OoO register renaming is a nearly orthogonal concept compared to SPARC style register windows. And I say nearly, mainly because if you try to implement both it increases the complexity more than you would think due to microarchitectual interactions between the two concepts.
Also, it's not really an x86 thing (for instance most Atoms don't have these extra registers), it's an in-order vs out-of-order thing. Most Power cores do have the larger bank and renaming.
Also, it's not really an x86 thing (for instance most Atoms don't have these extra registers), it's an in-order vs out-of-order thing. Most Power cores do have the larger bank and renaming.