Optimizing Parallel Programs with Explicit Synchronization

Abstract

We present compiler analyses and optimizations for explicitly parallel programs that communicate through a shared address space. Any type of code motion on explicitly parallel programs requires a new kind of analysis to ensure that operations reordered on one processor cannot be observed by another. The analysis, based on work by Shasha and Snir, checks for cycles among interfering accesses. We improve the accuracy of their analysis by using additional information from post-wait synchronization, barriers, and locks.