From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Schwab <schwab@linux-m68k.org>
Subject: Re: [PATCH net-next 09/10] net/mlx4_en: Manage flow steering rules with ethtool
Date: Mon, 02 Jul 2012 13:35:49 +0200
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Cc: "Joe Perches" <joe@perches.com>,
	"Ben Hutchings" <bhutchings@solarflare.com>,
	"Or Gerlitz" <ogerlitz@mellanox.com>, <davem@davemloft.net>,
	<roland@kernel.org>, <yevgenyp@mellanox.com>, <oren@mellanox.com>,
	<netdev@vger.kernel.org>, "Hadar Hen Zion" <hadarh@mellanox.co.il>
To: "David Laight" <David.Laight@ACULAB.COM>
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	(David Laight's message of "Mon, 2 Jul 2012 11:19:50 +0100")
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"David Laight" <David.Laight@ACULAB.COM> writes:

>  
>> > Or write it as (!field || !(typeof(field))~field) which more closely
>> > resembles what the macro name expresses.
>> 
>> Better still, or maybe:
>> 
>> 	field == 0 || field == (typeof field)~0
>
> Which doesn't work when sizeof(field) > sizeof(int).
> Needs another cast.
>
> 	field == 0 || field == (typeof field)~(typeof field)0

You can avoid that by using (typeof field)-1.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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"And now for something completely different."