[Ffmpeg-devel] ac3enc.c modifications

Guillaume POIRIER poirierg
Fri May 20 09:40:19 CEST 2005


Hi,

On 5/20/05, Rich Felker <dalias at aerifal.cx> wrote:
> On Thu, May 19, 2005 at 06:15:08PM -0600, Mike Melanson wrote:
> >       How about this scenario: Both the floating point op and integer op
> >       take the same amount of time, say, 1 clock cycle. Where is the advantage
> > for integer in this case?
> 
> Well-defined results that don't vary from one cpu to the next. :)
> 
> > Especially since the code probably has to do a
> > few more maintenance operations on the integer after the operation
> > (precision scaling, whatever).
> 
> I agree, and still maintain that this is a bad cpu design. If you can
> do any floating point op in one cycle, you should be able to do 2
> integer ops per cycle (or many more :)).

Doesn't the Intel P4 already do 2 integer ops per cycle? (at least, I
know that part of the core runs at double the frequency)...
Now I wonder why I brought this up, some people here don't have a high
opinion of Intel CPUs... ;-)

Guillaume





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