add isl_set_remove_divs_involving_dims

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

diff --git a/include/isl_set.h b/include/isl_set.h
index 650ae6c..3239e1d 100644 (file)
--- a/include/isl_set.h
+++ b/include/isl_set.h
@@ -281,6 +281,8 @@ struct isl_set *isl_set_eliminate_dims(struct isl_set *set,
                unsigned first, unsigned n);
 __isl_give isl_set *isl_set_remove_dims(__isl_take isl_set *bset,
        enum isl_dim_type type, unsigned first, unsigned n);
+__isl_give isl_set *isl_set_remove_divs_involving_dims(__isl_take isl_set *set,
+       enum isl_dim_type type, unsigned first, unsigned n);
 __isl_give isl_set *isl_set_remove_divs(__isl_take isl_set *set);
 __isl_give isl_set *isl_set_split_dims(__isl_take isl_set *set,
        enum isl_dim_type type, unsigned first, unsigned n);

diff --git a/isl_map.c b/isl_map.c
index b906139..ee43d40 100644 (file)
--- a/isl_map.c
+++ b/isl_map.c
@@ -1474,6 +1474,90 @@ error:
        return NULL;
 }
 
+/* Return true if the definition of the given div (recursively) involves
+ * any of the given variables.
+ */
+static int div_involves_vars(__isl_keep isl_basic_map *bmap, int div,
+       unsigned first, unsigned n)
+{
+       int i;
+       unsigned div_offset = isl_basic_map_offset(bmap, isl_dim_div);
+
+       if (isl_int_is_zero(bmap->div[div][0]))
+               return 0;
+       if (isl_seq_first_non_zero(bmap->div[div] + 1 + first, n) >= 0)
+               return 1;
+
+       for (i = bmap->n_div - 1; i >= 0; --i) {
+               if (isl_int_is_zero(bmap->div[div][1 + div_offset + i]))
+                       continue;
+               if (div_involves_vars(bmap, i, first, n))
+                       return 1;
+       }
+
+       return 0;
+}
+
+/* Remove all divs (recursively) involving any of the given dimensions
+ * in their definitions.
+ */
+__isl_give isl_basic_map *isl_basic_map_remove_divs_involving_dims(
+       __isl_take isl_basic_map *bmap,
+       enum isl_dim_type type, unsigned first, unsigned n)
+{
+       int i;
+
+       if (!bmap)
+               return NULL;
+       isl_assert(bmap->ctx, first + n <= isl_basic_map_dim(bmap, type),
+                       goto error);
+       first += isl_basic_map_offset(bmap, type);
+
+       for (i = bmap->n_div - 1; i >= 0; --i) {
+               if (!div_involves_vars(bmap, i, first, n))
+                       continue;
+               bmap = isl_basic_map_remove_dims(bmap, isl_dim_div, i, 1);
+       }
+
+       return bmap;
+error:
+       isl_basic_map_free(bmap);
+       return NULL;
+}
+
+__isl_give isl_map *isl_map_remove_divs_involving_dims(__isl_take isl_map *map,
+       enum isl_dim_type type, unsigned first, unsigned n)
+{
+       int i;
+
+       if (!map)
+               return NULL;
+       if (map->n == 0)
+               return map;
+
+       map = isl_map_cow(map);
+       if (!map)
+               return NULL;
+
+       for (i = 0; i < map->n; ++i) {
+               map->p[i] = isl_basic_map_remove_divs_involving_dims(map->p[i],
+                                                               type, first, n);
+               if (!map->p[i])
+                       goto error;
+       }
+       return map;
+error:
+       isl_map_free(map);
+       return NULL;
+}
+
+__isl_give isl_set *isl_set_remove_divs_involving_dims(__isl_take isl_set *set,
+       enum isl_dim_type type, unsigned first, unsigned n)
+{
+       return (isl_set *)isl_map_remove_divs_involving_dims((isl_map *)set,
+                                                             type, first, n);
+}
+
 __isl_give isl_basic_set *isl_basic_set_remove_dims(
        __isl_take isl_basic_set *bset,
        enum isl_dim_type type, unsigned first, unsigned n)