Variation of patch # 1624059 to speed up checking if an object is a subclass
of some of the common builtin types.
Use a bit in tp_flags for each common builtin type. Check the bit
to determine if any instance is a subclass of these common types.
The check avoids a function call and O(n) search of the base classes.
The check is done in the various Py*_Check macros rather than calling
PyType_IsSubtype().
All the bits are set in tp_flags when the type is declared
in the Objects/*object.c files because PyType_Ready() is not called
for all the types. Should PyType_Ready() be called for all types?
If so and the change is made, the changes to the Objects/*object.c files
can be reverted (remove setting the tp_flags). Objects/typeobject.c
would also have to be modified to add conditions
for Py*_CheckExact() in addition to each the PyType_IsSubtype check.
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 9532e32..9671692 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -95,14 +95,12 @@
/* */
#define PyExceptionClass_Check(x) \
- (PyClass_Check((x)) \
- || (PyType_Check((x)) && PyType_IsSubtype( \
- (PyTypeObject*)(x), (PyTypeObject*)PyExc_BaseException)))
-
+ (PyClass_Check((x)) || (PyType_Check((x)) && \
+ PyType_FastSubclass((PyTypeObject*)(x), Py_TPFLAGS_BASE_EXC_SUBCLASS)))
#define PyExceptionInstance_Check(x) \
(PyInstance_Check((x)) || \
- (PyType_IsSubtype((x)->ob_type, (PyTypeObject*)PyExc_BaseException)))
+ PyType_FastSubclass((x)->ob_type, Py_TPFLAGS_BASE_EXC_SUBCLASS))
#define PyExceptionClass_Name(x) \
(PyClass_Check((x)) \