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);
420 reorder_node(src_node);
421 reorder_node(other_node);
423 new_edge = get_edge(pbqp, tgt_node->index, other_node->index);
424 insert_into_rm_bucket(new_edge);
433 * Tries to apply RM for the target node of the given edge.
435 * Checks whether the target node of edge can be merged into the source node of
436 * edge, and performs the merge, if possible.
438 static void merge_target_into_source(pbqp *pbqp, pbqp_edge *edge)
456 src_node = edge->src;
457 tgt_node = edge->tgt;
461 src_vec = src_node->costs;
462 tgt_vec = tgt_node->costs;
466 src_len = src_vec->len;
467 tgt_len = tgt_vec->len;
469 /* Matrizes are normalized. */
476 mapping = NEW_ARR_F(unsigned, src_len);
478 /* Check that each row has at most one zero entry. */
479 for (src_index = 0; src_index < src_len; ++src_index) {
480 unsigned onlyOneZero = 0;
482 if (src_vec->entries[src_index].data == INF_COSTS)
485 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
486 if (tgt_vec->entries[tgt_index].data == INF_COSTS)
489 if (mat->entries[src_index * tgt_len + tgt_index] == INF_COSTS)
492 /* Matrix entry is finite. */
499 mapping[src_index] = tgt_index;
503 /* We know that we can merge the target node into the source node. */
504 edge_len = pbqp_node_get_degree(tgt_node);
510 /* Reconnect the target's edges with the source node. */
511 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
512 pbqp_edge *old_edge = tgt_node->edges[edge_index];
514 pbqp_matrix *old_matrix;
515 pbqp_matrix *new_matrix;
516 pbqp_node *other_node;
519 unsigned other_index;
524 if (old_edge == edge)
527 old_matrix = old_edge->costs;
530 if (old_edge->tgt == tgt_node) {
531 other_node = old_edge->src;
532 other_len = old_matrix->rows;
535 other_node = old_edge->tgt;
536 other_len = old_matrix->cols;
539 other_vec = other_node->costs;
541 new_matrix = pbqp_matrix_alloc(pbqp, src_len, other_len);
543 /* Target node selects the column of the old_matrix. */
544 if (old_edge->tgt == tgt_node) {
545 for (src_index = 0; src_index < src_len; ++src_index) {
546 unsigned tgt_index = mapping[src_index];
548 if (src_vec->entries[src_index].data == INF_COSTS)
551 for (other_index = 0; other_index < other_len; ++other_index) {
552 if (other_vec->entries[other_index].data == INF_COSTS)
555 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[other_index*tgt_len+tgt_index];
559 /* Source node selects the row of the old_matrix. */
561 for (src_index = 0; src_index < src_len; ++src_index) {
562 unsigned tgt_index = mapping[src_index];
564 if (src_vec->entries[src_index].data == INF_COSTS)
567 for (other_index = 0; other_index < other_len; ++other_index) {
568 if (other_vec->entries[other_index].data == INF_COSTS)
571 new_matrix->entries[src_index*other_len+other_index] = old_matrix->entries[tgt_index*other_len+other_index];
576 add_edge_costs(pbqp, src_node->index, other_node->index, new_matrix);
578 delete_edge(old_edge);
579 reorder_node(tgt_node);
580 reorder_node(other_node);
582 new_edge = get_edge(pbqp, src_node->index, other_node->index);
583 insert_into_rm_bucket(new_edge);
592 * Merge neighbors into the given node.
