[FFmpeg-devel] [PATCH] ffvorbis, better L1 cache use and simplification of code

Michael Niedermayer michaelni
Mon Sep 29 18:29:22 CEST 2008

On Mon, Sep 29, 2008 at 11:16:05AM +0300, Siarhei Siamashka wrote:
> Hi,
> Interleaved forward/backward channels processing in order to increase chances
> of stepping on already cached data for the cores with extremely small data
> cache. Ensure that IMDCT per-rotation does not introduce cache write misses
> (write misses on random memory accesses are bad for ARM cores with no
> write-allocate cache as they prevent combining data in the write buffer).
> ARM11 with 32K of L1 data cache (no L2) shows performance improvement in the
> range 0.5-1% which is not so bad considering that IMDCT/IFFT and also many
> other important dsputil functions are not assembly optimized for it yet.
> According to cachegrind simulation, there might be also some improvement for
> x86 cores with 16K of L1 data cache (decrease of the number of cache misses
> is most visible in this configuration).

patch looks ok

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
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