From: Ben Hutchings <bhutchings@solarflare.com>
To: Changli Gao <xiaosuo@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
"Pekka Savola (ipv6)" <pekkas@netcore.fi>,
James Morris <jmorris@namei.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Patrick McHardy <kaber@trash.net>,
netdev@vger.kernel.org
Subject: Re: [PATCH] net: remove tests on 64bit platforms
Date: Tue, 25 Jan 2011 14:28:49 +1000 [thread overview]
Message-ID: <1295929729.2896.26.camel@localhost> (raw)
In-Reply-To: <1295929298-13163-1-git-send-email-xiaosuo@gmail.com>
On Tue, 2011-01-25 at 12:21 +0800, Changli Gao wrote:
> On 64bit platforms, >31 bit shifting of a unsigned long variable is
> valid, so we can remove the related boundary tests, which may slow
> down the CPU if branch prediction fails.
[...]
It seems like it would be better to define generic shift functions that
correctly handle the case of a shift count >= word size. There are many
places these would be useful.
Ben.
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
next prev parent reply other threads:[~2011-01-25 4:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-25 4:21 [PATCH] net: remove tests on 64bit platforms Changli Gao
2011-01-25 4:28 ` Ben Hutchings [this message]
2011-01-25 7:30 ` David Miller
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