Abstract: A computer system includes a processor configured to generate a prediction by a branch predictor that a branch instruction will be taken or not taken by consulting a current state of a state machine, the state machine having at least one taken state and at least one not taken state. The processor is also configured to return the prediction to a processing unit and detect a result that the branch instruction was actually taken or actually not taken. The processor is further configured to, based on the prediction being different than the result or based on the prediction being weak and consistent with the result, consult a probability value being a static value and/or a value based on a history of outcomes of previous branch instructions, and based on the probability value having a selected value or being within a selected range, update the state machine.

Abstract: A computer system includes a first predictor circuit configured to generate a first predictor signal, and a second predictor circuit configured to generate a second predictor signal different from the first predictor signal. The computer system further includes a TIP arbiter configured to receive the first predictor signal and the second predictor signal, and to select one of the first predictor signal or the second predictor signal as a final prediction of a target address for a fetched branch instruction. The selection is based at least in part on a comparison between a branch address of the fetched branch instruction and a stored tag value, along with a counter value stored in the arbiter entry.

Abstract: A computer system includes a processor configured to generate a prediction by a branch predictor that a branch instruction will be taken or not taken by consulting a current state of a state machine, the state machine having at least one taken state and at least one not taken state. The processor is also configured to return the prediction to a processing unit and detect a result that the branch instruction was actually taken or actually not taken. The processor is further configured to, based on the prediction being different than the result or based on the prediction being weak and consistent with the result, consult a probability value being a static value and/or a value based on a history of outcomes of previous branch instructions, and based on the probability value having a selected value or being within a selected range, update the state machine.

Abstract: A processor comprising a processor pipeline comprising one or more execution units configured to execute branch instructions, a branch predictor associated with the processor pipeline and configured to predict a branch instruction prediction outcome, and the branch prediction unit. The branch predictor is turned off to save power and avoid miss-predictions when the branch predictor and/or branch prediction unit accuracy is lower than expected.

Abstract: A computer system includes a first predictor circuit configured to generate a first predictor signal, and a second predictor circuit configured to generate a second predictor signal different from the first predictor signal. The computer system further includes a TIP arbiter configured to receive the first predictor signal and the second predictor signal, and to select one of the first predictor signal or the second predictor signal as a final prediction of a target address for a fetched branch instruction. The selection is based at least in part on a comparison between a branch address of the fetched branch instruction and a stored tag value, along with a counter value stored in the arbiter entry.