp_t *pbqp, pbqp_edge_t *edge)
267 pbqp_node_t *src_node;
268 pbqp_node_t *tgt_node;
278 src_node = edge->src;
279 tgt_node = edge->tgt;
281 src_vec = src_node->costs;
282 tgt_vec = tgt_node->costs;
284 src_len = src_vec->len;
285 tgt_len = tgt_vec->len;
287 /* Matrizes are normalized. */
293 mapping = NEW_ARR_F(unsigned, tgt_len);
295 /* Check that each column has at most one zero entry. */
296 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
297 unsigned onlyOneZero = 0;
300 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
303 for (src_index = 0; src_index < src_len; ++src_index) {
304 if (src_vec->entries[src_index].data == INF_COSTS)
307 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
310 /* Matrix entry is finite. */
317 mapping[tgt_index] = src_index;
321 /* We know that we can merge the source node into the target node. */
322 edge_len = pbqp_node_get_degree(src_node);
329 if (pbqp->dump_file) {
331 sprintf(txt, "Merging n%d into n%d", src_node->index, tgt_node->index);
332 dump_section(pbqp->dump_file, 3, txt);
336 /* Reconnect the source's edges with the target node. */
337 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
338 pbqp_edge_t *old_edge = src_node->edges[edge_index];
339 pbqp_edge_t *new_edge;
340 pbqp_matrix_t *old_matrix;
341 pbqp_matrix_t *new_matrix;
342 pbqp_node_t *other_node;
345 unsigned other_index;
348 if (old_edge == edge)
351 old_matrix = old_edge->costs;
353 if (old_edge->tgt == src_node) {
354 other_node = old_edge->src;
355 other_len = old_matrix->rows;
358 other_node = old_edge->tgt;
359 other_len = old_matrix->cols;
361 other_vec = other_node->costs;
363 new_matrix = pbqp_matrix_alloc(pbqp, tgt_len, other_len);
365 /* Source node selects the column of the old_matrix. */
366 if (old_edge->tgt == src_node) {
367 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
368 unsigned src_index = mapping[tgt_index];
370 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
373 for (other_index = 0; other_index < other_len; ++other_index) {
374 if (other_vec->entries[other_index].data == INF_COSTS)
377 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[other_index*src_len+src_index];
381 /* Source node selects the row of the old_matrix. */
383 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
384 unsigned src_index = mapping[tgt_index];
386 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
389 for (other_index = 0; other_index < other_len; ++other_index) {
390 if (other_vec->entries[other_index].data == INF_COSTS)
393 new_matrix->entries[tgt_index*other_len+other_index] = old_matrix->entries[src_index*other_len+other_index];
398 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
400 add_edge_costs(pbqp, tgt_node->index, other_node->index, new_matrix);
402 if (new_edge == NULL) {
403 reorder_node_after_edge_insertion(tgt_node);
404 reorder_node_after_edge_insertion(other_node);
407 delete_edge(old_edge);
409 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
410 simplify_edge(pbqp, new_edge);
412 insert_into_rm_bucket(new_edge);
421 * Tries to apply RM for the target node of the given edge.
423 * Checks whether the target node of edge can be merged into the source node of
424 * edge, and performs the merge, if possible.
