this patch guards all missed half float functions based on the availabiltiy of the OpenCL extension cl_khr_fp16.
jerryct on May 6 2018, 3:42 AM.Authored by
I think the extension is for all half https://www.khronos.org/registry/OpenCL/sdk/1.2/docs/man/xhtml/cl_khr_fp16.html
This extension adds support for half scalar and vector types as built-in types that can be used for arithmetic operations, conversions, etc. An application that wants to use half and halfn types will need to include the directive shown above.