RE: [avr-gcc-list] Using in/out Instructions with ATmega128

[Weddington, Eric]

> -----Original Message-----
> From: Thomas D. Dean [mailto:address@hidden 
> Sent: Monday, May 04, 2009 5:24 PM
> To: Weddington, Eric
> Subject: RE: [avr-gcc-list] Using in/out Instructions with ATmega128
> 
> On Mon, 2009-05-04 at 17:08 -0600, Weddington, Eric wrote:
> 
> > Also, you need to turn optimization on to get those IN/OUT 
> instructions. 
> > Add -Os to your compiler flags.
> 
> Thanks, "-o3" gets covered by -o <fname> later in the command stream!

No. The switches are case sensitive, just like the C language itself. You want 
to use an uppercase 'O', not lowercase. It is better if you optimize for size, 
rather than for speed. This is why it is suggested to use -Os, not -O3.

And please also reply to the list and not just to me personally.