Method and apparatus for scheduling the dispatch of instructions from a reservation station

摘要

Entries in a reservation station are efficiently scanned to find data-ready instructions for dispatch. A pseudo-FIFO scheduling approach is implemented wherein, rather than scanning every entry in the reservation station, the reservation station is segmented into groups of entries with each entry being scanned to determine which has the oldest entry in it. It is from the group of entries having the oldest entry that a ready pointer is cycled to search for data-ready instructions for dispatch to waiting execution units.