REGISTER NAME CHANGE SYSTEM

PROBLEM TO BE SOLVED: To prevent data dependency and to execute a plurality of instructions at the same time. SOLUTION: This is a system for changing register names in a computer system where instructions can be executed in no special order, and composed of an instruction window 102 for storing the plurality of instructions, a temporary buffer 116 stored with instruction data in one of a plurality of storage locations in the instruction window, a dependency inspecting means 108 which confirms the dependency relation among the plurality of instructions, and a tag assigning means 122 which receives the data dependency result and outputs a tag indicating the address of the operated of a first instruction as one of the storage locations instead of a register address for the operand when the first instruction depends upon the last instruction among the plural instructions in the instruction window as to its operand.