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From: Emmanuel Marty <core@suntech.fr>
To : ggi-develop@eskimo.com
Date: Fri, 07 Aug 1998 08:29:18 +0000
Re: ggiGetPixelFormat and proposed new DirectBuffer scheme
Marcus Sundberg wrote:
> But IIRC we have some old Amiga coders (Emmanuel? ;) here with
> experience of such things, so it shouldn't be a problem, right?
Yup, I have been following the discussion somehow and didn't comment
since it was correct :)
On 68K you can do :
ror.w #8,d0 ; Exchange bits 0-7 & 8-15
swap d0 ; Exchange hi and low 16 bits
ror.w #8,d0 ; Exchange bits 0-7 & 8-15 again
Which is pretty much identical to i486 code with bswap.
On 68020 and up, the hardware barrel-shifter (like i386 and up) will make
it so that the ror executes in one cycle or so. I can do the assembler
optimizations
on i386 and m68K, that's not a problem - and Jason can do PPC ones now I s'pose
:)
--
Emmanuel
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