The problem isn't the hardware devoted to decoding or even executing instructions so much as the overall design and verification complexity. The existence of 2

The problem isn't the hardware devoted to decoding or even executing instructions so much as the overall design and verification complexity. The existence of 286 call gates has implications throughout the memory subsystem and now when you're adding your TSX transactional memory instructions you have to think carefully about how they interact with call gates and whether you could be introducing bugs and make sure you have unit tests to uncover those bugs.