+extern int references_value_p (const_rtx, int);
+extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
+typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
+extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int,
+ cselib_expand_callback, void *);
+extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int,
+ cselib_expand_callback, void *);