6 #include "isl_map_private.h"
7 #include "isl_equalities.h"
8 #include "isl_sample.h"
11 struct isl_basic_map *isl_basic_map_implicit_equalities(
12 struct isl_basic_map *bmap)
19 bmap = isl_basic_map_gauss(bmap, NULL);
20 if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
22 if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_NO_IMPLICIT))
24 if (bmap->n_ineq <= 1)
27 tab = isl_tab_from_basic_map(bmap);
28 tab = isl_tab_detect_implicit_equalities(tab);
29 bmap = isl_basic_map_update_from_tab(bmap, tab);
31 bmap = isl_basic_map_gauss(bmap, NULL);
32 ISL_F_SET(bmap, ISL_BASIC_MAP_NO_IMPLICIT);
36 struct isl_basic_set *isl_basic_set_implicit_equalities(
37 struct isl_basic_set *bset)
39 return (struct isl_basic_set *)
40 isl_basic_map_implicit_equalities((struct isl_basic_map*)bset);
43 struct isl_map *isl_map_implicit_equalities(struct isl_map *map)
50 for (i = 0; i < map->n; ++i) {
51 map->p[i] = isl_basic_map_implicit_equalities(map->p[i]);
62 /* Make eq[row][col] of both bmaps equal so we can add the row
63 * add the column to the common matrix.
64 * Note that because of the echelon form, the columns of row row
65 * after column col are zero.
67 static void set_common_multiple(
68 struct isl_basic_set *bset1, struct isl_basic_set *bset2,
69 unsigned row, unsigned col)
73 if (isl_int_eq(bset1->eq[row][col], bset2->eq[row][col]))
78 isl_int_lcm(m, bset1->eq[row][col], bset2->eq[row][col]);
79 isl_int_divexact(c, m, bset1->eq[row][col]);
80 isl_seq_scale(bset1->eq[row], bset1->eq[row], c, col+1);
81 isl_int_divexact(c, m, bset2->eq[row][col]);
82 isl_seq_scale(bset2->eq[row], bset2->eq[row], c, col+1);
87 /* Delete a given equality, moving all the following equalities one up.
89 static void delete_row(struct isl_basic_set *bset, unsigned row)
96 for (r = row; r < bset->n_eq; ++r)
97 bset->eq[r] = bset->eq[r+1];
98 bset->eq[bset->n_eq] = t;
101 /* Make first row entries in column col of bset1 identical to
102 * those of bset2, using the fact that entry bset1->eq[row][col]=a
103 * is non-zero. Initially, these elements of bset1 are all zero.
104 * For each row i < row, we set
105 * A[i] = a * A[i] + B[i][col] * A[row]
108 * A[i][col] = B[i][col] = a * old(B[i][col])
110 static void construct_column(
111 struct isl_basic_set *bset1, struct isl_basic_set *bset2,
112 unsigned row, unsigned col)
121 total = 1 + isl_basic_set_n_dim(bset1);
122 for (r = 0; r < row; ++r) {
123 if (isl_int_is_zero(bset2->eq[r][col]))
125 isl_int_gcd(b, bset2->eq[r][col], bset1->eq[row][col]);
126 isl_int_divexact(a, bset1->eq[row][col], b);
127 isl_int_divexact(b, bset2->eq[r][col], b);
128 isl_seq_combine(bset1->eq[r], a, bset1->eq[r],
129 b, bset1->eq[row], total);
130 isl_seq_scale(bset2->eq[r], bset2->eq[r], a, total);
134 delete_row(bset1, row);
137 /* Make first row entries in column col of bset1 identical to
138 * those of bset2, using only these entries of the two matrices.
139 * Let t be the last row with different entries.
140 * For each row i < t, we set
141 * A[i] = (A[t][col]-B[t][col]) * A[i] + (B[i][col]-A[i][col) * A[t]
142 * B[i] = (A[t][col]-B[t][col]) * B[i] + (B[i][col]-A[i][col) * B[t]
144 * A[i][col] = B[i][col] = old(A[t][col]*B[i][col]-A[i][col]*B[t][col])
146 static int transform_column(
147 struct isl_basic_set *bset1, struct isl_basic_set *bset2,
148 unsigned row, unsigned col)
154 for (t = row-1; t >= 0; --t)
155 if (isl_int_ne(bset1->eq[t][col], bset2->eq[t][col]))
160 total = 1 + isl_basic_set_n_dim(bset1);
164 isl_int_sub(b, bset1->eq[t][col], bset2->eq[t][col]);
165 for (i = 0; i < t; ++i) {
166 isl_int_sub(a, bset2->eq[i][col], bset1->eq[i][col]);
167 isl_int_gcd(g, a, b);
168 isl_int_divexact(a, a, g);
169 isl_int_divexact(g, b, g);
170 isl_seq_combine(bset1->eq[i], g, bset1->eq[i], a, bset1->eq[t],
172 isl_seq_combine(bset2->eq[i], g, bset2->eq[i], a, bset2->eq[t],
178 delete_row(bset1, t);
179 delete_row(bset2, t);
183 /* The implementation is based on Section 5.2 of Michael Karr,
184 * "Affine Relationships Among Variables of a Program",
185 * except that the echelon form we use starts from the last column
186 * and that we are dealing with integer coefficients.
