RE: Does Python optimize low-power functions?

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From	Nick Cash <nick.cash@npcinternational.com>
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Subject	RE: Does Python optimize low-power functions?
Thread-Topic	Does Python optimize low-power functions?
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Date	Fri, 6 Dec 2013 19:32:00 +0000
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>My question is, what do Python interpreters do with power operators where the power is a small constant, like 2?  Do they know to take the shortcut?

Nope:

Python 3.3.0 (default, Sep 25 2013, 19:28:08) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import dis
>>> dis.dis(lambda x: x*x)
  1           0 LOAD_FAST                0 (x) 
              3 LOAD_FAST                0 (x) 
              6 BINARY_MULTIPLY      
              7 RETURN_VALUE         
>>> dis.dis(lambda x: x**2)
  1           0 LOAD_FAST                0 (x) 
              3 LOAD_CONST               1 (2) 
              6 BINARY_POWER         
              7 RETURN_VALUE         


The reasons why have already been answered, I just wanted to point out that Python makes it extremely easy to check these sorts of things for yourself.

Thread

Does Python optimize low-power functions? John Ladasky <john_ladasky@sbcglobal.net> - 2013-12-06 10:16 -0800
  Re: Does Python optimize low-power functions? Neil Cerutti <neilc@norwich.edu> - 2013-12-06 19:01 +0000
  Re: Does Python optimize low-power functions? Robert Kern <robert.kern@gmail.com> - 2013-12-06 19:12 +0000
  RE: Does Python optimize low-power functions? Nick Cash <nick.cash@npcinternational.com> - 2013-12-06 19:32 +0000
    Re: Does Python optimize low-power functions? John Ladasky <john_ladasky@sbcglobal.net> - 2013-12-06 11:43 -0800
  Re: Does Python optimize low-power functions? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-12-06 20:57 +0000
  Re: Does Python optimize low-power functions? Michael Torrie <torriem@gmail.com> - 2013-12-07 19:00 -0700

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