426 static void merge_target_into_source(pbqp_t *pbqp, pbqp_edge_t *edge)
429 pbqp_node_t *src_node;
430 pbqp_node_t *tgt_node;
440 src_node = edge->src;
441 tgt_node = edge->tgt;
443 src_vec = src_node->costs;
444 tgt_vec = tgt_node->costs;
446 src_len = src_vec->len;
447 tgt_len = tgt_vec->len;
449 /* Matrizes are normalized. */
455 mapping = NEW_ARR_F(unsigned, src_len);
457 /* Check that each row has at most one zero entry. */
458 for (src_index = 0; src_index < src_len; ++src_index) {
459 unsigned onlyOneZero = 0;
462 if (src_vec->entries[src_index].data == INF_COSTS)
465 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
466 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
469 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
472 /* Matrix entry is finite. */
479 mapping[src_index] = tgt_index;
483 /* We know that we can merge the target node into the source node. */
484 edge_len = pbqp_node_get_degree(tgt_node);
491 if (pbqp->dump_file) {
493 sprintf(txt, "Merging n%d into n%d", tgt_node->index, src_node->index);
494 dump_section(pbqp->dump_file, 3, txt);
498 /* Reconnect the target's edges with the source node. */
499 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
500 pbqp_edge_t *old_edge = tgt_node->edges[edge_index];
501 pbqp_edge_t *new_edge;
502 pbqp_matrix_t *old_matrix;
503 pbqp_matrix_t *new_matrix;
504 pbqp_node_t *other_node;
507 unsigned other_index;
511 if (old_edge == edge)
514 old_matrix = old_edge->costs;
516 if (old_edge->tgt == tgt_node) {
517 other_node = old_edge->src;
518 other_len = old_matrix->rows;
521 other_node = old_edge->tgt;
522 other_len = old_matrix->cols;
524 other_vec = other_node->costs;
526 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
528 /* Target node selects the column of the old_matrix. */
529 if (old_edge->tgt == tgt_node) {
530 for (src_index = 0; src_index < src_len; ++src_index) {
531 unsigned tgt_index = mapping[src_index];
533 if (src_vec->entries[src_index].data == INF_COSTS)
536 for (other_index = 0; other_index < other_len; ++other_index) {
537 if (other_vec->entries[other_index].data == INF_COSTS)
540 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
544 /* Source node selects the row of the old_matrix. */
546 for (src_index = 0; src_index < src_len; ++src_index) {
547 unsigned tgt_index = mapping[src_index];
549 if (src_vec->entries[src_index].data == INF_COSTS)
552 for (other_index = 0; other_index < other_len; ++other_index) {
553 if (other_vec->entries[other_index].data == INF_COSTS)
556 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
561 new_edge = get_edge(pbqp, src_node->index, other_node->index);
563 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
565 if (new_edge == NULL) {
566 reorder_node_after_edge_insertion(src_node);
567 reorder_node_after_edge_insertion(other_node);
570 delete_edge(old_edge);
572 new_edge = get_edge(pbqp, src_node->index, other_node->index);
573 simplify_edge(pbqp, new_edge);
575 insert_into_rm_bucket(new_edge);
584 * Merge neighbors into the given node.
586 void apply_RM(pbqp_t *pbqp, pbqp_node_t *node)
593 edge_len = pbqp_node_get_degree(node);
595 /* Check all incident edges. */
596 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
597 pbqp_edge_t *edge = edges[edge_index];
599 insert_into_rm_bucket(edge);
602 /* ALAP: Merge neighbors into given node. */
603 while(edge_bucket_get_length(rm_bucket) > 0) {
604 pbqp_edge_t *edge = edge_bucket_pop(&rm_bucket);
606 /* If the edge is not deleted: Try a merge. */
607 if (edge->src == node)
608 merge_target_into_source(pbqp, edge);
609 else if (edge->tgt == node)
610 merge_source_into_target(pbqp, edge);
616 void reorder_node_after_edge_deletion(pbqp_node_t *node)
618 unsigned degree = pbqp_node_get_degree(node);
619 /* Assume node lost one incident edge. */
620 unsigned old_degree = degree + 1;
622 if (!buckets_filled) return;
624 /* Same bucket as before */
625 if (degree > 2) return;
627 /* Delete node from old bucket... */
628 node_bucket_remove(&node_buckets[old_degree], node);
630 /* ..and add to new one. */
631 node_bucket_insert(&node_buckets[degree], node);
634 void reorder_node_after_edge_insertion(pbqp_node_t *node)
