Leaf routines
Leaf routines are routines that do not call any other routines
(with the possible exception of routines that are inlined). Leaf routines
that have the following characteristics do not need to allocate a
stack frame. Such routines are called Sleaf routines and they may
use truncated prologs and epilogs:
- whose work area requirements may be obtained from the stack segment pad
- which are not vararg
- which do not perform stack frame extension
- which are not bilingual
Note: When entered at the +16 Entry Point, the value of
the NAB in the caller's DSA provides 256 bytes of pad area that can
be used by the current routine to store data into.