From: Paul Mackerras <paulus@samba.org>
To: Bernard Dautrevaux <Dautrevaux@microprocess.com>
Cc: "'Tom Rini'" <trini@kernel.crashing.org>,
Momchil Velikov <velco@fadata.bg>,
linux-kernel@vger.kernel.org, gcc@gcc.gnu.org,
linuxppc-dev@lists.linuxppc.org
Subject: RE: [PATCH] C undefined behavior fix
Date: Thu, 3 Jan 2002 10:02:12 +1100 (EST) [thread overview]
Message-ID: <15411.37236.181936.39729@argo.ozlabs.ibm.com> (raw)
In-Reply-To: <17B78BDF120BD411B70100500422FC6309E3ED@IIS000>
In-Reply-To: <17B78BDF120BD411B70100500422FC6309E3ED@IIS000>
Bernard Dautrevaux writes:
> > 1) gcc shouldn't be making this optimization, and Paulus (who
> > wrote the
> > code) disliked this new feature.
>
> Why? If memcpy can then be expanded in line, and the string is short, this
> can be a *huge* win...
Show me a place in the kernel which is performance-critical where we
do strcpy(p, "string"). I can't think of one. The stuff in prom.c
isn't performance-critical.
> I think we MUST modify the RELOC macro. Currently the code has an undefined
> meaning WRT th eC standard, so is allowed to do almost anything from working
> as expected (quite bad in fact: it may suddenly fail when sth is modified
> elsewhere), to triggering the 3rd World War :-)
As I said in another email, if the gcc maintainers want to change gcc
so that pointer arithmetic can do anything other than an ordinary 2's
complement addition operation, then we will stop using gcc.
Paul.
next prev parent reply other threads:[~2002-01-02 23:16 UTC|newest]
Thread overview: 202+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-02 10:02 Bernard Dautrevaux
2002-01-02 23:02 ` Paul Mackerras [this message]
2002-01-02 23:27 ` Momchil Velikov
-- strict thread matches above, loose matches on Subject: below --
2002-01-10 19:01 Bernard Dautrevaux
2002-01-10 12:18 dewar
2002-01-10 12:37 ` Erik Trulsson
2002-01-10 15:27 ` Florian Weimer
2002-01-10 9:03 Bernard Dautrevaux
2002-01-10 10:40 ` David Weinehall
2002-01-10 4:33 dewar
2002-01-10 2:16 dewar
2002-01-10 1:22 dewar
2002-01-10 1:21 dewar
2002-01-10 4:37 ` Tim Hollebeek
2002-01-09 21:54 dewar
2002-01-09 20:32 dewar
2002-01-09 21:43 ` Paul Koning
2002-01-09 20:08 dewar
2002-01-09 19:53 mike stump
2002-01-09 20:12 ` Paul Koning
2002-01-09 10:42 dewar
2002-01-09 10:41 Bernard Dautrevaux
2002-01-09 21:59 ` Gérard Roudier
2002-01-09 10:40 dewar
2002-01-09 9:06 Bernard Dautrevaux
2002-01-09 9:25 ` Bernd Petrovitsch
2002-01-09 2:18 dewar
2002-01-09 2:13 dewar
2002-01-09 1:51 mike stump
2002-01-09 1:19 dewar
2002-01-09 0:51 dewar
2002-01-08 11:12 Bernard Dautrevaux
