> (This is an excerpt from ping.c:in_cksum in netkit-0.10, sent to me by Petr
> Vandrovec):
>
> register u_short *w = addr;
> register int sum = 0;
> u_short answer = 0;
> ....
> *(u_char*)(&answer) = *(u_char*)w;
> sum += answer;
>
> This is a dumb way to write this.
>
> egcs-19990405 generates code that gets the right value, others (including
> egcs-1.0.3 used to build RedHat-5.2, AFAIKS) break, as they don't respect
> the initialization and put a random byte in the higher half.
>
> A better way to write the above is just:
>
> sum += *(u_char*)w;
But, isn't this a compiler bug anyway? It shouldn't ignore the initialization
in this case - actually I wonder why it would decide to.
Vojtech
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