Method and system for power conservation in a hierarchical branch predictor

A system for conserving power in a hierarchical branch predictor system, comprising:

• a processor;
• multiple branch predictors, each of the branch predictors comprising various sizes of hierarchical storage, the branch predictors storing information about previously encountered branch instructions;
• and
• predictor logic and loop logic implemented by the processor, the predictor logic and the loop logic collectively performing a method, comprising:
• addressing the multiple branch predictors in parallel or sequentially;
• comparing the first branch prediction with previously-stored branch predictions to determine the existence of a branch prediction loop responsive to receiving a first branch prediction from one or more of the branch predictors, the branch prediction loop including a sequence of branch predictions that repeat as long as constituent predictions of the branches remain unchanged;
• associating the branch prediction loop with the branch predictors that provided each branch prediction, responsive to determining that a branch prediction loop exists;
• activating power saving on the branch predictors that are not associated with the branch prediction loop;
• and
• deactivating power saving upon determining that branch predictions are needed from branch predictors not associated with the branch prediction loop.