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Date: Tue, 15 Aug 2006 00:38:42 +1000
From: Anton Blanchard <anton@samba.org>
To: =?iso-8859-1?Q?J=F6rn?= Engel <joern@wohnheim.fh-wedel.de>
Cc: Jan-Bernd Themann <ossthema@de.ibm.com>, netdev <netdev@vger.kernel.org>,
       linux-ppc <linuxppc-dev@ozlabs.org>,
       linux-kernel <linux-kernel@vger.kernel.org>,
       Marcus Eder <meder@de.ibm.com>, Christoph Raisch <raisch@de.ibm.com>,
       Thomas Klein <tklein@de.ibm.com>
Subject: Re: [PATCH 1/6] ehea: interface to network stack
Message-ID: <20060814143842.GM479@krispykreme>
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> Is a conditional cheaper than a divide?  In case of a misprediction I
> would assume it to be significantly slower and I don't know the ratio
> of mispredictions for this branch.

A quick scan of the web shows 40 cycles for athlon64 idiv, and its
similarly slow on many other cpus. Even assuming you mispredict every
branch its going to be a win.

Anton