gh-148083: Constant-fold _CONTAINS_OP_SET for frozenset (gh-148084)

diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index 022f05bbe37fa42e804894b32fdd7ff7fc79bfaa..56f90194b480a17c91ffae2de0428b12623aee97 100644 (file)
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -23,6 +23,9 @@ GLOBAL_136154 = 42
 # For frozendict JIT tests
 FROZEN_DICT_CONST = frozendict(x=1, y=2)
 
+# For frozenset JIT tests
+FROZEN_SET_CONST = frozenset({1, 2, 3})
+
 class _GenericKey:
     pass
 
@@ -2169,7 +2172,8 @@ class TestUopsOptimization(unittest.TestCase):
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
         self.assertNotIn("_GUARD_TOS_ANY_SET", uops)
-        self.assertIn("_CONTAINS_OP_SET", uops)
+        # _CONTAINS_OP_SET is constant-folded away for frozenset literals
+        self.assertIn("_INSERT_2_LOAD_CONST_INLINE_BORROW", uops)
 
     def test_remove_guard_for_known_type_tuple(self):
         def f(n):
@@ -4399,6 +4403,20 @@ class TestUopsOptimization(unittest.TestCase):
         # lookup result is folded to constant 1, so comparison is optimized away
         self.assertNotIn("_COMPARE_OP_INT", uops)
 
+    def test_contains_op_frozenset_const_fold(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                if 1 in FROZEN_SET_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.assertNotIn("_CONTAINS_OP_SET", uops)
+
     def test_binary_subscr_list_slice(self):
         def testfunc(n):
             x = 0

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-04-04-20-59-12.gh-issue-148083.9ZHNBN.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-04-20-59-12.gh-issue-148083.9ZHNBN.rst
new file mode 100644 (file)
index 0000000..fea4659
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-04-04-20-59-12.gh-issue-148083.9ZHNBN.rst
@@ -0,0 +1 @@
+Constant-fold ``_CONTAINS_OP_SET`` for :class:`frozenset`. Patch by Donghee Na.

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 4672a272fc92034cf89af2a026a06da8667dfb21..2953311b3926002ceb45b1fb4bccedd0d139bd39 100644 (file)
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -30,6 +30,7 @@
 #include "pycore_unicodeobject.h"
 #include "pycore_ceval.h"
 #include "pycore_floatobject.h"
+#include "pycore_setobject.h"
 
 #include <stdarg.h>
 #include <stdbool.h>

diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index dfb97625bf924fcbfecf773c581cc23b70688727..6e9a34384ba5319931662d6c5540834075dd0ef9 100644 (file)
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -706,6 +706,9 @@ dummy_func(void) {
         b = sym_new_type(ctx, &PyBool_Type);
         l = left;
         r = right;
+        if (sym_matches_type(right, &PyFrozenSet_Type)) {
+            REPLACE_OPCODE_IF_EVALUATES_PURE(left, right, b);
+        }
     }
 
     op(_CONTAINS_OP_DICT, (left, right -- b, l, r)) {

diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 4643a0ed0c5f9d5adbf8c5780d325e414ccd5632..dc00b6bc1397f54f0c575329d07c4c5f3d5a6a14 100644 (file)
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -2993,6 +2993,50 @@
             b = sym_new_type(ctx, &PyBool_Type);
             l = left;
             r = right;
+            if (sym_matches_type(right, &PyFrozenSet_Type)) {
+                if (
+                    sym_is_safe_const(ctx, left) &&
+                    sym_is_safe_const(ctx, right)
+                ) {
+                    JitOptRef left_sym = left;
+                    JitOptRef right_sym = right;
+                    _PyStackRef left = sym_get_const_as_stackref(ctx, left_sym);
+                    _PyStackRef right = sym_get_const_as_stackref(ctx, right_sym);
+                    _PyStackRef b_stackref;
+                    _PyStackRef l_stackref;
+                    _PyStackRef r_stackref;
+                    /* Start of uop copied from bytecodes for constant evaluation */
+                    PyObject *left_o = PyStackRef_AsPyObjectBorrow(left);
+                    PyObject *right_o = PyStackRef_AsPyObjectBorrow(right);
+                    assert(PyAnySet_CheckExact(right_o));
+                    STAT_INC(CONTAINS_OP, hit);
+                    int res = _PySet_Contains((PySetObject *)right_o, left_o);
+                    if (res < 0) {
+                        JUMP_TO_LABEL(error);
+                    }
+                    b_stackref = (res ^ oparg) ? PyStackRef_True : PyStackRef_False;
+                    l_stackref = left;
+                    r_stackref = right;
+                    /* End of uop copied from bytecodes for constant evaluation */
+                    (void)l_stackref;
+                    (void)r_stackref;
+                    b = sym_new_const_steal(ctx, PyStackRef_AsPyObjectSteal(b_stackref));
+                    if (sym_is_const(ctx, b)) {
+                        PyObject *result = sym_get_const(ctx, b);
+                        if (_Py_IsImmortal(result)) {
+                            // Replace with _INSERT_2_LOAD_CONST_INLINE_BORROW since we have two inputs and an immortal result
+                            ADD_OP(_INSERT_2_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
+                        }
+                    }
+                    CHECK_STACK_BOUNDS(1);
+                    stack_pointer[-2] = b;
+                    stack_pointer[-1] = l;
+                    stack_pointer[0] = r;
+                    stack_pointer += 1;
+                    ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
+                    break;
+                }
+            }
             CHECK_STACK_BOUNDS(1);
             stack_pointer[-2] = b;
             stack_pointer[-1] = l;

diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index a0ee175fd10c1a909a73d58e37c9404e8c3d8791..2614bcd430a2c50336f99a225a4485c97763a66b 100644 (file)
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -283,7 +283,8 @@ _Py_uop_sym_is_safe_const(JitOptContext *ctx, JitOptRef sym)
            (typ == &PyFloat_Type) ||
            (typ == &_PyNone_Type) ||
            (typ == &PyBool_Type) ||
-           (typ == &PyFrozenDict_Type);
+           (typ == &PyFrozenDict_Type) ||
+           (typ == &PyFrozenSet_Type);
 }
 
 void