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add isl_constraint_get_dim
[isl.git] / isl_map_subtract.c
blobdc20d91098d0a012c875b379e439639f4f690df9
1 /*
2 * Copyright 2008-2009 Katholieke Universiteit Leuven
3 *
4 * Use of this software is governed by the GNU LGPLv2.1 license
5 *
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8 */
9
10 #include <isl_map_private.h>
11 #include <isl/seq.h>
12 #include <isl/set.h>
13 #include <isl/map.h>
14 #include "isl_tab.h"
15 #include <isl_point_private.h>
16
17 static void expand_constraint(isl_vec *v, unsigned dim,
18 isl_int *c, int *div_map, unsigned n_div)
19 {
20 int i;
21
22 isl_seq_cpy(v->el, c, 1 + dim);
23 isl_seq_clr(v->el + 1 + dim, v->size - (1 + dim));
24
25 for (i = 0; i < n_div; ++i)
26 isl_int_set(v->el[1 + dim + div_map[i]], c[1 + dim + i]);
27 }
28
29 /* Add all constraints of bmap to tab. The equalities of bmap
30 * are added as a pair of inequalities.
31 */
32 static int tab_add_constraints(struct isl_tab *tab,
33 __isl_keep isl_basic_map *bmap, int *div_map)
34 {
35 int i;
36 unsigned dim;
37 unsigned tab_total;
38 unsigned bmap_total;
39 isl_vec *v;
40
41 if (!tab || !bmap)
42 return -1;
43
44 tab_total = isl_basic_map_total_dim(tab->bmap);
45 bmap_total = isl_basic_map_total_dim(bmap);
46 dim = isl_dim_total(tab->bmap->dim);
47
48 if (isl_tab_extend_cons(tab, 2 * bmap->n_eq + bmap->n_ineq) < 0)
49 return -1;
50
51 v = isl_vec_alloc(bmap->ctx, 1 + tab_total);
52 if (!v)
53 return -1;
54
55 for (i = 0; i < bmap->n_eq; ++i) {
56 expand_constraint(v, dim, bmap->eq[i], div_map, bmap->n_div);
57 if (isl_tab_add_ineq(tab, v->el) < 0)
58 goto error;
59 isl_seq_neg(bmap->eq[i], bmap->eq[i], 1 + bmap_total);
60 expand_constraint(v, dim, bmap->eq[i], div_map, bmap->n_div);
61 if (isl_tab_add_ineq(tab, v->el) < 0)
62 goto error;
63 isl_seq_neg(bmap->eq[i], bmap->eq[i], 1 + bmap_total);
64 if (tab->empty)
65 break;
66 }
67
68 for (i = 0; i < bmap->n_ineq; ++i) {
69 expand_constraint(v, dim, bmap->ineq[i], div_map, bmap->n_div);
70 if (isl_tab_add_ineq(tab, v->el) < 0)
71 goto error;
72 if (tab->empty)
73 break;
74 }
75
76 isl_vec_free(v);
77 return 0;
78 error:
79 isl_vec_free(v);
80 return -1;
81 }
82
83 /* Add a specific constraint of bmap (or its opposite) to tab.
84 * The position of the constraint is specified by "c", where
85 * the equalities of bmap are counted twice, once for the inequality
86 * that is equal to the equality, and once for its negation.
