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From: "J.K.Annot.at.Infor at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/47732] counter decremented to zero not detected when other counter overflows
Date: Tue, 15 Feb 2011 14:25:00 -0000	[thread overview]
Message-ID: <bug-47732-4-hOWLG1VWDk@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-47732-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47732

--- Comment #2 from Jan Koen Annot <J.K.Annot.at.Infor at gmail dot com> 2011-02-15 14:21:16 UTC ---
(In reply to comment #1)
> And overflow is undefined in C/C++ so you are invoking undefined behavior here.

Wow! This is an eye-opener for me! I am quite accustomed to assume two's
complement arithmetic with implicit wrap-around for signed integers.

After your remark I googled a bit and found several articles about undefined
behavior, e.g. John Regehr's "A Guide to Undefined Behavior in C and C++, Part
1".
Very instructive.


      parent reply	other threads:[~2011-02-15 14:22 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-14 14:34 [Bug c/47732] New: " J.K.Annot.at.Infor at gmail dot com
2011-02-14 18:27 ` [Bug c/47732] " pinskia at gcc dot gnu.org
2011-02-15 14:25 ` J.K.Annot.at.Infor at gmail dot com [this message]

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