International Business Machines Corporation
Hybrid and aggregrate branch prediction system with a tagged branch orientation predictor for prediction override or pass-through

Abstract:

Branch prediction in an instruction using a tag orientation predictor (TOP) is described. When a branch instruction is hotly mis-predicted by a hybrid branch predictor, the branch is tracked over a longer time period using the TOP. Once the TOP has collected enough data to confidently predict a branch prediction, the TOP is used to override a branch prediction from the hybrid predictor when the TOP branch prediction.