Maybe is that because you have missed the start of the discussion, where I've said :
(...)Therefore if you dig into the A8 arm documentation > CortexA_ProgGuide.pdf that you can easily download from Arm website ( > free account is required) as the question was about Angstrom only, and I was refering to the Arm documentation you will find : > *Floating-point code generation* > *neon + hard = VFPv3 and Advanced SIMD code, where the floating-point and > SIMD types use the hardware FP registers > * >From my understanding Neon and vfp have a tight relationship, they even use the same registers. Anyway the compiler is free to use any NEON or VFPv3 registers for floating-point values. Nevertheless, I could eventually misunderstanding the documentation, please then let me know. Le mercredi 30 octobre 2013 15:53:29 UTC+1, RobertCNelson a écrit : > > On Wed, Oct 30, 2013 at 9:42 AM, dlewin555 <[email protected]<javascript:>> > wrote: > > I think that it can be -at worst -ambiguous, not so wrong: let me resay > it : > > > > "Nevertheless,the only reference to the fp operation context switch cost > > I've found is related to the VFP which we don't use ONLY with the Sitara > > under Angstrom" as we are talking about hardfloat and softfloat , vfpv3 > is > > not used as is ( read soft/softfp) . when hard for gcc option is used > this > > implies neon : then your code will be VFP3 and SIMD codes. > > Hope this is clearer. > > "hard" with gcc doesn't actually imply neon either.. > > 'armhf' in ubuntu/debian is actually built for "--with-fpu=vfpv3-d16 > --with-float=hard --with-mode=thumb" which allows "non-neon" > implementations (such as the tegra2 and one marvel chip) to use it. > > Whereas Angstrom for the beagle has always used the full floating > point resources as the omap/sitara parts from TI have the full 32 > register vfpv3 with neon implementation.. > > Regards, > > -- > Robert Nelson > http://www.rcn-ee.com/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
