Question

Hello so I have ran several openCL kernels in double precision on GPU with the following defined:

#ifndef GPU_AMD
#pragma OPENCL EXTENSION cl_khr_fp64: enable
#else
#pragma OPENCL EXTENSION cl_amd_fp64 : enable
#endif

And now I would like to run the same openCL kernels in double precision but on CPU instead, and am wondering if I need the extensions like above? Or is there another openCL extension I have to enable before using double in cpu?

thanks

Answer 1

You should just be able to use the cl_khr_fp64 extension. The cl_amd_fp64 extension is actually just a subset of the cl_khr_fp64 extension for AMD GPUs.

Some AMD GPUs will actually support the full cl_khr_fp64 extension these days, so check (with CLInfo perhaps) to see if that is a possibility.

See this question for more information.