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.

9 files changed, 30 insertions, 9 deletions

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 1cb3ee6..587dad3 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2112,7 +2112,7 @@ PyTypeObject PyDict_Type = {
 	0,					/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_DICT_SUBCLASS,	/* tp_flags */
 	dictionary_doc,				/* tp_doc */
 	dict_traverse,				/* tp_traverse */
 	dict_tp_clear,				/* tp_clear */
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 0cd819c..c6ea6a4 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -300,7 +300,8 @@ static PyTypeObject _PyExc_BaseException = {
     PyObject_GenericGetAttr,    /*tp_getattro*/
     PyObject_GenericSetAttr,    /*tp_setattro*/
     0,                          /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,  /*tp_flags*/
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC |
+    	Py_TPFLAGS_BASE_EXC_SUBCLASS,  /*tp_flags*/
     PyDoc_STR("Common base class for all exceptions"), /* tp_doc */
     (traverseproc)BaseException_traverse, /* tp_traverse */
     (inquiry)BaseException_clear, /* tp_clear */
diff --git a/Objects/intobject.c b/Objects/intobject.c
index f504af7..9ffc295 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -1138,7 +1138,7 @@ PyTypeObject PyInt_Type = {
 	0,					/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_INT_SUBCLASS,	/* tp_flags */
 	int_doc,				/* tp_doc */
 	0,					/* tp_traverse */
 	0,					/* tp_clear */
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 3083b5f..2ac5e86 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2672,7 +2672,7 @@ PyTypeObject PyList_Type = {
 	0,					/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_LIST_SUBCLASS,	/* tp_flags */
  	list_doc,				/* tp_doc */
  	(traverseproc)list_traverse,		/* tp_traverse */
  	(inquiry)list_clear,			/* tp_clear */
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 4d886cd..ef3e242 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -3418,7 +3418,7 @@ PyTypeObject PyLong_Type = {
 	0,					/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_LONG_SUBCLASS,	/* tp_flags */
 	long_doc,				/* tp_doc */
 	0,					/* tp_traverse */
 	0,					/* tp_clear */
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 416457d..ca94d72 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -4017,7 +4017,7 @@ PyTypeObject PyString_Type = {
 	0,					/* tp_setattro */
 	&string_as_buffer,			/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_STRING_SUBCLASS,		/* tp_flags */
 	string_doc,				/* tp_doc */
 	0,					/* tp_traverse */
 	0,					/* tp_clear */
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index c85b35a..dacc3ee 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -669,7 +669,7 @@ PyTypeObject PyTuple_Type = {
 	0,					/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_TUPLE_SUBCLASS, /* tp_flags */
 	tuple_doc,				/* tp_doc */
  	(traverseproc)tupletraverse,		/* tp_traverse */
 	0,					/* tp_clear */
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 20b530c..4b0816e 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2288,7 +2288,7 @@ PyTypeObject PyType_Type = {
 	(setattrofunc)type_setattro,		/* tp_setattro */
 	0,					/* tp_as_buffer */
 	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
-		Py_TPFLAGS_BASETYPE,		/* tp_flags */
+		Py_TPFLAGS_BASETYPE | Py_TPFLAGS_TYPE_SUBCLASS,	/* tp_flags */
 	type_doc,				/* tp_doc */
 	(traverseproc)type_traverse,		/* tp_traverse */
 	(inquiry)type_clear,			/* tp_clear */
@@ -2967,6 +2967,26 @@ inherit_special(PyTypeObject *type, PyTypeObject *base)
 	if (type->tp_flags & base->tp_flags & Py_TPFLAGS_HAVE_CLASS) {
 		COPYVAL(tp_dictoffset);
 	}
+
+	/* Setup fast subclass flags */
+	if (PyType_IsSubtype(base, (PyTypeObject*)PyExc_BaseException))
+		type->tp_flags |= Py_TPFLAGS_BASE_EXC_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyType_Type))
+		type->tp_flags |= Py_TPFLAGS_TYPE_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyInt_Type))
+		type->tp_flags |= Py_TPFLAGS_INT_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyLong_Type))
+		type->tp_flags |= Py_TPFLAGS_LONG_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyString_Type))
+		type->tp_flags |= Py_TPFLAGS_STRING_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyUnicode_Type))
+		type->tp_flags |= Py_TPFLAGS_UNICODE_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyTuple_Type))
+		type->tp_flags |= Py_TPFLAGS_TUPLE_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyList_Type))
+		type->tp_flags |= Py_TPFLAGS_LIST_SUBCLASS;
+	else if (PyType_IsSubtype(base, &PyDict_Type))
+		type->tp_flags |= Py_TPFLAGS_DICT_SUBCLASS;
 }
 
 static void
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 290e8df..a49fe39 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -7967,7 +7967,7 @@ PyTypeObject PyUnicode_Type = {
     0,			 		/* tp_setattro */
     &unicode_as_buffer,			/* tp_as_buffer */
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
-	    Py_TPFLAGS_BASETYPE,	/* tp_flags */
+	    Py_TPFLAGS_BASETYPE | Py_TPFLAGS_UNICODE_SUBCLASS,	/* tp_flags */
     unicode_doc,			/* tp_doc */
     0,					/* tp_traverse */
     0,					/* tp_clear */