python · brandtbucher · Apr 8, 2025 · Apr 8, 2025 · Apr 8, 2025
diff --git a/Lib/test/test_opcache.py b/Lib/test/test_opcache.py
@@ -550,6 +550,58 @@ def instantiate():
        with self.assertRaises(TypeError):
            instantiate()

+    def test_call_specialized_non_method_on_class(self):
+        class C:
+            pass
+        o = C()
+        for callable in (isinstance, len, str, tuple, type):
+            setattr(C, callable.__name__, callable)
+        for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
+            self.assertIs(o.isinstance("Spam", str), True)
+            self.assertEqual(o.len("Spam"), 4)
+            self.assertEqual(o.str("Spam"), "Spam")
+            self.assertEqual(o.tuple("Spam"), ("S", "p", "a", "m"))
+            self.assertIs(o.type("Spam"), str)
+
+    def test_call_specialized_non_method_on_instance(self):
+        class C:
+            pass
+        o = C()
+        for callable in (isinstance, len, str, tuple, type):
+            setattr(o, callable.__name__, callable)
+        for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
+            self.assertIs(o.isinstance("Spam", str), True)
+            self.assertEqual(o.len("Spam"), 4)
+            self.assertEqual(o.str("Spam"), "Spam")
+            self.assertEqual(o.tuple("Spam"), ("S", "p", "a", "m"))
+            self.assertIs(o.type("Spam"), str)
+
+    def test_call_specialized_method_on_class(self):
+        class C:
+            pass
+        o = C()
+        for callable in (isinstance, len, str, tuple, type):
+            setattr(C, callable.__name__, types.MethodType(callable, "Spam"))
+        for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
+            self.assertIs(o.isinstance(str), True)
+            self.assertEqual(o.len(), 4)
+            self.assertEqual(o.str(), "Spam")
+            self.assertEqual(o.tuple(), ("S", "p", "a", "m"))
+            self.assertIs(o.type(), str)
+
+    def test_call_specialized_method_on_instance(self):
+        class C:
+            pass
+        o = C()
+        for callable in (isinstance, len, str, tuple, type):
+            setattr(o, callable.__name__, types.MethodType(callable, "Spam"))
+        for _ in range(_testinternalcapi.SPECIALIZATION_THRESHOLD):
+            self.assertIs(o.isinstance(str), True)
+            self.assertEqual(o.len(), 4)
+            self.assertEqual(o.str(), "Spam")
+            self.assertEqual(o.tuple(), ("S", "p", "a", "m"))
+            self.assertIs(o.type(), str)
+

 def make_deferred_ref_count_obj():
    """Create an object that uses deferred reference counting.

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-04-08-08-59-25.gh-issue-131798.WrcdVS.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-04-08-08-59-25.gh-issue-131798.WrcdVS.rst
@@ -0,0 +1,2 @@
+Remove some unnecessary checks for some non-method :opcode:`CALL`
+specializations.
@@ -3912,10 +3912,10 @@ dummy_func(
            PyObject *arg_o = PyStackRef_AsPyObjectBorrow(arg);

            assert(oparg == 1);
-            DEOPT_IF(!PyStackRef_IsNull(null));
-            DEAD(null);
            DEOPT_IF(callable_o != (PyObject *)&PyType_Type);
            DEAD(callable);
+            assert(PyStackRef_IsNull(null));
+            DEAD(null);
            STAT_INC(CALL, hit);
            res = PyStackRef_FromPyObjectNew(Py_TYPE(arg_o));
            PyStackRef_CLOSE(arg);
@@ -3926,8 +3926,8 @@ dummy_func(
            PyObject *arg_o = PyStackRef_AsPyObjectBorrow(arg);

            assert(oparg == 1);
-            DEOPT_IF(!PyStackRef_IsNull(null));
            DEOPT_IF(callable_o != (PyObject *)&PyUnicode_Type);
+            assert(PyStackRef_IsNull(null));
            STAT_INC(CALL, hit);
            PyObject *res_o = PyObject_Str(arg_o);
            DEAD(null);
@@ -3948,8 +3948,8 @@ dummy_func(
            PyObject *arg_o = PyStackRef_AsPyObjectBorrow(arg);

