diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-07-06-18-44-00.gh-issue-94603.Q_03xV.rst b/Misc/NEWS.d/next/Core and Builtins/2022-07-06-18-44-00.gh-issue-94603.Q_03xV.rst
new file mode 100644
index 00000000000000..de4fe4d6df8c3a
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-07-06-18-44-00.gh-issue-94603.Q_03xV.rst
@@ -0,0 +1 @@
+Improve performance of ``list.pop`` for small lists.
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 1d32915b17a14b..b093f88a35fc47 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1022,21 +1022,29 @@ list_pop_impl(PyListObject *self, Py_ssize_t index)
PyErr_SetString(PyExc_IndexError, "pop index out of range");
return NULL;
}
- v = self->ob_item[index];
- if (index == Py_SIZE(self) - 1) {
- status = list_resize(self, Py_SIZE(self) - 1);
- if (status >= 0)
- return v; /* and v now owns the reference the list had */
- else
- return NULL;
+
+ PyObject **items = self->ob_item;
+ v = items[index];
+ const Py_ssize_t size_after_pop = Py_SIZE(self) - 1;
+ if (size_after_pop == 0) {
+ Py_INCREF(v);
+ status = _list_clear(self);
}
- Py_INCREF(v);
- status = list_ass_slice(self, index, index+1, (PyObject *)NULL);
- if (status < 0) {
- Py_DECREF(v);
+ else {
+ if ((size_after_pop - index) > 0) {
+ memmove(&items[index], &items[index+1], (size_after_pop - index) * sizeof(PyObject *));
+ }
+ status = list_resize(self, size_after_pop);
+ }
+ if (status >= 0) {
+ return v; // and v now owns the reference the list had
+ }
+ else {
+ // list resize failed, need to restore
+ memmove(&items[index+1], &items[index], (size_after_pop - index)* sizeof(PyObject *));
+ items[index] = v;
return NULL;
}
- return v;
}
/* Reverse a slice of a list in place, from lo up to (exclusive) hi. */
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