STINNER Victor <vstin...@python.org> added the comment:
Py_OVERFLOWED() documentation says that the function is not reliable since C99. Python is using C99 since Python 3.6. /* Py_OVERFLOWED(X) * Return 1 iff a libm function overflowed. Set errno to 0 before calling * a libm function, and invoke this macro after, passing the function * result. * Caution: * This isn't reliable. C99 no longer requires libm to set errno under * any exceptional condition, but does require +- HUGE_VAL return * values on overflow. A 754 box *probably* maps HUGE_VAL to a * double infinity, and we're cool if that's so, unless the input * was an infinity and an infinity is the expected result. A C89 * system sets errno to ERANGE, so we check for that too. We're * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or * if the returned result is a NaN, or if a C89 box returns HUGE_VAL * in non-overflow cases. * X is evaluated more than once. * Some platforms have better way to spell this, so expect some #ifdef'ery. * * OpenBSD uses 'isinf()' because a compiler bug on that platform causes * the longer macro version to be mis-compiled. This isn't optimal, and * should be removed once a newer compiler is available on that platform. * The system that had the failure was running OpenBSD 3.2 on Intel, with * gcc 2.95.3. * * According to Tim's checkin, the FreeBSD systems use isinf() to work * around a FPE bug on that platform. */ ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45412> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
