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Date: Thu, 10 May 2001 16:51:17 +0600 (LKT)
From: Anuradha Ratnaweera <anuradha@gnu.org>
To: "J . A . Magallon" <jamagallon@able.es>
cc: Helge Hafting <helgehaf@idb.hist.no>,
        Tobias Ringstrom <tori@tellus.mine.nu>, linux-kernel@vger.kernel.org
Subject: Re: page_launder() bug
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On Mon, 7 May 2001, J . A . Magallon wrote:

> 
> On 05.07 Helge Hafting wrote:
> >
> > !0 is 1.  !(anything else) is 0.  It is zero and one, not
> > zero and "non-zero".  So a !! construction gives zero if you have
> > zero, and one if you had anything else.  There's no doubt about it.
> > >
> 
> Isn't this asking for trouble with the optimizer ? It could kill both
> !!. Using that is like trusting on a certain struct padding-alignment.
> 

It isn't, or rather it can't. Because !!x is not x unless x is one or
zero.

Anuradha