Replace PyObject_CallFunctionObjArgs() with fastcall

* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)

PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.

_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.

This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.

1 files changed, 2 insertions, 2 deletions

diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index 428d83c..eac07fb 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -1939,7 +1939,7 @@ struct_get_unpacker(const char *fmt, Py_ssize_t itemsize)
     if (format == NULL)
         goto error;
 
-    structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
+    structobj = _PyObject_CallArg1(Struct, format);
     if (structobj == NULL)
         goto error;
 
@@ -1978,7 +1978,7 @@ struct_unpack_single(const char *ptr, struct unpacker *x)
     PyObject *v;
 
     memcpy(x->item, ptr, x->itemsize);
-    v = PyObject_CallFunctionObjArgs(x->unpack_from, x->mview, NULL);
+    v = _PyObject_CallArg1(x->unpack_from, x->mview);
     if (v == NULL)
         return NULL;