[Ffmpeg-devel] [PATCH] (somewhat) optimized C aes 128 bit

Michael Niedermayer michaelni
Sun Jan 14 14:57:46 CET 2007


Hi

On Sun, Jan 14, 2007 at 01:03:40PM +0100, Reimar D?ffinger wrote:
> Hello,
> even though Michael already started with a more generic implementation I
> want to propose this since I did quite a bit of optimizations (not all
> benchmarked though).
> Main bottleneck seems to be SUBSTSHIFTROWS, for which I have no idea how
> to optimize it further right now in C.
> SSE shuffle instruction could probably be very useful to optimize the
> shifting, but the invsubst table lookup still seems not nice - except
> maybe by using a 64k size table and thus always looking up two at once...

cant the substitution stuff be merged into the multbl? i think it should
be possible ...

and feel free to commit your aes128.c we can always svn remove it later
in case we agree that my code is better ...

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

I count him braver who overcomes his desires than him who conquers his
enemies for the hardest victory is over self. -- Aristotle
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