PERLVAR(Ibitcount, char *)
#ifdef USE_THREADS
-PERLVAR(Ithr_key, perl_key) /* For per-thread struct perl_thread* */
PERLVAR(Isv_mutex, perl_mutex) /* Mutex for allocating SVs in sv.c */
PERLVAR(Ieval_mutex, perl_mutex) /* Mutex for doeval */
PERLVAR(Ieval_cond, perl_cond) /* Condition variable for doeval */