Apparatus and method of branch prediction utilizing a comparison of a branch history table to an aliasing table

摘要

Improved conditional branch instruction prediction by detecting branch aliasing in a branch history table. Each entry in an aliasing table is associated with only one of a plurality of conditional branch instructions tracked by the branch history table. Prior to executing a conditional branch instruction, outcome of the execution of the conditional branch instruction is predicted utilizing the branch history table entry associated with the conditional branch instruction. Outcome of the execution of the conditional branch instruction is also predicted utilizing the aliasing table entry associated with the conditional branch instruction. Branch aliasing is detected by comparing the prediction made utilizing the branch history table with the prediction made utilizing the aliasing table. In response to the predictions being different, a determination is made that branch aliasing occurred, and the prediction made utilizing the aliasing table is utilized for predicting the outcome of the execution of the conditional branch instruction.