A Table-Based Application-Specific Prefetch Engine for Object-Oriented Embedded Systems

A table-based application-specific data prefetching mechanism is presented in this paper. This mechanism is proposed to improve the performance of the application specific instruction-set processors (ASIP) we develop customized to an object-oriented application. In this approach, we divide the data accesses of a class method into two conditional and unconditional parts. We supply the prefetch engine with the static information about each part to prefetch all data fields of an object required by a class method when the class method is invoked. Effective management of memory access patterns by dividing them based on the method to which they belong and storing the access information of nested loops using a simple structure are the merits of the proposed mechanism. In addition, by adding a prefetch flag to cache blocks, we eliminate a large number of prefetch related tag comparisons. The results show that the proposed mechanism reduces the cache miss ratio and prefetch related tag comparisons on average by 66% and 21%, respectively