+/**
+ * Checks if the irn is a non-interfering argument of a node which 'is_optimizable'
+ */
+int co_is_optimizable_arg(const copy_opt_t *co, ir_node *irn);
+
+/**
+ * Computes the costs of a copy according to loop depth
+ * @param pos: the argument position of arg in the root arguments
+ * @return Must be >= 0 in all cases.
+ */
+int co_get_costs_loop_depth(ir_node *root, ir_node* arg, int pos);
+
+/**
+ * All costs equal 1. Using this will reduce the _number_ of copies.
+ * @return Must be >= 0 in all cases.
+ */
+int co_get_costs_all_one(ir_node *root, ir_node* arg, int pos);