isl_map_inline_foreach_basic_map: drop basic maps that have become empty

[platform/upstream/isl.git] / isl_map.c

diff --git a/isl_map.c b/isl_map.c
index b383cfe..b0554cf 100644 (file)
--- a/isl_map.c
+++ b/isl_map.c
@@ -3220,6 +3220,8 @@ __isl_give isl_basic_map *isl_basic_map_move_dims(
        res = isl_basic_map_alloc_space(isl_basic_map_get_space(bmap),
                        bmap->n_div, bmap->n_eq, bmap->n_ineq);
        bmap = isl_basic_map_add_constraints_dim_map(res, bmap, dim_map);
+       if (!bmap)
+               goto error;
 
        bmap->dim = isl_space_move_dims(bmap->dim, dst_type, dst_pos,
                                        src_type, src_pos, n);
@@ -5329,6 +5331,39 @@ static int remove_if_empty(__isl_keep isl_map *map, int i)
        return 0;
 }
 
+/* Perform "fn" on each basic map of "map", where we may not be holding
+ * the only reference to "map".
+ * In particular, "fn" should be a semantics preserving operation
+ * that we want to apply to all copies of "map".  We therefore need
+ * to be careful not to modify "map" in a way that breaks "map"
+ * in case anything goes wrong.
+ */
+__isl_give isl_map *isl_map_inline_foreach_basic_map(__isl_take isl_map *map,
+       __isl_give isl_basic_map *(*fn)(__isl_take isl_basic_map *bmap))
+{
+       struct isl_basic_map *bmap;
+       int i;
+
+       if (!map)
+               return NULL;
+
+       for (i = map->n - 1; i >= 0; --i) {
+               bmap = isl_basic_map_copy(map->p[i]);
+               bmap = fn(bmap);
+               if (!bmap)
+                       goto error;
+               isl_basic_map_free(map->p[i]);
+               map->p[i] = bmap;
+               if (remove_if_empty(map, i) < 0)
+                       goto error;
+       }
+
+       return map;
+error:
+       isl_map_free(map);
+       return NULL;
+}
+
 struct isl_map *isl_map_fix_si(struct isl_map *map,
                enum isl_dim_type type, unsigned pos, int value)
 {