Prefetching for array data in embedded Java hardware accelerator

Abstract

For improving the efficiency of a program, it is important to reduce stalls caused by memory access. Traditional programs usually spend much time on memory stalls when accessing lower-level memory, and so do Java programs. In order to reduce memory stall time, prefetching is a feasible solution. We observed some obvious properties of array access so that we could prefetch array data by taking advantage of these properties. We analyzed these properties and proposed a suitable array prefetching mechanism for embedded Java hardware accelerators so as to reduce the time spent on memory stalls. Our approach eliminates about 25% of array stall time on average and even up to 50% for some array-based programs.