From: Mark Dickinson <dickinsm@gmail.com>
Date: Mon, 23 Mar 2009 18:46:40 +0000 (+0000)
Subject: Blocked revisions 70547 via svnmerge
X-Git-Tag: 3.0~298
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a3bd7ed86be4f9ce2a2f3787fcc19504ac746936;p=thirdparty%2FPython%2Fcpython.git

Blocked revisions 70547 via svnmerge

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  r70547 | mark.dickinson | 2009-03-23 18:44:57 +0000 (Mon, 23 Mar 2009) | 21 lines

  Merged revisions 70542 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

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    r70542 | mark.dickinson | 2009-03-23 18:25:13 +0000 (Mon, 23 Mar 2009) | 14 lines

    Issue #5512: speed up the long division algorithm for Python longs.
    The basic algorithm remains the same; the most significant speedups
    come from the following three changes:

      (1) normalize by shifting instead of multiplying and dividing
      (2) the old algorithm usually did an unnecessary extra iteration of
          the outer loop; remove this.  As a special case, this means that
          long divisions with a single-digit result run twice as fast as
          before.
      (3) make inner loop much tighter.

    Various benchmarks show speedups of between 50% and 150% for long
    integer divisions and modulo operations.
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