From: Sengan Baring-Gould <sengan@seqnet.net>
  To  : ggi-develop@eskimo.com
  Date: Sat, 08 Aug 1998 21:48:44 -0600

Re: ggiGetPixelFormat and proposed new DirectBuffer scheme

Emmanuel Marty wrote:

> Sengan Baring-Gould wrote:
>
> > Hey dude... That's an Amiga Coder. You need to talk to an Atari ST coder to get
> > the best 68000 ;-)
>
> Bah, of course, the Atari was a PC w/ a 68000, so you needed to do
> everything with the CPU, so you had to optimize *duck* :-)
>
> > movep.l d0, (address)
> >
> > 24 cycles versus ( ror = 6+2n = 6 + 16 = 22 cycles, swap is 4 if I remember
> > correctly,
> > making a total of 48 CYCLES (TWICE AS MUCH) for Manu's optimized solution)
>
> Hey now, I didn't claim it was an optimized solution :) I was just illustrating
> Marcus'
> bswap explanation and similarity with m68K :) This said, I thought movep stored
> bytes noncontiguously or something ? (an instruction I never recall using on the
> amiga, but which was most useful on the ST with the fscked-up interleaved
> bitplanes words and such? :)

Shit... yes that's true, but I do remember using it for byte-swapping, and it was
faster than the above... Gee, don't code for 7 years a 68000 and you forget it all.

Oh well,


Sengan