+/* If there is an edge from the given source to the given destination
+ * of any type then return this edge.
+ * Otherwise, return NULL.
+ */
+static struct isl_sched_edge *graph_find_any_edge(struct isl_sched_graph *graph,
+ struct isl_sched_node *src, struct isl_sched_node *dst)
+{
+ enum isl_edge_type i;
+ struct isl_sched_edge *edge;
+
+ for (i = isl_edge_first; i <= isl_edge_last; ++i) {
+ edge = graph_find_edge(graph, i, src, dst);
+ if (edge)
+ return edge;
+ }
+
+ return NULL;
+}
+
+/* Remove the given edge from all the edge_tables that refer to it.
+ */
+static void graph_remove_edge(struct isl_sched_graph *graph,
+ struct isl_sched_edge *edge)
+{
+ isl_ctx *ctx = isl_map_get_ctx(edge->map);
+ enum isl_edge_type i;
+
+ for (i = isl_edge_first; i <= isl_edge_last; ++i) {
+ struct isl_hash_table_entry *entry;
+
+ entry = graph_find_edge_entry(graph, i, edge->src, edge->dst);
+ if (!entry)
+ continue;
+ if (entry->data != edge)
+ continue;
+ isl_hash_table_remove(ctx, graph->edge_table[i], entry);
+ }
+}
+
+/* Check whether the dependence graph has any edge
+ * between the given two nodes.
+ */
+static int graph_has_any_edge(struct isl_sched_graph *graph,
+ struct isl_sched_node *src, struct isl_sched_node *dst)
+{
+ enum isl_edge_type i;
+ int r;
+
+ for (i = isl_edge_first; i <= isl_edge_last; ++i) {
+ r = graph_has_edge(graph, i, src, dst);
+ if (r < 0 || r)
+ return r;
+ }
+
+ return r;
+}
+
+/* Check whether the dependence graph has a validity edge
+ * between the given two nodes.
+ */
+static int graph_has_validity_edge(struct isl_sched_graph *graph,
+ struct isl_sched_node *src, struct isl_sched_node *dst)
+{
+ return graph_has_edge(graph, isl_edge_validity, src, dst);
+}
+