636 unsigned degree = pbqp_node_get_degree(node);
637 /* Assume node lost one incident edge. */
638 unsigned old_degree = degree - 1;
640 if (!buckets_filled) return;
642 /* Same bucket as before */
643 if (old_degree > 2) return;
645 /* Delete node from old bucket... */
646 node_bucket_remove(&node_buckets[old_degree], node);
648 /* ..and add to new one. */
649 node_bucket_insert(&node_buckets[degree], node);
652 void simplify_edge(pbqp_t *pbqp, pbqp_edge_t *edge)
655 pbqp_node_t *src_node;
656 pbqp_node_t *tgt_node;
664 src_node = edge->src;
665 tgt_node = edge->tgt;
669 /* If edge are already deleted, we have nothing to do. */
670 if (is_deleted(edge))
674 if (pbqp->dump_file) {
676 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
677 dump_section(pbqp->dump_file, 3, txt);
681 src_vec = src_node->costs;
682 tgt_vec = tgt_node->costs;
684 src_len = src_vec->len;
685 tgt_len = tgt_vec->len;
692 if (pbqp->dump_file) {
693 fputs("Input:<br>\n", pbqp->dump_file);
694 dump_simplifyedge(pbqp, edge);
698 normalize_towards_source(edge);
699 normalize_towards_target(edge);
702 if (pbqp->dump_file) {
703 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
704 dump_simplifyedge(pbqp, edge);
708 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
710 if (pbqp->dump_file) {
711 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
723 void initial_simplify_edges(pbqp_t *pbqp)
729 ir_timer_t *t_int_simpl = ir_timer_new();
730 ir_timer_start(t_int_simpl);
734 if (pbqp->dump_file) {
735 pbqp_dump_input(pbqp);
736 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
740 node_len = pbqp->num_nodes;
744 /* First simplify all edges. */
745 for (node_index = 0; node_index < node_len; ++node_index) {
747 pbqp_node_t *node = get_node(pbqp, node_index);
754 edge_len = pbqp_node_get_degree(node);
756 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
757 pbqp_edge_t *edge = edges[edge_index];
759 /* Simplify only once per edge. */
760 if (node != edge->src) continue;
762 simplify_edge(pbqp, edge);
767 ir_timer_stop(t_int_simpl);
768 printf("PBQP Initial simplify edges: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
772 num determine_solution(pbqp_t *pbqp)
779 ir_timer_t *t_det_solution = ir_timer_new();
780 ir_timer_reset_and_start(t_det_solution);
790 file = pbqp->dump_file;
793 dump_section(file, 1, "4. Determine Solution/Minimum");
794 dump_section(file, 2, "4.1. Trivial Solution");
798 /* Solve trivial nodes and calculate solution. */
799 node_len = node_bucket_get_length(node_buckets[0]);
802 pbqp->num_r0 = node_len;
805 for (node_index = 0; node_index < node_len; ++node_index) {
806 pbqp_node_t *node = node_buckets[0][node_index];
808 node->solution = vector_get_min_index(node->costs);
809 solution = pbqp_add(solution,
810 node->costs->entries[node->solution].data);
814 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
815 dump_node(file, node);
822 dump_section(file, 2, "Minimum");
823 #if KAPS_USE_UNSIGNED
824 fprintf(file, "Minimum is equal to %u.", solution);
826 fprintf(file, "Minimum is equal to %lld.", solution);
832 ir_timer_stop(t_det_solution);
833 printf("PBQP Determine Solution: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
839 static void back_propagate_RI(pbqp_t *pbqp, pbqp_node_t *node)
848 edge = node->edges[0];
850 is_src = edge->src == node;
855 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
858 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
862 if (pbqp->dump_file) {
863 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
868 static void back_propagate_RII(pbqp_t *pbqp, pbqp_node_t *node)
870 pbqp_edge_t *src_edge = node->edges[0];
871 pbqp_edge_t *tgt_edge = node->edges[1];
872 int src_is_src = src_edge->src == node;
873 int tgt_is_src = tgt_edge->src == node;
874 pbqp_matrix_t *src_mat;
875 pbqp_matrix_t *tgt_mat;
876 pbqp_node_t *src_node;
877 pbqp_node_t *tgt_node;
884 src_node = src_edge->tgt;
886 src_node = src_edge->src;
890 tgt_node = tgt_edge->tgt;
892 tgt_node = tgt_edge->src;
895 /* Swap nodes if necessary. */
896 if (tgt_node->index < src_node->index) {
897 pbqp_node_t *tmp_node;
898 pbqp_edge_t *tmp_edge;
