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 subbuffer objects


There may be situations when you may want to create a subbuffer out of the existing buffer object. For this purpose OpenCL provides the API.

cl_mem clCreateSubBuffer (cl_mem buffer,cl_mem_flags flags,cl_buffer_create_type buffer_create_type,const void *buffer_create_info,cl_int *errcode_ret)

The clCreateSubBuffer function can be used to create a new partial buffer object (referred to as a subbuffer object) from an existing OpenCL cl_mem buffer object.

Parameter name

Description

buffer

Must be a valid buffer object created using the clCreateBuffer API and cannot itself be a subbuffer object.

flags

This parameter takes the same values as described in the table of cl_mem_flags shown earlier. The values taken by the flags variable should not get into any mutual exclusion condition with the flags of the original buffer. For example, if the original cl_mem object buffer is created with CL_MEM_HOST_WRITE_ONLY and the flag specified is CL_MEM_HOST_READ_ONLY, then the...