isl_printer_print_pw_qpolynomial_fold: use consistent names in C format
[platform/upstream/isl.git] / isl_convex_hull.c
index 834d278..1552492 100644 (file)
@@ -10,7 +10,7 @@
 #include "isl_lp.h"
 #include "isl_map.h"
 #include "isl_map_private.h"
-#include "isl_mat.h"
+#include <isl_mat_private.h>
 #include "isl_set.h"
 #include "isl_seq.h"
 #include "isl_equalities.h"
@@ -79,7 +79,7 @@ int isl_basic_set_constraint_is_redundant(struct isl_basic_set **bset,
                        (struct isl_basic_map **)bset, c, opt_n, opt_d);
 }
 
-/* Compute the convex hull of a basic map, by removing the redundant
+/* Remove redundant
  * constraints.  If the minimal value along the normal of a constraint
  * is the same if the constraint is removed, then the constraint is redundant.
  *
@@ -87,7 +87,8 @@ int isl_basic_set_constraint_is_redundant(struct isl_basic_set **bset,
  * corresponding equality and the checked if the dimension was that
  * of a facet.
  */
-struct isl_basic_map *isl_basic_map_convex_hull(struct isl_basic_map *bmap)
+__isl_give isl_basic_map *isl_basic_map_remove_redundancies(
+       __isl_take isl_basic_map *bmap)
 {
        struct isl_tab *tab;
 
@@ -103,7 +104,8 @@ struct isl_basic_map *isl_basic_map_convex_hull(struct isl_basic_map *bmap)
                return bmap;
 
        tab = isl_tab_from_basic_map(bmap);
-       tab = isl_tab_detect_implicit_equalities(tab);
+       if (isl_tab_detect_implicit_equalities(tab) < 0)
+               goto error;
        if (isl_tab_detect_redundant(tab) < 0)
                goto error;
        bmap = isl_basic_map_update_from_tab(bmap, tab);
@@ -117,10 +119,11 @@ error:
        return NULL;
 }
 
-struct isl_basic_set *isl_basic_set_convex_hull(struct isl_basic_set *bset)
+__isl_give isl_basic_set *isl_basic_set_remove_redundancies(
+       __isl_take isl_basic_set *bset)
 {
        return (struct isl_basic_set *)
-               isl_basic_map_convex_hull((struct isl_basic_map *)bset);
+               isl_basic_map_remove_redundancies((struct isl_basic_map *)bset);
 }
 
 /* Check if the set set is bound in the direction of the affine
@@ -212,6 +215,9 @@ static struct isl_basic_set *isl_basic_set_add_equality(
        int i;
        unsigned dim;
 
+       if (!bset)
+               return NULL;
+
        if (ISL_F_ISSET(bset, ISL_BASIC_SET_EMPTY))
                return bset;
 
@@ -377,6 +383,7 @@ isl_int *isl_set_wrap_facet(__isl_keep isl_set *set,
        isl_int *facet, isl_int *ridge)
 {
        int i;
+       isl_ctx *ctx;
        struct isl_mat *T = NULL;
        struct isl_basic_set *lp = NULL;
        struct isl_vec *obj;
@@ -384,11 +391,14 @@ isl_int *isl_set_wrap_facet(__isl_keep isl_set *set,
        isl_int num, den;
        unsigned dim;
 
+       if (!set)
+               return NULL;
+       ctx = set->ctx;
        set = isl_set_copy(set);
        set = isl_set_set_rational(set);
 
