New submission from STINNER Victor: The algorithm for 2 ** n (long_pow) is slower than 1 << n algorithm (long_lshift). I propose to compute x**y as 1<<y if x==2 and y >= 0.
Attached patch implements this idea. According to my microbenchmark, it is 4x faster to small power (2**0 .. 2**1024) and up to 340x faster for large power (2**(2**28)). ---------- files: pow2.patch keywords: patch messages: 217800 nosy: haypo priority: normal severity: normal status: open title: Optimize 2 ** n: implement it as 1 << n type: performance versions: Python 3.5 Added file: http://bugs.python.org/file35138/pow2.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21420> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
