Re: AW: AW: AW: [avr-gcc-list] avr-gcc bug: global register variable isbroken

[Erik Christiansen]

On Thu, Dec 02, 2004 at 04:22:21PM +0100, Klaus Rudolph wrote:
> > 2.) Number of registers available for variable passing 

[snip]

> And that only every second register is used for chars seems not ok.
> There is a movw instruction which needs that kind of allocation if 16
> Bit ints are used. But this makes only sense on controllers which
> support this. And it make only sense for vars which are 16 bits or
> more I think. In my personal code every second register is gone
> whithout any usage. That is a lot for an embedded system :-)

Yes, however, the reason for this may be one of those "promotion of char
to int before processing" gotchas in the C standard. While lots of libc
functions handle chars as ints, they do so explicitly, e.g.

       int putchar(int c);

so I can only think that care has been exercised here, to observe the
standard.

Erik