Thread (55 messages) 55 messages, 12 authors, 2007-03-22

Re: [RFC] div64_64 support

From: Roland Kuhn <hidden>
Date: 2007-03-06 15:10:26
Also in: lkml

Hi Andi!

On 6 Mar 2007, at 15:45, Andi Kleen wrote:
quoted
<rant>
Let me see... You throw code like that and expect someone to actually
understand it in one year, and be able to correct a bug ?
To be honest I don't expect any bugs in this function.
quoted
</rant>

Please add something, an URL or even better a nice explanation,  
per favor...
It's straight out of Hacker's delight which is referenced in the  
commit
log.
And it's pretty neat, too. Hint: (y+1)**3 = y**3 + 3*y**2 + 3*y + 1.  
The algorithm is exactly the same as for calculating the cubic root  
on paper, digit by digit. I found that algo in the school notebook of  
my grandpa (late 1920ies), a pity that it's not taught anymore...  
pocket calculators _do_ have downsides ;-)

Ciao,
                     Roland

--
TU Muenchen, Physik-Department E18, James-Franck-Str., 85748 Garching
Telefon 089/289-12575; Telefax 089/289-12570
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--
Any society that would give up a little liberty to gain a little
security will deserve neither and lose both.  - Benjamin Franklin
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GS/CS/M/MU d-(++) s:+ a-> C+++ UL++++ P+++ L+++ E(+) W+ !N K- w--- M 
+ !V Y+
PGP++ t+(++) 5 R+ tv-- b+ DI++ e+++>++++ h---- y+++
------END GEEK CODE BLOCK------

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