        dim = 1 + isl_set_n_dim(set);
-       T = isl_mat_alloc(set->ctx, 3, dim);
+       T = isl_mat_alloc(ctx, 3, dim);
        if (!T)
                goto error;
        isl_int_set_si(T->row[0][0], 1);
@@ -401,7 +411,7 @@ isl_int *isl_set_wrap_facet(__isl_keep isl_set *set,
        if (!set)
                goto error;
        lp = wrap_constraints(set);
-       obj = isl_vec_alloc(set->ctx, 1 + dim*set->n);
+       obj = isl_vec_alloc(ctx, 1 + dim*set->n);
        if (!obj)
                goto error;
        isl_int_set_si(obj->block.data[0], 0);
@@ -413,17 +423,20 @@ isl_int *isl_set_wrap_facet(__isl_keep isl_set *set,
        isl_int_init(num);
        isl_int_init(den);
        res = isl_basic_set_solve_lp(lp, 0,
-                           obj->block.data, set->ctx->one, &num, &den, NULL);
+                           obj->block.data, ctx->one, &num, &den, NULL);
        if (res == isl_lp_ok) {
                isl_int_neg(num, num);
                isl_seq_combine(facet, num, facet, den, ridge, dim);
+               isl_seq_normalize(ctx, facet, dim);
        }
        isl_int_clear(num);
        isl_int_clear(den);
        isl_vec_free(obj);
        isl_basic_set_free(lp);
        isl_set_free(set);
-       isl_assert(set->ctx, res == isl_lp_ok || res == isl_lp_unbounded, 
+       if (res == isl_lp_error)
+               return NULL;
+       isl_assert(ctx, res == isl_lp_ok || res == isl_lp_unbounded, 
                   return NULL);
        return facet;
 error:
@@ -450,7 +463,6 @@ static __isl_give isl_mat *initial_facet_constraint(__isl_keep isl_set *set)
 {
        struct isl_set *slice = NULL;
        struct isl_basic_set *face = NULL;
-       struct isl_mat *m, *U, *Q;
        int i;
        unsigned dim = isl_set_n_dim(set);
        int is_bound;
@@ -464,7 +476,9 @@ static __isl_give isl_mat *initial_facet_constraint(__isl_keep isl_set *set)
        isl_seq_clr(bounds->row[0], dim);
        isl_int_set_si(bounds->row[0][1 + dim - 1], 1);
        is_bound = uset_is_bound(set, bounds->row[0], 1 + dim);
-       isl_assert(set->ctx, is_bound == 1, goto error);
+       if (is_bound < 0)
+               goto error;
+       isl_assert(set->ctx, is_bound, goto error);
        isl_seq_normalize(set->ctx, bounds->row[0], 1 + dim);
        bounds->n_row = 1;
 
@@ -559,7 +573,8 @@ static struct isl_basic_set *compute_facet(struct isl_set *set, isl_int *c)
        set = isl_set_preimage(set, U);
        facet = uset_convex_hull_wrap_bounded(set);
        facet = isl_basic_set_preimage(facet, Q);
-       isl_assert(ctx, facet->n_eq == 0, goto error);
+       if (facet)
+               isl_assert(ctx, facet->n_eq == 0, goto error);
        return facet;
 error:
        isl_basic_set_free(facet);
@@ -613,11 +628,13 @@ static struct isl_basic_set *extend(struct isl_basic_set *hull,
                hull_facet = isl_basic_set_add_equality(hull_facet, hull->ineq[i]);
                hull_facet = isl_basic_set_gauss(hull_facet, NULL);
                hull_facet = isl_basic_set_normalize_constraints(hull_facet);
-               if (!facet)
+               if (!facet || !hull_facet)
                        goto error;
                hull = isl_basic_set_cow(hull);
                hull = isl_basic_set_extend_dim(hull,
                        isl_dim_copy(hull->dim), 0, 0, facet->n_ineq);
+               if (!hull)
+                       goto error;
                for (j = 0; j < facet->n_ineq; ++j) {
                        for (f = 0; f < hull_facet->n_ineq; ++f)
                                if (isl_seq_eq(facet->ineq[j],
@@ -773,7 +790,7 @@ error:
 static struct isl_set *set_project_out(struct isl_ctx *ctx,
        struct isl_set *set, unsigned n)
 {
-       return isl_set_remove_dims(set, isl_set_n_dim(set) - n, n);
+       return isl_set_remove_dims(set, isl_dim_set, isl_set_n_dim(set) - n, n);
 }
 
