Re: [avr-libc-dev] [bugs #11396] Large number jumps to hyperspace

[Russell Shaw]

Joerg Wunsch wrote:
> As anonymous wrote:
>
>
> > Summary:  Large number jumps to hyperspace
>
>
> > Original Submission:  This code:
>
>
> >  uint16_t baud=9600
> >  uint16_t reg=16000000/(16*baud) - 1;
>
>
> > makes an atmega16 jump to some spurious place and crash.  Using
> > avr-libc 1.0.5 avr-gcc (GCC) 3.4.3 GNU avr-ld version 2.15
>
>
> Sounds more like a GCC bug to me.
>
> Anyway, as this code cannot `jump' at all (nothing is really
> executed), do you perhaps have a complete compilable example where
> this can be reproduced?

It's a total pain trying to find tool bugs by looking at the
asm output in a simulator. I've been looking at:

#include<inttypes.h>

int
main(void)
{
    uint16_t baud=9600;
    uint16_t reg=16000000/(16*baud) - 1;
    return 0;
}

using gcc flags to put out rtl code (it'll take me a while
to understand it).