I want to use [opencl](https://www.khronos.org/opencl/) on blender, libreoffice, and davinci but my AMD GPU prevents success. 

I've used Linux since 1999 (slackware) and compiled kernels back then. But now at 2019 owning an AMD graphics card and I am unable to use opencl in any application at all.

On Arch Linux there's a package on aur repository with the name opencl-amd which, if installed, you can actually use opencl without installing the proprietary driver that brings so many problems.

My 18.04.3 installation that I had the amdgpu-pro driver installed just could not start xorg after updates. I can't find a way and installing the amdgpu-pro driver is not a choice. You help would be appreciated.

This is pretty important: davinci will not launch without opencl, blender and libreoffice will run faster with opencl and do more complex stuff. It is needed.