Register file circuitry

摘要

Register file circuitry, for use in a processor or processor core, comprises a plurality of physical registers (320-32D-1) and a plurality of tag storing portions (340-34D-1) corresponding respectively to the physical registers. Each tag storing portion stores a tag representing a logical register ID allocated to the corresponding physical registers. A register selection unit (36) receives a logical register ID (R) and selects that one of the logical registers whose tag matches the received logical register ID. A tag changing unit (38) changes the stored tags so as to change a mapping between at least one physical register ID and one of the physical registers. Such register file circuitry can permit a mapping between logical register IDs and physical registers to be changed quickly and efficiently and can permit a desired physical register to be selected quickly.