RockPro64 and Neon

[rapier1]

Does it actually have neon support? I notice that it's not listed in /proc/cpuinfo. If it is supported does anyone have a good way to identify it in a configure script so I can actually build a project that supports neon? 

Thanks

Chris

[CounterPillow]

Yes, in armv8 nomenclature this is "asimd" in /proc/cpuinfo for advanced simd extensions. Your compilers will automatically pick it up, as far as I know, as it's a base feature of Armv8.0-A I believe.

The gcc manual confirms my belief here by straight up saying +simd is default on armv8-a:



So nothing special is needed in any configure script, any build for aarch64 will use simd, though auto-vectorisation might not occur on lower optimisation levels.

[rapier1]

Yes, in armv8 nomenclature this is "asimd" in /proc/cpuinfo for advanced simd extensions. Your compilers will automatically pick it up, as far as I know, as it's a base feature of Armv8.0-A I believe.

Okay, I think I know what is going on then. I've been working with the optimized poly1305 MAC code from floodyberry (github.com/floodyberry/poly1305-opt) and the problem seems to be that it just is too old to properly support armv8. Specifically in that the assembly was only written for 32bit processors. I was getting turned around buy an error message that, for some reason, made me think that it was a problem with the neon code and not the armv6 assembly. 

Thanks!