Squeeze the flag elsewhere

Author: mdboom

Include/cpython/tupleobject.h

@@ -6,7 +6,6 @@ typedef struct {
     PyObject_VAR_HEAD
     /* Cached hash.  Initially set to -1. */
     Py_hash_t ob_hash;
-    int contains_mortal;
     /* ob_item contains space for 'ob_size' elements.
        Items must normally not be NULL, except during construction when
        the tuple is not yet visible outside the function that builds it. */
@@ -29,6 +28,8 @@ static inline Py_ssize_t PyTuple_GET_SIZE(PyObject *op) {
 
 #define PyTuple_GET_ITEM(op, index) (_PyTuple_CAST(op)->ob_item[(index)])
 
+#define _PyTuple_UPDATE_IMMORTAL_CHILD(tuple, item) if (!_Py_IsImmortal((item))) { ((PyObject *)tuple)->ob_flags &= ~_Py_IMMORTAL_CHILDREN_FLAG; }
+
 /* Function *only* to be used to fill in brand new tuples */
 static inline void
 PyTuple_SET_ITEM(PyObject *op, Py_ssize_t index, PyObject *value) {
@@ -37,7 +38,7 @@ PyTuple_SET_ITEM(PyObject *op, Py_ssize_t index, PyObject *value) {
     assert(index < Py_SIZE(tuple));
     tuple->ob_item[index] = value;
     if (value != NULL) {
-        tuple->contains_mortal |= !_Py_IsImmortal(value);
+        _PyTuple_UPDATE_IMMORTAL_CHILD(tuple, value);
     }
 }
 #define PyTuple_SET_ITEM(op, index, value) \

Include/internal/pycore_runtime_init.h

@@ -108,7 +108,6 @@ extern PyTypeObject _PyExc_MemoryError;
                 .tuple_empty = { \
                     .ob_base = _PyVarObject_HEAD_INIT(&PyTuple_Type, 0), \
                     .ob_hash = _PyTuple_HASH_EMPTY, \
-                    .contains_mortal = 0, \
                 }, \
                 .hamt_bitmap_node_empty = { \
                     .ob_base = _PyVarObject_HEAD_INIT(&_PyHamt_BitmapNode_Type, 0), \

Include/internal/pycore_tuple.h

@@ -44,7 +44,7 @@ typedef struct {
 static inline void
 _PyTuple_Recycle(PyObject *op)
 {
-    ((PyTupleObject *)op)->contains_mortal = 0;
+    op->ob_flags |= _Py_IMMORTAL_CHILDREN_FLAG;
     _PyTuple_RESET_HASH_CACHE(op);
     if (!_PyObject_GC_IS_TRACKED(op)) {
         _PyObject_GC_TRACK(op);

Include/refcount.h

@@ -21,6 +21,7 @@ cleanup during runtime finalization.
 
 #define _Py_STATICALLY_ALLOCATED_FLAG 4
 #define _Py_IMMORTAL_FLAGS 1
+#define _Py_IMMORTAL_CHILDREN_FLAG 2
 
 #if SIZEOF_VOID_P > 4
 /*