SYSTEM AND METHOD FOR FAST REGISTER RENAMING BY COUNTING

摘要

PROBLEM TO BE SOLVED: To use the register set in a processor more efficiently by mapping sources and target architecture registers in instructions to one group of physical registers and generating a list of tags corresponding to physical registers which are not used here. SOLUTION: One given instruction is loaded to one execution unit and the list of tags corresponding to specific registers which are not used is generated. All the items in a table A for the physical registers are linked on logical OR basis to generate a vector for accurately discriminating which register is used by an instruction being executed. This vector is passed to a structure B which generates the tag of a physical register possibly assigned as a target to a following target although it is not used. The vector structure B generates a bit indicating the adequacy of the generated tag as well. The generated tag becomes ineffective only when the number of usable physical registers is insufficient.