Re: optimization/7799: [3.2/3.3 regression] Loop bug withoptimization flag -Os in gcc

[Andrew Pinski <pinskia at physics dot uc dot edu>]

In fact the old test for gcc.c-torture/execute/loop-2e.c was using nmap
before I said something because I getting a PASS on i686-unknown-openbsd
when it was giving the same assembly as i686-pc-gnu-linux.

Thanks,
Andrew Pinski


On Friday, Dec 13, 2002, at 08:28 US/Pacific, Morten Welinder wrote:

> Andreas Schwab writes:
>
> > "Christian Ehrhardt" <ehrhardt@mathematik.uni-ulm.de> writes:
> > |> By calling fill ((int*) 0xffffffc, q);
> > Undefined behaviour.
> True, but its_somewhere_in_my_libc() is not.  Implementation defined,
> yes, but not undefined.
>
> A quick scan of mmap's manual page suggests that it is not completely
> ruled out that you would get 0xfffffffc for an area that includes
> space for ten ints thereafter.  (Perhaps you would have to ask for
> memory starting a bit earlier, namely at the start of a page.)
>
> With PROT_NONE this would merely be absurd behaviour, IMHO, as opposed
> to certifiably insane.
>
> Morten