[Ffmpeg-cvslog] r6573 - trunk/libavcodec/cabac.h

[Michael Niedermayer]

Hi

On Sat, Oct 07, 2006 at 06:53:35PM +0300, Uoti Urpala wrote:
> On Sat, 2006-10-07 at 16:42 +0200, Michael Niedermayer wrote:
> > could you test every of the alternative asms? iam not surprised that
> > this one is slower on amd
> 
> I did overall performance benchmarks for them and they're all slower
> than the C  version. My first benchmark (under MPlayer) was with a
> --enable-debug compile, the differences were somewhat bigger with a
> default compile. The first and second alternatives (P3:683 and P3:680)
> were around 1% slower, the other 3 over 2% slower.

ive run my own tests on athlon and i cannot confirm your results, actually
gcc here turns the c code into the lea,shr,shl,shl sequence from the first
asm, the result is also running at the same speed as the c code (not 
surprising)
ive not done any overall speed tests as the code is the same and the function
itself runs at the same speed  ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is