A compiler-directed cache coherence scheme using data prefetching

Abstract

Cache coherence enforcement and memory latency reduction and hiding are very important problems in the design of large-scale shared-memory multiprocessors. The authors propose a compiler-directed cache coherence scheme which makes use of data prefetching. The cache coherence with data prefetching (CCDP) scheme uses compiler analysis techniques to identify potentially-stale data references, which are references to invalid copies of cached data. The key idea of the CCDP scheme is to enforce cache coherence by prefetching the up-to-date data corresponding to these potentially-stale references from the main memory. Application case studies were conducted to gain a quantitative idea of the performance potential of the CCDP scheme on a real system. They applied the CCDP scheme on four benchmark programs from the SPEC CFP95 and CFP92 suites, and executed them on the Cray T3D. The experimental results show that for the programs studied, the scheme provides significant performance improvements by caching shared data and reducing the remote shared-memory access penalty incurred by the programs.