87 */
88 static int tab_add_constraint(struct isl_tab *tab,
89 __isl_keep isl_basic_map *bmap, int *div_map, int c, int oppose)
90 {
91 unsigned dim;
92 unsigned tab_total;
93 unsigned bmap_total;
94 isl_vec *v;
95 int r;
96
97 if (!tab || !bmap)
98 return -1;
99
100 tab_total = isl_basic_map_total_dim(tab->bmap);
101 bmap_total = isl_basic_map_total_dim(bmap);
102 dim = isl_dim_total(tab->bmap->dim);
103
104 v = isl_vec_alloc(bmap->ctx, 1 + tab_total);
105 if (!v)
106 return -1;
107
108 if (c < 2 * bmap->n_eq) {
109 if ((c % 2) != oppose)
110 isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
111 1 + bmap_total);
112 if (oppose)
113 isl_int_sub_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
114 expand_constraint(v, dim, bmap->eq[c/2], div_map, bmap->n_div);
115 r = isl_tab_add_ineq(tab, v->el);
116 if (oppose)
117 isl_int_add_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
118 if ((c % 2) != oppose)
119 isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
120 1 + bmap_total);
121 } else {
122 c -= 2 * bmap->n_eq;
123 if (oppose) {
124 isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
125 1 + bmap_total);
126 isl_int_sub_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
127 }
128 expand_constraint(v, dim, bmap->ineq[c], div_map, bmap->n_div);
129 r = isl_tab_add_ineq(tab, v->el);
130 if (oppose) {
131 isl_int_add_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
132 isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
133 1 + bmap_total);
134 }
135 }
136
137 isl_vec_free(v);
138 return r;
139 }
140
141 static int tab_add_divs(struct isl_tab *tab, __isl_keep isl_basic_map *bmap,
142 int **div_map)
143 {
144 int i, j;
145 struct isl_vec *vec;
146 unsigned total;
147 unsigned dim;
148
149 if (!bmap)
150 return -1;
151 if (!bmap->n_div)
152 return 0;
153
154 if (!*div_map)
155 *div_map = isl_alloc_array(bmap->ctx, int, bmap->n_div);
156 if (!*div_map)
157 return -1;
158
159 total = isl_basic_map_total_dim(tab->bmap);
160 dim = total - tab->bmap->n_div;
161 vec = isl_vec_alloc(bmap->ctx, 2 + total + bmap->n_div);
162 if (!vec)
163 return -1;
164
165 for (i = 0; i < bmap->n_div; ++i) {
166 isl_seq_cpy(vec->el, bmap->div[i], 2 + dim);
167 isl_seq_clr(vec->el + 2 + dim, tab->bmap->n_div);
168 for (j = 0; j < i; ++j)
169 isl_int_set(vec->el[2 + dim + (*div_map)[j]],
170 bmap->div[i][2 + dim + j]);
171 for (j = 0; j < tab->bmap->n_div; ++j)
172 if (isl_seq_eq(tab->bmap->div[j],
173 vec->el, 2 + dim + tab->bmap->n_div))
174 break;
175 (*div_map)[i] = j;
176 if (j == tab->bmap->n_div) {
177 vec->size = 2 + dim + tab->bmap->n_div;
178 if (isl_tab_add_div(tab, vec, NULL, NULL) < 0)
179 goto error;
180 }
181 }
182
183 isl_vec_free(vec);
184
185 return 0;
186 error:
187 isl_vec_free(vec);
188
189 return -1;
190 }
191
192 /* Freeze all constraints of tableau tab.
193 */
194 static int tab_freeze_constraints(struct isl_tab *tab)
195 {
196 int i;
197
198 for (i = 0; i < tab->n_con; ++i)
199 if (isl_tab_freeze_constraint(tab, i) < 0)
200 return -1;
201
202 return 0;
203 }
204
205 /* Check for redundant constraints starting at offset.
206 * Put the indices of the redundant constraints in index
207 * and return the number of redundant constraints.
208 */
209 static int n_non_redundant(isl_ctx *ctx, struct isl_tab *tab,
210 int offset, int **index)
211 {
212 int i, n;
213 int n_test = tab->n_con - offset;
214
215 if (isl_tab_detect_redundant(tab) < 0)
216 return -1;
217
218 if (!*index)
219 *index = isl_alloc_array(ctx, int, n_test);
220 if (!*index)
221 return -1;
222
223 for (n = 0, i = 0; i < n_test; ++i) {
224 int r;
225 r = isl_tab_is_redundant(tab, offset + i);
226 if (r < 0)
227 return -1;
228 if (r)
229 continue;
230 (*index)[n++] = i;
231 }
232
233 return n;
234 }
235
236 /* basic_map_collect_diff calls add on each of the pieces of
237 * the set difference between bmap and map until the add method
238 * return a negative value.
239 */
240 struct isl_diff_collector {
241 int (*add)(struct isl_diff_collector *dc,
242 __isl_take isl_basic_map *bmap);
243 };
244
245 /* Compute the set difference between bmap and map and call
246 * dc->add on each of the piece until this function returns
247 * a negative value.
248 * Return 0 on success and -1 on error. dc->add returning
249 * a negative value is treated as an error, but the calling
250 * function can interpret the results based on the state of dc.
251 *
252 * Assumes that map has known divs.
253 *
254 * The difference is computed by a backtracking algorithm.
255 * Each level corresponds to a basic map in "map".
256 * When a node in entered for the first time, we check
257 * if the corresonding basic map intersects the current piece
258 * of "bmap". If not, we move to the next level.
