[tremor] A possible improvement for some of the processor where tables hit hard

[marc dukette]

would bits ever be 0? why?
----- Original Message -----
From: "Monty" <xiphmont at xiph.org>
To: <tremor at xiph.org>
Sent: Wednesday, October 16, 2002 5:22 AM
Subject: Re: [tremor] A possible improvement for some of the processor where
tables hit hard

<p>>
>
>
> On Sun, Oct 13, 2002 at 04:01:56PM -0400, marc dukette wrote:
> > I have replaced the mask table in bitwise.c with the following, and
while it
> > has little to no effect on an SA processor it does appear to help the
> > version we have running on MIPS, so it may be of value to other
processors
> > as well:
> >
> > old:
> >   unsigned long m= mask[bits];
> >
> > new:
> >   unsigned long m= (((unsigned int)-1)>>(32-bits));
> >
> > and of course you can now remove the mask table.  I'm just throwing this
> > out, not sure if it's worth adding to the standard or not.
>
> Good basic idea, but not equivalent.  In the case where bits==0...
>
> Monty
> --- >8 ----
> List archives:  http://www.xiph.org/archives/
> Ogg project homepage: http://www.xiph.org/ogg/
> To unsubscribe from this list, send a message to 'tremor-request at xiph.org'
> containing only the word 'unsubscribe' in the body.  No subject is needed.
> Unsubscribe messages sent to the list will be ignored/filtered.

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'tremor-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.