extern bool ref_maybe_used_by_stmt_p (gimple, tree);
extern bool stmt_may_clobber_ref_p (gimple, tree);
extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
+extern tree get_continuation_for_phi (gimple, ao_ref *, bitmap *);
extern void *walk_non_aliased_vuses (ao_ref *, tree,
void *(*)(ao_ref *, tree, void *),
void *(*)(ao_ref *, tree, void *), void *);