> > Here's where the in-line assembler pays off:
> >
> > link a6,#0
> > move.l d3,-(sp)
> > move.b 8(a6),d1
> > moveq #0,d0
> > moveq #7,d3
> > 1$ lsr.b d1
> > lsl.b d0
> > dbra.b d3,1$
> > move.l (sp)+,d3
> > unlk a6
> > rts
> >
> > The lsr, lsl, and dbra instructions all fit into the instruction fetch
> > registers, and so once they fetched from memory the first time, the
> > remainder of the loop runs with NO memory cycles!
>
> D2 is also a scratch register. Use it instead of D3, and you don't have to save
> or restore D3. And as long as you're using inline assembly, you might as well
> get rid of those LINK and UNLK statements.
True. I left those in because I didn't want to bother with
recalculating the stack references in my head, just for the sake of the
example.
> Not that any program would be better for these changes... :-)
Maybe not better from a performance or maintenance point of view, but
it sure is prettier :-)
--
Roger Chaplin
<[EMAIL PROTECTED]>
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