PROCESSOR WITH SECOND JUMP EXECUTION UNIT FOR BRANCH MISPREDICTION

摘要

A secondary jump execution unit (JEU) is incorporated in a micro-processor to operate concurrently with a primary JEU, enabling the execution of simultaneous branch operations with possible detection of multiple branch mispredicts. When branch operations are executed on both JEUs in a same instruction cycle, mispredict processing for the secondary JEU is skidded into the primary JEU's dispatch pipeline such that the branch processing for the secondary JEU occurs after processing of the branch for the primary JEU and while the primary JEU is not processing a branch. Moreover, in cases when a nuke command is also received from a reorder buffer of the processor, the branch processing for the secondary JEU is further delayed to accommodate processing of the nuke on the primary JEU. Further embodiments support the promotion of the secondary JEU to have access to the mispredict mechanisms of the primary JEU in certain circumstances.

主权项

1. A processor comprising:
a first jump execution unit (JEU) to evaluate a first branch for a first branch mispredict; and a second JEU to evaluate a second branch for a second branch mispredict, the first branch and the second branch being evaluated concurrently.