This paper introduces a compiler-orchestrated prefetching system as a unified framework geared toward ameliorating the gap between processing speeds and memory access latencies. We focus the scope of the optimization on specific subsets of the program dependence graph that succinctly characterize the memory access pattern of both regular array-based applications and irregular pointer-intensive programs. We illustrate how program embedded precomputation via speculative execution can accurately predict and effectively prefetch future memory references with negligible overhead. The proposed techniques reduce the total running time of seven SPEC benchmarks and two OLDEN benchmarks by 27% on an Itanium 2 processor. The improvements are in addition to several state-of-the-art optimizations including software pipelining and data prefetching. In addition, we use cycle-accurate simulations to identify important and lightweight architectural innovations that further mitigate the memory system...
Rodric M. Rabbah, Hariharan Sandanagobalane, Mongk