* Make a new Perm node.
*/
ir_node *be_new_Perm(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, int arity, ir_node *in[]);
+
+/**
+ * Reduce a Perm.
+ * Basically, we provide a map to remap the Perm's arguments. If an entry in the
+ * map is -1, the argument gets deleted.
+ * This function takes care, that the register data and the input array reflects
+ * the changes described by the map.
+ * This is needed by the Perm optimization/movement in belower.c, see push_through_perm().
+ * @param perm The perm node.
+ * @param new_size The new number of arguments (must be smaller or equal to the current one).
+ * @param map A map assigning each operand a new index (or -1 to indicate deletion).
+ */
+void be_Perm_reduce(ir_node *perm, int new_size, int *map);
+
/**
* Create a new MemPerm node.
*/