Distributed Shared Memory , such as that provided by Intel’s Cluster OpenMP, lets programmers treat the combined memory systems of a cluster of workstations as a single large address space. This relieves the programmer of the burden of explicitly transferring data: a correct OpenMP program should still work with Cluster OpenMP. However, by hiding data transfers, such systems also hide a major p...

Locality of computation is key to obtaining high performance on a broad variety of parallel architectures and applications. It is moreover an essential component of strategies for energy-efficient computing. OpenMP is a widely available industry standard for shared memory programming. With the pervasive deployment of multicore computers and the steady growth in core count, a productive programm...

In the last two years, OpenMP has been gaining popularity as a standard for developing portable shared memory parallel programs. With the improvements in centralized shared memory technologies and the emergence of distributed shared memory (DSM) architectures, several medium-to-large physical and logical shared memory con gurations are now available. Thus, OpenMP stands to be a promising medium...

Tiling is widely used by compilers and programmer to optimize scientific and engineering code for better performance. Many parallel programming languages support tile/tiling directly through first-class language constructs or library routines. However, the current OpenMP programming language is tile oblivious, although it is the de facto standard for writing parallel programs on shared memory s...

OpenMP is a widely used programming standard for a broad range of parallel systems. In the OpenMP programming model, synchronization points are specified by implicit or explicit barrier operations within a parallel region. However, certain classes of computations, such as stencil algorithms, can be supported with better synchronization efficiency and data locality when using doacross parallelis...

In this paper we present JaMP, an adaptation of the OpenMP standard. JaMP is fitted to Jackal, a software-based DSM implementation for Java. While the set of supported directives is directly adopted from the OpenMP standard, we also satisfy all requirements that are enforced by the Java Language Specification and the Java Memory Model. JaMP implements a (large) subset of the OpenMP specificatio...

Machines comprised of a distributed collection of shared memory or SMP nodes are becoming common for parallel computing. OpenMP can be combined with MPI on many such machines. Motivations for combing OpenMP and MPI are discussed. While OpenMP is typically used for exploiting loop-level parallelism it can also be used to enable coarse grain parallelism, potentially leading to less overhead. We s...

This paper shows several optimization techniques in OpenMP and investigates their impact using the MGCG method. MGCG is important for not only an e cient solver but also benchmarking since it includes several essential operations for high-performance computing. We evaluate several optimizing techniques on an SGI Origin 2000 using the SGI MIPSpro compiler and the RWCP Omni OpenMP compiler. In th...

In this paper, we present the design and experiments of a practical OpenMP compiler for SMP, called CCRG OpenMP Compiler, with the focus on its performance comparison with commercial Intel Fortran Compiler 8.0 using SPEC OMPM2001 benchmarks. The preliminary experiments showed that CCRG OpenMP is a quite robust and efficient compiler for most of the benchmarks except mgrid and wupwise. Then, fur...

Writing correct and eÆcient parallel programs is more diÆcult than doing so for sequential programs. One of the challenges comes from the nature of concurrent execution of a parallel program by di erent threads. Determining exact concurrency is NP-hard[10], and is impossible for real-world programs at compile time. OpenMP provides an easy and incremental way to write parallel programs. The well...