# include "irnode.h"
-/* Accessing the dominator datastructure.
+/** Accessing the dominator datastructure.
*
* These routines only work properly if the ir_graph is in state
* dom_consistent or dom_inconsistent.
+ *
+ * If the block is not reachable from Start, returns a Bad node.
*/
ir_node *get_Block_idom(ir_node *bl);
void set_Block_idom(ir_node *bl, ir_node *n);