259 * Otherwise, we split the current piece into as many
260 * pieces as there are non-redundant constraints of the current
261 * basic map in the intersection. Each of these pieces is
262 * handled by a child of the current node.
263 * In particular, if there are n non-redundant constraints,
264 * then for each 0 <= i < n, a piece is cut off by adding
265 * constraints 0 <= j < i and adding the opposite of constraint i.
266 * If there are no non-redundant constraints, meaning that the current
267 * piece is a subset of the current basic map, then we simply backtrack.
268 *
269 * In the leaves, we check if the remaining piece has any integer points
270 * and if so, pass it along to dc->add. As a special case, if nothing
271 * has been removed when we end up in a leaf, we simply pass along
272 * the original basic map.
273 */
274 static int basic_map_collect_diff(__isl_take isl_basic_map *bmap,
275 __isl_take isl_map *map, struct isl_diff_collector *dc)
276 {
277 int i;
278 int modified;
279 int level;
280 int init;
281 int empty;
282 isl_ctx *ctx;
283 struct isl_tab *tab = NULL;
284 struct isl_tab_undo **snap = NULL;
285 int *k = NULL;
286 int *n = NULL;
287 int **index = NULL;
288 int **div_map = NULL;
289
290 empty = isl_basic_map_is_empty(bmap);
291 if (empty) {
292 isl_basic_map_free(bmap);
293 isl_map_free(map);
294 return empty < 0 ? -1 : 0;
295 }
296
297 bmap = isl_basic_map_cow(bmap);
298 map = isl_map_cow(map);
299
300 if (!bmap || !map)
301 goto error;
302
303 ctx = map->ctx;
304 snap = isl_alloc_array(map->ctx, struct isl_tab_undo *, map->n);
305 k = isl_alloc_array(map->ctx, int, map->n);
306 n = isl_alloc_array(map->ctx, int, map->n);
307 index = isl_calloc_array(map->ctx, int *, map->n);
308 div_map = isl_calloc_array(map->ctx, int *, map->n);
309 if (!snap || !k || !n || !index || !div_map)
310 goto error;
311
312 bmap = isl_basic_map_order_divs(bmap);
313 map = isl_map_order_divs(map);
314
315 tab = isl_tab_from_basic_map(bmap);
316 if (isl_tab_track_bmap(tab, isl_basic_map_copy(bmap)) < 0)
317 goto error;
318
319 modified = 0;
320 level = 0;
321 init = 1;
322
323 while (level >= 0) {
324 if (level >= map->n) {
325 int empty;
326 struct isl_basic_map *bm;
327 if (!modified) {
328 if (dc->add(dc, isl_basic_map_copy(bmap)) < 0)
329 goto error;
330 break;
331 }
332 bm = isl_basic_map_copy(tab->bmap);
333 bm = isl_basic_map_cow(bm);
334 bm = isl_basic_map_update_from_tab(bm, tab);
335 bm = isl_basic_map_simplify(bm);
336 bm = isl_basic_map_finalize(bm);
337 empty = isl_basic_map_is_empty(bm);
338 if (empty)
339 isl_basic_map_free(bm);
340 else if (dc->add(dc, bm) < 0)
341 goto error;
342 if (empty < 0)
343 goto error;
344 level--;
345 init = 0;
346 continue;
347 }
348 if (init) {
349 int offset;
350 struct isl_tab_undo *snap2;
351 snap2 = isl_tab_snap(tab);
352 if (tab_add_divs(tab, map->p[level],
353 &div_map[level]) < 0)
354 goto error;
355 offset = tab->n_con;
356 snap[level] = isl_tab_snap(tab);
357 if (tab_freeze_constraints(tab) < 0)
358 goto error;
359 if (tab_add_constraints(tab, map->p[level],
360 div_map[level]) < 0)
361 goto error;
362 k[level] = 0;
363 n[level] = 0;
364 if (tab->empty) {
365 if (isl_tab_rollback(tab, snap2) < 0)
366 goto error;
367 level++;
368 continue;
369 }
370 modified = 1;
371 n[level] = n_non_redundant(ctx, tab, offset,
372 &index[level]);
373 if (n[level] < 0)
374 goto error;
375 if (n[level] == 0) {
376 level--;
377 init = 0;
378 continue;
379 }
380 if (isl_tab_rollback(tab, snap[level]) < 0)
381 goto error;
382 if (tab_add_constraint(tab, map->p[level],
383 div_map[level], index[level][0], 1) < 0)
384 goto error;
385 level++;
386 continue;
