Using thread-level speculation to simplify manual parallelization

In this paper, we provide examples of how thread-level speculation (TLS) simplifies manual parallelization and enhances its performance. A number of techniques for manual parallelization using TLS are presented and results are provided that indicate the performance contribution of each technique on seven SPEC CPU2000 benchmark applications. We also provide indications of the programming effort required to parallelize each benchmark. TLS parallelization yielded a 110% speedup on our four floating point applications and a 70% speedup on our three integer applications, while requiring only approximately 80 programmer hours and 150 lines of non-template code per application. These results support the idea that manual parallelization using TLS is an efficient way to extract fine-grain thread-level parallelism.