From: Vincent Lefevre <vincent@vinc17.net>
To: zsh-workers@zsh.org
Subject: Re: PATCH: prevent SIGFPE on systems where LONG_MIN < -LONG_MAX
Date: Wed, 5 Sep 2012 01:50:34 +0200 [thread overview]
Message-ID: <20120904235034.GQ19561@xvii.vinc17.org> (raw)
In-Reply-To: <20120904192644.661329c3@pws-pc.ntlworld.com>
On 2012-09-04 19:26:44 +0100, Peter Stephenson wrote:
> > > The shell should not crash, neither should it return incorrect
> > > results.
> >
> > Agreed.
>
> Well, that depends what you mean by an incorrect result. Mathematically
> incorrect results are inevitable if you don't account of the precision,
> but we don't warn for any other rounding error so I agree there's no
> reason to here.
Here these are integer operations, and it seems that zsh chose
modular arithmetic, so that a "correct" representable result
is always possible under these conditions ("correct" but not
necessarily meaningful, but no-one can prevent the user from
writing meaningless expressions).
--
Vincent Lefèvre <vincent@vinc17.net> - Web: <http://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
prev parent reply other threads:[~2012-09-04 23:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 14:32 Jérémie Roquet
2012-09-03 14:40 ` Mikael Magnusson
2012-09-03 14:57 ` Peter Stephenson
2012-09-03 15:08 ` Jérémie Roquet
2012-09-03 16:26 ` Vincent Lefevre
2012-09-04 18:26 ` Peter Stephenson
2012-09-04 23:50 ` Vincent Lefevre [this message]
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