Branch misprediction behavior suppression on zero predicate branch mispredict

摘要

A method for suppressing branch misprediction behavior is contemplated in which a conditional branch instruction that would cause the flow of control to branch around instructions in response to a determination that a predicate vector is null is predicted not taken. However, in response to detecting that the prediction is incorrect, misprediction behavior is inhibited.

主权项

1. A method comprising:
generating a prediction that predicts that a flow of control of program instruction execution is not altered responsive to execution of a conditional flow control instruction, wherein the conditional flow control instruction alters the flow of control in response to a determination that each of one or more elements of a predicate vector are null; detecting that the prediction is incorrect; and inhibiting misprediction behavior for the conditional flow control instruction in response to detecting that the prediction is incorrect, wherein inhibiting misprediction behavior includes inhibiting a flush, from an execution pipeline of a processor, of program instructions in program order between the conditional flow control instruction and an instruction target.