Mark Dickinson <dicki...@gmail.com> added the comment:
There's also a potential double-rounding issue with ldexp, when the first argument is an int: ldexp(n, e) will first round n to a float, and then (again for results in the subnormal range) potentially also need to round the result. >>> n = 2**53 + 1 >>> e = -1128 >>> math.ldexp(n, e) 0.0 >>> n / (1 << -e) 5e-324 I'm a bit (but only a bit) surprised and disappointed by the Windows issue; thanks, Tim. It seems to be okay on Mac (Intel, macOS 11.6.1): >>> import math >>> d = math.nextafter(0.0, 1.0) >>> d 5e-324 >>> d3 = 7 * d >>> d3 3.5e-323 >>> d3 / 4.0 1e-323 >>> math.ldexp(d3, -2) 1e-323 ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45876> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
