automatically exploiting cross-invocation parallelism using runtime ...

Chapter 6Conclusion and Future Direction6.1 ConclusionExploiting the performance of multi-core processors requires scalable parallel programs.Most automatic parallelization techniques parallelize iterations within the same loop invocationand synchronize threads at the end of each parallel invocation. Unfortunately,frequent synchronization limits the scalability of many software programs. In practice,iterations in different invocations of a parallel loop are often independent. In order to exploitadditional cross-invocation parallelism, this thesis work proposes two novel automaticparallelization techniques. DOMORE and SPECCROSS synchronizes iterations using runtimeinformation, and can therefore adapt to dependence patterns manifested by particularinputs. As a non-speculative technique, DOMORE is designed for programs with morefrequently manifesting cross-invocation dependences.SPECCROSS, on the other hand,yields better performance when those dependences seldom manifest at runtime. Evaluationdemonstrates that among twenty programs from seven benchmark suites, DOMOREcan be automatically applied to parallelize six of them and achieves a geomean speedupof 2.1× over codes without cross-invocation parallelization and 3.2× over the original sequentialperformance on 24 cores. SPECCROSS is found to be applicable to eight of the93