BabelStream/src/OCLStream.cpp

#include "OCLStream.h"

std::string kernels{R"CLC(

  constant TYPE scalar = 3.0;

  kernel void copy(
    global const TYPE * restrict a,
    global TYPE * restrict c)
  {
    const size_t i = get_global_id(0);
    c[i] = a[i];
  }

  kernel void mul(
    global TYPE * restrict b,
    global const TYPE * restrict c)
  {
    const size_t i = get_global_id(0);
    b[i] = scalar * c[i];
  }

  kernel void add(
    global const TYPE * restrict a,
    global const TYPE * restrict b,
    global TYPE * restrict c)
  {
    const size_t i = get_global_id(0);
    c[i] = a[i] + b[i];
  }

  kernel void triad(
    global TYPE * restrict a,
    global const TYPE * restrict b,
    global const TYPE * restrict c)
  {
    const size_t i = get_global_id(0);
    a[i] = b[i] + scalar * c[i];
  }

)CLC"};


template <class T>
OCLStream<T>::OCLStream(const unsigned int ARRAY_SIZE)
{
  array_size = ARRAY_SIZE;

  // Setup default OpenCL GPU
  context = cl::Context::getDefault();
  queue = cl::CommandQueue::getDefault();

  // Create program
  cl::Program program(kernels);
  if (sizeof(T) == sizeof(double))
    program.build("-DTYPE=double");
  else if (sizeof(T) == sizeof(float))
    program.build("-DTYPE=float");

  // Create kernels
  copy_kernel = new cl::KernelFunctor<cl::Buffer, cl::Buffer>(program, "copy");
  mul_kernel = new cl::KernelFunctor<cl::Buffer, cl::Buffer>(program, "mul");
  add_kernel = new cl::KernelFunctor<cl::Buffer, cl::Buffer, cl::Buffer>(program, "add");
  triad_kernel = new cl::KernelFunctor<cl::Buffer, cl::Buffer, cl::Buffer>(program, "triad");

  // Create buffers
  d_a = cl::Buffer(context, CL_MEM_READ_WRITE, sizeof(T) * ARRAY_SIZE);
  d_b = cl::Buffer(context, CL_MEM_READ_WRITE, sizeof(T) * ARRAY_SIZE);
  d_c = cl::Buffer(context, CL_MEM_READ_WRITE, sizeof(T) * ARRAY_SIZE);

}

template <class T>
OCLStream<T>::~OCLStream()
{
  delete[] copy_kernel;
  delete[] mul_kernel;
  delete[] add_kernel;
  delete[] triad_kernel;
}

template <class T>
void OCLStream<T>::copy()
{
  (*copy_kernel)(
    cl::EnqueueArgs(queue, cl::NDRange(array_size)),
    d_a, d_c
  );
  queue.finish();
}

template <class T>
void OCLStream<T>::mul()
{
  (*mul_kernel)(
    cl::EnqueueArgs(queue, cl::NDRange(array_size)),
    d_b, d_c
  );
  queue.finish();
}

template <class T>
void OCLStream<T>::add()
{
  (*add_kernel)(
    cl::EnqueueArgs(queue, cl::NDRange(array_size)),
    d_a, d_b, d_c
  );
  queue.finish();
}

template <class T>
void OCLStream<T>::triad()
{
  (*triad_kernel)(
    cl::EnqueueArgs(queue, cl::NDRange(array_size)),
    d_a, d_b, d_c
  );
  queue.finish();
}

template <class T>
void OCLStream<T>::write_arrays(const std::vector<T>& a, const std::vector<T>& b, const std::vector<T>& c)
{
  cl::copy(a.begin(), a.end(), d_a);
  cl::copy(b.begin(), b.end(), d_b);
  cl::copy(c.begin(), c.end(), d_c);
}

template <class T>
void OCLStream<T>::read_arrays(std::vector<T>& a, std::vector<T>& b, std::vector<T>& c)
{
  cl::copy(d_a, a.begin(), a.end());
  cl::copy(d_b, b.begin(), b.end());
  cl::copy(d_c, c.begin(), c.end());
}

// Cache list of devices
bool cached = false;
std::vector<cl::Device> devices;

void getDeviceList(void)
{
  // Get list of platforms
  std::vector<cl::Platform> platforms;
  cl::Platform::get(&platforms);

  // Enumerate devices
  for (unsigned i = 0; i < platforms.size(); i++)
  {
    std::vector<cl::Device> plat_devices;
    platforms[i].getDevices(CL_DEVICE_TYPE_ALL, &plat_devices);
    devices.insert(devices.end(), plat_devices.begin(), plat_devices.end());
  }
  cached = true;
}

void listDevices(void)
{
  getDeviceList();

  // Print device names
  if (devices.size() == 0)
  {
    std::cerr << "No devices found." << std::endl;
  }
  else
  {
    std::cout << std::endl;
    std::cout << "Devices:" << std::endl;
    for (int i = 0; i < devices.size(); i++)
    {
      std::cout << i << ": " << getDeviceName(i) << std::endl;
    }
    std::cout << std::endl;
  }


}

std::string getDeviceName(const int device)
{
  if (!cached)
    getDeviceList();

  std::string name;
  cl_device_info info = CL_DEVICE_NAME;

  if (device < devices.size())
  {
    devices[device].getInfo(info, &name);
  }
  else
  {
    throw std::runtime_error("Error asking for name for non-existant device");
  }

  return name;

}

std::string getDeviceDriver(const int device)
{
  if (!cached)
    getDeviceList();

  std::string driver;

  if (device < devices.size())
  {
    devices[device].getInfo(CL_DRIVER_VERSION, &driver);
  }
  else
  {
    throw std::runtime_error("Error asking for driver for non-existant device");
  }

  return driver;
}


template class OCLStream<float>;
template class OCLStream<double>;