594 void apply_RM(pbqp *pbqp, pbqp_node *node)
604 edge_len = pbqp_node_get_degree(node);
606 /* Check all incident edges. */
607 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
608 pbqp_edge *edge = edges[edge_index];
610 insert_into_rm_bucket(edge);
613 /* ALAP: Merge neighbors into given node. */
614 while(edge_bucket_get_length(rm_bucket) > 0) {
615 pbqp_edge *edge = edge_bucket_pop(&rm_bucket);
618 if (edge->src == node)
619 merge_target_into_source(pbqp, edge);
621 merge_source_into_target(pbqp, edge);
627 void reorder_node(pbqp_node *node)
629 unsigned degree = pbqp_node_get_degree(node);
630 /* Assume node lost one incident edge. */
631 unsigned old_degree = degree + 1;
633 if (!buckets_filled) return;
635 /* Same bucket as before */
636 if (degree > 2) return;
638 if (!node_bucket_contains(node_buckets[old_degree], node)) {
639 /* Old arity is new arity, so we have nothing to do. */
640 assert(node_bucket_contains(node_buckets[degree], node));
644 /* Delete node from old bucket... */
645 node_bucket_remove(&node_buckets[old_degree], node);
647 /* ..and add to new one. */
648 node_bucket_insert(&node_buckets[degree], node);
651 void simplify_edge(pbqp *pbqp, pbqp_edge *edge)
666 src_node = edge->src;
667 tgt_node = edge->tgt;
671 /* If edge are already deleted, we have nothing to do. */
672 if (!is_connected(src_node, edge) || !is_connected(tgt_node, edge))
676 if (pbqp->dump_file) {
678 sprintf(txt, "Simplification of Edge n%d-n%d", src_node->index, tgt_node->index);
679 dump_section(pbqp->dump_file, 3, txt);
683 src_vec = src_node->costs;
684 tgt_vec = tgt_node->costs;
688 src_len = src_vec->len;
689 tgt_len = tgt_vec->len;
697 if (pbqp->dump_file) {
698 fputs("Input:<br>\n", pbqp->dump_file);
699 dump_simplifyedge(pbqp, edge);
703 normalize_towards_source(edge);
704 normalize_towards_target(edge);
707 if (pbqp->dump_file) {
708 fputs("<br>\nOutput:<br>\n", pbqp->dump_file);
709 dump_simplifyedge(pbqp, edge);
713 if (pbqp_matrix_is_zero(mat, src_vec, tgt_vec)) {
715 if (pbqp->dump_file) {
716 fputs("edge has been eliminated<br>\n", pbqp->dump_file);
725 reorder_node(src_node);
726 reorder_node(tgt_node);
730 void initial_simplify_edges(pbqp *pbqp)
738 ir_timer_t *t_int_simpl = ir_timer_new();
739 ir_timer_start(t_int_simpl);
743 if (pbqp->dump_file) {
744 pbqp_dump_input(pbqp);
745 dump_section(pbqp->dump_file, 1, "2. Simplification of Cost Matrices");
749 node_len = pbqp->num_nodes;
753 /* First simplify all edges. */
754 for (node_index = 0; node_index < node_len; ++node_index) {
756 pbqp_node *node = get_node(pbqp, node_index);
763 edge_len = pbqp_node_get_degree(node);
765 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
766 pbqp_edge *edge = edges[edge_index];
768 /* Simplify only once per edge. */
769 if (node != edge->src) continue;
771 simplify_edge(pbqp, edge);
776 ir_timer_stop(t_int_simpl);
777 printf("PBQP Initial simplify edges: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_int_simpl) / 1000.0);
781 num determine_solution(pbqp *pbqp)
788 ir_timer_t *t_det_solution = ir_timer_new();
789 ir_timer_reset_and_start(t_det_solution);
801 file = pbqp->dump_file;
804 dump_section(file, 1, "4. Determine Solution/Minimum");
805 dump_section(file, 2, "4.1. Trivial Solution");
809 /* Solve trivial nodes and calculate solution. */
810 node_len = node_bucket_get_length(node_buckets[0]);
813 pbqp->num_r0 = node_len;
816 for (node_index = 0; node_index < node_len; ++node_index) {
817 pbqp_node *node = node_buckets[0][node_index];
820 node->solution = vector_get_min_index(node->costs);
821 solution = pbqp_add(solution,
822 node->costs->entries[node->solution].data);
