-/** Set predecessor n */
-void set_irn_out(ir_node *node, int pos, ir_node *out);
+/**
+ * Get the User and its input position from the Def-Use edge of def
+ * at position pos.
+ */
+ir_node *get_irn_out_ex(const ir_node *def, int pos, int *in_pos);
+
+/**
+ * Set the User at position pos.
+ *
+ * @param def the Def node
+ * @param pos the number of the Def-Use edge tat is modified
+ * @param use the Use node
+ * @param in_pos the number of the corresponding Use-Def edge in the use node in array
+ */
+void set_irn_out(ir_node *def, int pos, ir_node *use, int in_pos);