[MPlayer-dev-eng] [PATCH] Saturation & PSWAPD bugfix in mp3lib/dct64_3dnow.c & mp3lib/dct64_k7.c

[Zuxy Meng]

Hi,

2007/3/17, Thomas Orgis <thomas-forum at orgis.org>:
> Am Fri, 7 Jul 2006 15:24:33 +0200
> schrieb Diego Biurrun <diego at biurrun.de>:
>
> > It seems to work on my K6-III.  I played an MP3 file without problems.
>
> Sorry for digging this old thing out, but Diego, did you observe any
> improvement by using the 3DNowExt compared to plain 3DNow on the
> K6-III+ (I suppose your's is a "+" one)?
> I tested the mpg123 svn where I included the mp3lib K7 code a bit on my
> own K6-III+.
> It works, but it seems like 3DNowExt is actually a bit slower than
> normal 3DNow:
>
> thomas at knecht:~/mpg123-svn$ time src/mpg123 --cpu 3dnow -q -t $one_mp3_album
> decoder: 3DNow
>
> real    2m8.520s
> user    2m6.690s
> sys     0m1.610s
>
> thomas at knecht:~/mpg123-svn$ time src/mpg123 -q -t $one_mp3_album
> decoder: 3DNowExt
>
> real    2m21.548s
> user    2m20.040s
> sys     0m1.270s
>
> Can you confirm this? Perhaps one should still select plain 3DNow even if K6-III+
> supports the extended one... or the 3DNowExt routine could be improved for
> non-athlons. I guess that the 3DNow extensions aren't necessarily bad in the K6-III+.

Did u test with a K7 or K8? If the 3DNow version is even faster on
these CPUs then I can submit a patch to use the 3DNow way for
float->int conversion for dct64_k7.c.

> On an Athlon64 (32bit), I remember that 3DNowExt improved and catched up with
> SSE (but don't have numbers now, as well as I don't remember if it was a bit faster
> or slower).

IIRC 3DNowExt is faster on Athlon XP/K8 but this shouldn't hold
anymore when K10 comes out with SSE128.

-- 
Zuxy
Beauty is truth,
While truth is beauty.
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