[FFmpeg-devel] [PATCH 1/9] SBR DSP x86: implement SSE qmf_pre_shuffle

Michael Niedermayer michaelni at gmx.at
Sat Apr 6 14:46:32 CEST 2013

On Sat, Apr 06, 2013 at 11:26:54AM +0200, Christophe Gisquet wrote:
> 2013/4/5 Michael Niedermayer <michaelni at gmx.at>:
> > using simpler memory indexing ([r2q + n*mmsize] and [zq])
> > and incremeanting them seperately seems 1-2 cpu cycles faster here
> In general, and most particularly here, could you provide whatever
> form (except machine code ;) of the code you tested?

it seems the speed gain of this change depends on using the slower
SSE variants of the instructions.
I suspect the extra complexity of 2 seperate ways of indexing isnt
worth the gain

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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