[Speex-dev] Encoder performance on ARM9

Jean-Marc Valin Jean-Marc.Valin at USherbrooke.ca
Fri May 6 14:12:24 PDT 2005


Hi llandre,

I think it's worth trying the float version on your CPU. However, I
wouldn't be surprised if the fixed-point was still faster than float.
BTW, you can use --enable-arm5-asm instead of --enable-arm4-asm. While
both are currently almost the same, eventually it would be possible to
get better performance using the ARM5E DSP-like instructions.

	Jean-Marc

> This processor integrates a so-called MaverickCrunch coprocessor.
> This coprocessor accelerates both IEEE-754 floating point and 32-bit
> and 64-bit fixed point operations. Datasheet claims it is considerable
> faster than ARM920T MAC operation.
> So we can enable/disable at least four parameters:
> 1) fixed-point implementation (--enable-fixed-point)
> 2) ARM4T assembly optimization (--enable-arm4-asm)
> 3) support for MaverickCrunch (if this is enabled, I think
> point 1 and 2 become meaningless)
> 4) command-line comp parameter
> 
> Clearly the best solution is exploiting the MaverickCrunch coprocessor.
> Assuming we have MaverickCrunch-enabled GCC e glibc, do you suggest
> to use e full floating point implementation or to use the
> --enable-fixed-point anyway?
> 
> 
> 
> Thanks in advance and best regards,
> 
> llandre
> 
> DAVE Electronics System House - R&D Department
> web:   http://www.dave-tech.it
> email: r&d2 at dave-tech.it
> 
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-- 
Jean-Marc Valin <Jean-Marc.Valin at USherbrooke.ca>
Universite de Sherbrooke



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