+/** Visit each node in the value table of a graph. */
+void visit_all_identities(ir_graph *irg, irg_walk_func visit, void *env);
+
+/**
+ * Normalize a node by putting constants (and operands with larger
+ * node index) on the right (operator side).
+ *
+ * @param n The node to normalize
+ */
+void ir_normalize_node(ir_node *n);
+
+ir_node *optimize_node(ir_node *n);
+
+ir_node *optimize_in_place_2(ir_node *n);
+
+/**
+ * The value_of operation.
+ * This operation returns for every IR node an associated tarval if existing,
+ * returning tarval_bad otherwise.
+ * No calculations are done here, just a lookup.
+ */
+typedef tarval *(*value_of_func)(const ir_node *self);
+
+extern value_of_func value_of_ptr;
+
+/**
+ * Set a new value_of function.
+ *
+ * @param func the function, NULL restores the default behavior
+ */
+void set_value_of_func(value_of_func func);
+