isl_map_simple_hull: compute affine hull before aligning divs

Computing the affine hull may change the internal representation.
In particular, it may simplify div constraints that are added
during the alignment to constraints that did not appear in the
original set and we do not want to introduce such constraints
in the simple hull.

diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index 9430efc..be21837 100644 (file)
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -1727,26 +1727,17 @@ static struct isl_basic_set *uset_simple_hull(struct isl_set *set)
                n_ineq += 2 * set->p[i]->n_eq + set->p[i]->n_ineq;
        }
 
-       hull = isl_set_affine_hull(isl_set_copy(set));
-       if (!hull)
-               goto error;
-       hull = isl_basic_set_cow(hull),
-       hull = isl_basic_set_extend_dim(hull, isl_dim_copy(hull->dim),
-                                       0, 0, n_ineq);
+       hull = isl_basic_set_alloc_dim(isl_dim_copy(set->dim), 0, 0, n_ineq);
        if (!hull)
                goto error;
 
        data = sh_data_alloc(set, n_ineq);
        if (!data)
                goto error;
-       if (hash_basic_set(data->hull_table, hull) < 0)
-               goto error;
 
        for (i = 0; i < set->n; ++i)
                hull = add_bounds(hull, data, set, i);
 
-       hull = isl_basic_set_convex_hull(hull);
-
        sh_data_free(data);
        isl_set_free(set);
 
@@ -1766,6 +1757,7 @@ struct isl_basic_map *isl_map_simple_hull(struct isl_map *map)
        struct isl_set *set = NULL;
        struct isl_basic_map *model = NULL;
        struct isl_basic_map *hull;
+       struct isl_basic_map *affine_hull;
        struct isl_basic_set *bset = NULL;
 
        if (!map)
@@ -1782,6 +1774,7 @@ struct isl_basic_map *isl_map_simple_hull(struct isl_map *map)
        }
 
        map = isl_map_detect_equalities(map);
+       affine_hull = isl_map_affine_hull(isl_map_copy(map));
        map = isl_map_align_divs(map);
        model = isl_basic_map_copy(map->p[0]);
 
@@ -1791,6 +1784,8 @@ 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);
        ISL_F_SET(hull, ISL_BASIC_MAP_NO_IMPLICIT);
        ISL_F_SET(hull, ISL_BASIC_MAP_ALL_EQUALITIES);