diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-04-03-02-44-15.bpo-43706.jjsXlT.rst b/Misc/NEWS.d/next/Core and Builtins/2021-04-03-02-44-15.bpo-43706.jjsXlT.rst new file mode 100644 index 00000000000..ee859e37911 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2021-04-03-02-44-15.bpo-43706.jjsXlT.rst @@ -0,0 +1,2 @@ +Speed up calls to ``enumerate()`` by using the :pep:`590` ``vectorcall`` +calling convention. Patch by Dong-hee Na. diff --git a/Objects/enumobject.c b/Objects/enumobject.c index 4513831545b..b78230ddaeb 100644 --- a/Objects/enumobject.c +++ b/Objects/enumobject.c @@ -81,6 +81,45 @@ enum_new_impl(PyTypeObject *type, PyObject *iterable, PyObject *start) return (PyObject *)en; } +// TODO: Use AC when bpo-43447 is supported +static PyObject * +enumerate_vectorcall(PyObject *type, PyObject *const *args, + size_t nargsf, PyObject *kwnames) +{ + assert(PyType_Check(type)); + PyTypeObject *tp = (PyTypeObject *)type; + Py_ssize_t nargs = PyVectorcall_NARGS(nargsf); + Py_ssize_t nkwargs = 0; + if (nargs == 0) { + PyErr_SetString(PyExc_TypeError, + "enumerate() missing required argument 'iterable'"); + return NULL; + } + if (kwnames != NULL) { + nkwargs = PyTuple_GET_SIZE(kwnames); + } + + if (nargs + nkwargs == 2) { + if (nkwargs == 1) { + PyObject *kw = PyTuple_GET_ITEM(kwnames, 0); + if (!_PyUnicode_EqualToASCIIString(kw, "start")) { + PyErr_Format(PyExc_TypeError, + "'%S' is an invalid keyword argument for enumerate()", kw); + return NULL; + } + } + return enum_new_impl(tp, args[0], args[1]); + } + + if (nargs == 1 && nkwargs == 0) { + return enum_new_impl(tp, args[0], NULL); + } + + PyErr_Format(PyExc_TypeError, + "enumerate() takes at most 2 arguments (%d given)", nargs + nkwargs); + return NULL; +} + static void enum_dealloc(enumobject *en) { @@ -261,6 +300,7 @@ PyTypeObject PyEnum_Type = { PyType_GenericAlloc, /* tp_alloc */ enum_new, /* tp_new */ PyObject_GC_Del, /* tp_free */ + .tp_vectorcall = (vectorcallfunc)enumerate_vectorcall }; /* Reversed Object ***************************************************************/