https://github.com/python/cpython/commit/5992238986df094e890a89376970aab6058a0759
commit: 5992238986df094e890a89376970aab6058a0759
branch: main
author: Donghee Na <[email protected]>
committer: corona10 <[email protected]>
date: 2026-03-28T09:48:53+09:00
summary:
gh-146381: Constant-fold frozendict subscript lookups via
REPLACE_OPCODE_IF_EVALUATES_PURE (gh-146490)
files:
M Lib/test/test_capi/test_opt.py
M Python/optimizer_bytecodes.c
M Python/optimizer_cases.c.h
M Python/optimizer_symbols.c
diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index 126bcedef99993..60f5cb6edbce43 100644
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -20,6 +20,10 @@
#For test of issue 136154
GLOBAL_136154 = 42
+# For frozendict JIT tests
+FROZEN_DICT_CONST = frozendict(x=1, y=2)
+
+
@contextlib.contextmanager
def clear_executors(func):
# Clear executors in func before and after running a block
@@ -4155,6 +4159,35 @@ def testfunc(n):
self.assertLessEqual(count_ops(ex, "_POP_TOP_INT"), 1)
self.assertIn("_POP_TOP_NOP", uops)
+ def test_binary_subscr_frozendict_lowering(self):
+ def testfunc(n):
+ x = 0
+ for _ in range(n):
+ x += FROZEN_DICT_CONST['x']
+ return x
+
+ res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+ self.assertEqual(res, TIER2_THRESHOLD)
+ self.assertIsNotNone(ex)
+ uops = get_opnames(ex)
+ self.assertIn("_INSERT_2_LOAD_CONST_INLINE_BORROW", uops)
+ self.assertNotIn("_BINARY_OP_SUBSCR_DICT", uops)
+
+ def test_binary_subscr_frozendict_const_fold(self):
+ def testfunc(n):
+ x = 0
+ for _ in range(n):
+ if FROZEN_DICT_CONST['x'] == 1:
+ 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)
+ # lookup result is folded to constant 1, so comparison is optimized
away
+ self.assertNotIn("_COMPARE_OP_INT", uops)
+
def test_binary_subscr_list_slice(self):
def testfunc(n):
x = 0
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index f5d059dea3ef0b..6702f3c5665133 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -485,6 +485,9 @@ dummy_func(void) {
res = sym_new_not_null(ctx);
ds = dict_st;
ss = sub_st;
+ if (sym_matches_type(dict_st, &PyFrozenDict_Type)) {
+ REPLACE_OPCODE_IF_EVALUATES_PURE(dict_st, sub_st, res);
+ }
}
op(_BINARY_OP_SUBSCR_LIST_SLICE, (list_st, sub_st -- res, ls, ss)) {
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index ba6817cfdf2c0b..dd1d2813a215ca 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -1327,6 +1327,54 @@
res = sym_new_not_null(ctx);
ds = dict_st;
ss = sub_st;
+ if (sym_matches_type(dict_st, &PyFrozenDict_Type)) {
+ if (
+ sym_is_safe_const(ctx, dict_st) &&
+ sym_is_safe_const(ctx, sub_st)
+ ) {
+ JitOptRef dict_st_sym = dict_st;
+ JitOptRef sub_st_sym = sub_st;
+ _PyStackRef dict_st = sym_get_const_as_stackref(ctx,
dict_st_sym);
+ _PyStackRef sub_st = sym_get_const_as_stackref(ctx,
sub_st_sym);
+ _PyStackRef res_stackref;
+ _PyStackRef ds_stackref;
+ _PyStackRef ss_stackref;
+ /* Start of uop copied from bytecodes for constant
evaluation */
+ PyObject *sub = PyStackRef_AsPyObjectBorrow(sub_st);
+ PyObject *dict = PyStackRef_AsPyObjectBorrow(dict_st);
+ assert(PyAnyDict_CheckExact(dict));
+ STAT_INC(BINARY_OP, hit);
+ PyObject *res_o;
+ int rc = PyDict_GetItemRef(dict, sub, &res_o);
+ if (rc == 0) {
+ _PyErr_SetKeyError(sub);
+ }
+ if (rc <= 0) {
+ JUMP_TO_LABEL(error);
+ }
+ res_stackref = PyStackRef_FromPyObjectSteal(res_o);
+ ds_stackref = dict_st;
+ ss_stackref = sub_st;
+ /* End of uop copied from bytecodes for constant
evaluation */
+ (void)ds_stackref;
+ (void)ss_stackref;
+ res = sym_new_const_steal(ctx,
PyStackRef_AsPyObjectSteal(res_stackref));
+ if (sym_is_const(ctx, res)) {
+ PyObject *result = sym_get_const(ctx, res);
+ 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] = res;
+ stack_pointer[-1] = ds;
+ stack_pointer[0] = ss;
+ stack_pointer += 1;
+ ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
+ break;
+ }
+ }
CHECK_STACK_BOUNDS(1);
stack_pointer[-2] = res;
stack_pointer[-1] = ds;
diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index 0bc3c5055812c4..d6f1c09490aac9 100644
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -282,7 +282,8 @@ _Py_uop_sym_is_safe_const(JitOptContext *ctx, JitOptRef sym)
return (typ == &PyUnicode_Type) ||
(typ == &PyFloat_Type) ||
(typ == &_PyNone_Type) ||
- (typ == &PyBool_Type);
+ (typ == &PyBool_Type) ||
+ (typ == &PyFrozenDict_Type);
}
void
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