https://github.com/python/cpython/commit/972cfaae3f1349a2b822a0003e96e980c59a402f commit: 972cfaae3f1349a2b822a0003e96e980c59a402f branch: main author: Marc Mueller <[email protected]> committer: JelleZijlstra <[email protected]> date: 2026-09-26T13:00:10-07:00 summary:
gh-138912: Add fast path for match class patterns without sub-patterns (#144820) Co-authored-by: Pieter Eendebak <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2026-02-14-16-19-22.gh-issue-138912.TKMC9K.rst M Doc/library/dis.rst M Include/internal/pycore_intrinsics.h M Lib/test/test_capi/test_opt.py M Python/codegen.c M Python/intrinsics.c diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst index ced19268dea2364..73e77f4707cf92a 100644 --- a/Doc/library/dis.rst +++ b/Doc/library/dis.rst @@ -1899,32 +1899,38 @@ iterations of the loop. The operand determines which intrinsic function is called: - +------------------------------------------+-----------------------------------+ - | Operand | Description | - +==========================================+===================================+ - | ``INTRINSIC_2_INVALID`` | Not valid | - +------------------------------------------+-----------------------------------+ - | ``INTRINSIC_PREP_RERAISE_STAR`` | Calculates the | - | | :exc:`ExceptionGroup` to raise | - | | from a ``try-except*``. | - +------------------------------------------+-----------------------------------+ - | ``INTRINSIC_TYPEVAR_WITH_BOUND`` | Creates a :class:`typing.TypeVar` | - | | with a bound. | - +------------------------------------------+-----------------------------------+ - | ``INTRINSIC_TYPEVAR_WITH_CONSTRAINTS`` | Creates a | - | | :class:`typing.TypeVar` with | - | | constraints. | - +------------------------------------------+-----------------------------------+ - | ``INTRINSIC_SET_FUNCTION_TYPE_PARAMS`` | Sets the ``__type_params__`` | - | | attribute of a function. | - +------------------------------------------+-----------------------------------+ - | ``INTRINSIC_ADD_CONDITIONAL_ANNOTATION`` | Adds an annotation index to the | - | | ``__conditional_annotations__`` | - | | set. | - +------------------------------------------+-----------------------------------+ + +------------------------------------------+-----------------------------------------+ + | Operand | Description | + +==========================================+=========================================+ + | ``INTRINSIC_2_INVALID`` | Not valid | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_PREP_RERAISE_STAR`` | Calculates the | + | | :exc:`ExceptionGroup` to raise | + | | from a ``try-except*``. | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_TYPEVAR_WITH_BOUND`` | Creates a :class:`typing.TypeVar` | + | | with a bound. | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_TYPEVAR_WITH_CONSTRAINTS`` | Creates a | + | | :class:`typing.TypeVar` with | + | | constraints. | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_SET_FUNCTION_TYPE_PARAMS`` | Sets the ``__type_params__`` | + | | attribute of a function. | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_ADD_CONDITIONAL_ANNOTATION`` | Adds an annotation index to the | + | | ``__conditional_annotations__`` | + | | set. | + +------------------------------------------+-----------------------------------------+ + | ``INTRINSIC_MATCH_CLASS_ISINSTANCE`` | Do :func:`isinstance` checks for | + | | :ref:`Class patterns <class-patterns>`. | + +------------------------------------------+-----------------------------------------+ .. versionadded:: 3.12 + .. versionchanged:: 3.16 + Added ``INTRINSIC_MATCH_CLASS_ISINSTANCE``. + .. opcode:: LOAD_SPECIAL diff --git a/Include/internal/pycore_intrinsics.h b/Include/internal/pycore_intrinsics.h index 447cea91716eca9..e8ddafed9123409 100644 --- a/Include/internal/pycore_intrinsics.h +++ b/Include/internal/pycore_intrinsics.h @@ -31,8 +31,9 @@ #define INTRINSIC_SET_FUNCTION_TYPE_PARAMS 4 #define INTRINSIC_SET_TYPEPARAM_DEFAULT 5 #define INTRINSIC_ADD_CONDITIONAL_ANNOTATION 6 +#define INTRINSIC_MATCH_CLASS_ISINSTANCE 7 -#define MAX_INTRINSIC_2 6 +#define MAX_INTRINSIC_2 7 typedef PyObject *(*intrinsic_func1)(PyThreadState* tstate, PyObject *value); typedef PyObject *(*intrinsic_func2)(PyThreadState* tstate, PyObject *value1, PyObject *value2); diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py index 36efab518781410..ca0545dba264f2a 100644 --- a/Lib/test/test_capi/test_opt.py +++ b/Lib/test/test_capi/test_opt.py @@ -5752,12 +5752,13 @@ def testfunc(n): def test_match_class(self): def testfunc(n): class A: + __match_args__ = ("val",) val = 1 x = A() ret = 0 for _ in range(n): match x: - case A(): + case A(1): ret += x.val return ret @@ -5766,7 +5767,7 @@ class A: uops = get_opnames(ex) self.assertIn("_MATCH_CLASS", uops) - self.assertEqual(count_ops(ex, "_POP_TOP_NOP"), 4) + self.assertEqual(count_ops(ex, "_POP_TOP_NOP"), 5) def test_dict_update(self): def testfunc(n): diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-02-14-16-19-22.gh-issue-138912.TKMC9K.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-14-16-19-22.gh-issue-138912.TKMC9K.rst new file mode 100644 index 000000000000000..6236c6335ceca3c --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-14-16-19-22.gh-issue-138912.TKMC9K.rst @@ -0,0 +1,2 @@ +Add fast path for :keyword:`match` class patterns without any sub-patterns +to improve performance by ~15%. diff --git a/Python/codegen.c b/Python/codegen.c index 71ec33724684dc6..7143d9abc4255e8 100644 --- a/Python/codegen.c +++ b/Python/codegen.c @@ -6245,6 +6245,13 @@ codegen_pattern_class(compiler *c, pattern_ty p, pattern_context *pc) if (nattrs) { RETURN_IF_ERROR(validate_kwd_attrs(c, kwd_attrs, kwd_patterns)); } + if (nargs + nattrs == 0) { + // Fast path if there are no sub-patterns + VISIT(c, expr, p->v.MatchClass.cls); + ADDOP_I(c, LOC(p), CALL_INTRINSIC_2, INTRINSIC_MATCH_CLASS_ISINSTANCE); + RETURN_IF_ERROR(jump_to_fail_pop(c, LOC(p), pc, POP_JUMP_IF_FALSE)); + return SUCCESS; + } VISIT(c, expr, p->v.MatchClass.cls); PyObject *attr_names = PyTuple_New(nattrs); if (attr_names == NULL) { diff --git a/Python/intrinsics.c b/Python/intrinsics.c index 52e2dc8a99d8640..dfa81baa654e123 100644 --- a/Python/intrinsics.c +++ b/Python/intrinsics.c @@ -287,6 +287,25 @@ add_conditional_annotation(PyThreadState* tstate, PyObject *conditional_annotati Py_RETURN_NONE; } +static PyObject * +match_class_isinstance(PyThreadState* tstate, PyObject *subject, PyObject *type) +{ + /* Fast path for class patterns with no sub-patterns, e.g. `case C():` + Equivalent to the isinstance check performed by _PyEval_MatchClass, + including the same TypeError when the pattern does not refer to a + class. */ + if (!PyType_Check(type)) { + _PyErr_SetString(tstate, PyExc_TypeError, + "class pattern must refer to a class"); + return NULL; + } + int res = PyObject_IsInstance(subject, type); + if (res < 0) { + return NULL; + } + return res ? Py_True : Py_False; +} + const intrinsic_func2_info _PyIntrinsics_BinaryFunctions[] = { INTRINSIC_FUNC_ENTRY(INTRINSIC_2_INVALID, no_intrinsic2) @@ -296,6 +315,7 @@ _PyIntrinsics_BinaryFunctions[] = { INTRINSIC_FUNC_ENTRY(INTRINSIC_SET_FUNCTION_TYPE_PARAMS, _Py_set_function_type_params) INTRINSIC_FUNC_ENTRY(INTRINSIC_SET_TYPEPARAM_DEFAULT, _Py_set_typeparam_default) INTRINSIC_FUNC_ENTRY(INTRINSIC_ADD_CONDITIONAL_ANNOTATION, add_conditional_annotation) + INTRINSIC_FUNC_ENTRY(INTRINSIC_MATCH_CLASS_ISINSTANCE, match_class_isinstance) }; #undef INTRINSIC_FUNC_ENTRY _______________________________________________ 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]