188 static struct isl_basic_set *affine_hull(
189 struct isl_basic_set *bset1, struct isl_basic_set *bset2)
195 total = 1 + isl_basic_set_n_dim(bset1);
198 for (col = total-1; col >= 0; --col) {
199 int is_zero1 = row >= bset1->n_eq ||
200 isl_int_is_zero(bset1->eq[row][col]);
201 int is_zero2 = row >= bset2->n_eq ||
202 isl_int_is_zero(bset2->eq[row][col]);
203 if (!is_zero1 && !is_zero2) {
204 set_common_multiple(bset1, bset2, row, col);
206 } else if (!is_zero1 && is_zero2) {
207 construct_column(bset1, bset2, row, col);
208 } else if (is_zero1 && !is_zero2) {
209 construct_column(bset2, bset1, row, col);
211 if (transform_column(bset1, bset2, row, col))
215 isl_basic_set_free(bset2);
216 isl_assert(bset1->ctx, row == bset1->n_eq, goto error);
217 bset1 = isl_basic_set_normalize_constraints(bset1);
220 isl_basic_set_free(bset1);
224 /* Find an integer point in the set represented by "tab"
225 * that lies outside of the equality "eq" e(x) = 0.
226 * If "up" is true, look for a point satisfying e(x) - 1 >= 0.
227 * Otherwise, look for a point satisfying -e(x) - 1 >= 0 (i.e., e(x) <= -1).
228 * The point, if found, is returned.
229 * If no point can be found, a zero-length vector is returned.
231 * Before solving an ILP problem, we first check if simply
232 * adding the normal of the constraint to one of the known
233 * integer points in the basic set represented by "tab"
234 * yields another point inside the basic set.
236 * The caller of this function ensures that the tableau is bounded or
237 * that tab->basis and tab->n_unbounded have been set appropriately.
239 static struct isl_vec *outside_point(struct isl_tab *tab, isl_int *eq, int up)
242 struct isl_vec *sample = NULL;
243 struct isl_tab_undo *snap;
252 sample = isl_vec_alloc(ctx, 1 + dim);
255 isl_int_set_si(sample->el[0], 1);
256 isl_seq_combine(sample->el + 1,
257 ctx->one, tab->bmap->sample->el + 1,
258 up ? ctx->one : ctx->negone, eq + 1, dim);
259 if (isl_basic_map_contains(tab->bmap, sample))
261 isl_vec_free(sample);
264 snap = isl_tab_snap(tab);
267 isl_seq_neg(eq, eq, 1 + dim);
268 isl_int_sub_ui(eq[0], eq[0], 1);
270 if (isl_tab_extend_cons(tab, 1) < 0)
272 if (isl_tab_add_ineq(tab, eq) < 0)
275 sample = isl_tab_sample(tab);
277 isl_int_add_ui(eq[0], eq[0], 1);
279 isl_seq_neg(eq, eq, 1 + dim);
281 if (isl_tab_rollback(tab, snap) < 0)
286 isl_vec_free(sample);
290 struct isl_basic_set *isl_basic_set_recession_cone(struct isl_basic_set *bset)
294 bset = isl_basic_set_cow(bset);
297 isl_assert(bset->ctx, bset->n_div == 0, goto error);
299 for (i = 0; i < bset->n_eq; ++i)
300 isl_int_set_si(bset->eq[i][0], 0);
302 for (i = 0; i < bset->n_ineq; ++i)
303 isl_int_set_si(bset->ineq[i][0], 0);
305 ISL_F_CLR(bset, ISL_BASIC_SET_NO_IMPLICIT);
306 return isl_basic_set_implicit_equalities(bset);
308 isl_basic_set_free(bset);
312 /* Extend an initial (under-)approximation of the affine hull of basic
313 * set represented by the tableau "tab"
314 * by looking for points that do not satisfy one of the equalities
315 * in the current approximation and adding them to that approximation
316 * until no such points can be found any more.
