A computer system comprising a data file having entries each of which is designed to hold data, an advanced and a completed mapping file each having entries each of which is designed to hold a data-file-entry address, an operation window that is a buffer to hold substances of operations waiting execution, and a state-modification queue that is designed to be able to hold a substance of a modification on the advanced mapping file for each clock cycle; wherein making a modification on the advanced mapping file, entering the substance of this modification into the state-modification queue, and entering substances of operations into the operation window are each to be done in one clock cycle, and operations held in the operation window are to be executed out of order. The system can attain high performance easily and utilize programs described in any machine language for traditional register-based/stack-based processors.