Re: [avr-gcc-list] What GCC bug currently effect the AVR port of GCC?

[E. Weddington]

Joerg Wunsch wrote:

> "E. Weddington" <address@hidden> wrote:
>
>  
>
> > > One should probably add a reminder for the 16-Bit peripheral
> > > registers to update the specification and warn users when using
> > > pointers to peripheral registers. Possibly in the libc manual?
> > >      
>
>  
>
> > Yes, that would be the place. Perhaps in the FAQ. Let's see what
> > Jörg has to say.
> >    
>
> I think it even is there, still.
>
> http://uriah.heep.sax.de/avr-libc/FAQ.html#faq_port_pass
>  

Hmm. That's not a real obvious place to look. And then it's waaaay down 
at the bottom. It would probably be better off if it had it's own, 
seperate item.

> Well, it claims GCC 3.3 had been fixed for the "volatile" case.
> Strange, why has that fix been undone then?
>
>  
Even the sentence in the FAQ seems to be misleading:
-------------------------------------------------------------------------------
avr-gcc versions after 3.3 have been fixed in a way where this 
optimization will be disabled if the respective pointer variable is 
declared to be |volatile|, so the correct behaviour for 16-bit IO ports 
can be forced that way.
-------------------------------------------------------------------------------

If the premise is true, then that sentence should be reworded for clarity.

Eric