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To: Narvi <narvi@haldjas.folklore.ee>
cc: fs@freebsd.org
Subject: Re: the namei cache... 
In-reply-to: Your message of "Fri, 25 Apr 1997 11:08:55 +0300."
             <Pine.BSF.3.95.970425103425.26643A-100000@haldjas.folklore.ee> 
From: David Greenman <dg@root.com>
Reply-To: dg@root.com
Date: Fri, 25 Apr 1997 01:35:51 -0700
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>On Thu, 24 Apr 1997, David Greenman wrote:
>
>> >about 1/4th of the additions. Getting reed of the div wouldn't also be bad
>> >but might not be worth it.
>> 
>>    Not worth it? At greater than 50 cycles, the divide is more expensive
>> than the entire add loop.
>
>Well, it seems that division has become more expensive over time. :-( 
>The only processor related book I had around was about the 286 and there
>it cost only 28 so I figured we might be hard pressed coming up something

   Occording to my Intel Pentium databook, a 32bit divide takes 41 cycles
on a Pentium; the 386 databook says 41 cycles for a 386.

-DG

David Greenman
Core-team/Principal Architect, The FreeBSD Project