Re: [Discuss-gnuradio] Performance on ARM Cortex-A8

[Marcus D. Leech]

On 07/13/2011 04:40 AM, Riadh Elloumi wrote:
> Hi all,
>
> I complied DAB demodulation for ARM Cortex-A8 (TI OMAP 3). It
> successfully demodulate DAB+ but spends 13 seconds decoding 1 second of
> radio baseband (USRP file).
>
> I used all the optimized code for Cortex-A8 like dotprod_ccf_armv7_a.c.
> My compilation flags are: -mcpu=cortex-a8 -mfloat-abi=softfp -mfpu=neon
> -O2. I used fftw-3.2.2.
What does -mfloat-abi=softfp do?  Does that cause software 
floating-point to be used?
  If it does, then your floating-point performance is going to be 
completely awful.

A good test for comparing oranges/oranges would be to construct  simple 
C program
  that does, let's say, 10e6 single-precision floating-point 
multiply/accumulate operations,
  and compare among platforms with simiilar clock speeds, etc.

> Why is gnu radio too slow demodulating DAB+? Do you have some figures of
> CPU consumption on ARM Cortex cores? Is there some optimization I missed
> for the platform?


--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org