Messages in this thread | | | Date | Mon, 26 Feb 2007 16:07:08 -0800 | From | Stephen Hemminger <> | Subject | Re: [RFC] div64_64 support |
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On Tue, 27 Feb 2007 01:05:26 +0100 (MET) Jan Engelhardt <jengelh@linux01.gwdg.de> wrote:
> > On Feb 26 2007 15:44, Stephen Hemminger wrote: > >> >- x = (2 * x + (uint32_t) div64_64(a, x*x)) / 3; > >> >+ x = (2 * x + (u32) (a / x*x)) / 3; > >> > >> Previously there was div64_64(a, x*x) which is equivalent to > >> (a)/(x*x), or just: a/(x^2). But now you do a/x*x, which is > >> equivalent to a*x/x (in the domain of real numbers). Furthermore, > >> a/x*x is a-(a%x), which does not even remotely match a/(x^2). > >> > >Been there, done that, don't want to repeat it... > > I am sorry I don't quite follow.
Once before a missed paren's caused a TCP congestion window bug that took 6 months before it was found...
-- Stephen Hemminger <shemminger@linux-foundation.org> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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