On Sat, Dec 18, 2021 at 9:24 AM Oscar Benjamin <oscar.j.benja...@gmail.com> wrote: > When I timed the result in Julia and in Python I found that the Julia > code was slower than the Python code. Of course I don't know how to > optimise Julia code so I asked one of my colleagues who does (and who > likes to proselytise about Julia). He pointed me to here where the > creator of Julia says "BigInts are currently pretty slow in Julia": > https://stackoverflow.com/questions/37193586/bigints-seem-slow-in-julia#:~:text=BigInts%20are%20currently%20pretty%20slow,that%20basic%20operations%20are%20fast. > I should make clear here that I used the gmpy2 library in Python for > the basic integer operations which is a wrapper around the same gmp > library that is used by Julia. That means that the basic integer > operations were being done by the same gmp library (a C library) in > each case. The timing differences between Python and Julia are purely > about overhead around usage of the same underlying C library.
Point of note: "Python actually uses a hybrid approach where small integer values are represented inline and only when values get too large are they represented as BigInts" might be sorta-kinda true for Python 2, but it's not true for Python 3. In all versions of CPython to date, all integers are objects, they're not "represented inline" (there *are* some languages that do this intrinsically, and I think that PyPy can sometimes unbox integers, but CPython never will); and the performance advantage of Py2's machine-sized integers clearly wasn't worth recreating in Py3. (It would be possible to implement it in Py3 as an optimization, while still having the same 'int' type for both, but nobody's done it.) So if Python's integers are faster than Julia's, it's not because there's any sort of hybrid approach, it's simply because CPython is more heavily optimized for that sort of work. (That said: I have no idea whether a StackOverflow answer from 2016 is still applicable.) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
