Message-ID: <4D093580.9000303@zytor.com>
Date: Wed, 15 Dec 2010 13:39:12 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>, Tejun Heo <tj@kernel.org>,
        Pekka Enbeerg <penberg@cs.helsinki.fi>, linux-kernel@vger.kernel.org,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: x86: A fast way to check capabilities of the current cpu
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On 12/15/2010 01:30 PM, Miguel Ojeda wrote:
> 
> In this case it this_cpu_*_test_bit() return an int, but they act as a
> bool and are used in if()s; where is the catch?
> 

If they aren't, and are stored in a variable for whatever reason, then
the || form will generate additional instructions to booleanize the
value for no good reason.

	-hpa
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