Bug#738981: Fwd: Bug#738981: Switch to use generic_fpu for ARM

[Thomas Orgis]

Am Tue, 4 Mar 2014 11:10:25 -0300
schrieb Felipe Sateler <fsateler at debian.org>: 

> #decoder        t_s16/s t_f32/s
> ARM     86.26   90.66
> generic 102.80  100.06
> generic_dither  121.10  100.84

Yes, a difference, but aguably a lot less than comparing VPU code to
NEON. With the feature to produce float output from all decoders, it is
your (debian's) option to prefer decoding speed by building a libmpg123
with arm_nofpu and use it on armhf machines without NEON via the
library loading mechanism. Or you decide for offering "proper" floating
point output that needs some 25-50 % more CPU time.

I am even more interested in a comparison with the runtime of madplay
in that configuration. Perhaps its fixed-point math with 24 bit output
is still faster than using the VFP with mpg123. Of course, I'd be
interested to know if that's not the case (mpg123 rulez!;-). But if it
is, it wouldn't totally surprise me.


Alrighty then,

Thomas

PS: You still have to decide for --enable-int-quality or not, for a
smaller impact on CPU time and basically one bit of precision.
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