Re: [avr-gcc-list] avr-gcc bug

[Klaus Rotter]

On Sat, Apr 21, 2001 at 12:41:10PM -0300, Francisco T. A. Silva wrote:
> int main(void)
> {
>     unsigned int i;
>     for(i = 31533; i > 0; i--);
> }

I can verify this with an older version of avr-gcc
(gcc version 2.97 20010108 (experimental)). A much older version of avr-gcc
(2.95.2) behaves like you expected. If you want dead loops (e.g. for delay
lines), a possible solution may be to use volatile variables:

int main(void)
{  
    volatile unsigned int i;
    for(i = 31533; i > 0; i--);
}                                                                               
      > avr-gcc-list mailing list

Then you get what you expect (even with -O3):

avr-gcc -O3 -S t.c 

[...]
        ldi r24,lo8(31533)
        ldi r25,hi8(31533)
        std Y+1,r24
        std Y+2,r25
.L5:        
        sbiw r24,3        
        brne .L5
[...]

--
 Klaus Rotter * address@hidden