When it comes to being able to run OpenCL kernels on CPUs, the main option at this point for Linux systems is POCL as the Portable Computing Language. While POCL 1.2 was released just this past September, we're still very much looking forward to the upcoming POCL 1.3 release with more improvements for this portable OpenCL 1.2~2.0 implementation.

The CHANGES were updated in its latest development code, reflecting the latest state of POCL 1.3:

- There is the experimental support for HSA with native ISA compilation on top of the Heterogeneous System Architecture run-time rather than just targeting the HSA IL. This is building on top of POCL's HSA work they've been pursuing since around 2015. The HSA-native back-end also now supports device-side printf capabilities.

- Support for building POCL without CPU back-end drivers.

- Updates to the POCL binary format.

- Fixes for building with CUDA support on LLVM 7 and GCC 8.2.

- POCL now uses the LLVM Clang driver API for the final linking step.

- A major cleanup to their pthread CPU driver code.

For POCL 1.3 there doesn't appear to be any progress on SPIR-V support. Those wishing to learn more about the Portable Computing Language implementation and its multiple back-ends can visit PortableCL.org.