 static struct isl_basic_set *convex_hull_0d(struct isl_set *set)
@@ -852,8 +869,8 @@ static struct isl_basic_set *convex_hull_pair_elim(struct isl_basic_set *bset1,
                isl_int_set_si(hull->eq[k][2*(1+dim)+j], 1);
        }
        hull = isl_basic_set_set_rational(hull);
-       hull = isl_basic_set_remove_dims(hull, dim, 2*(1+dim));
-       hull = isl_basic_set_convex_hull(hull);
+       hull = isl_basic_set_remove_dims(hull, isl_dim_set, dim, 2*(1+dim));
+       hull = isl_basic_set_remove_redundancies(hull);
        isl_basic_set_free(bset1);
        isl_basic_set_free(bset2);
        return hull;
@@ -864,21 +881,52 @@ error:
        return NULL;
 }
 
-static int isl_basic_set_is_bounded(struct isl_basic_set *bset)
+/* Is the set bounded for each value of the parameters?
+ */
+int isl_basic_set_is_bounded(__isl_keep isl_basic_set *bset)
 {
        struct isl_tab *tab;
        int bounded;
 
-       tab = isl_tab_from_recession_cone(bset);
+       if (!bset)
+               return -1;
+       if (isl_basic_set_fast_is_empty(bset))
+               return 1;
+
+       tab = isl_tab_from_recession_cone(bset, 1);
        bounded = isl_tab_cone_is_bounded(tab);
        isl_tab_free(tab);
        return bounded;
 }
 
-static int isl_set_is_bounded(struct isl_set *set)
+/* Is the image bounded for each value of the parameters and
+ * the domain variables?
+ */
+int isl_basic_map_image_is_bounded(__isl_keep isl_basic_map *bmap)
+{
+       unsigned nparam = isl_basic_map_dim(bmap, isl_dim_param);
+       unsigned n_in = isl_basic_map_dim(bmap, isl_dim_in);
+       int bounded;
+
+       bmap = isl_basic_map_copy(bmap);
+       bmap = isl_basic_map_cow(bmap);
+       bmap = isl_basic_map_move_dims(bmap, isl_dim_param, nparam,
+                                       isl_dim_in, 0, n_in);
+       bounded = isl_basic_set_is_bounded((isl_basic_set *)bmap);
+       isl_basic_map_free(bmap);
+
+       return bounded;
+}
+
+/* Is the set bounded for each value of the parameters?
+ */
+int isl_set_is_bounded(__isl_keep isl_set *set)
 {
        int i;
 
+       if (!set)
+               return -1;
+
        for (i = 0; i < set->n; ++i) {
                int bounded = isl_basic_set_is_bounded(set->p[i]);
                if (!bounded || bounded < 0)
@@ -995,7 +1043,7 @@ static struct isl_basic_set *modulo_lineality(struct isl_set *set,
        Q = isl_mat_lin_to_aff(Q);
 
        set = isl_set_preimage(set, U);
-       set = isl_set_remove_dims(set, total - lin_dim, lin_dim);
+       set = isl_set_remove_dims(set, isl_dim_set, total - lin_dim, lin_dim);
        hull = uset_convex_hull(set);
        hull = isl_basic_set_preimage(hull, Q);
 
