isl_map_intersect_domain: avoid useless double reverse

Implementing isl_map_intersect_domain in terms of isl_map_intersect_range
was easier than a proper implementation, but the two calls to
isl_map_reverse can lead to needless inefficiencies.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_map.c b/isl_map.c
index 5ad2364..0b3af21 100644 (file)
--- a/isl_map.c
+++ b/isl_map.c
@@ -6519,24 +6519,20 @@ struct isl_set *isl_set_union(struct isl_set *set1, struct isl_set *set2)
                isl_map_union((struct isl_map *)set1, (struct isl_map *)set2);
 }
 
-static __isl_give isl_map *map_intersect_range(__isl_take isl_map *map,
-       __isl_take isl_set *set)
+/* Apply "fn" to pairs of elements from "map" and "set" and collect
+ * the results.
+ *
+ * "map" and "set" are assumed to be compatible and non-NULL.
+ */
+static __isl_give isl_map *map_intersect_set(__isl_take isl_map *map,
+       __isl_take isl_set *set,
+       __isl_give isl_basic_map *fn(__isl_take isl_basic_map *bmap,
+               __isl_take isl_basic_set *bset))
 {
        unsigned flags = 0;
        struct isl_map *result;
        int i, j;
 
-       if (!map || !set)
-               goto error;
-
-       if (!isl_space_match(map->dim, isl_dim_param, set->dim, isl_dim_param))
-               isl_die(set->ctx, isl_error_invalid,
-                       "parameters don't match", goto error);
-
-       if (!isl_map_compatible_range(map, set))
-               isl_die(set->ctx, isl_error_invalid,
-                       "incompatible spaces", goto error);
-
        if (isl_set_plain_is_universe(set)) {
                isl_set_free(set);
                return map;
@@ -6548,20 +6544,31 @@ static __isl_give isl_map *map_intersect_range(__isl_take isl_map *map,
 
        result = isl_map_alloc_space(isl_space_copy(map->dim),
                                        map->n * set->n, flags);
-       if (!result)
-               goto error;
-       for (i = 0; i < map->n; ++i)
+       for (i = 0; result && i < map->n; ++i)
                for (j = 0; j < set->n; ++j) {
                        result = isl_map_add_basic_map(result,
-                           isl_basic_map_intersect_range(
-                               isl_basic_map_copy(map->p[i]),
-                               isl_basic_set_copy(set->p[j])));
+                                       fn(isl_basic_map_copy(map->p[i]),
+                                           isl_basic_set_copy(set->p[j])));
                        if (!result)
-                               goto error;
+                               break;
                }
+
        isl_map_free(map);
        isl_set_free(set);
        return result;
+}
+
+static __isl_give isl_map *map_intersect_range(__isl_take isl_map *map,
+       __isl_take isl_set *set)
+{
+       if (!map || !set)
+               goto error;
+
+       if (!isl_map_compatible_range(map, set))
+               isl_die(set->ctx, isl_error_invalid,
+                       "incompatible spaces", goto error);
+
+       return map_intersect_set(map, set, &isl_basic_map_intersect_range);
 error:
        isl_map_free(map);
        isl_set_free(set);
@@ -6574,11 +6581,28 @@ __isl_give isl_map *isl_map_intersect_range(__isl_take isl_map *map,
        return isl_map_align_params_map_map_and(map, set, &map_intersect_range);
 }
 
-struct isl_map *isl_map_intersect_domain(
-               struct isl_map *map, struct isl_set *set)
+static __isl_give isl_map *map_intersect_domain(__isl_take isl_map *map,
+       __isl_take isl_set *set)
+{
+       if (!map || !set)
+               goto error;
+
+       if (!isl_map_compatible_domain(map, set))
+               isl_die(set->ctx, isl_error_invalid,
+                       "incompatible spaces", goto error);
+
+       return map_intersect_set(map, set, &isl_basic_map_intersect_domain);
+error:
+       isl_map_free(map);
+       isl_set_free(set);
+       return NULL;
+}
+
+__isl_give isl_map *isl_map_intersect_domain(__isl_take isl_map *map,
+       __isl_take isl_set *set)
 {
-       return isl_map_reverse(
-               isl_map_intersect_range(isl_map_reverse(map), set));
+       return isl_map_align_params_map_map_and(map, set,
+                                               &map_intersect_domain);
 }
 
 static __isl_give isl_map *map_apply_domain(__isl_take isl_map *map1,