RESERVATION STATION CIRCUIT FOR EXECUTION OF LOOP INSTRUCTIONS BY OUT-OF-ORDER PROCESSOR, ΑΝD RELATED METHOD, AND COMPUTER-READABLE MEDIA

摘要

Providing lower-overhead management of dataflow execution of loop instructions by out-of-order processors (OOPs), and related circuits, methods, and computer-readable media are disclosed. In one aspect, a reservation station circuit including multiple reservation station segments, each storing a loop instruction of a computer program loop is provided. Each reservation station segment also stores an instruction execution credit indicator indicative of whether the corresponding loop instruction may be provided for dataflow execution. The reservation station circuit further includes a dataflow monitor providing an entry for each loop instruction, each entry comprising a consumer count indicator and a reservation station (RS) tag count indicator. The dataflow monitor is configured to determine whether all consumer instructions of a loop instruction have executed based on the consumer count indicator and the RS tag count indicator for the loop instruction. If so, the dataflow monitor issues an instruction execution credit to the loop instruction.