Re: [avr-gcc-list] cbr and negative numbers

[Ruud Vlaming]

On Wednesday 10 September 2008 16:01, you wrote:
> 
> > -----Original Message-----
> > However, if you activate the 8 bit integer option -mint8 
> Full halt.
> 
> -mint8 is not really supported. Yes, we know it causes all sorts of 
> problems. It should never be used. I'd really like to see it ripped 
> out of the AVR port of GCC.  

Me too. I assume you will replace it by true eight bit arithmetic?

Since we don't live in an ideal world we have to stick with mint8 
for a while. If you care to complete reading my original post
you will see that this has nothing to with the usual complaints
about mint8, most of which i am aware of. The problem i am pointing
out can (easily) be solved by letting gcc emit only positive/hexadecimal 
operands or by a minimal change in the way the cbr instruction
calculates its operand: (0xFF-x) -> (0xFF - (x & 0xFF)).
If you do not care to read it to the end, well, in any case it is known
from know on, that you cannot use the cbr instruction reliably with mint8.

Cheers
Ruud.