2002-01-11 9:52 ` Horst von Brand
2002-01-08 9:44 Bernard Dautrevaux
2002-01-08 11:44 ` 'jtv'
2002-01-08 0:16 mike stump
2002-01-08 11:33 ` jtv
2002-01-07 23:46 mike stump
2002-01-07 23:20 dewar
2002-01-07 23:15 dewar
2002-01-07 23:12 dewar
2002-01-07 23:11 dewar
2002-01-07 22:56 mike stump
2002-01-07 22:26 Tim McDaniel
2002-01-07 19:36 mike stump
2002-01-07 21:21 ` Theodore Tso
2002-01-08 0:19 ` Paul Mackerras
2002-01-08 1:02 ` Richard Henderson
2002-01-07 19:18 mike stump
2002-01-07 19:17 Bernard Dautrevaux
2002-01-07 18:38 mike stump
2002-01-07 13:29 Bernard Dautrevaux
2002-01-07 13:24 Bernard Dautrevaux
2002-01-07 21:49 ` jtv
2002-01-07 22:28 ` Tim Hollebeek
2002-01-07 22:16 ` jtv
2002-01-08 0:27 ` J.A. Magallon
2002-01-08 11:41 ` jtv
2002-01-08 12:36 ` Alexandre Oliva
2002-01-08 12:58 ` jtv
2002-01-09 19:47 ` Gérard Roudier
2002-01-09 20:44 ` jtv
2002-01-09 23:49 ` J.A. Magallon
2002-01-10 10:13 ` Matthias Benkmann
2002-01-10 0:19 ` Peter Barada
2002-01-10 1:47 ` Fergus Henderson
2002-01-10 15:30 ` Peter Barada
2002-01-10 10:44 ` Bernd Petrovitsch
2002-01-06 19:32 dewar
2002-01-06 19:29 dewar
2002-01-06 19:29 dewar
2002-01-06 18:37 mike stump
2002-01-06 18:24 mike stump
2002-01-06 20:37 ` Gabriel Dos Reis
2002-01-06 21:59 ` Paul Mackerras
2002-01-06 22:19 ` Jakub Jelinek
2002-01-07 0:09 ` Tom Rini
2002-01-07 1:40 ` Alexandre Oliva
2002-01-06 18:20 mike stump
2002-01-06 16:22 dewar
2002-01-06 16:39 ` Alan Cox
2002-01-06 19:27 ` Laurent Guerby
2002-01-06 19:43 ` Alan Cox
2002-01-06 13:43 dewar
2002-01-06 13:55 ` Laurent Guerby
2002-01-06 13:41 dewar
2002-01-06 16:58 ` Gabriel Dos Reis
2002-01-06 13:16 dewar
2002-01-06 13:22 ` Gabriel Dos Reis
2002-01-06 13:07 dewar
2002-01-06 13:05 dewar
2002-01-06 13:41 ` Laurent Guerby
2002-01-06 7:56 mike stump
2002-01-06 4:26 dewar
2002-01-06 5:32 ` Paul Mackerras
2002-01-06 11:09 ` Momchil Velikov
2002-01-06 0:52 dewar
2002-01-04 22:43 dewar
2002-01-06 3:40 ` Paul Mackerras
2002-01-04 12:15 dewar
2002-01-04 12:14 dewar
2002-01-03 13:28 dewar
2002-01-04 8:38 ` Florian Weimer
2002-01-04 11:35 ` Joseph S. Myers
2002-01-05 19:25 ` jkl
2002-01-05 19:37 ` Joseph S. Myers
2002-01-05 20:06 ` jkl
2002-01-05 21:42 ` Joseph S. Myers
2002-01-05 20:01 ` Florian Weimer
2002-01-05 20:17 ` jkl
2002-01-05 20:51 ` Florian Weimer
2002-01-06 4:09 ` Paul Mackerras
2002-01-03 12:51 dewar
2002-01-03 10:35 Bernard Dautrevaux
2002-01-03 10:05 Bernard Dautrevaux
2002-01-03 10:49 ` Paul Mackerras
2002-01-03 11:59 ` Lars Brinkhoff
2002-01-03 23:53 ` Paul Mackerras
2002-01-04 9:52 ` Lars Brinkhoff
2002-01-05 6:45 ` Paul Mackerras
