fast arefs

[Dan Aronson <Dan@think.com>]

Does anyone know how to do really fast arefs on the lispm (even faster than
sys:array-register).  I have complete control over my arrays, I can wire
them down if necessary.  

I have found sys:%make-pointer-offset and
sys:%p-contents-increment-pointer, which probably play a role, but I don't
know how to use them.  Has anyone had any experience trying to do this?

--Dan Aronson
(dan@think.com)