908 src_is_src = src_edge->src == node;
909 tgt_is_src = tgt_edge->src == node;
912 src_mat = src_edge->costs;
913 tgt_mat = tgt_edge->costs;
915 node_vec = node->costs;
917 row_index = src_node->solution;
918 col_index = tgt_node->solution;
920 vec = vector_copy(pbqp, node_vec);
923 vector_add_matrix_col(vec, src_mat, row_index);
925 vector_add_matrix_row(vec, src_mat, row_index);
929 vector_add_matrix_col(vec, tgt_mat, col_index);
931 vector_add_matrix_row(vec, tgt_mat, col_index);
934 node->solution = vector_get_min_index(vec);
937 if (pbqp->dump_file) {
938 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
942 obstack_free(&pbqp->obstack, vec);
945 void back_propagate(pbqp_t *pbqp)
948 unsigned node_len = node_bucket_get_length(reduced_bucket);
951 if (pbqp->dump_file) {
952 dump_section(pbqp->dump_file, 2, "Back Propagation");
956 for (node_index = node_len; node_index > 0; --node_index) {
957 pbqp_node_t *node = reduced_bucket[node_index - 1];
959 switch (pbqp_node_get_degree(node)) {
961 back_propagate_RI(pbqp, node);
964 back_propagate_RII(pbqp, node);
967 panic("Only nodes with degree one or two should be in this bucket");
972 void apply_edge(pbqp_t *pbqp)
974 pbqp_edge_t *edge = edge_bucket_pop(&edge_bucket);
976 simplify_edge(pbqp, edge);
979 void apply_RI(pbqp_t *pbqp)
981 pbqp_node_t *node = node_bucket_pop(&node_buckets[1]);
982 pbqp_edge_t *edge = node->edges[0];
983 pbqp_matrix_t *mat = edge->costs;
984 int is_src = edge->src == node;
985 pbqp_node_t *other_node;
988 assert(pbqp_node_get_degree(node) == 1);
991 other_node = edge->tgt;
993 other_node = edge->src;
997 if (pbqp->dump_file) {
999 sprintf(txt, "RI-Reduction of Node n%d", node->index);
1000 dump_section(pbqp->dump_file, 2, txt);
1001 pbqp_dump_graph(pbqp);
1002 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1003 dump_node(pbqp->dump_file, node);
1004 dump_node(pbqp->dump_file, other_node);
1005 dump_edge(pbqp->dump_file, edge);
1010 pbqp_matrix_add_to_all_cols(mat, node->costs);
1011 normalize_towards_target(edge);
1013 pbqp_matrix_add_to_all_rows(mat, node->costs);
1014 normalize_towards_source(edge);
1016 disconnect_edge(other_node, edge);
1019 if (pbqp->dump_file) {
1020 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1021 dump_node(pbqp->dump_file, other_node);
1025 reorder_node_after_edge_deletion(other_node);
1031 /* Add node to back propagation list. */
1032 node_bucket_insert(&reduced_bucket, node);
1035 void apply_RII(pbqp_t *pbqp)
1037 pbqp_node_t *node = node_bucket_pop(&node_buckets[2]);
1038 pbqp_edge_t *src_edge = node->edges[0];
1039 pbqp_edge_t *tgt_edge = node->edges[1];
1040 int src_is_src = src_edge->src == node;
1041 int tgt_is_src = tgt_edge->src == node;
1042 pbqp_matrix_t *src_mat;
1043 pbqp_matrix_t *tgt_mat;
1044 pbqp_node_t *src_node;
1045 pbqp_node_t *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_t *tmp_node;
1074 pbqp_edge_t *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;
1113 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1115 for (row_index = 0; row_index < row_len; ++row_index) {
1116 for (col_index = 0; col_index < col_len; ++col_index) {
1117 vec = vector_copy(pbqp, node_vec);
1120 vector_add_matrix_col(vec, src_mat, row_index);
1122 vector_add_matrix_row(vec, src_mat, row_index);
1126 vector_add_matrix_col(vec, tgt_mat, col_index);
1128 vector_add_matrix_row(vec, tgt_mat, col_index);
1131 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1133 obstack_free(&pbqp->obstack, vec);
1137 edge = get_edge(pbqp, src_node->index, tgt_node->index);
1139 /* Disconnect node. */
1140 disconnect_edge(src_node, src_edge);
1141 disconnect_edge(tgt_node, tgt_edge);
1147 /* Add node to back propagation list. */
1148 node_bucket_insert(&reduced_bucket, node);
1151 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1154 pbqp_matrix_add(edge->costs, mat);
1156 /* Free local matrix. */
1157 obstack_free(&pbqp->obstack, mat);
1159 reorder_node_after_edge_deletion(src_node);
1160 reorder_node_after_edge_deletion(tgt_node);
1164 if (pbqp->dump_file) {
1165 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1166 dump_edge(pbqp->dump_file, edge);
1170 /* Edge has changed so we simplify it. */