318 * The caller of this function ensures that "tab" is bounded or
319 * that tab->basis and tab->n_unbounded have been set appropriately.
321 static struct isl_basic_set *extend_affine_hull(struct isl_tab *tab,
322 struct isl_basic_set *hull)
332 if (isl_tab_extend_cons(tab, 2 * dim + 1) < 0)
335 for (i = 0; i < dim; ++i) {
336 struct isl_vec *sample;
337 struct isl_basic_set *point;
338 for (j = 0; j < hull->n_eq; ++j) {
339 sample = outside_point(tab, hull->eq[j], 1);
342 if (sample->size > 0)
344 isl_vec_free(sample);
345 sample = outside_point(tab, hull->eq[j], 0);
348 if (sample->size > 0)
350 isl_vec_free(sample);
352 tab = isl_tab_add_eq(tab, hull->eq[j]);
359 tab = isl_tab_add_sample(tab, isl_vec_copy(sample));
362 point = isl_basic_set_from_vec(sample);
363 hull = affine_hull(hull, point);
368 isl_basic_set_free(hull);
372 /* Drop all constraints in bset that involve any of the dimensions
373 * first to first+n-1.
375 static struct isl_basic_set *drop_constraints_involving
376 (struct isl_basic_set *bset, unsigned first, unsigned n)
383 bset = isl_basic_set_cow(bset);
385 for (i = bset->n_eq - 1; i >= 0; --i) {
386 if (isl_seq_first_non_zero(bset->eq[i] + 1 + first, n) == -1)
388 isl_basic_set_drop_equality(bset, i);
391 for (i = bset->n_ineq - 1; i >= 0; --i) {
392 if (isl_seq_first_non_zero(bset->ineq[i] + 1 + first, n) == -1)
394 isl_basic_set_drop_inequality(bset, i);
400 /* Look for all equalities satisfied by the integer points in bset,
401 * which is assumed to be bounded.
403 * The equalities are obtained by successively looking for
404 * a point that is affinely independent of the points found so far.
405 * In particular, for each equality satisfied by the points so far,
406 * we check if there is any point on a hyperplane parallel to the
407 * corresponding hyperplane shifted by at least one (in either direction).
409 static struct isl_basic_set *uset_affine_hull_bounded(struct isl_basic_set *bset)
411 struct isl_vec *sample = NULL;
412 struct isl_basic_set *hull;
413 struct isl_tab *tab = NULL;
416 if (isl_basic_set_fast_is_empty(bset))
419 dim = isl_basic_set_n_dim(bset);
421 if (bset->sample && bset->sample->size == 1 + dim) {
422 int contains = isl_basic_set_contains(bset, bset->sample);
428 sample = isl_vec_copy(bset->sample);
430 isl_vec_free(bset->sample);
435 tab = isl_tab_from_basic_set(bset);
440 isl_vec_free(sample);
441 return isl_basic_set_set_to_empty(bset);
443 if (isl_tab_track_bset(tab, isl_basic_set_copy(bset)) < 0)
447 struct isl_tab_undo *snap;
448 snap = isl_tab_snap(tab);
449 sample = isl_tab_sample(tab);
450 if (isl_tab_rollback(tab, snap) < 0)
452 isl_vec_free(tab->bmap->sample);
453 tab->bmap->sample = isl_vec_copy(sample);
458 if (sample->size == 0) {
460 isl_vec_free(sample);
461 return isl_basic_set_set_to_empty(bset);
464 hull = isl_basic_set_from_vec(sample);
466 isl_basic_set_free(bset);
467 hull = extend_affine_hull(tab, hull);
472 isl_vec_free(sample);
474 isl_basic_set_free(bset);
478 /* Given an unbounded tableau and an integer point satisfying the tableau,
479 * construct an intial affine hull containing the recession cone
480 * shifted to the given point.
482 * The unbounded directions are taken from the last rows of the basis,
483 * which is assumed to have been initialized appropriately.
