[tremor] [PATCH] reworked bitrev12() for better performance on ARM

Monty xiphmont at xiph.org
Wed Sep 11 21:18:27 PDT 2002



On Wed, Sep 11, 2002 at 10:38:57PM -0400, Nicolas Pitre wrote:
> 
> The current bitrev12() implementation, although quite elegant, produces 
> pretty bad ARM assembly due to the many constants larger than 8 bit wide.  
> Attached is a patch for a much faster implementation on ARM and probably 
> other processors as well.

Heh, I'd actually implemented an identical patch, but forgotton to
commit with the rest.  Literally, the only difference was I used hex
in the lookup, you used decimal :-)

This and the other patch to be applied shortly.

Monty
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