Mail Archives: djgpp/2000/04/18/13:49:55
Alexei A. Frounze wrote:
>Dieter Buerssner wrote:
>> Alexei A. Frounze wrote:
>>
>> >3. Dieter, I hope you won't try to convert span() to plane C. :)
>> ^^^^^
>> (Nice misspelling. With optimizing plane C-compiler, you shouldn't
>> need any assembly for 3d graphics ;)
>
>So why Doom,Quake,... and Allegro have ASM???
I made a joke. I am no native English speaker (neither are you).
Perhaps, the joke was bad/wrong. Don't you see, that a plane C
(not *plain*), should be able to texture planes quite efficiently.
I just thought, this was a *nice* misspelling.
>> > };
>> ^
>> Why this semicolon? The same thing I see everywhere in your sources.
>
>Do you think this semicolon makes something slower?
No. But why the semicolon. It seems highly unconventional to me.
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>And they differ. 57 vs 70. Is it an improvement???
I don't doubt your numbers at all. Perhaps in my configuration, the
speed is limited by the access to the screen, and not in your config.
But it is clear, that the interface change (pointers vs. integer)
could make a small difference. When you call span(..., &u1, &u2, ...),
gcc most probably will not be able to hold u1 and u2 in registers.
I already said, that your ASM for span looks highly optimized,
so I was really surprised by my findings. It may also be a
BUG in my CPU, or a cache issue. Your version unrolls by an higher
factor.
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