826 fprintf(file, "node n%d is set to %d<br>\n", node->index, node->solution);
827 dump_node(file, node);
834 dump_section(file, 2, "Minimum");
835 #if KAPS_USE_UNSIGNED
836 fprintf(file, "Minimum is equal to %u.", solution);
838 fprintf(file, "Minimum is equal to %lld.", solution);
844 ir_timer_stop(t_det_solution);
845 printf("PBQP Determine Solution: %10.3lf msec\n", (double)ir_timer_elapsed_usec(t_det_solution) / 1000.0);
851 static void back_propagate_RI(pbqp *pbqp, pbqp_node *node)
864 edge = node->edges[0];
866 is_src = edge->src == node;
873 node->solution = pbqp_matrix_get_col_min_index(mat, other->solution, vec);
878 node->solution = pbqp_matrix_get_row_min_index(mat, other->solution, vec);
882 if (pbqp->dump_file) {
883 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
888 static void back_propagate_RII(pbqp *pbqp, pbqp_node *node)
890 pbqp_edge *src_edge = node->edges[0];
891 pbqp_edge *tgt_edge = node->edges[1];
892 int src_is_src = src_edge->src == node;
893 int tgt_is_src = tgt_edge->src == node;
894 pbqp_matrix *src_mat;
895 pbqp_matrix *tgt_mat;
906 src_node = src_edge->tgt;
908 src_node = src_edge->src;
912 tgt_node = tgt_edge->tgt;
914 tgt_node = tgt_edge->src;
917 /* Swap nodes if necessary. */
918 if (tgt_node->index < src_node->index) {
930 src_is_src = src_edge->src == node;
931 tgt_is_src = tgt_edge->src == node;
934 src_mat = src_edge->costs;
935 tgt_mat = tgt_edge->costs;
937 node_vec = node->costs;
939 row_index = src_node->solution;
940 col_index = tgt_node->solution;
942 vec = vector_copy(pbqp, node_vec);
945 vector_add_matrix_col(vec, src_mat, row_index);
947 vector_add_matrix_row(vec, src_mat, row_index);
951 vector_add_matrix_col(vec, tgt_mat, col_index);
953 vector_add_matrix_row(vec, tgt_mat, col_index);
956 node->solution = vector_get_min_index(vec);
959 if (pbqp->dump_file) {
960 fprintf(pbqp->dump_file, "node n%d is set to %d<br>\n", node->index, node->solution);
964 obstack_free(&pbqp->obstack, vec);
967 void back_propagate(pbqp *pbqp)
970 unsigned node_len = node_bucket_get_length(reduced_bucket);
975 if (pbqp->dump_file) {
976 dump_section(pbqp->dump_file, 2, "Back Propagation");
980 for (node_index = node_len; node_index > 0; --node_index) {
981 pbqp_node *node = reduced_bucket[node_index - 1];
983 switch (pbqp_node_get_degree(node)) {
985 back_propagate_RI(pbqp, node);
988 back_propagate_RII(pbqp, node);
991 panic("Only nodes with degree one or two should be in this bucket");
997 void apply_edge(pbqp *pbqp)
999 pbqp_edge *edge = edge_bucket_pop(&edge_bucket);
1001 simplify_edge(pbqp, edge);
1004 void apply_RI(pbqp *pbqp)
1006 pbqp_node *node = node_bucket_pop(&node_buckets[1]);
1007 pbqp_edge *edge = node->edges[0];
1008 pbqp_matrix *mat = edge->costs;
1009 int is_src = edge->src == node;
1010 pbqp_node *other_node;
1013 assert(pbqp_node_get_degree(node) == 1);
1016 other_node = edge->tgt;
1018 other_node = edge->src;
1022 if (pbqp->dump_file) {
1024 sprintf(txt, "RI-Reduction of Node n%d", node->index);
1025 dump_section(pbqp->dump_file, 2, txt);
1026 pbqp_dump_graph(pbqp);
1027 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1028 dump_node(pbqp->dump_file, node);
1029 dump_node(pbqp->dump_file, other_node);
1030 dump_edge(pbqp->dump_file, edge);
1035 pbqp_matrix_add_to_all_cols(mat, node->costs);
1036 normalize_towards_target(edge);
1038 pbqp_matrix_add_to_all_rows(mat, node->costs);
1039 normalize_towards_source(edge);
1041 disconnect_edge(other_node, edge);
1044 if (pbqp->dump_file) {
1045 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1046 dump_node(pbqp->dump_file, other_node);
