On Fri, 2011-07-15 at 16:24 -0400, Marcus D. Leech wrote: > 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.
Counterintuitively, that flag doesn't mean "use emulated fp". However, gcc is notoriously bad at vectorizing code for the NEON vfpu. The upcoming Volkification of gnuradio-core will hopefully do a lot to improve E100 performance on CPU-intensive flowgraphs. --n > > 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? > > > > > > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