387 } else {
388 if (k[level] + 1 >= n[level]) {
389 level--;
390 continue;
391 }
392 if (isl_tab_rollback(tab, snap[level]) < 0)
393 goto error;
394 if (tab_add_constraint(tab, map->p[level],
395 div_map[level],
396 index[level][k[level]], 0) < 0)
397 goto error;
398 snap[level] = isl_tab_snap(tab);
399 k[level]++;
400 if (tab_add_constraint(tab, map->p[level],
401 div_map[level],
402 index[level][k[level]], 1) < 0)
403 goto error;
404 level++;
405 init = 1;
406 continue;
407 }
408 }
409
410 isl_tab_free(tab);
411 free(snap);
412 free(n);
413 free(k);
414 for (i = 0; index && i < map->n; ++i)
415 free(index[i]);
416 free(index);
417 for (i = 0; div_map && i < map->n; ++i)
418 free(div_map[i]);
419 free(div_map);
420
421 isl_basic_map_free(bmap);
422 isl_map_free(map);
423
424 return 0;
425 error:
426 isl_tab_free(tab);
427 free(snap);
428 free(n);
429 free(k);
430 for (i = 0; index && i < map->n; ++i)
431 free(index[i]);
432 free(index);
433 for (i = 0; div_map && i < map->n; ++i)
434 free(div_map[i]);
435 free(div_map);
436 isl_basic_map_free(bmap);
437 isl_map_free(map);
438 return -1;
439 }
440
441 /* A diff collector that actually collects all parts of the
442 * set difference in the field diff.
443 */
444 struct isl_subtract_diff_collector {
445 struct isl_diff_collector dc;
446 struct isl_map *diff;
447 };
448
449 /* isl_subtract_diff_collector callback.
450 */
451 static int basic_map_subtract_add(struct isl_diff_collector *dc,
452 __isl_take isl_basic_map *bmap)
453 {
454 struct isl_subtract_diff_collector *sdc;
455 sdc = (struct isl_subtract_diff_collector *)dc;
456
457 sdc->diff = isl_map_union_disjoint(sdc->diff,
458 isl_map_from_basic_map(bmap));
459
460 return sdc->diff ? 0 : -1;
461 }
462
463 /* Return the set difference between bmap and map.
464 */
465 static __isl_give isl_map *basic_map_subtract(__isl_take isl_basic_map *bmap,
466 __isl_take isl_map *map)
467 {
468 struct isl_subtract_diff_collector sdc;
469 sdc.dc.add = &basic_map_subtract_add;
470 sdc.diff = isl_map_empty_like_basic_map(bmap);
471 if (basic_map_collect_diff(bmap, map, &sdc.dc) < 0) {
472 isl_map_free(sdc.diff);
473 sdc.diff = NULL;
474 }
475 return sdc.diff;
476 }
477
478 /* Return the set difference between map1 and map2.
479 * (U_i A_i) \ (U_j B_j) is computed as U_i (A_i \ (U_j B_j))
480 */
481 struct isl_map *isl_map_subtract(struct isl_map *map1, struct isl_map *map2)
482 {
483 int i;
484 struct isl_map *diff;
485
486 if (!map1 || !map2)
487 goto error;
488
489 isl_assert(map1->ctx, isl_dim_equal(map1->dim, map2->dim), goto error);
490
491 if (isl_map_is_empty(map2)) {
492 isl_map_free(map2);
493 return map1;
494 }
495
496 map1 = isl_map_compute_divs(map1);
497 map2 = isl_map_compute_divs(map2);
498 if (!map1 || !map2)
499 goto error;
500
501 map1 = isl_map_remove_empty_parts(map1);
502 map2 = isl_map_remove_empty_parts(map2);
503
504 diff = isl_map_empty_like(map1);
505 for (i = 0; i < map1->n; ++i) {
506 struct isl_map *d;
507 d = basic_map_subtract(isl_basic_map_copy(map1->p[i]),
508 isl_map_copy(map2));
509 if (ISL_F_ISSET(map1, ISL_MAP_DISJOINT))
510 diff = isl_map_union_disjoint(diff, d);
511 else
512 diff = isl_map_union(diff, d);
513 }
514
515 isl_map_free(map1);
516 isl_map_free(map2);
517
518 return diff;
519 error:
520 isl_map_free(map1);
521 isl_map_free(map2);
522 return NULL;
523 }
524
525 struct isl_set *isl_set_subtract(struct isl_set *set1, struct isl_set *set2)
526 {
527 return (struct isl_set *)
528 isl_map_subtract(
529 (struct isl_map *)set1, (struct isl_map *)set2);
530 }
531
532 /* A diff collector that aborts as soon as its add function is called,
533 * setting empty to 0.
