Predictors with Adaptive Prediction Threshold

A computer program product in a computer usable medium having computer usable program code stored thereon, the computer usable program code for execution by a computer, comprising:

• computer usable program code for obtaining a count value of a prediction state counter in an entry in a pattern history table, wherein the count value represents a prediction state of a prediction state machine for the entry;
• computer usable program code for changing one or more count values in a set of counters allocated to the entry in the pattern history table based on the count value of the prediction state counter in the entry;
• and
• computer usable program code for adjusting a prediction threshold of the prediction state machine for the entry based on an analysis of the changed one or more count values in the set of counters, wherein the prediction threshold is adjusted by changing a count value in a prediction threshold counter in the entry in the pattern history table, and wherein adjusting the prediction threshold redefines predictions provided by the prediction state machine.

An apparatus comprising:

• a bus;
• a storage device connected to the bus, wherein the storage device contains computer usable code;
• at least one managed device connected to the bus;
• a communications unit connected to the bus;
• and
• a processing unit connected to the bus, wherein the processing unit executes the computer usable code to obtain a count value of a prediction state counter in an entry in a pattern history table, wherein the count value represents a prediction state of a prediction state machine for the entry;
• change one or more count values in a set of counters allocated to the entry in the pattern history table based on the count value of the prediction state counter in the entry;
• and adjust a prediction threshold of the prediction state machine for the entry based on an analysis of the changed one or more count values in the set of counters, wherein the prediction threshold is adjusted by changing a count value in a prediction threshold counter in the entry in the pattern history table, and wherein adjusting the prediction threshold redefines predictions provided by the prediction state machine.