Graphical Process Unit.
Radeon Vulkan “RADV” driver has enabled the Valve-backed ACO shader compiler by default rather than AMD's official AMDGPU LLVM shader compiler back-end. It has feature parity with the AMDGPU LLVM back-end, RADV is now defaulting to using ACO in place of the AMDGPU LLVM shader compiler.
Vulkan tests https://github.com/SaschaWillems/Vulkan