534 */
535 struct isl_is_empty_diff_collector {
536 struct isl_diff_collector dc;
537 int empty;
538 };
539
540 /* isl_is_empty_diff_collector callback.
541 */
542 static int basic_map_is_empty_add(struct isl_diff_collector *dc,
543 __isl_take isl_basic_map *bmap)
544 {
545 struct isl_is_empty_diff_collector *edc;
546 edc = (struct isl_is_empty_diff_collector *)dc;
547
548 edc->empty = 0;
549
550 isl_basic_map_free(bmap);
551 return -1;
552 }
553
554 /* Check if bmap \ map is empty by computing this set difference
555 * and breaking off as soon as the difference is known to be non-empty.
556 */
557 static int basic_map_diff_is_empty(__isl_keep isl_basic_map *bmap,
558 __isl_keep isl_map *map)
559 {
560 int r;
561 struct isl_is_empty_diff_collector edc;
562
563 r = isl_basic_map_fast_is_empty(bmap);
564 if (r)
565 return r;
566
567 edc.dc.add = &basic_map_is_empty_add;
568 edc.empty = 1;
569 r = basic_map_collect_diff(isl_basic_map_copy(bmap),
570 isl_map_copy(map), &edc.dc);
571 if (!edc.empty)
572 return 0;
573
574 return r < 0 ? -1 : 1;
575 }
576
577 /* Check if map1 \ map2 is empty by checking if the set difference is empty
578 * for each of the basic maps in map1.
579 */
580 static int map_diff_is_empty(__isl_keep isl_map *map1, __isl_keep isl_map *map2)
581 {
582 int i;
583 int is_empty = 1;
584
585 if (!map1 || !map2)
586 return -1;
587
588 for (i = 0; i < map1->n; ++i) {
589 is_empty = basic_map_diff_is_empty(map1->p[i], map2);
590 if (is_empty < 0 || !is_empty)
591 break;
592 }
593
594 return is_empty;
595 }
596
597 /* Return 1 if "bmap" contains a single element.
598 */
599 int isl_basic_map_fast_is_singleton(__isl_keep isl_basic_map *bmap)
600 {
601 if (!bmap)
602 return -1;
603 if (bmap->n_div)
604 return 0;
605 if (bmap->n_ineq)
606 return 0;
607 return bmap->n_eq == isl_basic_map_total_dim(bmap);
608 }
609
610 /* Return 1 if "map" contains a single element.
611 */
612 int isl_map_fast_is_singleton(__isl_keep isl_map *map)
613 {
614 if (!map)
615 return -1;
616 if (map->n != 1)
617 return 0;
618
619 return isl_basic_map_fast_is_singleton(map->p[0]);
620 }
621
622 /* Given a singleton basic map, extract the single element
623 * as an isl_point.
624 */
625 static __isl_give isl_point *singleton_extract_point(
626 __isl_keep isl_basic_map *bmap)
627 {
628 int i, j;
629 unsigned dim;
630 struct isl_vec *point;
631 isl_int m;
632
633 if (!bmap)
634 return NULL;
635
636 dim = isl_basic_map_total_dim(bmap);
637 isl_assert(bmap->ctx, bmap->n_eq == dim, return NULL);
638 point = isl_vec_alloc(bmap->ctx, 1 + dim);
639 if (!point)
640 return NULL;
641
642 isl_int_init(m);
643
644 isl_int_set_si(point->el[0], 1);
645 for (j = 0; j < bmap->n_eq; ++j) {
646 int s;
647 int i = dim - 1 - j;
648 isl_assert(bmap->ctx,
649 isl_seq_first_non_zero(bmap->eq[j] + 1, i) == -1,
650 goto error);
651 isl_assert(bmap->ctx,
652 isl_int_is_one(bmap->eq[j][1 + i]) ||
653 isl_int_is_negone(bmap->eq[j][1 + i]),
654 goto error);
655 isl_assert(bmap->ctx,
656 isl_seq_first_non_zero(bmap->eq[j]+1+i+1, dim-i-1) == -1,
657 goto error);
658
659 isl_int_gcd(m, point->el[0], bmap->eq[j][1 + i]);
660 isl_int_divexact(m, bmap->eq[j][1 + i], m);
661 isl_int_abs(m, m);
662 isl_seq_scale(point->el, point->el, m, 1 + i);
663 isl_int_divexact(m, point->el[0], bmap->eq[j][1 + i]);
664 isl_int_neg(m, m);
665 isl_int_mul(point->el[1 + i], m, bmap->eq[j][0]);
666 }
667
668 isl_int_clear(m);
669 return isl_point_alloc(isl_basic_map_get_dim(bmap), point);
670 error:
671 isl_int_clear(m);
672 isl_vec_free(point);
673 return NULL;
674 }
675
676 /* Return 1 is the singleton map "map1" is a subset of "map2",
677 * i.e., if the single element of "map1" is also an element of "map2".
