Merry Christmas Scott and other guys. ;)

Some magic is here. ;)

;       high=a.b low=c.d

        movlw   0xF0
        andwf   low,F   ;c.0
        swapf   low,F   ;0.c

        swapf   high,F  ;b.a
        andwf   high,W  ;b.0
        xorwf   low,F   ;b.c

        swapf   high,W  ;a.b
        addwf   low,F   ;a.b+b.c

        movlw   0x0F
        andwf   high,F  ;0.a
        skpnc
        incf    high,F  ;add carry

;12 clocks/words

WBR Dmitry.

> Division by 16 is trivial:
>
>    swapf  t2h,f
>    swapf  t2l,f
>    movlw  0x0f
>    andwf  t2l,f
>    andwf  t2h,w
>    xorwf  t2h,w
>    iorwf  t2l,f
>
> ;  xorwf  t2h,f  ; not needed because of trick below
>
>    ; now add 1/16 of the above to itself
>
>    swapf  t2h,w
>    addwf  t2l,f
>    movlw  0x0f
>    andwf  t2h,f
>    skpnc
>     incf  t2h,f
>
> One more instruction then the mystical 12 barrier - suggesting there's an
> optimization lurking somewhere.

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