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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/55616] bogus warning about undefined overflow after overflow check
Date: Thu, 31 Jan 2013 10:48:00 -0000 [thread overview]
Message-ID: <bug-55616-4-vA19cUMU3Y@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-55616-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55616
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> 2013-01-31 10:47:55 UTC ---
(In reply to comment #4)
> (In reply to comment #3)
> > I don't see anything bogus on the warning, it is useful to inform the developer
> > about potentially unintended optimization removing some conditional.
>
> Neither programmer wrote (X + c) < X, this pattern does not occur in Okular nor
> Qt. I'm open to labeling the warning as "very difficult to diagnose" or
> "unhelpful" in these cases, and not "bogus". But I think it's a problem
> because it distracts from the real problems this warning intends to catch.
Well, but the possible overflow is present in the literal
'number_of_elements_in_path+100'. Yes, hard to track the warning down to
that possible issue, but I don't think we can improve much on that front.
next prev parent reply other threads:[~2013-01-31 10:48 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-07 14:03 [Bug tree-optimization/55616] New: " fweimer at redhat dot com
2012-12-07 14:39 ` [Bug tree-optimization/55616] " rguenth at gcc dot gnu.org
2013-01-31 9:50 ` fweimer at redhat dot com
2013-01-31 10:09 ` jakub at gcc dot gnu.org
2013-01-31 10:26 ` fweimer at redhat dot com
2013-01-31 10:48 ` rguenth at gcc dot gnu.org [this message]
2013-01-31 10:52 ` jakub at gcc dot gnu.org
2013-01-31 11:06 ` fweimer at redhat dot com
2013-01-31 11:14 ` than at redhat dot com
2013-01-31 11:21 ` jakub at gcc dot gnu.org
2021-09-28 9:37 ` pinskia at gcc dot gnu.org
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