Re-order buffer: subtleties

• ROB is also a good place to do memory disambiguation and to delay memory writes until committed
• ROB must actually commit multiple inst$^{\rm n}$s per cycle if it is to keep up with multiple issue
• What happens when a second conditional branch is encountered before a preceding one is committed?
• How to reduce misprediction penalty?
• How big should the ROB be?

  (ROB size is sometimes called the window, since this is the extent to which the processor looks ahead to find work to do)