gh-131798: Constant-fold _CONTAINS_OP_DICT for frozendict

Lib/test/test_capi/test_opt.py

@@ -4646,7 +4646,7 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
-        self.assertIn("_LOAD_CONST_INLINE_BORROW", uops)
+        self.assertGreaterEqual(count_ops(ex, "_LOAD_CONST_INLINE_BORROW"), 2)
         self.assertNotIn("_BINARY_OP_SUBSCR_DICT", uops)
 
     def test_binary_subscr_frozendict_const_fold(self):
@@ -4661,6 +4661,7 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
+        self.assertGreaterEqual(count_ops(ex, "_LOAD_CONST_INLINE_BORROW"), 3)
         # lookup result is folded to constant 1, so comparison is optimized away
         self.assertNotIn("_COMPARE_OP_INT", uops)
 
@@ -4676,8 +4677,39 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
+        self.assertGreaterEqual(count_ops(ex, "_LOAD_CONST_INLINE_BORROW"), 3)
         self.assertNotIn("_CONTAINS_OP_SET", uops)
 
+    def test_contains_op_frozendict_const_fold(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                if 'x' in FROZEN_DICT_CONST:
+                    x += 1
+            return x
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertGreaterEqual(count_ops(ex, "_LOAD_CONST_INLINE_BORROW"), 3)
+        self.assertNotIn("_CONTAINS_OP_DICT", uops)
+
+    def test_not_contains_op_frozendict_const_fold(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                if 'z' not in FROZEN_DICT_CONST:
+                    x += 1
+            return x
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertGreaterEqual(count_ops(ex, "_LOAD_CONST_INLINE_BORROW"), 3)
+        self.assertNotIn("_CONTAINS_OP_DICT", uops)
+
     def test_binary_subscr_list_slice(self):
         def testfunc(n):
             x = 0

Python/optimizer_bytecodes.c

@@ -761,6 +761,10 @@ dummy_func(void) {
         b = sym_new_type(ctx, &PyBool_Type);
         l = left;
         r = right;
+        if (sym_is_not_container(left) &&
+            sym_matches_type(right, &PyFrozenDict_Type)) {
+            REPLACE_OPCODE_IF_EVALUATES_PURE(left, right, b);
+        }
     }
 
     op(_LOAD_CONST, (-- value)) {