1171 simplify_edge(pbqp, edge);
1174 static void select_column(pbqp_edge_t *edge, unsigned col_index)
1177 pbqp_node_t *src_node;
1178 pbqp_node_t *tgt_node;
1184 unsigned new_infinity = 0;
1186 src_node = edge->src;
1187 tgt_node = edge->tgt;
1189 src_vec = src_node->costs;
1190 tgt_vec = tgt_node->costs;
1192 src_len = src_vec->len;
1193 tgt_len = tgt_vec->len;
1194 assert(src_len > 0);
1195 assert(tgt_len > 0);
1199 for (src_index = 0; src_index < src_len; ++src_index) {
1200 num elem = mat->entries[src_index * tgt_len + col_index];
1203 if (elem == INF_COSTS && src_vec->entries[src_index].data != INF_COSTS)
1206 src_vec->entries[src_index].data = pbqp_add(
1207 src_vec->entries[src_index].data, elem);
1212 unsigned edge_index;
1213 unsigned edge_len = pbqp_node_get_degree(src_node);
1215 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1216 pbqp_edge_t *edge_candidate = src_node->edges[edge_index];
1218 if (edge_candidate != edge) {
1219 insert_into_edge_bucket(edge_candidate);
1227 static void select_row(pbqp_edge_t *edge, unsigned row_index)
1230 pbqp_node_t *tgt_node;
1234 unsigned new_infinity = 0;
1236 tgt_node = edge->tgt;
1238 tgt_vec = tgt_node->costs;
1240 tgt_len = tgt_vec->len;
1241 assert(tgt_len > 0);
1245 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
1246 num elem = mat->entries[row_index * tgt_len + tgt_index];
1249 if (elem == INF_COSTS && tgt_vec->entries[tgt_index].data != INF_COSTS)
1252 tgt_vec->entries[tgt_index].data = pbqp_add(
1253 tgt_vec->entries[tgt_index].data, elem);
1258 unsigned edge_index;
1259 unsigned edge_len = pbqp_node_get_degree(tgt_node);
1261 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1262 pbqp_edge_t *edge_candidate = tgt_node->edges[edge_index];
1264 if (edge_candidate != edge) {
1265 insert_into_edge_bucket(edge_candidate);
1273 void select_alternative(pbqp_node_t *node, unsigned selected_index)
1275 unsigned edge_index;
1276 unsigned node_index;
1279 unsigned max_degree = pbqp_node_get_degree(node);
1281 node->solution = selected_index;
1282 node_vec = node->costs;
1283 node_len = node_vec->len;
1284 assert(selected_index < node_len);
1286 /* Set all other costs to infinity. */
1287 for (node_index = 0; node_index < node_len; ++node_index) {
1288 if (node_index != selected_index) {
1289 node_vec->entries[node_index].data = INF_COSTS;
1293 /* Select corresponding row/column for incident edges. */
1294 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1295 pbqp_edge_t *edge = node->edges[edge_index];
1297 if (edge->src == node)
1298 select_row(edge, selected_index);
1300 select_column(edge, selected_index);
1304 pbqp_node_t *get_node_with_max_degree(void)
1306 pbqp_node_t **bucket = node_buckets[3];
1307 unsigned bucket_len = node_bucket_get_length(bucket);
1308 unsigned bucket_index;
1309 unsigned max_degree = 0;
1310 pbqp_node_t *result = NULL;
1312 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1313 pbqp_node_t *candidate = bucket[bucket_index];
1314 unsigned degree = pbqp_node_get_degree(candidate);
1316 if (degree > max_degree) {
1318 max_degree = degree;
1325 unsigned get_local_minimal_alternative(pbqp_t *pbqp, pbqp_node_t *node)
1331 unsigned edge_index;
1332 unsigned max_degree;
1333 unsigned node_index;
1335 unsigned min_index = 0;
1336 num min = INF_COSTS;
1339 node_vec = node->costs;
1340 node_len = node_vec->len;
1341 max_degree = pbqp_node_get_degree(node);
1343 for (node_index = 0; node_index < node_len; ++node_index) {
1344 num value = node_vec->entries[node_index].data;
1346 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1347 edge = node->edges[edge_index];
1349 is_src = edge->src == node;
1352 vec = vector_copy(pbqp, edge->tgt->costs);
1353 vector_add_matrix_row(vec, mat, node_index);
1355 vec = vector_copy(pbqp, edge->src->costs);
1356 vector_add_matrix_col(vec, mat, node_index);
1359 value = pbqp_add(value, vector_get_min(vec));
1361 obstack_free(&pbqp->obstack, vec);
1366 min_index = node_index;
1373 int node_is_reduced(pbqp_node_t *node)
1375 if (!reduced_bucket) return 0;
1377 if (pbqp_node_get_degree(node) == 0) return 1;
1379 return node_bucket_contains(reduced_bucket, node);