            assert(oparg == 1);
-            DEOPT_IF(!PyStackRef_IsNull(null));
            DEOPT_IF(callable_o != (PyObject *)&PyTuple_Type);
+            assert(PyStackRef_IsNull(null));
            STAT_INC(CALL, hit);
            PyObject *res_o = PySequence_Tuple(arg_o);
            DEAD(null);
@@ -4036,20 +4036,15 @@ dummy_func(
            PyObject *callable_o = PyStackRef_AsPyObjectBorrow(callable[0]);
            DEOPT_IF(!PyType_Check(callable_o));
            PyTypeObject *tp = (PyTypeObject *)callable_o;
-            int total_args = oparg;
-            _PyStackRef *arguments = args;
-            if (!PyStackRef_IsNull(self_or_null[0])) {
-                arguments--;
-                total_args++;
-            }
+            DEOPT_IF(!PyStackRef_IsNull(self_or_null[0]));
            DEOPT_IF(tp->tp_vectorcall == NULL);
            STAT_INC(CALL, hit);
-            STACKREFS_TO_PYOBJECTS(arguments, total_args, args_o);
+            STACKREFS_TO_PYOBJECTS(args, oparg, args_o);
            if (CONVERSION_FAILED(args_o)) {
                DECREF_INPUTS();
                ERROR_IF(true, error);
            }
-            PyObject *res_o = tp->tp_vectorcall((PyObject *)tp, args_o, total_args, NULL);
+            PyObject *res_o = tp->tp_vectorcall((PyObject *)tp, args_o, oparg, NULL);
            STACKREFS_TO_PYOBJECTS_CLEANUP(args_o);
            DECREF_INPUTS();
            ERROR_IF(res_o == NULL, error);
@@ -4175,14 +4170,10 @@ dummy_func(
            /* len(o) */
            PyObject *callable_o = PyStackRef_AsPyObjectBorrow(callable[0]);

-            int total_args = oparg;
-            if (!PyStackRef_IsNull(self_or_null[0])) {
-                args--;
-                total_args++;
-            }
-            DEOPT_IF(total_args != 1);
+            assert(oparg == 1);
            PyInterpreterState *interp = tstate->interp;
            DEOPT_IF(callable_o != interp->callable_cache.len);
+            assert(PyStackRef_IsNull(self_or_null[0]));
            STAT_INC(CALL, hit);
            _PyStackRef arg_stackref = args[0];
            PyObject *arg = PyStackRef_AsPyObjectBorrow(arg_stackref);
@@ -4206,24 +4197,18 @@ dummy_func(
            /* isinstance(o, o2) */
            PyObject *callable_o = PyStackRef_AsPyObjectBorrow(callable);

-            int total_args = oparg;
-            _PyStackRef *arguments = args;
-            if (!PyStackRef_IsNull(self_or_null[0])) {
-                arguments--;
-                total_args++;
-            }
-            DEOPT_IF(total_args != 2);
+            assert(oparg == 2);
            PyInterpreterState *interp = tstate->interp;
            DEOPT_IF(callable_o != interp->callable_cache.isinstance);
+            assert(PyStackRef_IsNull(self_or_null[0]));
            STAT_INC(CALL, hit);
-            _PyStackRef cls_stackref = arguments[1];
-            _PyStackRef inst_stackref = arguments[0];
+            _PyStackRef cls_stackref = args[1];
+            _PyStackRef inst_stackref = args[0];
            int retval = PyObject_IsInstance(PyStackRef_AsPyObjectBorrow(inst_stackref), PyStackRef_AsPyObjectBorrow(cls_stackref));
            if (retval < 0) {
                ERROR_NO_POP();
            }
            res = retval ? PyStackRef_True : PyStackRef_False;
-            assert((!PyStackRef_IsNull(res)) ^ (_PyErr_Occurred(tstate) != NULL));
            DECREF_INPUTS();
        }


diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Remove some unnecessary checks for some non-method :opcode:`CALL`
		specializations.