2 * Copyright 2008-2009 Katholieke Universiteit Leuven
4 * Use of this software is governed by the GNU LGPLv2.1 license
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
13 #include "isl_map_private.h"
16 static void expand_constraint(isl_vec *v, unsigned dim,
17 isl_int *c, int *div_map, unsigned n_div)
21 isl_seq_cpy(v->el, c, 1 + dim);
22 isl_seq_clr(v->el + 1 + dim, v->size - (1 + dim));
24 for (i = 0; i < n_div; ++i)
25 isl_int_set(v->el[1 + dim + div_map[i]], c[1 + dim + i]);
28 /* Add all constraints of bmap to tab. The equalities of bmap
29 * are added as a pair of inequalities.
31 static int tab_add_constraints(struct isl_tab *tab,
32 __isl_keep isl_basic_map *bmap, int *div_map)
43 tab_total = isl_basic_map_total_dim(tab->bmap);
44 bmap_total = isl_basic_map_total_dim(bmap);
45 dim = isl_dim_total(tab->bmap->dim);
47 if (isl_tab_extend_cons(tab, 2 * bmap->n_eq + bmap->n_ineq) < 0)
50 v = isl_vec_alloc(bmap->ctx, 1 + tab_total);
52 for (i = 0; i < bmap->n_eq; ++i) {
53 expand_constraint(v, dim, bmap->eq[i], div_map, bmap->n_div);
54 if (isl_tab_add_ineq(tab, v->el) < 0)
56 isl_seq_neg(bmap->eq[i], bmap->eq[i], 1 + bmap_total);
57 expand_constraint(v, dim, bmap->eq[i], div_map, bmap->n_div);
58 if (isl_tab_add_ineq(tab, v->el) < 0)
60 isl_seq_neg(bmap->eq[i], bmap->eq[i], 1 + bmap_total);
65 for (i = 0; i < bmap->n_ineq; ++i) {
66 expand_constraint(v, dim, bmap->ineq[i], div_map, bmap->n_div);
67 if (isl_tab_add_ineq(tab, v->el) < 0)
80 /* Add a specific constraint of bmap (or its opposite) to tab.
81 * The position of the constraint is specified by "c", where
82 * the equalities of bmap are counted twice, once for the inequality
83 * that is equal to the equality, and once for its negation.
85 static int tab_add_constraint(struct isl_tab *tab,
86 __isl_keep isl_basic_map *bmap, int *div_map, int c, int oppose)
97 tab_total = isl_basic_map_total_dim(tab->bmap);
98 bmap_total = isl_basic_map_total_dim(bmap);
99 dim = isl_dim_total(tab->bmap->dim);
101 v = isl_vec_alloc(bmap->ctx, 1 + tab_total);
105 if (c < 2 * bmap->n_eq) {
106 if ((c % 2) != oppose)
107 isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
110 isl_int_sub_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
111 expand_constraint(v, dim, bmap->eq[c/2], div_map, bmap->n_div);
112 r = isl_tab_add_ineq(tab, v->el);
114 isl_int_add_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
115 if ((c % 2) != oppose)
116 isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
121 isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
123 isl_int_sub_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
125 expand_constraint(v, dim, bmap->ineq[c], div_map, bmap->n_div);
126 r = isl_tab_add_ineq(tab, v->el);
128 isl_int_add_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
129 isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
138 static int tab_add_divs(struct isl_tab *tab, __isl_keep isl_basic_map *bmap,
152 *div_map = isl_alloc_array(bmap->ctx, int, bmap->n_div);
156 total = isl_basic_map_total_dim(tab->bmap);
157 dim = total - tab->bmap->n_div;
158 vec = isl_vec_alloc(bmap->ctx, 2 + total + bmap->n_div);
162 for (i = 0; i < bmap->n_div; ++i) {
163 isl_seq_cpy(vec->el, bmap->div[i], 2 + dim);
164 isl_seq_clr(vec->el + 2 + dim, tab->bmap->n_div);
165 for (j = 0; j < i; ++j)
166 isl_int_set(vec->el[2 + dim + (*div_map)[j]],
167 bmap->div[i][2 + dim + j]);
168 for (j = 0; j < tab->bmap->n_div; ++j)
169 if (isl_seq_eq(tab->bmap->div[j],
170 vec->el, 2 + dim + tab->bmap->n_div))
173 if (j == tab->bmap->n_div) {
174 vec->size = 2 + dim + tab->bmap->n_div;
175 if (isl_tab_add_div(tab, vec, NULL, NULL) < 0)
189 /* Freeze all constraints of tableau tab.
191 static int tab_freeze_constraints(struct isl_tab *tab)
195 for (i = 0; i < tab->n_con; ++i)
196 if (isl_tab_freeze_constraint(tab, i) < 0)
202 /* Check for redundant constraints starting at offset.
