I wouldn't call AMD a champion of OpenCL. Only OpenCL 2.0 is supported, and not completely on ROCm yet. OpenCL 2.0 isn't too hot on the AMDGPU-pro drivers either, and SPIR-V intermediate language doesn't really work well on AMD's GPUs (it either runs slowly or fails to run).
Frankly, it seems like AMD is going to be more successful with HCC and its HIP (CUDA-compatibility layer). It plays a distant 2nd place vs NVidia, but the CUDA-like single source environment is a superior development platform.
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OpenCL 2.2 seems to be only supported on Intel platforms. Either Intel GPUs, Intel CPUs (to AVX512), or Intel Altera FPGAs.
If I were to write OpenCL for AMD GPUs, I'd stick with OpenCL1.2 unless there was an absolute need for OpenCL 2.0 features. The OpenCL 1.2 stuff just seems more mature and better tested on AMD GPU Platforms. Hopefully ROCm changes that, but that's my opinion for the current state of affairs.
Frankly, it seems like AMD is going to be more successful with HCC and its HIP (CUDA-compatibility layer). It plays a distant 2nd place vs NVidia, but the CUDA-like single source environment is a superior development platform.
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OpenCL 2.2 seems to be only supported on Intel platforms. Either Intel GPUs, Intel CPUs (to AVX512), or Intel Altera FPGAs.
If I were to write OpenCL for AMD GPUs, I'd stick with OpenCL1.2 unless there was an absolute need for OpenCL 2.0 features. The OpenCL 1.2 stuff just seems more mature and better tested on AMD GPU Platforms. Hopefully ROCm changes that, but that's my opinion for the current state of affairs.