I just compiled a custom version of gr-osmosdr and had some performance issues with new hardware.
I ran the compilation process again with
-Dhave_mfpu_neon=1 -DCMAKE_CXX_FLAGS:STRING="-Ofast -march=native -mfpu=neon-fp-armv8 -mfloat-abi=hard -funsafe-math-optimizations" -DCMAKE_C_FLAGS:STRING="-Ofast -march=native -mfpu=neon-fp-armv8 -mfloat-abi=hard -funsafe-math-optimizations" and saw performance improvements of around 30-40% less CPU load when running satnogs_fm_demod.py, which I’d say is very nice.
I’m now wondering if there are other libraries (especially GnuRadio?) which would benefit from being compiled with Raspberry Pi 3 / neon-armv8 Instructions.
I don’t think the GnuRadio-packages included in Debian/Raspbian uses these instructions, because the same packages are also used for the old ARMv6/RPi1 hardware.
Does anyone have a cross-compilation setup and could try building a more HW-specific version of GnuRadio?
I don’t really want to do that on the Pi, there are reports online stating that that takes over 48hours (poor SD card…)