reversing a mask

[George Sicherman]

[Yuk!  Why would you want to eat THAT?]

> Ummm... it's easy to push the register mask when you moveml the registers
> to be saved on entry to a subroutine in the 68000, but moveml mask,(a7)-
> and moveml mask,(a7)+ expect the mask reversed from each other!  How
> do you propose to invert a 16-bit mask end-for-end (i.e. 11100...001
> <=> 100...00111 ) and still have a fast calling sequence?

What's the fastest way to reverse a 16-bit mask in C?  In 68000 asl?
(Maybe this should be in net.puzzle!)
-- 
Col. G. L. Sicherman
...seismo!rochester!rocksanne!rocksvax!sunybcs!gloria!colonel