return NULL;
}
-/* After computing the rational affine hull (by detecting the implicit
- * equalities), we remove all equalities found so far, compute
- * the integer affine hull of what is left, and then add the original
- * equalities back in.
+/* Look for all equalities satisfied by the integer points in bmap
+ * that are independent of the equalities already explicitly available
+ * in bmap.
+ *
+ * We first remove all equalities already explicitly available,
+ * then look for additional equalities in the reduced space
+ * and then transform the result to the original space.
+ * The original equalities are _not_ added to this set. This is
+ * the responsibility of the calling function.
+ * The resulting basic set has all meaning about the dimensions removed.
+ * In particular, dimensions that correspond to existential variables
+ * in bmap and that are found to be fixed are not removed.
*
- * The integer affine hull is constructed by successively looking
+ * The additional equalities are obtained by successively looking for
* a point that is affinely independent of the points found so far.
* In particular, for each equality satisfied by the points so far,
- * we check if there is any point on the corresponding hyperplane
- * shifted by one (in either direction).
+ * we check if there is any point on a hyperplane parallel to the
+ * corresponding hyperplane shifted by at least one (in either direction).
*/
-struct isl_basic_map *isl_basic_map_affine_hull(struct isl_basic_map *bmap)
+static struct isl_basic_set *equalities_in_underlying_set(
+ struct isl_basic_map *bmap)
{
int i, j;
struct isl_mat *T2 = NULL;
struct isl_ctx *ctx;
unsigned dim;
- bmap = isl_basic_map_implicit_equalities(bmap);
- if (!bmap)
- return NULL;
- ctx = bmap->ctx;
- if (bmap->n_ineq == 0)
- return bmap;
-
- if (F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL)) {
- bmap = isl_basic_map_cow(bmap);
- isl_basic_map_free_inequality(bmap, bmap->n_ineq);
- return bmap;
- }
-
- bset = isl_basic_map_underlying_set(isl_basic_map_copy(bmap));
+ bset = isl_basic_map_underlying_set(bmap);
bset = isl_basic_set_remove_equalities(bset, NULL, &T2);
+ if (!bset)
+ goto error;
+ ctx = bset->ctx;
sample = isl_basic_set_sample(isl_basic_set_copy(bset));
- hull = isl_basic_set_from_vec(ctx, sample);
+ if (!sample)
+ goto error;
+ if (sample->size == 0) {
+ isl_vec_free(ctx, sample);
+ hull = isl_basic_set_empty_like(bset);
+ } else
+ hull = isl_basic_set_from_vec(ctx, sample);
dim = isl_basic_set_n_dim(bset);
for (i = 0; i < dim; ++i) {
struct isl_basic_set *point;
+ if (F_ISSET(hull, ISL_BASIC_SET_EMPTY))
+ break;
for (j = 0; j < hull->n_eq; ++j) {
point = outside_point(ctx, bset, hull->eq[j], 1);
if (!point)
break;
hull = affine_hull(hull, point);
}
+ isl_basic_set_free(bset);
+ if (T2)
+ hull = isl_basic_set_preimage(ctx, hull, T2);
+ return hull;
+error:
+ isl_mat_free(ctx, T2);
isl_basic_set_free(bset);
- bset = NULL;
+ isl_basic_set_free(hull);
+ return NULL;
+}
+
+/* Detect and make explicit all equalities satisfied by the (integer)
+ * points in bmap.
+ */
+struct isl_basic_map *isl_basic_map_detect_equalities(
+ struct isl_basic_map *bmap)
+{
+ int i, j;
+ struct isl_basic_set *hull = NULL;
+
+ if (!bmap)
+ return NULL;
+ if (bmap->n_ineq == 0)
+ return bmap;
+ if (F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
+ return bmap;
+ if (F_ISSET(bmap, ISL_BASIC_MAP_ALL_EQUALITIES))
+ return bmap;
+ if (F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL))
+ return isl_basic_map_implicit_equalities(bmap);
+
+ hull = equalities_in_underlying_set(isl_basic_map_copy(bmap));
+ if (!hull)
+ goto error;
+ bmap = isl_basic_map_extend_dim(bmap, isl_dim_copy(bmap->dim), 0,
+ hull->n_eq, 0);
+ for (i = 0; i < hull->n_eq; ++i) {
+ j = isl_basic_map_alloc_equality(bmap);
+ if (j < 0)
+ goto error;
+ isl_seq_cpy(bmap->eq[j], hull->eq[i],
+ 1 + isl_basic_set_total_dim(hull));
+ }
+ isl_basic_set_free(hull);
+ F_SET(bmap, ISL_BASIC_MAP_NO_IMPLICIT | ISL_BASIC_MAP_ALL_EQUALITIES);
+ bmap = isl_basic_map_simplify(bmap);
+ return isl_basic_map_finalize(bmap);
+error:
+ isl_basic_set_free(hull);
+ isl_basic_map_free(bmap);
+ return NULL;
+}
+
+/* After computing the rational affine hull (by detecting the implicit
+ * equalities), we compute the additional equalities satisfied by
+ * the integer points (if any) and add the original equalities back in.
+ */
+struct isl_basic_map *isl_basic_map_affine_hull(struct isl_basic_map *bmap)
+{
+ struct isl_basic_set *hull = NULL;
+
+ bmap = isl_basic_map_implicit_equalities(bmap);
+ if (!bmap)
+ return NULL;
+ if (bmap->n_ineq == 0)
+ return bmap;
+
+ if (F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL)) {
+ bmap = isl_basic_map_cow(bmap);
+ isl_basic_map_free_inequality(bmap, bmap->n_ineq);
+ return bmap;
+ }
+
+ hull = equalities_in_underlying_set(isl_basic_map_copy(bmap));
+ if (!hull)
+ goto error;
+
bmap = isl_basic_map_cow(bmap);
if (!bmap)
goto error;
isl_basic_map_free_inequality(bmap, bmap->n_ineq);
- if (T2)
- hull = isl_basic_set_preimage(ctx, hull, T2);
bmap = isl_basic_map_intersect(bmap,
isl_basic_map_overlying_set(hull,
isl_basic_map_copy(bmap)));
return isl_basic_map_finalize(bmap);
error:
- isl_mat_free(ctx, T2);
- isl_basic_set_free(bset);
isl_basic_set_free(hull);
isl_basic_map_free(bmap);
return NULL;
projects / platform / upstream / isl.git / blobdiff