Load Latency Speculation In An Out-Of-Order Computer Processor

摘要

Load latency speculation in an out-of-order computer processor, including: issuing a load instruction for execution, wherein the load instruction has a predetermined expected execution latency; issuing a dependent instruction wakeup signal on an instruction wakeup bus, wherein the dependent instruction wakeup signal indicates that the load instruction will be completed upon the expiration of the expected execution latency; determining, upon the expiration of the expected execution latency, whether the load instruction has completed; and responsive to determining that the load instruction has not completed upon the expiration of the expected execution latency, issuing a negative dependent instruction wakeup signal on the instruction wakeup bus, wherein the negative dependent instruction wakeup signal indicates that the load instruction has not completed upon the expiration of the expected execution latency.

主权项

1. A method of load latency speculation in an out-of-order computer processor, the method comprising:
issuing a load instruction for execution, wherein the load instruction has a predetermined expected execution latency; issuing a dependent instruction wakeup signal on an instruction wakeup bus, wherein the dependent instruction wakeup signal indicates that the load instruction will be completed upon the expiration of the expected execution latency; determining, upon the expiration of the expected execution latency, whether the load instruction has completed; and responsive to determining that the load instruction has not completed upon the expiration of the expected execution latency, issuing a negative dependent instruction wakeup signal on the instruction wakeup bus, wherein the negative dependent instruction wakeup signal indicates that the load instruction has not completed upon the expiration of the expected execution latency.