A processor system and method that reduces the number of register value copying made from alias registers to corresponding real (architectural) registers. One method entails not performing an alias register to real register copying if the incoming instruction does not designate a real register. Another method entails delaying alias register to real register copying until the corresponding reorder buffer (ROB) entry is actually written to. Yet another method entails not performing an alias register to real register copying if the ROB entry is the same as the existing ROB entry. And, still another method entails further delaying or stalling the allocation of an ROB entry.