extern int subreg_realpart_p (rtx);
extern void reverse_comparison (rtx);
extern void set_new_first_and_last_insn (rtx, rtx);
-extern void set_new_first_and_last_label_num (int, int);
extern void set_new_last_label_num (int);
extern void unshare_all_rtl_again (rtx);
extern void unshare_all_rtl_in_chain (rtx);