Optimize.

Objects/classobject.c

@@ -135,23 +135,31 @@ method___reduce___impl(PyMethodObject *self)
     PyObject *funcself = PyMethod_GET_SELF(self);
     PyObject *func = PyMethod_GET_FUNCTION(self);
     PyObject *funcname = PyObject_GetAttr(func, &_Py_ID(__name__));
+    Py_ssize_t len;
     if (funcname == NULL) {
         return NULL;
     }
-    PyObject *name = PyObject_GetAttr((PyObject *)Py_TYPE(funcself),
-                                      &_Py_ID(__name__));
-    if (name == NULL) {
-        Py_DECREF(funcname);
-        return NULL;
-    }
-    PyObject *mangled = _Py_Mangle(name, funcname);
-    Py_DECREF(name);
-    Py_DECREF(funcname);
-    if (mangled == NULL) {
-        return NULL;
+    if (PyUnicode_Check(funcname) &&
+        (len = PyUnicode_GET_LENGTH(funcname)) > 2 &&
+        PyUnicode_READ_CHAR(funcname, 0) == '_' &&
+        PyUnicode_READ_CHAR(funcname, 1) == '_' &&
+        !(PyUnicode_READ_CHAR(funcname, len-1) == '_' &&
+          PyUnicode_READ_CHAR(funcname, len-2) == '_'))
+    {
+        PyObject *name = PyObject_GetAttr((PyObject *)Py_TYPE(funcself),
+                                          &_Py_ID(__name__));
+        if (name == NULL) {
+            Py_DECREF(funcname);
+            return NULL;
+        }
+        Py_SETREF(funcname, _Py_Mangle(name, funcname));
+        Py_DECREF(name);
+        if (funcname == NULL) {
+            return NULL;
+        }
     }
     return Py_BuildValue(
-            "N(ON)", _PyEval_GetBuiltin(&_Py_ID(getattr)), funcself, mangled);
+            "N(ON)", _PyEval_GetBuiltin(&_Py_ID(getattr)), funcself, funcname);
 }
 
 static PyMethodDef method_methods[] = {