From: Paolo Bonzini <bonzini@gnu.org>
To: gcc-patches@gcc.gnu.org
Cc: gcc@gcc.gnu.org
Subject: Re: [PATCH][4.3] Deprecate -ftrapv
Date: Sat, 01 Mar 2008 14:15:00 -0000 [thread overview]
Message-ID: <fqbo2o$g7j$1@ger.gmane.org> (raw)
In-Reply-To: <10803011408.AA02772@vlsi1.ultra.nyu.edu>
Richard Kenner wrote:
>> int f(int a, int b) { return 0 * (a + b); }
>>
>> get the potentially trapping arithmetic folded away. If -ftrapv is to
>> have properly defined semantics, those must include trapping if (a + b)
>> overflows in the above code.
>
> Why? Is there any language that requires such semantics?
Not C, since trapping overflow is just one facet of "undefined behavior"
and we can define that facet as we wish! :-)
Paolo
next prev parent reply other threads:[~2008-03-01 14:15 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.64.0803010041110.4133@zhemvz.fhfr.qr>
2008-03-01 0:04 ` Richard Guenther
2008-03-01 0:05 ` Mark Mitchell
2008-03-01 0:11 ` Richard Kenner
2008-03-01 2:05 ` Robert Dewar
2008-03-01 2:17 ` Joseph S. Myers
2008-03-01 2:33 ` Robert Dewar
2008-03-01 13:19 ` Joseph S. Myers
2008-03-01 14:05 ` Paolo Bonzini
2008-03-01 11:24 ` Richard Kenner
2008-03-01 13:55 ` Robert Dewar
2008-03-01 14:12 ` Richard Kenner
2008-03-01 14:18 ` Robert Dewar
2008-03-01 0:14 ` Richard Guenther
2008-03-01 1:04 ` Mark Mitchell
2008-03-01 1:49 ` Joseph S. Myers
2008-03-01 1:54 ` Mark Mitchell
2008-03-01 12:32 ` Richard Guenther
2008-03-01 13:10 ` Joseph S. Myers
2008-03-01 13:38 ` Robert Dewar
2008-03-01 13:57 ` Richard Guenther
2008-03-01 14:05 ` Robert Dewar
2008-03-01 19:53 ` Florian Weimer
2008-03-01 20:11 ` Robert Dewar
2008-03-01 21:19 ` Florian Weimer
2008-03-01 21:43 ` Robert Dewar
2008-03-01 21:48 ` Robert Dewar
2008-03-01 14:14 ` Richard Kenner
2008-03-01 13:50 ` Richard Guenther
2008-03-01 18:27 ` Joseph S. Myers
2008-03-01 14:06 ` Richard Kenner
2008-03-01 14:10 ` Richard Guenther
2008-03-01 14:15 ` Robert Dewar
2008-03-01 14:13 ` Robert Dewar
2008-03-01 14:15 ` Paolo Bonzini [this message]
2008-03-01 18:32 ` Joseph S. Myers
2008-03-02 10:47 ` Mark Mitchell
2008-03-02 11:08 ` Richard Guenther
2008-03-02 11:52 ` Robert Dewar
2008-03-03 22:45 ` Eric Botcazou
2008-03-04 2:38 ` Robert Dewar
2008-03-03 18:36 ` Ian Lance Taylor
2008-03-02 11:29 ` Robert Dewar
2008-03-02 11:36 ` Richard Kenner
2008-03-02 14:24 ` Frank Ch. Eigler
2008-03-02 14:31 ` Robert Dewar
2008-03-02 15:14 ` Frank Ch. Eigler
2008-03-02 15:21 ` Robert Dewar
2008-03-02 15:48 ` Frank Ch. Eigler
2008-03-02 16:08 ` Robert Dewar
2008-03-02 15:22 ` Robert Dewar
2008-03-01 19:58 ` Florian Weimer
2008-03-01 20:04 ` Florian Weimer
2008-03-01 20:12 ` Robert Dewar
2008-03-01 21:25 ` Florian Weimer
2008-03-01 21:45 ` Robert Dewar
2008-03-01 12:31 ` Richard Guenther
2008-03-01 14:00 ` Paolo Bonzini
2008-03-02 13:00 ` Joseph S. Myers
2008-03-02 13:03 ` Richard Guenther
2008-03-05 22:46 ` Ken Raeburn
2008-03-01 0:16 ` David Daney
2008-03-01 2:08 ` Robert Dewar
2008-03-01 6:54 ` Tom Tromey
2008-03-01 0:12 ` Joseph S. Myers
2008-03-01 0:23 ` Richard Guenther
2008-03-01 0:49 ` Joseph S. Myers
2008-03-01 1:57 ` Robert Dewar
2008-03-01 12:33 ` Richard Guenther
2008-03-01 13:08 ` Robert Dewar
[not found] ` <fqbn6k$d5j$1@ger.gmane.org>
2008-03-01 13:58 ` Robert Dewar
2008-03-01 14:00 ` Richard Guenther
2008-03-03 22:53 ` Eric Botcazou
2008-03-04 2:39 ` Robert Dewar
2008-03-01 22:16 FX Coudert
2008-03-01 22:31 ` Robert Dewar
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