Big claim in this paper， pushes against the common idea that more test-time compute should keep helping.

Claims a code model gets much better when it rethinks once （i.e. by looping once） inside itself， but worse when it keeps rethinking.

The first loop builds context， the second loop refines it， and later loops mostly disturb it.

The paper studies a faster design called Parallel Loop Transformer， where loops can run almost in parallel and share memory， so the authors can ask a cleaner question about how many loops are actually useful.