+ SV* accessed = *++mark;
+ SV* modified = *++mark;
+ void * utbufp = &utbuf;
+
+ /* be like C, and if both times are undefined, let the C
+ library figure out what to do. This usually means
+ "current time" */
+
+ if ( accessed == &PL_sv_undef && modified == &PL_sv_undef )
+ utbufp = NULL;
+