+/**
+ * Add a node to the identities value table.
+ */
+void add_identities(pset *value_table, ir_node *node);
+
+/**
+ * Compare function for two nodes in the hash table. Gets two
+ * nodes as parameters. Returns 0 if the nodes are a cse.
+ */
+int identities_cmp(const void *elt, const void *key);
+
+/**
+ * Return the canonical node computing the same value as n.
+ * Looks up the node in a hash table, enters it in the table
+ * if it isn't there yet.
+ */
+ir_node *identify_remember(pset *value_table, ir_node *n);
+
+/** Visit each node in the value table of a graph. */
+void visit_all_identities(ir_graph *irg, irg_walk_func visit, void *env);