Some tests in gcc.c-torture rely on undefined behaviour?

[Joe Buck]

On Tue, Jul 12, 2005 at 09:41:22AM -0500, Nicholas Nethercote wrote:
> I've been looking at the gcc.c-torture tests, it seems some of them rely 
> on undefined behaviour.  For example, 920612-1.c looks like this:
> 
>   f(j)int j;{return++j>0;}
>   main(){if(f((~0U)>>1))abort();exit(0);}

Wow.  It appears that it would be legal for a C compiler to optimize f() to

int f(int j) { return 1;}

since the compiler is entitled to assume that overflow does not occur.

Just the same, I don't think we necessarily want to take advantage of
every degree of freedom the standards give us (at least, not by default).

(Oh, crap; I see a massive thread re-emerging).