2002-01-06 0:20 ` Lars Brinkhoff
2002-01-09 9:28 ` Fergus Henderson
2002-01-09 10:58 ` Gabriel Dos Reis
2002-01-03 0:49 dewar
2002-01-03 0:12 dewar
2002-01-03 0:32 ` jtv
2002-01-06 19:37 ` Alexandre Oliva
2002-01-02 23:53 dewar
2002-01-02 23:59 ` Joe Buck
2002-01-03 3:12 ` Paul Mackerras
2002-01-03 15:45 ` Joe Buck
2002-01-02 17:40 Petr Vandrovec
2002-01-02 22:24 ` David Woodhouse
2002-01-02 22:39 ` Joe Buck
2002-01-02 22:59 ` David Woodhouse
2002-01-03 18:44 ` Alexandre Oliva
2002-01-01 23:03 Momchil Velikov
2002-01-01 23:43 ` Tom Rini
2002-01-02 6:54 ` Momchil Velikov
2002-01-02 15:39 ` Tom Rini
2002-01-02 15:50 ` Jakub Jelinek
2002-01-02 16:45 ` Paul Koning
2002-01-02 14:56 ` Joseph S. Myers
2002-01-02 22:56 ` Paul Mackerras
2002-01-02 23:37 ` Momchil Velikov
2002-01-03 2:51 ` Paul Mackerras
2002-01-03 6:29 ` law
2002-01-03 13:16 ` Lars Brinkhoff
2002-01-04 9:05 ` Florian Weimer
2002-01-04 22:14 ` Paul Mackerras
2002-01-02 10:29 ` Florian Weimer
2002-01-02 10:41 ` Momchil Velikov
2002-01-02 13:11 ` Jakub Jelinek
2002-01-02 15:54 ` Tom Rini
2002-01-02 11:28 ` Aaron Lehmann
2002-01-02 11:40 ` Momchil Velikov
2002-01-02 15:59 ` Tom Rini
2002-01-02 11:48 ` Alan Cox
2002-01-02 19:09 ` Tom Rini
2002-01-02 20:13 ` Joe Buck
2002-01-02 20:42 ` Tom Rini
2002-01-02 21:36 ` Richard Henderson
2002-01-02 22:05 ` Tom Rini
2002-01-02 22:23 ` jtv
2002-01-02 23:12 ` Tom Rini
2002-01-02 23:45 ` jtv
2002-01-03 0:01 ` Tom Rini
2002-01-03 0:07 ` Richard Henderson
2002-01-03 0:16 ` Tom Rini
2002-01-03 1:12 ` Richard Henderson
2002-01-03 0:20 ` jtv
2002-01-03 0:25 ` Alan Cox
2002-01-03 0:35 ` David Woodhouse
2002-01-03 2:10 ` Tom Rini
2002-01-03 22:39 ` Pavel Machek
2002-01-04 9:29 ` Paul Mackerras
2002-01-03 15:46 ` Edgar Toernig
2002-01-03 16:48 ` Momchil Velikov
2002-01-03 17:13 ` jtv
2002-01-03 21:26 ` Daniel Jacobowitz
2002-01-03 2:33 ` Paul Mackerras
2002-01-03 8:32 ` Richard Henderson
2002-01-03 10:03 ` Geert Uytterhoeven
2002-01-03 10:10 ` Paul Mackerras
2002-01-03 22:41 ` Tim Hollebeek
2002-01-04 8:48 ` Florian Weimer
2002-01-02 22:27 ` Richard Henderson
2002-01-02 22:35 ` Tom Rini
2002-01-02 22:44 ` Richard Henderson
2002-01-02 22:50 ` Tom Rini
2002-01-03 22:40 ` Pavel Machek
2002-01-04 8:42 ` Richard Henderson
2002-01-04 8:42 ` Florian Weimer
2002-01-02 23:11 ` Paul Mackerras
2002-01-02 23:26 ` Tom Rini
2002-01-02 23:28 ` Momchil Velikov
2002-01-02 23:34 ` Tom Rini
2002-01-03 0:19 ` jtv
2002-01-03 0:29 ` Tom Rini
2002-01-03 1:03 ` jtv
2002-01-03 1:17 ` Tom Rini
2002-01-03 17:44 ` jtv
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