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From: Paul Koning <pkoning@equallogic.com>
To: dewar@adacore.com
Cc: galibert@pobox.com, dave.korn@artimi.com, aph@redhat.com,
	gdr@integrable-solutions.net, pinskia@physics.uc.edu,
	gcc@gcc.gnu.org
Subject: Re: signed is undefined and has been since 1992 (in GCC)
Date: Tue, 28 Jun 2005 20:18:00 -0000	[thread overview]
Message-ID: <17089.45177.781373.794318@gargle.gargle.HOWL> (raw)
In-Reply-To: <42C1A318.4040407@adacore.com>

>>>>> "Robert" == Robert Dewar <dewar@adacore.com> writes:

 Robert> I am puzzled, why would *ANYONE* who knows C use int rather
 Robert> than unsigned if they want wrap around semantics?

Because most people don't follow the rule that "always use unsigned
variables unless you know that it really needs to be signed".

And also because most people believe that C applies normal computer
arithmetic, and they believe that normal computer arithmetic is
wrapped 2's complement.  (And indeed it usually is, give or take some
bizarre exceptions like MAX_INT % -1)

We all know better, but how tiny is the fraction of C programmers who
have ever even *seen* the ANSI C spec, much less know in detail what
it says?

	paul

  reply	other threads:[~2005-06-28 20:18 UTC|newest]

