Mark Dickinson <dicki...@gmail.com> added the comment: Just to confirm the above:
In 2.6, PyFloat_FromString in Objects/floatobject.c ends up using the system strtod to parse "nan" and "-nan" (except that if the system strtod fails to recognise "nan" for some reason then it returns the result of 0.0 * Infinity instead, and in that case disregards the sign). In 2.7 and 3.x, it ends up calling _Py_parse_inf_or_nan in Python/pystrtod.c, and this returns 0.0 * Infinity for "nan" and -(0.0 * Infinity) for "-nan". And depending on compiler flags, 0.0 * Infinity ends up being either +nan (this usually seems to happen when optimization is on, so that the compiler itself evaluates 0.0 * Infinity), or -nan (which happens when there's no optimization and the FPU ends up doing the 0.0 * Infinity multiplication at runtime.) This should explain the results you're seeing. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue7281> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
