list of @c idom. */
struct ir_node *first; /**< The first node in the list of nodes
this nodes dominates immediately. */
- int tree_pre_num; /**< The pre-order number from a dfs walk
+ unsigned tree_pre_num; /**< The pre-order number from a dfs walk
over the dominator tree. */
- int max_subtree_pre_num; /**< The largest tree pre num found in the
+ unsigned max_subtree_pre_num; /**< The largest tree pre num found in the
dominator subtree of this node. */
int pre_num; /**< pre-order graph-walk number */
int dom_depth; /**< depth in dominator-tree */