Dependency-based automatic parallelization of java applications

Abstract

There are billions of lines of sequential code inside nowadays software which do not benefit from the parallelism available in modern multicore architectures. Transforming legacy sequential code into a parallel version of the same programs is a complex and cumbersome task. Trying to perform such transformation automatically and without the intervention of a developer has been a striking research objective for a long time. This work proposes an elegant way of achieving such a goal. By targeting a task-based runtime which manages execution using a task dependency graph, we developed a translator for sequential JAVA code which generates a highly parallel version of the same program. The translation process interprets the AST nodes for signatures such as read-write access, execution-flow modifications, among others and generates a set of dependencies between executable tasks. This process has been applied to well known problems, such as the recursive Fibonacci and FFT algorithms, resulting in versions capable of maximizing resource usage. For the case of two CPU bounded applications we were able to obtain 10.97x and 9.0x speedup on a 12 core machine.