[PATCH 4/4] arm: Support VFP-D32 and Neon

[Sebastian Huber]

On 05/08/2013 07:39 PM, Claus, Ric wrote:
> Do all tasks pay the cost of context switching the FP context in this scheme, or just those tasks that are marked FP?  If there is only one FP task and many non-FP tasks in the system, is the FP context ever switched?

All tasks and interrupts can use floating point operations.  The thread switch 
overhead is not that high (64 bytes to save/restore).  The interrupt entry and 
exit latency might be noticeable (196 bytes to save/restore).  Everything has 
its price.  In theory it is possible to implement a lazy floating point context 
switching, but this is quite complex and I don't have the resources to 
implement it.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.