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Date:      Fri, 1 Mar 2013 02:46:41 +0000
From:      Alexey Dokuchaev <danfe@FreeBSD.org>
To:        Alexander Motin <mav@FreeBSD.org>
Cc:        Davide Italiano <davide@FreeBSD.org>, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r247460 - head/sys/dev/acpica
Message-ID:  <20130301024641.GA88239@FreeBSD.org>
In-Reply-To: <512F95DC.1040005@FreeBSD.org>
References:  <201302281127.r1SBR2VE068276@svn.freebsd.org> <20130228162522.GA41693@FreeBSD.org> <512F95DC.1040005@FreeBSD.org>

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On Thu, Feb 28, 2013 at 07:37:32PM +0200, Alexander Motin wrote:
> SBT_1US is 4294 (0x10c6). The best that compiler may do is replace
> division with multiplication. In fact, Clang even does this on amd64.
> But on i386 it calls __divdi3(), doing 64bit division in software. Shift
> is definitely cheaper and 5% precision is fine here.

I see, thanks for explanation.  I overlooked SBT_1US definition.

./danfe



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