Reducing build time through precompilations for evolving large software

Large-scale legacy programs take long time to compile, thereby hampering productivity. This paper presents algorithms that reduce compilation time by analyzing syntactic dependencies in fine-grain program units, and by removing redundancies as well as false dependencies. These algorithms are combined with parallel compilation techniques (compiler farms, compiler caches), to further reduce build time. We demonstrate through experiments their effectiveness in achieving significant speedup for both fresh and incremental builds.