Re: [avr-gcc-list] 8-bit return values again

[Wouter van Gulik]

Dusan Ferbas schreef:
> Hi guys,
>
> when I searched this list for "8-bit return values", I found 2 threads. 
> Described snippets seems to me more about switch/case & expression 
> optimization:
> http://lists.gnu.org/archive/html/avr-gcc-list/2003-06/msg00000.html
> http://lists.gnu.org/archive/html/avr-gcc-list/2003-06/msg00005.html
>
> ------------------
> I want to solve case, when a function is declared as u_char(char, int8, 
> etc.). It is compiled in a way, that it returns a value in the R24,R25 
> register pair. This is true not only with literals (see example below), 
> but also with byte variables. R25 value is never used in a calling code 
> (see assembler listing below).
>
> Any idea ? Any plans for resolving this ?

It seems that (at least some of) this is fixed in gcc 4.3.0
I currently don't have acces to 4.3.0 but Eric Weddington has, and his 
assembler output shows no clr r25. See:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33050

I don't know if this is always the case or just a lucky example.

HTH

Wouter