Patent ID: 9747103
Date: 2017-08-29
CPC Classifications: G06F

Claim:
1. A method for managing auxiliary branch prediction in a processing system comprising a primary branch predictor and an auxiliary branch predictor, the method comprising: locating a congruence class of the auxiliary branch predictor based on receiving a primary branch predictor misprediction indicator corresponding to a mispredicted target address of the primary branch predictor; identifying an entry in the congruence class having an auxiliary usefulness level set to a least useful level with respect to one or more other entries of the congruence class; installing auxiliary data corresponding to the mispredicted target address into the entry; initializing a protection limit of the entry to a non-zero value upon installing the auxiliary data; resetting the protection limit of the entry to the non-zero value based on determining that the auxiliary usefulness level of the entry exceeds a protection threshold; identifying the entry as unprotected based on having a zero value in the protection limit of the entry; identifying the entry as protected based on having the non-zero value in the protection limit of the entry; based on preventing an install of a protected least useful entry, decrementing the protection limit of the protected least useful entry; and resetting the auxiliary usefulness level of the entry to an initial value based on installing the auxiliary data.