[Python-Dev] 64 bit units in PyLong (original) (raw)
Victor Stinner victor.stinner at gmail.com
Mon Jul 3 04:05:20 EDT 2017
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2017-07-03 6:52 GMT+02:00 Siyuan Ren <netheril96 at gmail.com>:
The current PyLong implementation represents arbitrary precision integers in units of 15 or 30 bits. I presume the purpose is to avoid overflow in addition , subtraction and multiplication. But compilers these days offer intrinsics that allow one to access the overflow flag, and to obtain the result of 64 bit multiplication as a 128 bit number.
The question is the performance. Is it fast? :-)
You can try to write a patch and run a benchmark.
See for example http://pyperformance.readthedocs.io/ for benchmarks.
Victor
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