Two-level/Correlation predictor (Yeh-Patt’92,Pan-Soh-Rameh’92)

• Branches are correlated one to the other

• We keep a shift register with the most recent branch outcomes

• We index a bimodal table(Pattern History Table) with this branch history register (BHT)

• We can keep only one global BHT for all the branches (global 2-level predictor) or a BHT per each branch (local 2-level predictor). The same we can do for the PHT.

Author: Roberto Innocente