isl_map_convex_hull: check for boundedness using recession cone

diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index 477ec3c..bc81e97 100644 (file)
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -161,12 +161,12 @@ error:
        return -1;
 }
 
-/* Check if "c" is a direction with both a lower bound and an upper
- * bound in "set" that is independent of the previously found "n"
+/* Check if "c" is a direction that is independent of the previously found "n"
  * bounds in "dirs".
  * If so, add it to the list, with the negative of the lower bound
  * in the constant position, i.e., such that c corresponds to a bounding
  * hyperplane (but not necessarily a facet).
+ * Assumes set "set" is bounded.
  */
 static int is_independent_bound(struct isl_ctx *ctx,
        struct isl_set *set, isl_int *c,
@@ -195,11 +195,6 @@ static int is_independent_bound(struct isl_ctx *ctx,
                }
        }
 
-       isl_seq_neg(dirs->row[n] + 1, dirs->row[n] + 1, dirs->n_col - 1);
-       is_bound = uset_is_bound(ctx, set, dirs->row[n], dirs->n_col);
-       isl_seq_neg(dirs->row[n] + 1, dirs->row[n] + 1, dirs->n_col - 1);
-       if (is_bound != 1)
-               return is_bound;
        is_bound = uset_is_bound(ctx, set, dirs->row[n], dirs->n_col);
        if (is_bound != 1)
                return is_bound;
@@ -997,10 +992,34 @@ static struct isl_basic_set *uset_convex_hull_wrap_with_bounds(
 
        return convex_hull;
 error:
+       isl_mat_free(set->ctx, bounds);
        isl_set_free(set);
        return NULL;
 }
 
+static int isl_basic_set_is_bounded(struct isl_basic_set *bset)
+{
+       struct isl_tab *tab;
+       int bounded;
+
+       tab = isl_tab_from_recession_cone((struct isl_basic_map *)bset);
+       bounded = isl_tab_cone_is_bounded(bset->ctx, tab);
+       isl_tab_free(bset->ctx, tab);
+       return bounded;
+}
+
+static int isl_set_is_bounded(struct isl_set *set)
+{
+       int i;
+
+       for (i = 0; i < set->n; ++i) {
+               int bounded = isl_basic_set_is_bounded(set->p[i]);
+               if (!bounded || bounded < 0)
+                       return bounded;
+       }
+       return 1;
+}
+
 /* Compute the convex hull of a set without any parameters or
  * integer divisions.  Depending on whether the set is bounded,
  * we pass control to the wrapping based convex hull or
@@ -1011,7 +1030,7 @@ static struct isl_basic_set *uset_convex_hull(struct isl_set *set)
 {
        int i;
        struct isl_basic_set *convex_hull = NULL;
-       struct isl_mat *bounds;
+       struct isl_mat *bounds = NULL;
 
        if (isl_set_n_dim(set) == 0)
                return convex_hull_0d(set);
@@ -1031,14 +1050,13 @@ static struct isl_basic_set *uset_convex_hull(struct isl_set *set)
        if (isl_set_n_dim(set) == 1)
                return convex_hull_1d(set->ctx, set);
 
+       if (!isl_set_is_bounded(set))
+               return uset_convex_hull_elim(set);
+
        bounds = independent_bounds(set->ctx, set);
        if (!bounds)
                goto error;
-       if (bounds->n_row == isl_set_n_dim(set))
-               return uset_convex_hull_wrap_with_bounds(set, bounds);
-       isl_mat_free(set->ctx, bounds);
-
-       return uset_convex_hull_elim(set);
+       return uset_convex_hull_wrap_with_bounds(set, bounds);
 error:
        isl_set_free(set);
        isl_basic_set_free(convex_hull);