678 * Assumes "map2" has known divs.
679 */
680 static int map_is_singleton_subset(__isl_keep isl_map *map1,
681 __isl_keep isl_map *map2)
682 {
683 int i;
684 int is_subset = 0;
685 struct isl_point *point;
686
687 if (!map1 || !map2)
688 return -1;
689 if (map1->n != 1)
690 return -1;
691
692 point = singleton_extract_point(map1->p[0]);
693 if (!point)
694 return -1;
695
696 for (i = 0; i < map2->n; ++i) {
697 is_subset = isl_basic_map_contains_point(map2->p[i], point);
698 if (is_subset)
699 break;
700 }
701
702 isl_point_free(point);
703 return is_subset;
704 }
705
706 int isl_map_is_subset(struct isl_map *map1, struct isl_map *map2)
707 {
708 int is_subset = 0;
709 struct isl_map *diff;
710
711 if (!map1 || !map2)
712 return -1;
713
714 if (isl_map_is_empty(map1))
715 return 1;
716
717 if (isl_map_is_empty(map2))
718 return 0;
719
720 if (isl_map_fast_is_universe(map2))
721 return 1;
722
723 map2 = isl_map_compute_divs(isl_map_copy(map2));
724 if (isl_map_fast_is_singleton(map1)) {
725 is_subset = map_is_singleton_subset(map1, map2);
726 isl_map_free(map2);
727 return is_subset;
728 }
729 is_subset = map_diff_is_empty(map1, map2);
730 isl_map_free(map2);
731
732 return is_subset;
733 }
734
735 int isl_set_is_subset(struct isl_set *set1, struct isl_set *set2)
736 {
737 return isl_map_is_subset(
738 (struct isl_map *)set1, (struct isl_map *)set2);
739 }
740
741 __isl_give isl_map *isl_map_make_disjoint(__isl_take isl_map *map)
742 {
743 int i;
744 struct isl_subtract_diff_collector sdc;
745 sdc.dc.add = &basic_map_subtract_add;
746
747 if (!map)
748 return NULL;
749 if (ISL_F_ISSET(map, ISL_MAP_DISJOINT))
750 return map;
751 if (map->n <= 1)
752 return map;
753
754 map = isl_map_compute_divs(map);
755 map = isl_map_remove_empty_parts(map);
756
757 if (!map || map->n <= 1)
758 return map;
759
760 sdc.diff = isl_map_from_basic_map(isl_basic_map_copy(map->p[0]));
761
762 for (i = 1; i < map->n; ++i) {
763 struct isl_basic_map *bmap = isl_basic_map_copy(map->p[i]);
764 struct isl_map *copy = isl_map_copy(sdc.diff);
765 if (basic_map_collect_diff(bmap, copy, &sdc.dc) < 0) {
766 isl_map_free(sdc.diff);
767 sdc.diff = NULL;
768 break;
769 }
770 }
771
772 isl_map_free(map);
773
774 return sdc.diff;
775 }
776
777 __isl_give isl_set *isl_set_make_disjoint(__isl_take isl_set *set)
778 {
779 return (struct isl_set *)isl_map_make_disjoint((struct isl_map *)set);
780 }
781
782 __isl_give isl_set *isl_set_complement(__isl_take isl_set *set)
783 {
784 isl_set *universe;
785
786 if (!set)
787 return NULL;
788
789 universe = isl_set_universe(isl_set_get_dim(set));
790
791 return isl_set_subtract(universe, set);
792 }
Integer set library