gh-132657: optimize `PySet_Contains` for `frozenset` (#141183)

diff --git a/Objects/setobject.c b/Objects/setobject.c
index 213bd821d8a1b982bae221c60e335138fffc515f..2401176576eb62b415893a69e0135bcc3c46fc09 100644 (file)
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -2747,7 +2747,9 @@ PySet_Contains(PyObject *anyset, PyObject *key)
         PyErr_BadInternalCall();
         return -1;
     }
-
+    if (PyFrozenSet_CheckExact(anyset)) {
+        return set_contains_key((PySetObject *)anyset, key);
+    }
     int rv;
     Py_BEGIN_CRITICAL_SECTION(anyset);
     rv = set_contains_key((PySetObject *)anyset, key);