#
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if(GMX_DOUBLE)
    message(FATAL_ERROR "OpenCL not available in double precision - Yet!")
endif()

# Look for OpenCL
# TODO: FindOpenCL module is available in cmake starting with version 3.1.0.
# A modified version of that module is used here.
# Remove FindOpenCL.cmake file when GROMACS switches to cmake 3.1.0 or higher.
find_package(OpenCL)

if (OPENCL_FOUND)
    if (OPENCL_VERSION_STRING VERSION_LESS REQUIRED_OPENCL_MIN_VERSION)
        message(FATAL_ERROR "OpenCL " "${OPENCL_VERSION_STRING}" " is not supported. OpenCL version " "${REQUIRED_OPENCL_MIN_VERSION}" " or newer is required.")
        return ()
    endif()
else ()
    message(FATAL_ERROR "OpenCL not found.")
    return()
endif()

# Tell compiler to hide warnings for comments caused by cl_gl_ext.h on Linux
if (UNIX)
    set(OPENCL_DEFINITIONS ${OPENCL_DEFINITIONS} " -Wno-comment")
endif()

add_definitions(${OPENCL_DEFINITIONS})

include_directories(${OPENCL_INCLUDE_DIRS})

macro(gmx_gpu_setup)
    # no OpenMP is no good!
    if(NOT GMX_OPENMP)
        message(WARNING "To use GPU acceleration efficiently, mdrun requires OpenMP multi-threading. Without OpenMP a single CPU core can be used with a GPU which is not optimal. Note that with MPI multiple processes can be forced to use a single GPU, but this is typically inefficient. You need to set both C and C++ compilers that support OpenMP (CC and CXX environment variables, respectively) when using GPUs.")
    endif()
endmacro()