The Basic Building Blocks of Parallel Tasks

Abstract

Discovery of parallelization opportunities in sequential programs can greatly reduce the time and effort required to parallelize any application. Identification and analysis of code that contains little to no internal parallelism can also help expose potential parallelism. This paper provides a technique to identify a block of code called Computational Unit (CU) that performs a unit of work in a program. A CU can assist in discovering the potential parallelism in a sequential program by acting as a basic building block for tasks. CUs are used along with dynamic analysis information to identify the tasks that contain tightly coupled code within them. This process in turn reveals the tasks that are weakly dependent or independent. The independent tasks can be run in parallel and the dependent tasks can be analyzed to check if the dependences can be resolved. To evaluate our technique, different benchmark applications are parallelized using our identified tasks and the speedups are reported. In addition, existing parallel implementations of the applications are compared with the identified tasks for the respective applications.