The PRECALL/CALL bytecode pair for calls is new (still in review at time of writing) and is not as efficient as it could be. Some possible improvements are: Transfer refcount of func when making a frame. NULL call_shape.kwnames after use instead of in PRECALL, as many specialized instructions already assert that it is NULL. Specialize the PRECALL instructions. Either for simple cases like `type(arg)` so we can skip the CALL, or for complex cases like `PythonClass(args)` where PRECALL can create object, and set up the frame so that `CALL` calls the __init__ function.

Possibly consider replacing the specializations for `str(arg)` and `tuple(arg)` with a more general bytecode that can be used for other objects as well.

 New changeset 2cea8c29cf975a8ad7d8c3ff19d1e836c2d54707 by Mark Shannon in branch 'main': bpo-46532: Reduce number of memory writes to update call_shape.kwnames. (GH-31231) https://github.com/python/cpython/commit/2cea8c29cf975a8ad7d8c3ff19d1e836c2d54707