OpenCL 3.0.9 Specification Released

Written by Michael Larabel in Standards on 15 October 2021 at 07:32 PM EDT. 7 Comments
The Khronos Group's OpenCL working group did a quiet Friday evening tagging of OpenCL 3.0.9.

Most notable with OpenCL 3.0.9 as this routine specification update are the specification sources now being included for the provisional extensions adding semaphores and external memory support to OpenCL. Those extensions were originally announced this spring as part of OpenCL 3.0.7 but the specification ASCII doc sources were not included until now.

Those now documented extensions are cl_khr_semaphore, cl_khr_external_semaphore, and cl_khr_external_memory. The cl_khr_semaphore provisional extension is for semaphores to synchronize between the host and the device along with cross-device scenarios. This is similar the semaphores work with Khronos' OpenGL and Vulkan APIs and part of improving the cross-API interoperability. It's with cl_khr_external_semaphore that is for sharing semaphores created in an external API and importing/exporting to OpenCL.

Also documented now is cl_khr_external_memory for sharing buffer and image objects between OpenCL and other APIs. OpenCL 3.0.9 also has a new version (v2) of the cl_khr_integer_dot_product extension that now makes 8-bit support mandatory and adds 8-bit acceleration properties.

A new extension to OpenCL 3.0.9 is cl_pocl_content_size is a new extension from the POCL project to indicate a buffer is going to hold the number of meaningful bytes in another buffer after kernel execution. This is basically used as an optimization hint.

The OpenCL 3.0.9 spec is available from GitHub.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week