[Findecanor]

> That said, the penalty for spilling the RSE (They called this part the Register Stack Engine) for say, an OS context switch was quite heavy since you'd have to write the whoe RSE state to memory.

I've read that the original intention for the RSE was that it would have saved its state in the background during spare bus cycles, which would have reduced the amount of data to save when a context switch happened.

Supposedly, this was not implemented in early models of the Itanium. Was it ever?