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From: "acoplan at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/106064] Wrong code comparing two global zero-sized arrays
Date: Mon, 27 Jun 2022 14:25:29 +0000 [thread overview]
Message-ID: <bug-106064-4-fCvO2axtDN@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-106064-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106064
--- Comment #13 from Alex Coplan <acoplan at gcc dot gnu.org> ---
(In reply to Richard Earnshaw from comment #12)
> (In reply to Alex Coplan from comment #11)
> > (In reply to Jakub Jelinek from comment #8)
> > > The IMHO UB case is for a != b when one address is at the start of one
> > > object and the other address is at the end of another one
> >
> > Just to dig a little deeper on this, what makes this case UB? Is there
> > something in the standard to this effect?
>
> As stated in #6, zero-sized objects are a GNU extension. I guess that means
> we get to define what the behaviour should be :)
Sure, but Jakub's reply seemed to get at some underlying principle as opposed
to just saying "zero-sized objects are a GNU extension and we declare this case
to be undefined".
next prev parent reply other threads:[~2022-06-27 14:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 12:36 [Bug tree-optimization/106064] New: " acoplan at gcc dot gnu.org
2022-06-23 16:21 ` [Bug tree-optimization/106064] " ktkachov at gcc dot gnu.org
2022-06-24 9:56 ` mikpelinux at gmail dot com
2022-06-24 10:20 ` pinskia at gcc dot gnu.org
2022-06-24 10:21 ` pinskia at gcc dot gnu.org
2022-06-24 10:28 ` acoplan at gcc dot gnu.org
2022-06-24 10:30 ` rguenth at gcc dot gnu.org
2022-06-24 10:34 ` acoplan at gcc dot gnu.org
2022-06-24 10:50 ` jakub at gcc dot gnu.org
2022-06-27 10:15 ` acoplan at gcc dot gnu.org
2022-06-27 10:19 ` jakub at gcc dot gnu.org
2022-06-27 12:21 ` acoplan at gcc dot gnu.org
2022-06-27 14:18 ` rearnsha at gcc dot gnu.org
2022-06-27 14:25 ` acoplan at gcc dot gnu.org [this message]
2022-07-08 17:02 ` acoplan at gcc dot gnu.org
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