DRA829J: warning: call to function without interrupt attribute could clobber interruptee's VFP registers; consider using the `interrupt_save_fp` attribute to prevent this behavior [-Wextra]

Hi Stanley,

If an ISR on a R5F core use floating point, do i have to save/restore the FPU Registers by myself (I do not use an OS)?
Which FPU Registers have to be saved/restored?
This will not be solved by the attribute 'interrupt_save_fp'?

Regards 
Ralph

Please see the documentation of the interrupt function attribute from the tiarmclang online manual.  Note how it states: FPU Registers are Not Automatically Preserved by Interrupt Functions.  

Internal discussion about the attribute interrupt_save_fp is still ongoing.  At this point it seems likely that the compiler will get changed to not emit this diagnostic ...

Ralph Neumann said:

call to function without interrupt attribute could clobber interruptee's VFP registers; consider using the `interrupt_save_fp` attribute to prevent this behavior [-Wextra]

... and interrupt_save_fp will continue to not be documented, and thus should not be used.  I'll get back to you on that.

Thanks and regards,

-George