> Actually, I lie, there is one *very* useful application for "sublw" and that
> is to negate the value in "w" and that's done by:
>
>   sublw 0                               ;  Negate the value in "w"

Actually, even this isn't all that useful when you consider that even on
the '5x parts you can do the same thing with:

        addwf   31,w
        subwf   31,w

nb: I was trying to find the shortest instruction sequence for this, so I
wrote a QBASIC program to try all sequences of 6 or less; when this one
popped out, I thought my program was broken until I checked it out and it
actually worked!