Tim Peters <t...@python.org> added the comment:
Well, details matter ;-) Division in Python is expensive. In the exponentiation algorithm each reduction (in general) requires a 122-by-61 bit division. In egcd, after it gets going nothing exceeds 61 bits, and across iterations the inputs to the division step get smaller each time around. So, e.g., when Raymond tried a Fraction with denominator 5813, "almost all" the egcd divisions involved inputs each with a single internal Python "digit". But "almost all" the raise-to-the-(P-2) divisions involve a numerator with 5 internal digts and 3 in the denominator. Big difference, even if the total number of divisions is about the same. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue37863> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
