Variant of SF patch 423181

For rich comparisons, use instance_getattr2() when possible to avoid
the expense of setting an AttributeError.  Also intern the name_op[]
table and use the interned strings rather than creating a new string
and interning it each time through.

Objects/classobject.c

@@ -1651,31 +1651,60 @@ instance_ipow(PyObject *v, PyObject *w, PyObject *z)
 
 
 /* Map rich comparison operators to their __xx__ namesakes */
-static char *name_op[] = {
+#define NAME_OPS 6
+static PyObject **name_op = NULL;
+
+static int 
+init_name_op()
+{
+	int i;
+	char *_name_op[] = {
 		"__lt__",
 		"__le__",
 		"__eq__",
 		"__ne__",
 		"__gt__",
 		"__ge__",
-};
+	};
+
+	name_op = (PyObject **)malloc(sizeof(PyObject *) * NAME_OPS);
+	if (name_op == NULL)
+		return -1;
+	for (i = 0; i < NAME_OPS; ++i) {
+		name_op[i] = PyString_InternFromString(_name_op[i]);
+		if (name_op[i] == NULL)
+			return -1;
+	}
+	return 0;
+}
 
 static PyObject *
 half_richcompare(PyObject *v, PyObject *w, int op)
 {
-	PyObject *name;
 	PyObject *method;
 	PyObject *args;
 	PyObject *res;
 
 	assert(PyInstance_Check(v));
 
-	name = PyString_InternFromString(name_op[op]);
-	if (name == NULL)
+	if (name_op == NULL) {
+		if (init_name_op() < 0)
 			return NULL;
-
-	method = PyObject_GetAttr(v, name);
-	Py_DECREF(name);
+	}
+	/* If the instance doesn't define an __getattr__ method, use
+	   instance_getattr2 directly because it will not set an
+	   exception on failure. */
+	if (((PyInstanceObject *)v)->in_class->cl_getattr == NULL) {
+		method = instance_getattr2((PyInstanceObject *)v, 
+					   name_op[op]);
+		if (method == NULL) {
+			assert(!PyErr_Occurred());
+			res = Py_NotImplemented;
+			Py_INCREF(res);
+			return res;
+		}
+	} else {
+		method = PyObject_GetAttr(v, name_op[op]);
 		if (method == NULL) {
 			if (!PyErr_ExceptionMatches(PyExc_AttributeError))
 				return NULL;
@@ -1684,6 +1713,7 @@ half_richcompare(PyObject *v, PyObject *w, int op)
 			Py_INCREF(res);
 			return res;
 		}
+	}
 
 	args = Py_BuildValue("(O)", w);
 	if (args == NULL) {