203 * Put the indices of the redundant constraints in index
204 * and return the number of redundant constraints.
206 static int n_non_redundant(struct isl_tab *tab, int offset, int **index)
209 int n_test = tab->n_con - offset;
211 if (isl_tab_detect_redundant(tab) < 0)
215 *index = isl_alloc_array(tab->mat->ctx, int, n_test);
219 for (n = 0, i = 0; i < n_test; ++i) {
221 r = isl_tab_is_redundant(tab, offset + i);
232 /* basic_map_collect_diff calls add on each of the pieces of
233 * the set difference between bmap and map until the add method
234 * return a negative value.
236 struct isl_diff_collector {
237 int (*add)(struct isl_diff_collector *dc,
238 __isl_take isl_basic_map *bmap);
241 /* Compute the set difference between bmap and map and call
242 * dc->add on each of the piece until this function returns
244 * Return 0 on success and -1 on error. dc->add returning
245 * a negative value is treated as an error, but the calling
246 * function can interpret the results based on the state of dc.
248 * Assumes that both bmap and map have known divs.
250 * The difference is computed by a backtracking algorithm.
251 * Each level corresponds to a basic map in "map".
252 * When a node in entered for the first time, we check
253 * if the corresonding basic map intersects the current piece
254 * of "bmap". If not, we move to the next level.
255 * Otherwise, we split the current piece into as many
256 * pieces as there are non-redundant constraints of the current
257 * basic map in the intersection. Each of these pieces is
258 * handled by a child of the current node.
259 * In particular, if there are n non-redundant constraints,
260 * then for each 0 <= i < n, a piece is cut off by adding
261 * constraints 0 <= j < i and adding the opposite of constraint i.
262 * If there are no non-redundant constraints, meaning that the current
263 * piece is a subset of the current basic map, then we simply backtrack.
265 * In the leaves, we check if the remaining piece has any integer points
266 * and if so, pass it along to dc->add. As a special case, if nothing
267 * has been removed when we end up in a leaf, we simply pass along
268 * the original basic map.
270 static int basic_map_collect_diff(__isl_take isl_basic_map *bmap,
271 __isl_take isl_map *map, struct isl_diff_collector *dc)
278 struct isl_tab *tab = NULL;
279 struct isl_tab_undo **snap = NULL;
283 int **div_map = NULL;
285 empty = isl_basic_map_is_empty(bmap);
287 isl_basic_map_free(bmap);
289 return empty < 0 ? -1 : 0;
292 bmap = isl_basic_map_cow(bmap);
293 map = isl_map_cow(map);
298 snap = isl_alloc_array(map->ctx, struct isl_tab_undo *, map->n);
299 k = isl_alloc_array(map->ctx, int, map->n);
300 n = isl_alloc_array(map->ctx, int, map->n);
301 index = isl_calloc_array(map->ctx, int *, map->n);
302 div_map = isl_calloc_array(map->ctx, int *, map->n);
303 if (!snap || !k || !n || !index || !div_map)
306 bmap = isl_basic_map_order_divs(bmap);
307 map = isl_map_order_divs(map);
309 tab = isl_tab_from_basic_map(bmap);
310 if (isl_tab_track_bmap(tab, isl_basic_map_copy(bmap)) < 0)
318 if (level >= map->n) {
320 struct isl_basic_map *bm;
322 if (dc->add(dc, isl_basic_map_copy(bmap)) < 0)
326 bm = isl_basic_map_copy(tab->bmap);
327 bm = isl_basic_map_cow(bm);
328 bm = isl_basic_map_update_from_tab(bm, tab);
329 bm = isl_basic_map_simplify(bm);
330 bm = isl_basic_map_finalize(bm);
331 empty = isl_basic_map_is_empty(bm);
333 isl_basic_map_free(bm);
334 else if (dc->add(dc, bm) < 0)
344 struct isl_tab_undo *snap2;
345 snap2 = isl_tab_snap(tab);
346 if (tab_add_divs(tab, map->p[level],
347 &div_map[level]) < 0)
350 snap[level] = isl_tab_snap(tab);
351 if (tab_freeze_constraints(tab) < 0)
353 if (tab_add_constraints(tab, map->p[level],
359 if (isl_tab_rollback(tab, snap2) < 0)
365 n[level] = n_non_redundant(tab, offset, &index[level]);
373 if (isl_tab_rollback(tab, snap[level]) < 0)
375 if (tab_add_constraint(tab, map->p[level],
376 div_map[level], index[level][0], 1) < 0)
381 if (k[level] + 1 >= n[level]) {
385 if (isl_tab_rollback(tab, snap[level]) < 0)
387 if (tab_add_constraint(tab, map->p[level],
389 index[level][k[level]], 0) < 0)
391 snap[level] = isl_tab_snap(tab);
393 if (tab_add_constraint(tab, map->p[level],
395 index[level][k[level]], 1) < 0)
407 for (i = 0; index && i < map->n; ++i)
410 for (i = 0; div_map && i < map->n; ++i)
414 isl_basic_map_free(bmap);
423 for (i = 0; index && i < map->n; ++i)
426 for (i = 0; div_map && i < map->n; ++i)
429 isl_basic_map_free(bmap);
434 /* A diff collector that actually collects all parts of the
435 * set difference in the field diff.
