gh-148210: fix incorrect _BINARY_OP_SUBSCR_DICT JIT optimization (GH-148213)

Author: kumaraditya303

Lib/test/test_capi/test_opt.py

@@ -2340,6 +2340,21 @@ def testfunc(n):
         self.assertIn("_BINARY_OP_SUBSCR_DICT_KNOWN_HASH", uops)
         self.assertNotIn("_BINARY_OP_SUBSCR_DICT", uops)
 
+
+    def test_binary_op_subscr_constant_frozendict_known_hash(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                x += FROZEN_DICT_CONST['x']
+            return x
+
+        res, ex = self._run_with_optimizer(testfunc, 2 * TIER2_THRESHOLD)
+        self.assertEqual(res, 2 * TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertNotIn("_BINARY_OP_SUBSCR_DICT_KNOWN_HASH", uops)
+        self.assertNotIn("_BINARY_OP_SUBSCR_DICT", uops)
+
     def test_store_subscr_dict_known_hash(self):
         # str, int, bytes, float, complex, tuple and any python object which has generic hash
         def testfunc(n):

Python/optimizer_bytecodes.c

@@ -515,18 +515,18 @@ dummy_func(void) {
     }
 
     op(_BINARY_OP_SUBSCR_DICT, (dict_st, sub_st -- res, ds, ss)) {
-        PyObject *sub = sym_get_const(ctx, sub_st);
-        if (sub != NULL) {
-            optimize_dict_known_hash(ctx, dependencies, this_instr,
-                                     sub, _BINARY_OP_SUBSCR_DICT_KNOWN_HASH);
-        }
         res = sym_new_not_null(ctx);
         ds = dict_st;
         ss = sub_st;
+        PyObject *sub = sym_get_const(ctx, sub_st);
         if (sym_is_not_container(sub_st) &&
             sym_matches_type(dict_st, &PyFrozenDict_Type)) {
             REPLACE_OPCODE_IF_EVALUATES_PURE(dict_st, sub_st, res);
         }
+        else if (sub != NULL) {
+            optimize_dict_known_hash(ctx, dependencies, this_instr,
+                                     sub, _BINARY_OP_SUBSCR_DICT_KNOWN_HASH);
+        }
     }
 
     op(_BINARY_OP_SUBSCR_LIST_SLICE, (list_st, sub_st -- res, ls, ss)) {