+/**
+ * Optimize CopyB(mem, x, x) into a Nop
+ */
+static ir_node *equivalent_node_CopyB(ir_node *n)
+{
+ ir_node *a = get_CopyB_dst(n);
+ ir_node *b = get_CopyB_src(n);
+
+ if (a == b) {
+ /* Turn CopyB into a tuple (mem, bad, bad) */
+ ir_node *mem = get_CopyB_mem(n);
+ turn_into_tuple(n, pn_CopyB_max);
+ set_Tuple_pred(n, pn_CopyB_M, mem);
+ set_Tuple_pred(n, pn_CopyB_X_except, new_Bad()); /* no exception */
+ set_Tuple_pred(n, pn_Call_M_except, new_Bad());
+ }
+ return n;
+}
+