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-28  4:08 Andrew Pinski
2005-06-28  4:20 ` Michael Veksler
2005-06-28  9:49   ` Robert Dewar
2005-06-28  4:34 ` Gabriel Dos Reis
2005-06-28  4:50   ` Andrew Pinski
2005-06-28  5:13     ` Gabriel Dos Reis
2005-06-28  5:34       ` Andrew Pinski
2005-06-28  6:01         ` Gabriel Dos Reis
2005-06-28  9:18           ` Robert Dewar
2005-06-28 11:50             ` Gabriel Dos Reis
2005-06-28 12:07               ` Robert Dewar
2005-06-28 12:33                 ` Gabriel Dos Reis
2005-06-28 12:57                   ` Robert Dewar
2005-06-28 13:19                     ` Gabriel Dos Reis
2005-06-28 22:58                       ` Georg Bauhaus
2005-06-28 23:53                         ` Gabriel Dos Reis
2005-06-29  0:27                           ` Robert Dewar
2005-06-29  0:43                             ` Gabriel Dos Reis
2005-06-29  0:48                               ` Robert Dewar
2005-06-29  1:14                                 ` Gabriel Dos Reis
2005-06-29  1:21                                   ` Diego Novillo
2005-06-29  2:19                                     ` Marcin Dalecki
2005-06-29  3:13                                       ` Scott Robert Ladd
2005-06-28 14:24                     ` Olivier Galibert
2005-06-28 14:28                       ` Jonathan Wilson
2005-06-28 14:42                         ` Olivier Galibert
2005-06-28 14:39                       ` Dave Korn
2005-06-28 14:52                         ` Olivier Galibert
2005-06-28 15:01                           ` Robert Dewar
2005-06-28 15:04                           ` Andrew Haley
2005-06-28 17:18                             ` Olivier Galibert
2005-06-28 17:36                               ` Dave Korn
2005-06-28 18:02                                 ` Olivier Galibert
2005-06-28 18:36                                   ` Dave Korn
2005-06-28 18:56                                     ` Gabriel Dos Reis
2005-06-28 19:10                                     ` Olivier Galibert
2005-06-28 19:13                                       ` Andrew Pinski
2005-06-28 19:20                                         ` Robert Dewar
2005-06-28 21:48                                           ` Joe Buck
2005-06-28 19:25                                         ` Gabriel Dos Reis
2005-06-28 19:32                                           ` Robert Dewar
2005-06-28 19:48                                             ` Gabriel Dos Reis
2005-06-28 20:37                                               ` Robert Dewar
2005-06-28 20:58                                                 ` Gabriel Dos Reis
2005-06-28 21:57                                                   ` Robert Dewar
2005-06-28 21:44                                             ` Joe Buck
2005-06-28 21:50                                               ` Olivier Galibert
2005-06-28 21:59                                               ` Robert Dewar
2005-06-28 18:52                                   ` Robert Dewar
2005-06-28 19:17                                     ` Olivier Galibert
2005-06-28 19:21                                       ` Robert Dewar
2005-06-28 20:18                                         ` Paul Koning [this message]
2005-06-28 20:24                                           ` Robert Dewar
2005-06-28 21:41                                             ` Joe Buck
2005-06-28 21:53                                         ` Michael Veksler
2005-06-28 23:05                                           ` Michael Veksler
2005-07-02 17:15                                         ` Florian Weimer
2005-07-02 18:59                                           ` Gabriel Dos Reis
2005-07-02 23:20                                             ` Robert Dewar
2005-07-03  0:07                                               ` Gabriel Dos Reis
2005-07-03  9:49                                                 ` Robert Dewar
2005-07-02 23:12                                           ` Nicholas Nethercote
2005-07-02 23:20                                           ` Robert Dewar
2005-07-03  0:13                                             ` Gabriel Dos Reis
2005-07-03  9:54                                               ` Robert Dewar
2005-07-03 10:02                                                 ` Florian Weimer
2005-07-03 10:10                                                   ` Robert Dewar
2005-07-03 12:01                                                 ` Gabriel Dos Reis
2005-07-14  7:21                                           ` Marc Espie
2005-07-02 17:06                                 ` Florian Weimer
2005-06-28 17:51                               ` Joe Buck
2005-06-28 18:21                                 ` Gabriel Dos Reis
2005-06-28 18:53                                   ` Robert Dewar
2005-06-28 18:28                                 ` Olivier Galibert
2005-06-28 18:38                                   ` Dave Korn
2005-06-28 18:50                               ` Robert Dewar
2005-06-28 19:02                                 ` Gabriel Dos Reis
2005-06-28 19:17                                   ` Robert Dewar
2005-06-28 19:43                                     ` Gabriel Dos Reis
2005-06-28 20:31                                       ` Robert Dewar
2005-06-28 20:51                                         ` Gabriel Dos Reis
2005-06-28 20:59                                           ` Robert Dewar
2005-06-28 21:20                                             ` Gabriel Dos Reis
2005-06-28 21:27                                               ` Paul Koning
2005-06-28 21:39                                                 ` Andreas Schwab
2005-06-28 21:35                                               ` Joe Buck
2005-06-28 22:09                                     ` Joseph S. Myers
2005-06-28 22:16                                       ` Falk Hueffner
2005-06-29  6:59                                         ` Eric Botcazou
2005-06-28 22:19                                       ` Robert Dewar
2005-06-28 16:42                         ` Joe Buck
2005-06-28 17:10                           ` Dave Korn
2005-06-28 17:21                             ` Joe Buck
2005-06-28 22:41                               ` Georg Bauhaus
2005-06-28 14:47                       ` Gabriel Dos Reis
2005-06-28 16:38                     ` Joe Buck
2005-06-28 21:59                     ` Mike Stump
2005-06-28 13:47                   ` Gabriel Paubert
2005-06-28 13:52                     ` Andrew Pinski
2005-06-28 14:33                     ` Robert Dewar
2005-06-28 12:08               ` Robert Dewar
2005-06-28 12:34                 ` Gabriel Dos Reis
2005-06-28  7:25         ` Michael Veksler
2005-06-28 16:32           ` Joe Buck
2005-06-28 16:56             ` Joe Buck
2005-06-28 17:03             ` Gabriel Dos Reis
2005-06-28 17:34               ` Joe Buck
2005-06-28 18:09                 ` Gabriel Dos Reis
2005-06-28 17:35               ` Diego Novillo
2005-06-28  6:55       ` Steven Bosscher
2005-06-28  7:20         ` Michael Veksler
2005-06-28  7:39           ` Falk Hueffner
2005-06-28 12:08             ` Gabriel Dos Reis
2005-06-28 12:01         ` Gabriel Dos Reis
2005-06-28 16:59 Morten Welinder
2005-06-28 17:23 ` Olivier Galibert
2005-06-28 18:44 ` Michael Veksler
2005-06-28 17:41 Paul Schlie
     [not found] <2382433.1119938227627.JavaMail.root@dtm1eusosrv72.dtm.ops.eu.uu.net>
2005-06-28 19:44 ` Toon Moene

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