passing floats

[tkunze@mvax.kgw.tu-berlin.de (Tobias Kunze)]

I apologize that this is one of the candidates for the Lisp FAQ's, and
I remember there were discussions in this group concerned with it, but,
just to make sure: is there (or, *are* there) recommended ways to 
pass floats--that is, both, IEEE 8-byte and Apple 10-byte 'extended'
floats--back and forth easily between Lisp and C using the ff-interface.
?
I'm well aware of the some three or four functions in ff-source.lisp,
but I'm missing something like %put-xfloat and %get-xfloat to pass
arrays of extended floats to C; after all, MPW seems to treat every
'double' as extended.