Processor including age tracking of issue queue instructions

摘要

An information handling system includes a processor with an instruction issue queue (IQ) that may perform age tracking operations. The issue queue IQ maintains or stores instructions that may issue out-of-order in an internal data store IDS. The IDS organizes instructions in a queue position (QPOS) addressing arrangement. An age matrix of the IQ maintains a record of relative instruction aging for those instructions within the IDS. The age matrix updates latches or other memory cell data to reflect the changes in IDS instruction ages during a dispatch operation into the IQ. During dispatch of one or more instructions, the age matrix may update only those latches that require data change to reflect changing IDS instruction ages. The age matrix employs row and column data and clock controls to individually update those latches requiring update. The issue queue may selectively clock a row and a column of cells of the age matrix that correspond to a dispatched instruction's queue position while leaving other cells unclocked to conserve power.