This is the fastest I could get on Intel GCC. I kept the memset() in to clear

the newly created tuples, but tuples added in the freelist are now cleared in
tupledealloc already (which is very cheap, because we are already
Py_XDECREF'ing all elements anyway).

Python should have a standard Py_ZAP macro like ZAP in pystate.c.

diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 159dc44fd07e7ee28622fb835f46a8eea5dd9912..9794bec8ba28dc1804fc3e1f02f3adc063d39ef7 100644 (file)
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -68,9 +68,8 @@ PyTuple_New(register int size)
                op = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
                if (op == NULL)
                        return NULL;
+               memset(op->ob_item, 0, size*sizeof(PyObject*));
        }
-       for (i=0; i < size; i++)
-               op->ob_item[i] = NULL;
 #if MAXSAVESIZE > 0
        if (size == 0) {
                free_tuples[0] = op;
@@ -165,19 +164,27 @@ tupledealloc(register PyTupleObject *op)
        Py_TRASHCAN_SAFE_BEGIN(op)
        if (len > 0) {
                i = len;
-               while (--i >= 0)
-                       Py_XDECREF(op->ob_item[i]);
 #if MAXSAVESIZE > 0
                if (len < MAXSAVESIZE &&
                    num_free_tuples[len] < MAXSAVEDTUPLES &&
                    op->ob_type == &PyTuple_Type)
                {
+                       while (--i >= 0) {
+                               PyObject* o = op->ob_item[i];
+                               if (o != NULL) {
+                                       op->ob_item[i] = NULL;
+                                       Py_DECREF(o);
+                               }
+                       }
                        op->ob_item[0] = (PyObject *) free_tuples[len];
                        num_free_tuples[len]++;
                        free_tuples[len] = op;
                        goto done; /* return */
                }
+               else
 #endif
+                       while (--i >= 0)
+                               Py_XDECREF(op->ob_item[i]);
        }
        op->ob_type->tp_free((PyObject *)op);
 done: