1 files changed, 25 insertions, 2 deletions
diff --git a/Python/specialize.c b/Python/specialize.c
index bdcba46ed4..5cf327df47 100644
--- a/Python/specialize.c
+++ b/Python/specialize.c
@@ -491,8 +491,10 @@ initial_counter_value(void) {
 #define SPEC_FAIL_PYCFUNCTION_NOARGS 16
 #define SPEC_FAIL_BAD_CALL_FLAGS 17
 #define SPEC_FAIL_CLASS 18
-#define SPEC_FAIL_C_METHOD_CALL 19
-#define SPEC_FAIL_METHDESCR_NON_METHOD 20
+#define SPEC_FAIL_PYTHON_CLASS 19
+#define SPEC_FAIL_C_METHOD_CALL 20
+#define SPEC_FAIL_METHDESCR_NON_METHOD 21
+#define SPEC_FAIL_METHOD_CALL_CLASS 22
 
 /* COMPARE_OP */
 #define SPEC_FAIL_STRING_COMPARE 13
@@ -1263,6 +1265,27 @@ specialize_class_call(
     PyObject *callable, _Py_CODEUNIT *instr,
     int nargs, SpecializedCacheEntry *cache)
 {
+    assert(PyType_Check(callable));
+    PyTypeObject *tp = (PyTypeObject *)callable;
+    if (_Py_OPCODE(instr[-1]) == PRECALL_METHOD) {
+        SPECIALIZATION_FAIL(CALL_NO_KW, SPEC_FAIL_METHOD_CALL_CLASS);
+        return -1;
+    }
+    if (tp->tp_new == PyBaseObject_Type.tp_new) {
+        SPECIALIZATION_FAIL(CALL_NO_KW, SPEC_FAIL_PYTHON_CLASS);
+        return -1;
+    }
+    if (nargs == 1) {
+        if (tp == &PyType_Type) {
+            *instr = _Py_MAKECODEUNIT(CALL_NO_KW_TYPE_1, _Py_OPARG(*instr));
+            return 0;
+        }
+        if ((tp->tp_flags & Py_TPFLAGS_IMMUTABLETYPE) && tp->tp_vectorcall != NULL) {
+            cache->adaptive.version = tp->tp_version_tag;
+            *instr = _Py_MAKECODEUNIT(CALL_NO_KW_BUILTIN_CLASS_1, _Py_OPARG(*instr));
+            return 0;
+        }
+    }
     SPECIALIZATION_FAIL(CALL_NO_KW, SPEC_FAIL_CLASS);
     return -1;
 }