set_using_visited(current_ir_graph);
inc_irg_visited(current_ir_graph);
nodes_touched = irg_walk_2(node, pre, post, env);
clear_using_visited(current_ir_graph);
set_using_visited(current_ir_graph);
inc_irg_visited(current_ir_graph);
nodes_touched = irg_walk_2(node, pre, post, env);
clear_using_visited(current_ir_graph);