Book Image

OpenCL Programming by Example

Book Image

OpenCL Programming by Example

Overview of this book

Research in parallel programming has been a mainstream topic for a decade, and will continue to be so for many decades to come. Many parallel programming standards and frameworks exist, but only take into account one type of hardware architecture. Today computing platforms come with many heterogeneous devices. OpenCL provides royalty free standard to program heterogeneous hardware. This guide offers you a compact coverage of all the major topics of OpenCL programming. It explains optimization techniques and strategies in-depth, using illustrative examples and also provides case studies from diverse fields. Beginners and advanced application developers will find this book very useful. Beginning with the discussion of the OpenCL models, this book explores their architectural view, programming interfaces and primitives. It slowly demystifies the process of identifying the data and task parallelism in diverse algorithms. It presents examples from different domains to show how the problems within different domains can be solved more efficiently using OpenCL. You will learn about parallel sorting, histogram generation, JPEG compression, linear and parabolic regression and k-nearest neighborhood, a clustering algorithm in pattern recognition. Following on from this, optimization strategies are explained with matrix multiplication examples. You will also learn how to do an interoperation of OpenGL and OpenCL. "OpenCL Programming by Example" explains OpenCL in the simplest possible language, which beginners will find it easy to understand. Developers and programmers from different domains who want to achieve acceleration for their applications will find this book very useful.
Table of Contents (18 chapters)
OpenCL Programming by Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Creating kernel objects


In this section we will discuss details about the kernel objects, and how kernel objects can be created using the program objects. Every program is a collection of kernels, you can consider a program object as a library of kernels. As shown in the following figure a program is associated with kernel1 and kernel2. The program is built with inputs as two devices device1 and device2. A kernel when enqueued on the command queue, the OpenCL runtime generates the binary for execution on the device. Note that each kernel can be executed on different devices. It is at the runtime the binaries are generated.

A kernel object can be created from a well formed OpenCL C program, which is built as discussed in the previous section. A kernel object is an encapsulation for a parallel executable entity. The kernel object is used to pass arguments using the clSetKernelArg API, before running the kernel using the clEnqueueNDRangeKernel API. Have a look at the following diagram:

Kernels...