Performance of int/long in Python 3
rosuav at gmail.com
Tue Mar 26 17:54:47 CET 2013
On Wed, Mar 27, 2013 at 3:41 AM, Cousin Stanley <cousinstanley at gmail.com> wrote:
> Chris Angelico wrote:
>> Once again, Py3 is slower on small integers than Py2.
> Chris Angelico
> Ubuntu Karmic.
> Pentium(R) Dual-Core CPU E6500 @ 2.93GHz.
> python inline range_sum forloop forloop_offset
> 2.6.4 2.7050 2.6492 6.5877 16.5168
> 3.1.1 4.4453 4.3731 12.4834 13.5001
> You do seem to have a slight py3 improvement
> under ubuntu for the forloop_offset case ....
Yes, that's correct. The forloop_offset one is using long integers in
all cases. (Well, on Py2 it's adding a series of ints to a long, but
the arithmetic always has to be done with longs.) Python 3 has had
some improvements done, but the main thing is that there's a massive
spike in the Py2 time, while Py3 has _already paid_ that cost - as
evidenced by the closeness of the forloop and forloop_offset times on
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