485 static __isl_give isl_basic_set *initial_hull(struct isl_tab *tab,
486 __isl_take isl_vec *vec)
490 struct isl_basic_set *bset = NULL;
497 isl_assert(ctx, vec->size != 0, goto error);
499 bset = isl_basic_set_alloc(ctx, 0, vec->size - 1, 0, vec->size - 1, 0);
502 dim = isl_basic_set_n_dim(bset) - tab->n_unbounded;
503 for (i = 0; i < dim; ++i) {
504 k = isl_basic_set_alloc_equality(bset);
507 isl_seq_cpy(bset->eq[k] + 1, tab->basis->row[1 + i] + 1,
509 isl_seq_inner_product(bset->eq[k] + 1, vec->el +1,
510 vec->size - 1, &bset->eq[k][0]);
511 isl_int_neg(bset->eq[k][0], bset->eq[k][0]);
514 bset = isl_basic_set_gauss(bset, NULL);
518 isl_basic_set_free(bset);
523 /* Given a tableau of a set and a tableau of the corresponding
524 * recession cone, detect and add all equalities to the tableau.
525 * If the tableau is bounded, then we can simply keep the
526 * tableau in its state after the return from extend_affine_hull.
527 * However, if the tableau is unbounded, then
528 * isl_tab_set_initial_basis_with_cone will add some additional
529 * constraints to the tableau that have to be removed again.
530 * In this case, we therefore rollback to the state before
531 * any constraints were added and then add the eqaulities back in.
533 struct isl_tab *isl_tab_detect_equalities(struct isl_tab *tab,
534 struct isl_tab *tab_cone)
537 struct isl_vec *sample;
538 struct isl_basic_set *hull;
539 struct isl_tab_undo *snap;
541 if (!tab || !tab_cone)
544 snap = isl_tab_snap(tab);
546 isl_mat_free(tab->basis);
549 isl_assert(tab->mat->ctx, tab->bmap, goto error);
550 isl_assert(tab->mat->ctx, tab->samples, goto error);
551 isl_assert(tab->mat->ctx, tab->samples->n_col == 1 + tab->n_var, goto error);
552 isl_assert(tab->mat->ctx, tab->n_sample > tab->n_outside, goto error);
554 if (isl_tab_set_initial_basis_with_cone(tab, tab_cone) < 0)
557 sample = isl_vec_alloc(tab->mat->ctx, 1 + tab->n_var);
561 isl_seq_cpy(sample->el, tab->samples->row[tab->n_outside], sample->size);
563 isl_vec_free(tab->bmap->sample);
564 tab->bmap->sample = isl_vec_copy(sample);
566 if (tab->n_unbounded == 0)
567 hull = isl_basic_set_from_vec(isl_vec_copy(sample));
569 hull = initial_hull(tab, isl_vec_copy(sample));
571 for (j = tab->n_outside + 1; j < tab->n_sample; ++j) {
572 isl_seq_cpy(sample->el, tab->samples->row[j], sample->size);
573 hull = affine_hull(hull,
574 isl_basic_set_from_vec(isl_vec_copy(sample)));
577 isl_vec_free(sample);
579 hull = extend_affine_hull(tab, hull);
583 if (tab->n_unbounded == 0) {
584 isl_basic_set_free(hull);
588 if (isl_tab_rollback(tab, snap) < 0)
591 if (hull->n_eq > tab->n_zero) {
592 for (j = 0; j < hull->n_eq; ++j) {
593 isl_seq_normalize(tab->mat->ctx, hull->eq[j], 1 + tab->n_var);
594 tab = isl_tab_add_eq(tab, hull->eq[j]);
598 isl_basic_set_free(hull);
606 /* Compute the affine hull of "bset", where "cone" is the recession cone
609 * We first compute a unimodular transformation that puts the unbounded
610 * directions in the last dimensions. In particular, we take a transformation
611 * that maps all equalities to equalities (in HNF) on the first dimensions.
612 * Let x be the original dimensions and y the transformed, with y_1 bounded
615 * [ y_1 ] [ y_1 ] [ Q_1 ]
616 * x = U [ y_2 ] [ y_2 ] = [ Q_2 ] x
618 * Let's call the input basic set S. We compute S' = preimage(S, U)
619 * and drop the final dimensions including any constraints involving them.
620 * This results in set S''.
621 * Then we compute the affine hull A'' of S''.
622 * Let F y_1 >= g be the constraint system of A''. In the transformed
623 * space the y_2 are unbounded, so we can add them back without any constraints,
627 * [ F 0 ] [ y_2 ] >= g
630 * [ F 0 ] [ Q_2 ] x >= g
634 * The affine hull in the original space is then obtained as
635 * A = preimage(A'', Q_1).
