[LLVMdev] MachineOperand Fixed Register

[dag at cray.com]

Is there any way to determine if a Register-type MachineOperand
represents a fixed machine register?  For example, call arguments must
end up in specific machine register but I don't see any way to ascertain
this from the information in MachineOperand.  Basically, I need to know
if I am allowed to rename a MachineOperand or not after register
allocation.

Thanks!

                           -David