diff --git a/Misc/NEWS b/Misc/NEWS index dcccc4af66e..510748b2569 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -165,6 +165,7 @@ Core and Builtins - Issue #25660: Fix TAB key behaviour in REPL with readline. +- Issue #26288: Optimize PyLong_AsDouble. Library ------- diff --git a/Objects/longobject.c b/Objects/longobject.c index d05de8bf07a..c1edeacf62e 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -2769,6 +2769,13 @@ PyLong_AsDouble(PyObject *v) PyErr_SetString(PyExc_TypeError, "an integer is required"); return -1.0; } + if (Py_ABS(Py_SIZE(v)) <= 1) { + /* Fast path; single digit will always fit decimal. + This improves performance of FP/long operations by at + least 20%. This is even visible on macro-benchmarks. + */ + return (double)MEDIUM_VALUE((PyLongObject *)v); + } x = _PyLong_Frexp((PyLongObject *)v, &exponent); if ((x == -1.0 && PyErr_Occurred()) || exponent > DBL_MAX_EXP) { PyErr_SetString(PyExc_OverflowError,