PROVIDING LOWER-OVERHEAD MANAGEMENT OF DATAFLOW EXECUTION OF LOOP INSTRUCTIONS BY OUT-OF-ORDER PROCESSORS (OOPs), AND RELATED CIRCUITS, METHODS, 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.

主权项

1. A reservation station circuit for managing dataflow execution of loop instructions in an out-of-order processor (OOP), comprising:
a plurality of reservation station segments, each comprising:
a loop instruction register configured to store a loop instruction; andan instruction execution credit indicator configured to store an instruction execution credit indicative of whether the loop instruction may be provided for dataflow execution; and a dataflow monitor comprising a plurality of entries corresponding to the loop instructions of the plurality of reservation station segments, each entry comprising:
a consumer count indicator indicative of a number of consumer instructions of a corresponding loop instruction; anda reservation station (RS) tag count indicator indicative of a number of executions of the consumer instructions; the dataflow monitor configured to:
determine whether all of the consumer instructions of a first loop instruction have executed based on the consumer count indicator and the RS tag count indicator for the first loop instruction; andresponsive to determining that all of the consumer instructions of the first loop instruction have executed, issue an instruction execution credit to a reservation station segment of the first loop instruction.