[FFmpeg-devel] [PATCH] mpegaudio: simplify failed optimisation attempt

Michael Niedermayer michaelni
Wed May 6 03:04:30 CEST 2009

On Tue, May 05, 2009 at 06:18:44PM +0100, Mans Rullgard wrote:
> Total speedup 50% on PPC G4, 13% on ARM.
> ---
>  libavcodec/mpegaudiodec.c |   17 ++++++-----------
>  1 files changed, 6 insertions(+), 11 deletions(-)

why is it faster?
Is this a workaround for a gcc bug? If so i do not think removing
optimizations that gcc chokes on is the correct solution.
Naively SUM8P2 should be faster because it does fewer memory reads.
Also this code should be written in asm
and similar code like iqmf() in atrac3.c could maybe be factored
with it.

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
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