637 static struct isl_basic_set *affine_hull_with_cone(struct isl_basic_set *bset,
638 struct isl_basic_set *cone)
642 struct isl_basic_set *hull;
643 struct isl_mat *M, *U, *Q;
648 total = isl_basic_set_total_dim(cone);
649 cone_dim = total - cone->n_eq;
651 M = isl_mat_sub_alloc(bset->ctx, cone->eq, 0, cone->n_eq, 1, total);
652 M = isl_mat_left_hermite(M, 0, &U, &Q);
657 U = isl_mat_lin_to_aff(U);
658 bset = isl_basic_set_preimage(bset, isl_mat_copy(U));
660 bset = drop_constraints_involving(bset, total - cone_dim, cone_dim);
661 bset = isl_basic_set_drop_dims(bset, total - cone_dim, cone_dim);
663 Q = isl_mat_lin_to_aff(Q);
664 Q = isl_mat_drop_rows(Q, 1 + total - cone_dim, cone_dim);
666 if (bset && bset->sample && bset->sample->size == 1 + total)
667 bset->sample = isl_mat_vec_product(isl_mat_copy(Q), bset->sample);
669 hull = uset_affine_hull_bounded(bset);
674 struct isl_vec *sample = isl_vec_copy(hull->sample);
675 U = isl_mat_drop_cols(U, 1 + total - cone_dim, cone_dim);
676 if (sample && sample->size > 0)
677 sample = isl_mat_vec_product(U, sample);
680 hull = isl_basic_set_preimage(hull, Q);
681 isl_vec_free(hull->sample);
682 hull->sample = sample;
685 isl_basic_set_free(cone);
689 isl_basic_set_free(bset);
690 isl_basic_set_free(cone);
694 /* Look for all equalities satisfied by the integer points in bset,
695 * which is assumed not to have any explicit equalities.
697 * The equalities are obtained by successively looking for
698 * a point that is affinely independent of the points found so far.
699 * In particular, for each equality satisfied by the points so far,
700 * we check if there is any point on a hyperplane parallel to the
701 * corresponding hyperplane shifted by at least one (in either direction).
703 * Before looking for any outside points, we first compute the recession
704 * cone. The directions of this recession cone will always be part
705 * of the affine hull, so there is no need for looking for any points
706 * in these directions.
707 * In particular, if the recession cone is full-dimensional, then
708 * the affine hull is simply the whole universe.
710 static struct isl_basic_set *uset_affine_hull(struct isl_basic_set *bset)
712 struct isl_basic_set *cone;
714 if (isl_basic_set_fast_is_empty(bset))
717 cone = isl_basic_set_recession_cone(isl_basic_set_copy(bset));
720 if (cone->n_eq == 0) {
721 struct isl_basic_set *hull;
722 isl_basic_set_free(cone);
723 hull = isl_basic_set_universe_like(bset);
724 isl_basic_set_free(bset);
728 if (cone->n_eq < isl_basic_set_total_dim(cone))
729 return affine_hull_with_cone(bset, cone);
731 isl_basic_set_free(cone);
732 return uset_affine_hull_bounded(bset);
734 isl_basic_set_free(bset);
738 /* Look for all equalities satisfied by the integer points in bmap
739 * that are independent of the equalities already explicitly available
742 * We first remove all equalities already explicitly available,
743 * then look for additional equalities in the reduced space
744 * and then transform the result to the original space.
745 * The original equalities are _not_ added to this set. This is
746 * the responsibility of the calling function.
747 * The resulting basic set has all meaning about the dimensions removed.
748 * In particular, dimensions that correspond to existential variables
749 * in bmap and that are found to be fixed are not removed.
