IMPROVING BRANCH PREDICTION ACCURACY IN A PROCESSOR THAT SUPPORTS SPECULATIVE EXECUTION
摘要
One embodiment of the present invention provides a system which improves branch prediction accuracy in a processor that supports speculative-execution. During normal-execution mode, the system issues instructions in program order. Upon encountering a launch condition which causes a processor to enter a speculative-execution mode, the system performs a checkpoint and begins executing instructions in a speculative-execution mode. Upon encountering a branch instruction during speculative-execution mode, the system selects the subsequent instruction to be executed based on a current state of a branch predictor and does not update the current state of the branch predictor, thereby preventing the branch predictor from being incorrectly updated twice when re-executing the branch instruction after returning to normal-execution mode.
申请公布号
WO2006081049(A3)
申请公布日期
2007.07.05
申请号
WO2006US00354
申请日期
2006.01.05
申请人
SUN MICROSYSTEMS, INC.;CAPRIOLI, PAUL;YIP, SHERMAN, H.;CHAUDHRY, SHAILENDER