437 struct isl_subtract_diff_collector {
438 struct isl_diff_collector dc;
439 struct isl_map *diff;
442 /* isl_subtract_diff_collector callback.
444 static int basic_map_subtract_add(struct isl_diff_collector *dc,
445 __isl_take isl_basic_map *bmap)
447 struct isl_subtract_diff_collector *sdc;
448 sdc = (struct isl_subtract_diff_collector *)dc;
450 sdc->diff = isl_map_union_disjoint(sdc->diff,
451 isl_map_from_basic_map(bmap));
453 return sdc->diff ? 0 : -1;
456 /* Return the set difference between bmap and map.
458 static __isl_give isl_map *basic_map_subtract(__isl_take isl_basic_map *bmap,
459 __isl_take isl_map *map)
461 struct isl_subtract_diff_collector sdc;
462 sdc.dc.add = &basic_map_subtract_add;
463 sdc.diff = isl_map_empty_like_basic_map(bmap);
464 if (basic_map_collect_diff(bmap, map, &sdc.dc) < 0) {
465 isl_map_free(sdc.diff);
471 /* Return the set difference between map1 and map2.
472 * (U_i A_i) \ (U_j B_j) is computed as U_i (A_i \ (U_j B_j))
474 struct isl_map *isl_map_subtract(struct isl_map *map1, struct isl_map *map2)
477 struct isl_map *diff;
482 isl_assert(map1->ctx, isl_dim_equal(map1->dim, map2->dim), goto error);
484 if (isl_map_is_empty(map2)) {
489 map1 = isl_map_compute_divs(map1);
490 map2 = isl_map_compute_divs(map2);
494 map1 = isl_map_remove_empty_parts(map1);
495 map2 = isl_map_remove_empty_parts(map2);
497 diff = isl_map_empty_like(map1);
498 for (i = 0; i < map1->n; ++i) {
500 d = basic_map_subtract(isl_basic_map_copy(map1->p[i]),
502 if (ISL_F_ISSET(map1, ISL_MAP_DISJOINT))
503 diff = isl_map_union_disjoint(diff, d);
505 diff = isl_map_union(diff, d);
518 struct isl_set *isl_set_subtract(struct isl_set *set1, struct isl_set *set2)
520 return (struct isl_set *)
522 (struct isl_map *)set1, (struct isl_map *)set2);
525 /* A diff collector that aborts as soon as its add function is called,
526 * setting empty to 0.
528 struct isl_is_empty_diff_collector {
529 struct isl_diff_collector dc;
533 /* isl_is_empty_diff_collector callback.
535 static int basic_map_is_empty_add(struct isl_diff_collector *dc,
536 __isl_take isl_basic_map *bmap)
538 struct isl_is_empty_diff_collector *edc;
539 edc = (struct isl_is_empty_diff_collector *)dc;
543 isl_basic_map_free(bmap);
547 /* Check if bmap \ map is empty by computing this set difference
548 * and breaking off as soon as the difference is known to be non-empty.
550 static int basic_map_diff_is_empty(__isl_keep isl_basic_map *bmap,
551 __isl_keep isl_map *map)
554 struct isl_is_empty_diff_collector edc;
556 r = isl_basic_map_fast_is_empty(bmap);
560 edc.dc.add = &basic_map_is_empty_add;
562 r = basic_map_collect_diff(isl_basic_map_copy(bmap),
563 isl_map_copy(map), &edc.dc);
567 return r < 0 ? -1 : 1;
570 /* Check if map1 \ map2 is empty by checking if the set difference is empty
571 * for each of the basic maps in map1.
573 static int map_diff_is_empty(__isl_keep isl_map *map1, __isl_keep isl_map *map2)
581 for (i = 0; i < map1->n; ++i) {
582 is_empty = basic_map_diff_is_empty(map1->p[i], map2);
583 if (is_empty < 0 || !is_empty)
590 /* Return 1 if "bmap" contains a single element.
592 int isl_basic_map_is_singleton(__isl_keep isl_basic_map *bmap)
600 return bmap->n_eq == isl_basic_map_total_dim(bmap);
603 /* Return 1 if "map" contains a single element.
