<? $sem = sem_get(999); ?>

This results in the following error on AIX 4.2:

Warning: semctl(SETVAL) failed for key 0x3e7: Result too large in /home/nsadmin/apache/htdocs/a.php on line 1

This is because of the following system call in functions/sysvsem.c:

semctl(semid, SYSVSEM_SEM, SETVAL, &max_acquire)

AIX's semctl expects the SETVAL value to be passed directly as the fourth argument, not indirectly via pointer.

The fix is very simple; just replace the code that reads

#if HAVE_SEMUN
...
#else
...
#endif

with

#if defined(_AIX)
...  /* same as #else case, but remove ampersand before max_acquire */
#elif HAVE_SEMUN
...
#else
...
#endif

The fix is trivial, but I'd be happy to submit a patch if necessary.