bpo-37207: Use PEP 590 vectorcall to speed up frozenset()

Misc/NEWS.d/next/Core and Builtins/2020-03-17-22-35-29.bpo-37207.sBAV1j.rst

@@ -0,0 +1,2 @@
+Speed up calls to ``frozenset()`` by using the :pep:`590` ``vectorcall``
+calling convention. Patch by Dong-hee Na.

Objects/setobject.c

@@ -1063,36 +1063,73 @@ make_new_set_basetype(PyTypeObject *type, PyObject *iterable)
 /* The empty frozenset is a singleton */
 static PyObject *emptyfrozenset = NULL;
 
+static PyObject *
+make_new_frozenset(PyTypeObject *type, PyObject *iterable)
+{
+ if (iterable != NULL) {
+ /* frozenset(f) is idempotent */
+ if (PyFrozenSet_CheckExact(iterable)) {
+ Py_INCREF(iterable);
+ return iterable;
+ }
+ PyObject *res = make_new_set((PyTypeObject *)type, iterable);
+ if (res == NULL || PySet_GET_SIZE(res)) {
+ return res;
+ }
+ Py_DECREF(res);
+ }
+
+ // The empty frozenset is a singleton
+ if (emptyfrozenset == NULL) {
+ emptyfrozenset = make_new_set((PyTypeObject *)type, NULL);
+ }
+ Py_XINCREF(emptyfrozenset);
+ return emptyfrozenset;
+}
+
 static PyObject *
 frozenset_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
- PyObject *iterable = NULL, *result;
+ PyObject *iterable = NULL;
 
- if (type == &PyFrozenSet_Type && !_PyArg_NoKeywords("frozenset", kwds))
+ if (type == &PyFrozenSet_Type && !_PyArg_NoKeywords("frozenset", kwds)) {
  return NULL;
+ }
 
- if (!PyArg_UnpackTuple(args, type->tp_name, 0, 1, &iterable))
+ if (!PyArg_UnpackTuple(args, type->tp_name, 0, 1, &iterable)) {
  return NULL;
+ }
 
- if (type != &PyFrozenSet_Type)
+ if (type != &PyFrozenSet_Type) {
  return make_new_set(type, iterable);
+ }
 
  if (iterable != NULL) {
- /* frozenset(f) is idempotent */
- if (PyFrozenSet_CheckExact(iterable)) {
- Py_INCREF(iterable);
- return iterable;
- }
- result = make_new_set(type, iterable);
- if (result == NULL || PySet_GET_SIZE(result))
- return result;
- Py_DECREF(result);
+ return make_new_frozenset(type, iterable);
  }
- /* The empty frozenset is a singleton */
- if (emptyfrozenset == NULL)
- emptyfrozenset = make_new_set(type, NULL);
- Py_XINCREF(emptyfrozenset);
- return emptyfrozenset;
+ return make_new_frozenset(type, NULL);
+}
+
+static PyObject *
+frozenset_vectorcall(PyObject *type, PyObject * const*args,
+ size_t nargsf, PyObject *kwnames)
+{
+ assert(PyType_Check(type));
+
+ if (!_PyArg_NoKwnames("frozenset", kwnames)) {
+ return NULL;
+ }
+
+ Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
+ if (!_PyArg_CheckPositional("frozenset", nargs, 0, 1)) {
+ return NULL;
+ }
+
+ if (nargs) {
+ return make_new_frozenset((PyTypeObject *)type, args[0]);
+ }
+
+ return make_new_frozenset((PyTypeObject *)type, NULL);
 }
 
 static PyObject *
@@ -2283,6 +2320,7 @@ PyTypeObject PyFrozenSet_Type = {
  PyType_GenericAlloc, /* tp_alloc */
  frozenset_new, /* tp_new */
  PyObject_GC_Del, /* tp_free */
+ .tp_vectorcall = frozenset_vectorcall,
 };