+extern void record_alias_subset (alias_set_type, alias_set_type);
+extern void record_component_aliases (tree);
+extern int alias_sets_conflict_p (alias_set_type, alias_set_type);
+extern int alias_sets_must_conflict_p (alias_set_type, alias_set_type);
+extern int objects_must_conflict_p (tree, tree);
+extern int nonoverlapping_memrefs_p (const_rtx, const_rtx, bool);