Simple compiler algorithms to reduce ownership overhead in cache coherence protocols

Abstract

We study in this paper the design and efficiency of compiler algorithms that remove ownership overhead in shared-memory multiprocessors with write-invalidate protocols. These algorithms detect loads followed by stores to the same address. Such loads are marked and constitute a hint to the cache to obtain an exclusive copy of the block. We consider three algorithms where the first one focuses on load-store sequences within each basic block of code and the other two analyse the existence of load-store sequences across basic blocks at the intra-procedural level. Since the dataflow analysis we adopt is a trivial variation of live-variable analysis, the algorithms are easily incorporated into a compiler.