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Date: Tue, 15 Apr 2003 07:35:44 -0700
From: "Martin J. Bligh" <mbligh@aracnet.com>
To: Duncan Sands <baldrick@wanadoo.fr>, Andrew Morton <akpm@digeo.com>
cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: BUGed to death
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>> Seems all these bug checks are fairly expensive. I can get 1%
>> back on system time for kernel compiles by changing BUG to
>> "do {} while (0)" to make them all compile away. Profiles aren't
>> very revealing though ... seems to be within experimental error ;-(
> 
> What happens if you just turn BUG_ON into "do {} while (0)"?

I believe I already did that by turning BUG() into a null expression.

#define BUG_ON(condition) 
	do { if (unlikely((condition)!=0)) BUG(); } while(0)

The compiler should be smart enough to optimise that away, methinks.

M.