-int (sched_get_time_step)(const ir_node *irn);
-int (sched_has_next)(const ir_node *irn);
-int (sched_has_prev)(const ir_node *irn);
-ir_node *(sched_next)(const ir_node *irn);
-ir_node *(sched_prev)(const ir_node *irn);
-ir_node *(sched_first)(const ir_node *block);
-ir_node *(sched_last)(const ir_node *block);
-ir_node *(sched_add_before)(ir_node *before, ir_node *irn);
-ir_node *(sched_add_after)(ir_node *before, ir_node *irn);
-void (sched_remove)(ir_node *irn);
+/**
+ * returns the time step of a node. Each node in a block has a timestep
+ * unique to that block. a node schedule before another node has a lower
+ * timestep than this node.
+ */
+int have_sched_info(const ir_graph *irg);
+int sched_get_time_step(const ir_node *irn);
+int sched_has_next(const ir_node *irn);
+int sched_has_prev(const ir_node *irn);
+int sched_is_scheduled(const ir_node *irn);
+ir_node *sched_next(const ir_node *irn);
+ir_node *sched_prev(const ir_node *irn);
+ir_node *sched_first(const ir_node *block);
+ir_node *sched_last(const ir_node *block);
+void sched_add_before(const ir_node *before, const ir_node *irn);
+void sched_add_after(const ir_node *after, const ir_node *irn);
+void sched_init_block(const ir_node *block);
+void sched_reset(const ir_node *node);
+void sched_remove(const ir_node *irn);