We present GPU and APU accelerated computations of Finite-Time Lyapunov Exponent (FTLE) fields. The calculation of FTLEs is a computationally intensive process, as in order to obtain the sharp ridges associated with the Lagrangian Coherent Structures an extensive resampling of the flow field is required. The computational performance of this resampling is limited by the memory bandwidth of the underlying computer architecture. The present technique harnesses data-parallel execution of many-core architectures and relies on fast and accurate evaluations of moment conserving functions for the mesh to particle interpolations. We demonstrate how the computation of FTLEs can be efficiently performed on a GPU and on an APU through OpenCL and we report over one order of magnitude improvements over multi-threaded executions in FTLE computations of bluff body flows. (Conti C., Rossinelli D., Koumoutsakos P., GPU and APU computations of Finite Time Lyapunov Exponent fields, Journal of Computational Physics, 231(5):2229–2244, 2012.

CLCC, the light-weight and flexible utility for integrating OpenCL source builds into your project has just been updated to version 0.3.0. This version allows developers to save compiled binaries as object files for distribution with their programs and adds a series of options to select specific target platform/device combinations. Documentation and further information is available at http://clcc.sourceforge.net.

Version 1.2.0 of the OpenCL-based C++ linear algebra library ViennaCL is now available for download! It features a high-level interface compatible with Boost.ublas, which allows for compact code and high productivity. Highlights of the new release are the following features (all experimental):

• Several algebraic multigrid preconditioners
• Sparse approximate inverse preconditioners
• Fast Fourier transform
• Structured dense matrices (circulant, Hankel, Toeplitz, Vandermonde)
• Reordering algorithms (Cuthill-McKee, Gibbs-Poole-Stockmeyer)
• Proxies for manipulating subvectors and submatrices

The features are expected to reach maturity in the 1.2.x branch. More information about the library including download links is available at http://viennacl.sourceforge.net.

FortranCL is an interface to OpenCL from Fortran90 programs, and it is distributed under the LGPL free software license. It allows Fortran programmer to directly execute code on GPUs or other massively parallel processors. The interface is designed to be as close to the C OpenCL interface as possible, and it is written in native Fortran 90 with type checking. FortranCL is not complete yet, but it includes enough subroutines to write GPU accelerated code in Fortran. More information: http://code.google.com/p/fortrancl/

Libra SDK is a sophisticated runtime including API, sample programs and documentation for massively accelerating software computations. This introduction tutorial provides an overview and usage examples of the powerful Libra API & math libraries executing on x86/x64, OpenCL, OpenGL and CUDA technology. Libra API enables generic and portable CPU/GPU computing within software development without the need to create multiple, specific and optimized code paths to support x86, OpenCL, OpenGL or CUDA devices. Link to PDF: www.gpusystems.com/doc/LibraGenericComputing.pdf

KOAP, pronounced “cope,” is a tool for developing OpenCL applications. It’s purpose is to allow the programmer to aggregate and simplify calls to the OpenCL API. KOAP accepts as input a file containing (or including) both the OpenCL program and the host C program. KOAP understands several directives, each of which is prefixed with a $ character. When KOAP is run, these directives are replaced with the requisite OpenCL API calls. Programs preprocessed by KOAP can run on any target supported by OpenCL, including both NVIDIA and AMD GPUs.

KOAP is now freely available as a source code tar file from http://aggregate.org/KOAP/.

OCLTools is a powerful, yet compact, suite of Open Source tools that provide OpenCL developers with more alternatives to kernel compilation. OCLTools enables developers to eliminate costly kernel compilation time from the runtime of your application. With OCLTools developers can embed the source code of their kernels (clear text or encrypted) directly into their program binaries, eliminating the need to distribute kernel source code in the open while still maintaining the flexibility of runtime compilation. Both source code and precompiled binaries can be embedded into OpenCL binaries, effectively eliminating the additional kernel compilation overhead from the run time of your application.

For more information go to http://www.clusterchimps.org

AMD just released to open source a project called Aparapi that started in their JavaLabs team. Aparapi is an API for expressing data parallel workloads in Java and a runtime component capable of converting the Java bytecode of compatible workloads into OpenCL™ so that it can be executed on a variety of GPU devices.  More information can be found in this blog entry.

libCL is an open-source parallel algorithm library written in C++ and OpenCL. Rather than a specific domain, libCL intends to encompass a wide range of parallel algorithms and data structures. The goal is to provide a comprehensive repository for high performance visual-centric computing ranging from fundamental primitives such as sorting, searching and algebra to advanced systems of algorithms for computational research and visualization. The current distribution of libCL already contains entirely parallelized implementations of the following algorithms:

• Bounding volume hierarchy construction
• Smoothed particle hydrodynamics
• Radix sort
• Adaptive tone-mapping
• Screen-space ambient occlusion culling
• Bilateral and Recursive Gaussian

libCL emerged out of OpenCL Studio, and as such integrates well with the development environment and its visualization capabilities. libCL is Open Source and released under the Apache license.

AMD announced a GPGPU coding competition, called AMD OpenCL Coding Competition. The first phase of the competition is an open innovation challenge that requires the use of the AMD APP SDK and OpenCL. The competition is heating up with the highest registration for a TopCoder innovation challenge to date. It’s not too late to sign up and show off your ideas! If you submit your abstract before June 30th you will get feedback from AMD, otherwise you will have up until the deadline to submit your OpenCL innovation challenge submission.

Phase two of the competition will be an OpenCL algorithm optimization match that will start later in September. Read more about it in this AMD blog.