Different subsets of OpenCL with different extensions work everywhere. If you want to use C++ then it definitely doesn't work everywhere. Precompiled kernels (

Different subsets of OpenCL with different extensions work everywhere. If you want to use C++ then it definitely doesn't work everywhere. Precompiled kernels (SPIR-V) also do not work (anywhere?). Writing a GPU C program that only gets compiled when you run your program is extra overhead on productivity.