[Patch,avr] Implement PR56254

[Weddington, Eric]

> -----Original Message-----
> From: Georg-Johann Lay 
> Sent: Friday, February 08, 2013 5:53 AM
> To: gcc-patches@gcc.gnu.org
> Cc: Denis Chertykov; Weddington, Eric
> Subject: [Patch,avr] Implement PR56254
> 
> This adds variable delays to __builtin_avr_delay_cycles.
> 
> Is this okay?
> 

What does this do? How does it work?

Could you explain the statement in the documentation "if ticks is not a compile-time constant, the delay might be overestimated by up to 15 cycles". Why would we want to do that? I thought the whole point of a builtin delay cycles function was to have an accurate delay.

Eric