Using ARM/Neon fp hardware with libc

Stefan Kalkowski stefan.kalkowski at ...1...
Tue Oct 6 08:35:50 CEST 2015


Hi Bob,

On 09/30/2015 09:14 PM, robjsstewart at ...9... wrote:
> Hi all,
> I'm exploring compiling a couple of targets in my Genode, base-hw system to use the hardware fp in the Neon coprocessor on an ARM Cortex A8 SOC, to get some performance improvement. I can add the CC_OPT line containing -mfloat-abi=hard and -mfu=neon-vfpv4 to appropreate target.mk. That should result in the Neon fp unit being called to perform the calculations. If I want use libc math functions I assume I must recompile libc with the same compile options added. Are there build variables that allow me to do that to the libc library? 

I just wanted to add that currently FPU context switching is implemented
in base-hw for Cortex A9 only. It might be no big deal to enable it for
Cortex A8 by looking at the other implementation. As long as more than
one of your components uses the FPU this has to be done first.

Regards
Stefan

> 
> I'm currently building on Genode 15.02.
> 
> Thanks for any info.
> 
> Bob Stewart
> 
> Sent from my android device.
> 
> 
> 
> ------------------------------------------------------------------------------
> 
> 
> 
> _______________________________________________
> genode-main mailing list
> genode-main at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/genode-main
> 

-- 
Stefan Kalkowski
Genode Labs

http://www.genode-labs.com/ ยท http://genode.org/




More information about the users mailing list