Re: Challenge: optimizing isqrt

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From	Serhiy Storchaka <storchaka@gmail.com>
Subject	Re: Challenge: optimizing isqrt
Date	Wed, 26 Nov 2014 18:24:59 +0200
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On 26.11.14 02:46, Dave Angel wrote:
> Unfortunately, for many values, the version of the function with >>1 is
> slower.  It's only when the argument is bigger than 10**40 that it's as
> much as 1% faster.  But it's true that for really large values, it's
> quicker.

Note that this path is used only for values above 2**53 (about 10**16). 
For all tested values from 10**16 to 10**40 the difference between two 
versions is not larger than 1% (in one or other direction). But the 
difference between different runs of the benchmark for the same version 
vary about 1%. So the difference between versions in this range doesn't 
matter.

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Thread

Challenge: optimizing isqrt Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-01 12:29 +1100
  Re: Challenge: optimizing isqrt Chris Angelico <rosuav@gmail.com> - 2014-11-01 13:12 +1100
  Re: Challenge: optimizing isqrt Christian Gollwitzer <auriocus@gmx.de> - 2014-11-01 09:02 +0100
    Re: Challenge: optimizing isqrt Christian Gollwitzer <auriocus@gmx.de> - 2014-11-01 09:09 +0100
    Re: Challenge: optimizing isqrt Chris Angelico <rosuav@gmail.com> - 2014-11-01 19:13 +1100
      Re: Challenge: optimizing isqrt Christian Gollwitzer <auriocus@gmx.de> - 2014-11-01 09:25 +0100
        Re: Challenge: optimizing isqrt Chris Angelico <rosuav@gmail.com> - 2014-11-01 19:33 +1100
          Re: Challenge: optimizing isqrt Christian Gollwitzer <auriocus@gmx.de> - 2014-11-01 09:38 +0100
            Re: Challenge: optimizing isqrt Chris Angelico <rosuav@gmail.com> - 2014-11-01 19:45 +1100
  Re: Challenge: optimizing isqrt Akira Li <4kir4.1i@gmail.com> - 2014-11-01 12:12 +0300
  Re: Challenge: optimizing isqrt Serhiy Storchaka <storchaka@gmail.com> - 2014-11-20 20:00 +0200
  Re: Challenge: optimizing isqrt Stephen Tucker <stephen_tucker@sil.org> - 2014-11-21 08:15 +0000
  Re: Challenge: optimizing isqrt Dave Angel <davea@davea.name> - 2014-11-23 10:43 -0500
  Re: Challenge: optimizing isqrt Serhiy Storchaka <storchaka@gmail.com> - 2014-11-25 21:31 +0200
  Re: Challenge: optimizing isqrt Dave Angel <davea@davea.name> - 2014-11-25 19:46 -0500
  Re: Challenge: optimizing isqrt Stephen Tucker <stephen_tucker@sil.org> - 2014-11-26 07:57 +0000
    Re: Challenge: optimizing isqrt Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-26 21:25 +1100
  Re: Challenge: optimizing isqrt Serhiy Storchaka <storchaka@gmail.com> - 2014-11-26 18:24 +0200

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