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

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


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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