@@ -1046,23 +1094,25 @@ static struct isl_basic_set *valid_direction_lp(
                if (k < 0)
                        goto error;
                n = 0;
-               isl_int_set_si(lp->eq[k][n++], 0);
+               isl_int_set_si(lp->eq[k][n], 0); n++;
                /* positivity constraint 1 >= 0 */
-               isl_int_set_si(lp->eq[k][n++], i == 0);
+               isl_int_set_si(lp->eq[k][n], i == 0); n++;
                for (j = 0; j < bset1->n_eq; ++j) {
-                       isl_int_set(lp->eq[k][n++], bset1->eq[j][i]);
-                       isl_int_neg(lp->eq[k][n++], bset1->eq[j][i]);
+                       isl_int_set(lp->eq[k][n], bset1->eq[j][i]); n++;
+                       isl_int_neg(lp->eq[k][n], bset1->eq[j][i]); n++;
+               }
+               for (j = 0; j < bset1->n_ineq; ++j) {
+                       isl_int_set(lp->eq[k][n], bset1->ineq[j][i]); n++;
                }
-               for (j = 0; j < bset1->n_ineq; ++j)
-                       isl_int_set(lp->eq[k][n++], bset1->ineq[j][i]);
                /* positivity constraint 1 >= 0 */
-               isl_int_set_si(lp->eq[k][n++], -(i == 0));
+               isl_int_set_si(lp->eq[k][n], -(i == 0)); n++;
                for (j = 0; j < bset2->n_eq; ++j) {
-                       isl_int_neg(lp->eq[k][n++], bset2->eq[j][i]);
-                       isl_int_set(lp->eq[k][n++], bset2->eq[j][i]);
+                       isl_int_neg(lp->eq[k][n], bset2->eq[j][i]); n++;
+                       isl_int_set(lp->eq[k][n], bset2->eq[j][i]); n++;
+               }
+               for (j = 0; j < bset2->n_ineq; ++j) {
+                       isl_int_neg(lp->eq[k][n], bset2->ineq[j][i]); n++;
                }
-               for (j = 0; j < bset2->n_ineq; ++j)
-                       isl_int_neg(lp->eq[k][n++], bset2->ineq[j][i]);
        }
        lp = isl_basic_set_gauss(lp, NULL);
        isl_basic_set_free(bset1);
@@ -1122,7 +1172,7 @@ static struct isl_vec *valid_direction(
        isl_seq_clr(dir->block.data + 1, dir->size - 1);
        n = 1;
        /* positivity constraint 1 >= 0 */
-       isl_int_set(dir->block.data[0], sample->block.data[n++]);
+       isl_int_set(dir->block.data[0], sample->block.data[n]); n++;
        for (i = 0; i < bset1->n_eq; ++i) {
                isl_int_sub(sample->block.data[n],
                            sample->block.data[n], sample->block.data[n+1]);
@@ -1280,6 +1330,8 @@ error:
 }
 
 static struct isl_basic_set *uset_convex_hull_wrap(struct isl_set *set);
+static struct isl_basic_set *modulo_affine_hull(
+       struct isl_set *set, struct isl_basic_set *affine_hull);
 
 /* Compute the convex hull of a pair of basic sets without any parameters or
  * integer divisions.
@@ -1287,6 +1339,9 @@ static struct isl_basic_set *uset_convex_hull_wrap(struct isl_set *set);
  * This function is called from uset_convex_hull_unbounded, which
  * means that the complete convex hull is unbounded.  Some pairs
  * of basic sets may still be bounded, though.
+ * They may even lie inside a lower dimensional space, in which
+ * case they need to be handled inside their affine hull since
+ * the main algorithm assumes that the result is full-dimensional.
  *
  * If the convex hull of the two basic sets would have a non-trivial
  * lineality space, we first project out this lineality space.
@@ -1294,9 +1349,17 @@ static struct isl_basic_set *uset_convex_hull_wrap(struct isl_set *set);
 static struct isl_basic_set *convex_hull_pair(struct isl_basic_set *bset1,
        struct isl_basic_set *bset2)
 {
-       struct isl_basic_set *lin;
+       isl_basic_set *lin, *aff;
        int bounded1, bounded2;
 
+       aff = isl_set_affine_hull(isl_basic_set_union(isl_basic_set_copy(bset1),
+                                                   isl_basic_set_copy(bset2)));
+       if (!aff)
+               goto error;
+       if (aff->n_eq != 0) 
+               return modulo_affine_hull(isl_basic_set_union(bset1, bset2), aff);
+       isl_basic_set_free(aff);
+
        bounded1 = isl_basic_set_is_bounded(bset1);
        bounded2 = isl_basic_set_is_bounded(bset2);
 
