backport 3.15

Author: cocolato

Include/internal/pycore_uop_ids.h

@@ -2423,7 +2423,18 @@ def f(n):
         self.assertEqual(uops.count("_STORE_SUBSCR_DICT_KNOWN_HASH"), 1)
         self.assertEqual(uops.count("_GUARD_NOS_DICT_SUBSCRIPT"), 0)
         self.assertEqual(uops.count("_GUARD_NOS_DICT_STORE_SUBSCRIPT"), 0)
-        self.assertEqual(uops.count("_GUARD_TYPE"), 1)
+        self.assertEqual(uops.count("_GUARD_NOS_TYPE"), 1)
+
+    def test_dict_subscr_probable_type(self):
+        def f(d):
+            for _ in range(TIER2_THRESHOLD):
+                value = d["key"]
+            return value
+
+        res, ex = self._run_with_optimizer(f, {"key": 1})
+        self.assertEqual(res, 1)
+        self.assertIsNotNone(ex)
+        self.assertIn("_GUARD_NOS_TYPE", get_opnames(ex))
 
     def test_dict_subclass_subscr_with_override(self):
         class MyDict(dict):

Include/internal/pycore_uop_metadata.h

@@ -0,0 +1 @@
+Fix incorrect type guards for ``dict`` reads and writes in the experimental JIT.

Lib/test/test_capi/test_opt.py

@@ -3876,9 +3876,9 @@ dummy_func(
             next = item;
         }
 
-        tier2 op(_GUARD_TYPE_ITER, (expected_type/4, iter, null_or_index -- iter, null_or_index)) {
-            PyObject *iter_o = PyStackRef_AsPyObjectBorrow(iter);
-            EXIT_IF(Py_TYPE(iter_o) != (PyTypeObject *)expected_type);
+        tier2 op(_GUARD_NOS_TYPE, (expected_type/4, nos, unused -- nos, unused)) {
+            PyObject *nos_o = PyStackRef_AsPyObjectBorrow(nos);
+            EXIT_IF(Py_TYPE(nos_o) != (PyTypeObject *)expected_type);
         }
 
         tier2 op(_ITER_NEXT_INLINE, (iternext_fn/4, iter, null_or_index -- iter, null_or_index, next)) {