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| author | Mark Dickinson <dickinsm@gmail.com> | 2009-03-23 18:44:57 (GMT) |
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| committer | Mark Dickinson <dickinsm@gmail.com> | 2009-03-23 18:44:57 (GMT) |
| commit | 17e4fddb57049ed3a29cb667b630698973d946b8 (patch) | |
| tree | 326235f8fd541d6fc73e4cc600d44872c0908d4b /Misc | |
| parent | 798ee1a4c6d60a2e497f91357aafba988bd28ba7 (diff) | |
| download | cpython-17e4fddb57049ed3a29cb667b630698973d946b8.zip cpython-17e4fddb57049ed3a29cb667b630698973d946b8.tar.gz cpython-17e4fddb57049ed3a29cb667b630698973d946b8.tar.bz2 | |
Merged revisions 70542 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
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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Diffstat (limited to 'Misc')
| -rw-r--r-- | Misc/NEWS | 4 |
1 files changed, 4 insertions, 0 deletions
@@ -12,6 +12,10 @@ What's New in Python 3.1 alpha 2? Core and Builtins ----------------- +- Issue #5512: Rewrite PyLong long division algorithm (x_divrem) to + improve its performance. Long divisions and remainder operations + are now between 50% and 150% faster. + - Issue #4258: Make it possible to use base 2**30 instead of base 2**15 for the internal representation of integers, for performance reasons. Base 2**30 is enabled by default on 64-bit machines. Add |