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Date: Wed, 25 Jan 2006 23:25:34 +0000
From: Ian Molton <spyro@f2s.com>
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To: Russell King <rmk+lkml@arm.linux.org.uk>
Subject: Re: [PATCH 3/6] C-language equivalents of include/asm-*/bitops.h
References: <20060125112625.GA18584@miraclelinux.com>
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Cc: linux-mips@linux-mips.org, linux-m68k@vger.kernel.org,
	linux-ia64@vger.kernel.org, Andi Kleen <ak@suse.de>,
	David Howells <dhowells@redhat.com>, linuxppc-dev@ozlabs.org,
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	Miles Bader <uclinux-v850@lsi.nec.co.jp>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Hirokazu Takata <takata@linux-m32r.org>,
	linuxsh-shmedia-dev@lists.sourceforge.net,
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	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	Richard Henderson <rth@twiddle.net>, Akinobu Mita <mita@miraclelinux.com>,
	Chris Zankel <chris@zankel.net>, dev-etrax@axis.com,
	ultralinux@vger.kernel.org, linux-kernel@vger.kernel.org,
	linuxsh-dev@lists.sourceforge.net, linux390@de.ibm.com,
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Russell King wrote:

> This code generates more expensive shifts than our (ARMs) existing C
> version.  This is a backward step.
> 
> Basically, shifts which depend on a variable are more expensive than
> constant-based shifts.

arm26 will have the same problem here.