System, apparatus and method for generating nonsequential predictions to access a memory

A nonsequential predictor for predicting accesses to a memory comprising:

• a prediction generator configured to generate indexes and tags from addresses, the prediction generator generating a plurality of nonsequential predications for an address;
• a target cache including a number of prioritized ways, the target cache coupled to said prediction generator to store a plurality of trigger-target associations for a trigger address, said target cache including a number of ways each having memory locations for storing trigger-target associations each trigger-target association corresponding to a nonsequential prediction;
• wherein a trigger-target association stored in a first way is associated with a higher priority than another trigger-target association stored in a second way;
• and
• a priority adjuster to discover trigger-target associations, prioritize the trigger-target associations from the most recent, successful target addresses to the least recent, successful target addresses, and in response to detecting two target addresses with priorities improperly swapped, reprioritize trigger-target associations by inserting a highest priority trigger-target association into a highest priority way and inserting a previous highest priority trigger-target association into a second highest priority way, wherein the priority adjuster receives an indication of success of target addresses in providing data requested from said memory;
• the non-sequential predictor using the prioritized trigger-target associations to generate predictions in order of priority to generate a configurable number of predictions in order of priority for a selected address.

A computing system configured to manage accesses to a memory comprising:

• a central processing unit for executing program instructions and processing program data;
• a system memory containing said program instructions and said processing program data;
• and
• a memory processor coupled to said central processing unit and said system memory and configured to control predictive accesses to said system memory, said memory processor including:
• a prediction generator configured to generate indexes and tags from addresses, the prediction generator generating a plurality of nonsequential predications for a trigger address;
• a target cache including a number of prioritized ways each having memory locations storing trigger-target associations, wherein a trigger-target association stored in a first way is associated with a higher priority than another trigger-target association stored in a second way each trigger address having one or more associated target addresses, with each target address associated with a trigger address corresponding to a nonsequential prediction wherein a trigger-target association stored in a first way is associated with a higher priority than another trigger-target association stored in a second way,
• a priority adjuster configured to modify a priority for one of said trigger-target associations having a target address that matches a second address, said priority adjuster to discover trigger-target associations, prioritize the trigger-target associations from the most recent, successful target addresses to the least recent, successful target addresses, and in response to detecting two target addresses with priorities improperly swapped, reprioritize trigger-target associations by inserting a highest priority trigger-target association into a highest priority way and inserting a previous highest priority trigger-target association into a second highest priority way, wherein the priority adjuster receives an indication of success of target addresses in providing data requested from said memory;
• and
• a cache memory configured to communicate a reference to said priority adjuster when said central processing unit requests predictive information associated with said reference;
• the memory processor using the prioritized trigger-target associations to generate predictions in order of priority to generate a configurable number of predictions in order of priority for the same trigger address.