605 int isl_map_is_singleton(__isl_keep isl_map *map)
612 return isl_basic_map_is_singleton(map->p[0]);
615 /* Given a singleton basic map, extract the single element
618 static __isl_give isl_vec *singleton_extract_point(__isl_keep isl_basic_map *bmap)
622 struct isl_vec *point;
628 dim = isl_basic_map_total_dim(bmap);
629 isl_assert(bmap->ctx, bmap->n_eq == dim, return NULL);
630 point = isl_vec_alloc(bmap->ctx, 1 + dim);
636 isl_int_set_si(point->el[0], 1);
637 for (j = 0; j < bmap->n_eq; ++j) {
640 isl_assert(bmap->ctx,
641 isl_seq_first_non_zero(bmap->eq[j] + 1, i) == -1,
643 isl_assert(bmap->ctx,
644 isl_int_is_one(bmap->eq[j][1 + i]) ||
645 isl_int_is_negone(bmap->eq[j][1 + i]),
647 isl_assert(bmap->ctx,
648 isl_seq_first_non_zero(bmap->eq[j]+1+i+1, dim-i-1) == -1,
651 isl_int_gcd(m, point->el[0], bmap->eq[j][1 + i]);
652 isl_int_divexact(m, bmap->eq[j][1 + i], m);
654 isl_seq_scale(point->el, point->el, m, 1 + i);
655 isl_int_divexact(m, point->el[0], bmap->eq[j][1 + i]);
657 isl_int_mul(point->el[1 + i], m, bmap->eq[j][0]);
668 /* Return 1 if "bmap" contains the point "point".
669 * "bmap" is assumed to have known divs.
670 * The point is first extended with the divs and then passed
671 * to basic_map_contains.
673 static int basic_map_contains_point(__isl_keep isl_basic_map *bmap,
674 __isl_keep isl_vec *point)
683 if (bmap->n_div == 0)
684 return isl_basic_map_contains(bmap, point);
686 dim = isl_basic_map_total_dim(bmap) - bmap->n_div;
687 vec = isl_vec_alloc(bmap->ctx, 1 + dim + bmap->n_div);
691 isl_seq_cpy(vec->el, point->el, point->size);
692 for (i = 0; i < bmap->n_div; ++i) {
693 isl_seq_inner_product(bmap->div[i] + 1, vec->el,
694 1 + dim + i, &vec->el[1+dim+i]);
695 isl_int_fdiv_q(vec->el[1+dim+i], vec->el[1+dim+i],
699 contains = isl_basic_map_contains(bmap, vec);
705 /* Return 1 is the singleton map "map1" is a subset of "map2",
706 * i.e., if the single element of "map1" is also an element of "map2".
708 static int map_is_singleton_subset(__isl_keep isl_map *map1,
709 __isl_keep isl_map *map2)
713 struct isl_vec *point;
720 point = singleton_extract_point(map1->p[0]);
724 for (i = 0; i < map2->n; ++i) {
725 is_subset = basic_map_contains_point(map2->p[i], point);
734 int isl_map_is_subset(struct isl_map *map1, struct isl_map *map2)
737 struct isl_map *diff;
742 if (isl_map_is_empty(map1))
745 if (isl_map_is_empty(map2))
748 if (isl_map_fast_is_universe(map2))
751 map1 = isl_map_compute_divs(isl_map_copy(map1));
752 map2 = isl_map_compute_divs(isl_map_copy(map2));
753 if (isl_map_is_singleton(map1)) {
754 is_subset = map_is_singleton_subset(map1, map2);
759 is_subset = map_diff_is_empty(map1, map2);
766 int isl_set_is_subset(struct isl_set *set1, struct isl_set *set2)
768 return isl_map_is_subset(
769 (struct isl_map *)set1, (struct isl_map *)set2);
772 __isl_give isl_map *isl_map_make_disjoint(__isl_take isl_map *map)
775 struct isl_subtract_diff_collector sdc;
776 sdc.dc.add = &basic_map_subtract_add;
780 if (ISL_F_ISSET(map, ISL_MAP_DISJOINT))
785 map = isl_map_compute_divs(map);
786 map = isl_map_remove_empty_parts(map);
788 if (!map || map->n <= 1)
791 sdc.diff = isl_map_from_basic_map(isl_basic_map_copy(map->p[0]));
793 for (i = 1; i < map->n; ++i) {
794 struct isl_basic_map *bmap = isl_basic_map_copy(map->p[i]);
795 struct isl_map *copy = isl_map_copy(sdc.diff);
796 if (basic_map_collect_diff(bmap, copy, &sdc.dc) < 0) {
797 isl_map_free(sdc.diff);
808 __isl_give isl_set *isl_set_make_disjoint(__isl_take isl_set *set)
810 return (struct isl_set *)isl_map_make_disjoint((struct isl_map *)set);
813 __isl_give isl_set *isl_set_complement(__isl_take isl_set *set)
820 universe = isl_set_universe(isl_set_get_dim(set));
822 return isl_set_subtract(universe, set);