751 static struct isl_basic_set *equalities_in_underlying_set(
752 struct isl_basic_map *bmap)
754 struct isl_mat *T1 = NULL;
755 struct isl_mat *T2 = NULL;
756 struct isl_basic_set *bset = NULL;
757 struct isl_basic_set *hull = NULL;
759 bset = isl_basic_map_underlying_set(bmap);
763 bset = isl_basic_set_remove_equalities(bset, &T1, &T2);
767 hull = uset_affine_hull(bset);
774 struct isl_vec *sample = isl_vec_copy(hull->sample);
775 if (sample && sample->size > 0)
776 sample = isl_mat_vec_product(T1, sample);
779 hull = isl_basic_set_preimage(hull, T2);
780 isl_vec_free(hull->sample);
781 hull->sample = sample;
787 isl_basic_set_free(bset);
788 isl_basic_set_free(hull);
792 /* Detect and make explicit all equalities satisfied by the (integer)
795 struct isl_basic_map *isl_basic_map_detect_equalities(
796 struct isl_basic_map *bmap)
799 struct isl_basic_set *hull = NULL;
803 if (bmap->n_ineq == 0)
805 if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
807 if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_ALL_EQUALITIES))
809 if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL))
810 return isl_basic_map_implicit_equalities(bmap);
812 hull = equalities_in_underlying_set(isl_basic_map_copy(bmap));
815 if (ISL_F_ISSET(hull, ISL_BASIC_SET_EMPTY)) {
816 isl_basic_set_free(hull);
817 return isl_basic_map_set_to_empty(bmap);
819 bmap = isl_basic_map_extend_dim(bmap, isl_dim_copy(bmap->dim), 0,
821 for (i = 0; i < hull->n_eq; ++i) {
822 j = isl_basic_map_alloc_equality(bmap);
825 isl_seq_cpy(bmap->eq[j], hull->eq[i],
826 1 + isl_basic_set_total_dim(hull));
828 isl_vec_free(bmap->sample);
829 bmap->sample = isl_vec_copy(hull->sample);
830 isl_basic_set_free(hull);
831 ISL_F_SET(bmap, ISL_BASIC_MAP_NO_IMPLICIT | ISL_BASIC_MAP_ALL_EQUALITIES);
832 bmap = isl_basic_map_simplify(bmap);
833 return isl_basic_map_finalize(bmap);
835 isl_basic_set_free(hull);
836 isl_basic_map_free(bmap);
840 __isl_give isl_basic_set *isl_basic_set_detect_equalities(
841 __isl_take isl_basic_set *bset)
843 return (isl_basic_set *)
844 isl_basic_map_detect_equalities((isl_basic_map *)bset);
847 struct isl_map *isl_map_detect_equalities(struct isl_map *map)
849 struct isl_basic_map *bmap;
855 for (i = 0; i < map->n; ++i) {
856 bmap = isl_basic_map_copy(map->p[i]);
857 bmap = isl_basic_map_detect_equalities(bmap);
860 isl_basic_map_free(map->p[i]);
870 __isl_give isl_set *isl_set_detect_equalities(__isl_take isl_set *set)
872 return (isl_set *)isl_map_detect_equalities((isl_map *)set);
875 /* After computing the rational affine hull (by detecting the implicit
876 * equalities), we compute the additional equalities satisfied by
877 * the integer points (if any) and add the original equalities back in.
879 struct isl_basic_map *isl_basic_map_affine_hull(struct isl_basic_map *bmap)
881 bmap = isl_basic_map_detect_equalities(bmap);
882 bmap = isl_basic_map_cow(bmap);
883 isl_basic_map_free_inequality(bmap, bmap->n_ineq);
887 struct isl_basic_set *isl_basic_set_affine_hull(struct isl_basic_set *bset)
889 return (struct isl_basic_set *)
890 isl_basic_map_affine_hull((struct isl_basic_map *)bset);
893 struct isl_basic_map *isl_map_affine_hull(struct isl_map *map)
896 struct isl_basic_map *model = NULL;
897 struct isl_basic_map *hull = NULL;
904 hull = isl_basic_map_empty_like_map(map);
909 map = isl_map_detect_equalities(map);
910 map = isl_map_align_divs(map);
913 model = isl_basic_map_copy(map->p[0]);
914 set = isl_map_underlying_set(map);
915 set = isl_set_cow(set);
919 for (i = 0; i < set->n; ++i) {
920 set->p[i] = isl_basic_set_cow(set->p[i]);
921 set->p[i] = isl_basic_set_affine_hull(set->p[i]);
922 set->p[i] = isl_basic_set_gauss(set->p[i], NULL);
926 set = isl_set_remove_empty_parts(set);
928 hull = isl_basic_map_empty_like(model);
929 isl_basic_map_free(model);
931 struct isl_basic_set *bset;
933 set->p[0] = affine_hull(set->p[0], set->p[--set->n]);
937 bset = isl_basic_set_copy(set->p[0]);
938 hull = isl_basic_map_overlying_set(bset, model);
941 hull = isl_basic_map_simplify(hull);
942 return isl_basic_map_finalize(hull);
944 isl_basic_map_free(model);
949 struct isl_basic_set *isl_set_affine_hull(struct isl_set *set)
951 return (struct isl_basic_set *)
952 isl_map_affine_hull((struct isl_map *)set);