1. An apparatus comprising: first storage logic to store a first portion of a dataword; second storage logic to store a second portion of the dataword; determination logic to determine a condition of the dataword; third storage logic to store a result generated by the determination logic; and selection logic to select, based on the contents of the third storage logic, one of the contents of the second storage logic and a replacement value that depends on the contents of a predetermined bit of the first storage logic.