1050 reorder_node(other_node);
1056 /* Add node to back propagation list. */
1057 node_bucket_insert(&reduced_bucket, node);
1060 void apply_RII(pbqp *pbqp)
1062 pbqp_node *node = node_bucket_pop(&node_buckets[2]);
1063 pbqp_edge *src_edge = node->edges[0];
1064 pbqp_edge *tgt_edge = node->edges[1];
1065 int src_is_src = src_edge->src == node;
1066 int tgt_is_src = tgt_edge->src == node;
1067 pbqp_matrix *src_mat;
1068 pbqp_matrix *tgt_mat;
1069 pbqp_node *src_node;
1070 pbqp_node *tgt_node;
1083 assert(pbqp_node_get_degree(node) == 2);
1086 src_node = src_edge->tgt;
1088 src_node = src_edge->src;
1092 tgt_node = tgt_edge->tgt;
1094 tgt_node = tgt_edge->src;
1097 /* Swap nodes if necessary. */
1098 if (tgt_node->index < src_node->index) {
1099 pbqp_node *tmp_node;
1100 pbqp_edge *tmp_edge;
1102 tmp_node = src_node;
1103 src_node = tgt_node;
1104 tgt_node = tmp_node;
1106 tmp_edge = src_edge;
1107 src_edge = tgt_edge;
1108 tgt_edge = tmp_edge;
1110 src_is_src = src_edge->src == node;
1111 tgt_is_src = tgt_edge->src == node;
1115 if (pbqp->dump_file) {
1117 sprintf(txt, "RII-Reduction of Node n%d", node->index);
1118 dump_section(pbqp->dump_file, 2, txt);
1119 pbqp_dump_graph(pbqp);
1120 fputs("<br>\nBefore reduction:<br>\n", pbqp->dump_file);
1121 dump_node(pbqp->dump_file, src_node);
1122 dump_edge(pbqp->dump_file, src_edge);
1123 dump_node(pbqp->dump_file, node);
1124 dump_edge(pbqp->dump_file, tgt_edge);
1125 dump_node(pbqp->dump_file, tgt_node);
1129 src_mat = src_edge->costs;
1130 tgt_mat = tgt_edge->costs;
1132 src_vec = src_node->costs;
1133 tgt_vec = tgt_node->costs;
1134 node_vec = node->costs;
1136 row_len = src_vec->len;
1137 col_len = tgt_vec->len;
1138 node_len = node_vec->len;
1140 mat = pbqp_matrix_alloc(pbqp, row_len, col_len);
1142 for (row_index = 0; row_index < row_len; ++row_index) {
1143 for (col_index = 0; col_index < col_len; ++col_index) {
1144 vec = vector_copy(pbqp, node_vec);
1147 vector_add_matrix_col(vec, src_mat, row_index);
1149 vector_add_matrix_row(vec, src_mat, row_index);
1153 vector_add_matrix_col(vec, tgt_mat, col_index);
1155 vector_add_matrix_row(vec, tgt_mat, col_index);
1158 mat->entries[row_index * col_len + col_index] = vector_get_min(vec);
1160 obstack_free(&pbqp->obstack, vec);
1164 pbqp_edge *edge = get_edge(pbqp, src_node->index, tgt_node->index);
1166 /* Disconnect node. */
1167 disconnect_edge(src_node, src_edge);
1168 disconnect_edge(tgt_node, tgt_edge);
1174 /* Add node to back propagation list. */
1175 node_bucket_insert(&reduced_bucket, node);
1178 edge = alloc_edge(pbqp, src_node->index, tgt_node->index, mat);
1181 pbqp_matrix_add(edge->costs, mat);
1183 /* Free local matrix. */
1184 obstack_free(&pbqp->obstack, mat);
1186 reorder_node(src_node);
1187 reorder_node(tgt_node);
1191 if (pbqp->dump_file) {
1192 fputs("<br>\nAfter reduction:<br>\n", pbqp->dump_file);
1193 dump_edge(pbqp->dump_file, edge);
1197 /* Edge has changed so we simplify it. */
1198 simplify_edge(pbqp, edge);
1201 static void select_column(pbqp_edge *edge, unsigned col_index)
1204 pbqp_node *src_node;
1205 pbqp_node *tgt_node;
1211 unsigned new_infinity = 0;
1215 src_node = edge->src;
1216 tgt_node = edge->tgt;
1220 src_vec = src_node->costs;
1221 tgt_vec = tgt_node->costs;
1225 src_len = src_vec->len;
1226 tgt_len = tgt_vec->len;
1227 assert(src_len > 0);
1228 assert(tgt_len > 0);
1233 for (src_index = 0; src_index < src_len; ++src_index) {
1234 num elem = mat->entries[src_index * tgt_len + col_index];
1237 if (elem == INF_COSTS && src_vec->entries[src_index].data != INF_COSTS)
1240 src_vec->entries[src_index].data = pbqp_add(
1241 src_vec->entries[src_index].data, elem);
