Java for numerically intensive computing: from flops to gigaflops

Java is not thought of as being competitive with Fortran for numerical programming. In this paper, we discuss technologies that can and will deliver Fortran-like performance in Java. These techniques include new and existing compiler technologies, the exploitation of parallelism, and a collection of Java libraries for numerical computing. We also present experimental data to show the effectiveness of our approaches. In particular we achieve 1 Gflops with a linear algebra kernel on an RS/6000 SMP machine. Most of these techniques require no language changes; a few depend on extensions to Java currently under consideration.