opencv_version --opencl

4.1.2-dev
OpenCL Platforms:
    Clover
        dGPU: Radeon RX 580 Series (POLARIS10, DRM 3.33.0, 5.3.0-24-generic, LLVM 9.0.1) (OpenCL 1.1 Mesa 20.0.0-devel (git-8259c97 2019-12-07 eoan-oibaf-ppa))
Current OpenCL device:
    Type = dGPU
    Name = Radeon RX 580 Series (POLARIS10, DRM 3.33.0, 5.3.0-24-generic, LLVM 9.0.1)
    Version = OpenCL 1.1 Mesa 20.0.0-devel (git-8259c97 2019-12-07 eoan-oibaf-ppa)
    Driver version = 20.0.0-devel
    Address bits = 64
    Compute units = 36
    Max work group size = 256
    Local memory size = 32 KB
    Max memory allocation size = 6 GB 409 MB 614 KB 409 B
    Double support = Yes
    Host unified memory = No
    Device extensions:
        cl_khr_byte_addressable_store
        cl_khr_global_int32_base_atomics
        cl_khr_global_int32_extended_atomics
        cl_khr_local_int32_base_atomics
        cl_khr_local_int32_extended_atomics
        cl_khr_int64_base_atomics
        cl_khr_int64_extended_atomics
        cl_khr_fp64
        cl_khr_fp16
    Has AMD Blas = No
    Has AMD Fft = No
    Preferred vector width char = 16
    Preferred vector width short = 8
    Preferred vector width int = 4
    Preferred vector width long = 2
    Preferred vector width float = 4
    Preferred vector width double = 2