1246 unsigned edge_index;
1247 unsigned edge_len = pbqp_node_get_degree(src_node);
1249 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1250 pbqp_edge *edge_candidate = src_node->edges[edge_index];
1252 if (edge_candidate != edge) {
1253 insert_into_edge_bucket(edge_candidate);
1259 reorder_node(src_node);
1260 reorder_node(tgt_node);
1263 static void select_row(pbqp_edge *edge, unsigned row_index)
1266 pbqp_node *src_node;
1267 pbqp_node *tgt_node;
1271 unsigned new_infinity = 0;
1275 src_node = edge->src;
1276 tgt_node = edge->tgt;
1279 tgt_vec = tgt_node->costs;
1282 tgt_len = tgt_vec->len;
1283 assert(tgt_len > 0);
1288 for (tgt_index = 0; tgt_index < tgt_len; ++tgt_index) {
1289 num elem = mat->entries[row_index * tgt_len + tgt_index];
1292 if (elem == INF_COSTS && tgt_vec->entries[tgt_index].data != INF_COSTS)
1295 tgt_vec->entries[tgt_index].data = pbqp_add(
1296 tgt_vec->entries[tgt_index].data, elem);
1301 unsigned edge_index;
1302 unsigned edge_len = pbqp_node_get_degree(tgt_node);
1304 for (edge_index = 0; edge_index < edge_len; ++edge_index) {
1305 pbqp_edge *edge_candidate = tgt_node->edges[edge_index];
1307 if (edge_candidate != edge) {
1308 insert_into_edge_bucket(edge_candidate);
1314 reorder_node(src_node);
1315 reorder_node(tgt_node);
1318 void select_alternative(pbqp_node *node, unsigned selected_index)
1320 unsigned edge_index;
1321 unsigned node_index;
1324 unsigned max_degree = pbqp_node_get_degree(node);
1327 node->solution = selected_index;
1328 node_vec = node->costs;
1329 node_len = node_vec->len;
1330 assert(selected_index < node_len);
1332 /* Set all other costs to infinity. */
1333 for (node_index = 0; node_index < node_len; ++node_index) {
1334 if (node_index != selected_index) {
1335 node_vec->entries[node_index].data = INF_COSTS;
1339 /* Select corresponding row/column for incident edges. */
1340 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1341 pbqp_edge *edge = node->edges[edge_index];
1343 if (edge->src == node)
1344 select_row(edge, selected_index);
1346 select_column(edge, selected_index);
1350 pbqp_node *get_node_with_max_degree(void)
1352 pbqp_node **bucket = node_buckets[3];
1353 unsigned bucket_len = node_bucket_get_length(bucket);
1354 unsigned bucket_index;
1355 unsigned max_degree = 0;
1356 pbqp_node *result = NULL;
1358 for (bucket_index = 0; bucket_index < bucket_len; ++bucket_index) {
1359 pbqp_node *candidate = bucket[bucket_index];
1360 unsigned degree = pbqp_node_get_degree(candidate);
1362 if (degree > max_degree) {
1364 max_degree = degree;
1371 unsigned get_local_minimal_alternative(pbqp *pbqp, pbqp_node *node)
1377 unsigned edge_index;
1378 unsigned max_degree;
1379 unsigned node_index;
1381 unsigned min_index = 0;
1382 num min = INF_COSTS;
1387 node_vec = node->costs;
1388 node_len = node_vec->len;
1389 max_degree = pbqp_node_get_degree(node);
1391 for (node_index = 0; node_index < node_len; ++node_index) {
1392 num value = node_vec->entries[node_index].data;
1394 for (edge_index = 0; edge_index < max_degree; ++edge_index) {
1395 edge = node->edges[edge_index];
1397 is_src = edge->src == node;
1400 vec = vector_copy(pbqp, edge->tgt->costs);
1401 vector_add_matrix_row(vec, mat, node_index);
1403 vec = vector_copy(pbqp, edge->src->costs);
1404 vector_add_matrix_col(vec, mat, node_index);
1407 value = pbqp_add(value, vector_get_min(vec));
1409 obstack_free(&pbqp->obstack, vec);
1414 min_index = node_index;
1421 int node_is_reduced(pbqp_node *node)
1423 if (!reduced_bucket) return 0;
1425 if (pbqp_node_get_degree(node) == 0) return 1;
1427 return node_bucket_contains(reduced_bucket, node);