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From: Joe Buck <Joe.Buck@synopsys.COM>
To: Dave Korn <dave.korn@artimi.com>
Cc: "'Olivier Galibert'" <galibert@pobox.com>,
	"'Robert Dewar'" <dewar@adacore.com>,
	"'Gabriel Dos Reis'" <gdr@integrable-solutions.net>,
	"'Andrew Pinski'" <pinskia@physics.uc.edu>,
	"'gcc mailing list'" <gcc@gcc.gnu.org>
Subject: Re: signed is undefined and has been since 1992 (in GCC)
Date: Tue, 28 Jun 2005 16:42:00 -0000	[thread overview]
Message-ID: <20050628164136.GD9524@synopsys.com> (raw)
In-Reply-To: <SERRANOQzV7r6pVu4Jb0000024f@SERRANO.CAM.ARTIMI.COM>

On Tue, Jun 28, 2005 at 03:39:38PM +0100, Dave Korn wrote:
> ----Original Message----
> >From: Olivier Galibert
> >Sent: 28 June 2005 15:25
> 
> > In particular, a very large number of C and C++ programs are written
> > with the assumptions:
> 
>   This is a bad line of reasoning in general.  There is a vast amount of bad
> software in the world, some blatantly buggy, some subtly-incorrect.  To
> attempt to fix it all in the compiler rather than the source seems a bit
> bass-ackwards to me!
> 
> > - sizeof(int) == 4, sizeof(long long) == 8
> > 
> > - sizeof(long) == sizeof(void *) == sizeof(void (*)())
> > 
> > Break them and see your compiler rejected by pretty much everybody.
> 
>   And what about 64 bit architectures?  Your assumptions are already widely
> invalid and only going to get more so.

No, all of Olivier's assumptions are valid on LP64 as well as ILP32
architectures.  They are invalid on most DSP architectures, as well as
on 16-bit embedded architectures, which I suppose you could call "widely
invalid" if you count # of shipping parts.  But they are a reasonable
engineering tradeoff in many cases (it's a waste of time in most cases
for a program that does a lot of bit manipulation to consider the case
of 37 bit one's complement architectures with an 11 bit byte).




  parent reply	other threads:[~2005-06-28 16:42 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
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 [this message]
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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