@@ -1773,6 +1836,9 @@ static struct isl_basic_set *uset_convex_hull_wrap_bounded(struct isl_set *set)
 {
        struct isl_basic_set *convex_hull = NULL;
 
+       if (!set)
+               goto error;
+
        if (isl_set_n_dim(set) == 0) {
                convex_hull = isl_basic_set_universe(isl_dim_copy(set->dim));
                isl_set_free(set);
@@ -1781,9 +1847,6 @@ static struct isl_basic_set *uset_convex_hull_wrap_bounded(struct isl_set *set)
        }
 
        set = isl_set_set_rational(set);
-
-       if (!set)
-               goto error;
        set = isl_set_coalesce(set);
        if (!set)
                goto error;
@@ -1856,6 +1919,8 @@ struct isl_basic_map *isl_map_convex_hull(struct isl_map *map)
 
        map = isl_map_detect_equalities(map);
        map = isl_map_align_divs(map);
+       if (!map)
+               goto error;
        model = isl_basic_map_copy(map->p[0]);
        set = isl_map_underlying_set(map);
        if (!set)
@@ -1872,6 +1937,8 @@ struct isl_basic_map *isl_map_convex_hull(struct isl_map *map)
        }
 
        convex_hull = isl_basic_map_overlying_set(bset, model);
+       if (!convex_hull)
+               return NULL;
 
        ISL_F_SET(convex_hull, ISL_BASIC_MAP_NO_IMPLICIT);
        ISL_F_SET(convex_hull, ISL_BASIC_MAP_ALL_EQUALITIES);
@@ -1889,6 +1956,19 @@ struct isl_basic_set *isl_set_convex_hull(struct isl_set *set)
                isl_map_convex_hull((struct isl_map *)set);
 }
 
+__isl_give isl_basic_map *isl_map_polyhedral_hull(__isl_take isl_map *map)
+{
+       isl_basic_map *hull;
+
+       hull = isl_map_convex_hull(map);
+       return isl_basic_map_remove_divs(hull);
+}
+
+__isl_give isl_basic_set *isl_set_polyhedral_hull(__isl_take isl_set *set)
+{
+       return (isl_basic_set *)isl_map_polyhedral_hull((isl_map *)set);
+}
+
 struct sh_data_entry {
        struct isl_hash_table   *table;
        struct isl_tab          *tab;
@@ -2037,7 +2117,7 @@ static int is_bound(struct sh_data *data, struct isl_set *set, int j,
 
        isl_int_clear(opt);
 
-       return res == isl_lp_ok ? 1 :
+       return (res == isl_lp_ok || res == isl_lp_empty) ? 1 :
               res == isl_lp_unbounded ? 0 : -1;
 }
 
@@ -2158,11 +2238,11 @@ static struct isl_basic_set *add_bounds(struct isl_basic_set *bset,
        for (j = 0; j < set->p[i]->n_eq; ++j) {
                for (k = 0; k < 2; ++k) {
                        isl_seq_neg(set->p[i]->eq[j], set->p[i]->eq[j], 1+dim);
-                       add_bound(bset, data, set, i, set->p[i]->eq[j]);
+                       bset = add_bound(bset, data, set, i, set->p[i]->eq[j]);
                }
        }
        for (j = 0; j < set->p[i]->n_ineq; ++j)
-               add_bound(bset, data, set, i, set->p[i]->ineq[j]);
+               bset = add_bound(bset, data, set, i, set->p[i]->ineq[j]);
        return bset;
 }
 
@@ -2244,7 +2324,7 @@ struct isl_basic_map *isl_map_simple_hull(struct isl_map *map)
        hull = isl_basic_map_overlying_set(bset, model);
 
        hull = isl_basic_map_intersect(hull, affine_hull);
-       hull = isl_basic_map_convex_hull(hull);
+       hull = isl_basic_map_remove_redundancies(hull);
        ISL_F_SET(hull, ISL_BASIC_MAP_NO_IMPLICIT);
        ISL_F_SET(hull, ISL_BASIC_MAP_ALL_EQUALITIES);