https://github.com/python/cpython/commit/1281be1caf9357ee2a68f7370a88b5cff0110e15 commit: 1281be1caf9357ee2a68f7370a88b5cff0110e15 branch: main author: Mikhail Efimov <[email protected]> committer: Fidget-Spinner <[email protected]> date: 2025-11-14T21:38:39Z summary:
gh-141367: Use CALL_LIST_APPEND instruction only for lists, not for list subclasses (GH-141398) Co-authored-by: Ken Jin <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2025-11-11-13-40-45.gh-issue-141367.I5KY7F.rst M Include/internal/pycore_code.h M Lib/test/test_opcache.py M Python/bytecodes.c M Python/executor_cases.c.h M Python/generated_cases.c.h M Python/specialize.c diff --git a/Include/internal/pycore_code.h b/Include/internal/pycore_code.h index 9748e036bf2874..cb9c0aa27a1785 100644 --- a/Include/internal/pycore_code.h +++ b/Include/internal/pycore_code.h @@ -311,8 +311,8 @@ PyAPI_FUNC(void) _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins _Py_CODEUNIT *instr, PyObject *name); PyAPI_FUNC(void) _Py_Specialize_StoreSubscr(_PyStackRef container, _PyStackRef sub, _Py_CODEUNIT *instr); -PyAPI_FUNC(void) _Py_Specialize_Call(_PyStackRef callable, _Py_CODEUNIT *instr, - int nargs); +PyAPI_FUNC(void) _Py_Specialize_Call(_PyStackRef callable, _PyStackRef self_or_null, + _Py_CODEUNIT *instr, int nargs); PyAPI_FUNC(void) _Py_Specialize_CallKw(_PyStackRef callable, _Py_CODEUNIT *instr, int nargs); PyAPI_FUNC(void) _Py_Specialize_BinaryOp(_PyStackRef lhs, _PyStackRef rhs, _Py_CODEUNIT *instr, diff --git a/Lib/test/test_opcache.py b/Lib/test/test_opcache.py index f23f8c053e8431..c7eea75117de8c 100644 --- a/Lib/test/test_opcache.py +++ b/Lib/test/test_opcache.py @@ -1872,6 +1872,33 @@ def for_iter_generator(): self.assert_specialized(for_iter_generator, "FOR_ITER_GEN") self.assert_no_opcode(for_iter_generator, "FOR_ITER") + @cpython_only + @requires_specialization_ft + def test_call_list_append(self): + # gh-141367: only exact lists should use + # CALL_LIST_APPEND instruction after specialization. + + r = range(_testinternalcapi.SPECIALIZATION_THRESHOLD) + + def list_append(l): + for _ in r: + l.append(1) + + list_append([]) + self.assert_specialized(list_append, "CALL_LIST_APPEND") + self.assert_no_opcode(list_append, "CALL_METHOD_DESCRIPTOR_O") + self.assert_no_opcode(list_append, "CALL") + + def my_list_append(l): + for _ in r: + l.append(1) + + class MyList(list): pass + my_list_append(MyList()) + self.assert_specialized(my_list_append, "CALL_METHOD_DESCRIPTOR_O") + self.assert_no_opcode(my_list_append, "CALL_LIST_APPEND") + self.assert_no_opcode(my_list_append, "CALL") + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-11-11-13-40-45.gh-issue-141367.I5KY7F.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-11-11-13-40-45.gh-issue-141367.I5KY7F.rst new file mode 100644 index 00000000000000..cb830fcd9e1270 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-11-11-13-40-45.gh-issue-141367.I5KY7F.rst @@ -0,0 +1,2 @@ +Specialize ``CALL_LIST_APPEND`` instruction only for lists, not for list +subclasses, to avoid unnecessary deopt. Patch by Mikhail Efimov. diff --git a/Python/bytecodes.c b/Python/bytecodes.c index 2c798855a71f55..8a7b784bb9eec2 100644 --- a/Python/bytecodes.c +++ b/Python/bytecodes.c @@ -3689,7 +3689,7 @@ dummy_func( #if ENABLE_SPECIALIZATION_FT if (ADAPTIVE_COUNTER_TRIGGERS(counter)) { next_instr = this_instr; - _Py_Specialize_Call(callable, next_instr, oparg + !PyStackRef_IsNull(self_or_null)); + _Py_Specialize_Call(callable, self_or_null, next_instr, oparg + !PyStackRef_IsNull(self_or_null)); DISPATCH_SAME_OPARG(); } OPCODE_DEFERRED_INC(CALL); @@ -4395,7 +4395,6 @@ dummy_func( assert(oparg == 1); PyObject *self_o = PyStackRef_AsPyObjectBorrow(self); - DEOPT_IF(!PyList_CheckExact(self_o)); DEOPT_IF(!LOCK_OBJECT(self_o)); STAT_INC(CALL, hit); int err = _PyList_AppendTakeRef((PyListObject *)self_o, PyStackRef_AsPyObjectSteal(arg)); diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h index 7ba2e9d0d92999..6796abf84ac5f4 100644 --- a/Python/executor_cases.c.h +++ b/Python/executor_cases.c.h @@ -6037,10 +6037,6 @@ callable = stack_pointer[-3]; assert(oparg == 1); PyObject *self_o = PyStackRef_AsPyObjectBorrow(self); - if (!PyList_CheckExact(self_o)) { - UOP_STAT_INC(uopcode, miss); - JUMP_TO_JUMP_TARGET(); - } if (!LOCK_OBJECT(self_o)) { UOP_STAT_INC(uopcode, miss); JUMP_TO_JUMP_TARGET(); diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h index a984da6dc912a2..01f65d9dd375f7 100644 --- a/Python/generated_cases.c.h +++ b/Python/generated_cases.c.h @@ -1533,7 +1533,7 @@ if (ADAPTIVE_COUNTER_TRIGGERS(counter)) { next_instr = this_instr; _PyFrame_SetStackPointer(frame, stack_pointer); - _Py_Specialize_Call(callable, next_instr, oparg + !PyStackRef_IsNull(self_or_null)); + _Py_Specialize_Call(callable, self_or_null, next_instr, oparg + !PyStackRef_IsNull(self_or_null)); stack_pointer = _PyFrame_GetStackPointer(frame); DISPATCH_SAME_OPARG(); } @@ -3470,11 +3470,6 @@ self = nos; assert(oparg == 1); PyObject *self_o = PyStackRef_AsPyObjectBorrow(self); - if (!PyList_CheckExact(self_o)) { - UPDATE_MISS_STATS(CALL); - assert(_PyOpcode_Deopt[opcode] == (CALL)); - JUMP_TO_PREDICTED(CALL); - } if (!LOCK_OBJECT(self_o)) { UPDATE_MISS_STATS(CALL); assert(_PyOpcode_Deopt[opcode] == (CALL)); diff --git a/Python/specialize.c b/Python/specialize.c index 2193596a331d3c..19433bc7a74319 100644 --- a/Python/specialize.c +++ b/Python/specialize.c @@ -1602,8 +1602,8 @@ specialize_class_call(PyObject *callable, _Py_CODEUNIT *instr, int nargs) } static int -specialize_method_descriptor(PyMethodDescrObject *descr, _Py_CODEUNIT *instr, - int nargs) +specialize_method_descriptor(PyMethodDescrObject *descr, PyObject *self_or_null, + _Py_CODEUNIT *instr, int nargs) { switch (descr->d_method->ml_flags & (METH_VARARGS | METH_FASTCALL | METH_NOARGS | METH_O | @@ -1627,8 +1627,11 @@ specialize_method_descriptor(PyMethodDescrObject *descr, _Py_CODEUNIT *instr, bool pop = (next.op.code == POP_TOP); int oparg = instr->op.arg; if ((PyObject *)descr == list_append && oparg == 1 && pop) { - specialize(instr, CALL_LIST_APPEND); - return 0; + assert(self_or_null != NULL); + if (PyList_CheckExact(self_or_null)) { + specialize(instr, CALL_LIST_APPEND); + return 0; + } } specialize(instr, CALL_METHOD_DESCRIPTOR_O); return 0; @@ -1766,7 +1769,7 @@ specialize_c_call(PyObject *callable, _Py_CODEUNIT *instr, int nargs) } Py_NO_INLINE void -_Py_Specialize_Call(_PyStackRef callable_st, _Py_CODEUNIT *instr, int nargs) +_Py_Specialize_Call(_PyStackRef callable_st, _PyStackRef self_or_null_st, _Py_CODEUNIT *instr, int nargs) { PyObject *callable = PyStackRef_AsPyObjectBorrow(callable_st); @@ -1784,7 +1787,9 @@ _Py_Specialize_Call(_PyStackRef callable_st, _Py_CODEUNIT *instr, int nargs) fail = specialize_class_call(callable, instr, nargs); } else if (Py_IS_TYPE(callable, &PyMethodDescr_Type)) { - fail = specialize_method_descriptor((PyMethodDescrObject *)callable, instr, nargs); + PyObject *self_or_null = PyStackRef_AsPyObjectBorrow(self_or_null_st); + fail = specialize_method_descriptor((PyMethodDescrObject *)callable, + self_or_null, instr, nargs); } else if (PyMethod_Check(callable)) { PyObject *func = ((PyMethodObject *)callable)->im_func; _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
