[vorbis-dev] int or float?

[Pattara Kiatisevi]

Hi Vorbis,

Now I get libvorbis-rc3 + integerized mdct_backward + integerized window
running. The sound output is ok. Now we have to go further on possible
optimization of the code in order to have the music played realtime on
our chip (LEON-Sparc). There are 2 possible ways:

1.Make everything integer, remove all floating point usage. Then we can
remove FPU and can run the chip at higher frequency, let's say 33 MHz (now
FPU limits the speed to be at only 25 MHz), then we achieve immediately
30% performance gain.

2.Keep the floating point code, and run with FPU at 25 MHz, then find
other ways to optimize the code. Maybe running with FPU is even faster
than Integer running at higher speed.

I'm not sure if 1) is possible (and if it is very difficult). And if it is
possible, is it really beneficial (as it is mentioned that FPU is somehow
faster esp. for multiplication than integer)? Thank you for all
suggestion.

Greeting from the south of Germany,
Pattara


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Ott Pattara Kiatisevi 				   T L W G
M.Sc. INFOTECH Student, Stuttgart, Germany	http://linux.thai.net/
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