
// =================================================================================================
// This file is part of the CLBlast project. Author(s):
//   Cedric Nugteren <www.cedricnugteren.nl>
//
// This file implements the Xamax class (see the header for information about the class).
//
// =================================================================================================

#include "routines/level1/xamax.hpp"

#include <cstddef>
#include <string>
#include <vector>

#include "routine.hpp"
#include "routines/common.hpp"
#include "utilities/backend.hpp"
#include "utilities/buffer_test.hpp"
#include "utilities/clblast_exceptions.hpp"
#include "utilities/utilities.hpp"

namespace clblast {
// =================================================================================================

// Constructor: forwards to base class constructor
template <typename T>
Xamax<T>::Xamax(Queue& queue, EventPointer event, const std::string& name)
    : Routine(queue, event, name, {"Xdot"}, PrecisionValue<T>(), {},
              {
#include "../../kernels/level1/xamax.opencl"
              }) {
}

// =================================================================================================

// The main routine
template <typename T>
void Xamax<T>::DoAmax(const size_t n, const Buffer<unsigned int>& imax_buffer, const size_t imax_offset,
                      const Buffer<T>& x_buffer, const size_t x_offset, const size_t x_inc) {
  // Makes sure all dimensions are larger than zero
  if (n == 0) {
    throw BLASError(StatusCode::kInvalidDimension);
  }

  // Tests the vectors for validity
  TestVectorX(n, x_buffer, x_offset, x_inc);
  TestVectorIndex(1, imax_buffer, imax_offset);

  // Retrieves the Xamax kernels from the compiled binary
  auto kernel1 = Kernel(program_, "Xamax");
  auto kernel2 = Kernel(program_, "XamaxEpilogue");

  // Creates the buffer for intermediate values
  auto temp_size = 2 * db_["WGS2"];
  auto temp_buffer1 = Buffer<T>(context_, temp_size);
  auto temp_buffer2 = Buffer<unsigned int>(context_, temp_size);

  // Sets the kernel arguments
  kernel1.SetArgument(0, static_cast<int>(n));
  kernel1.SetArgument(1, x_buffer());
  kernel1.SetArgument(2, static_cast<int>(x_offset));
  kernel1.SetArgument(3, static_cast<int>(x_inc));
  kernel1.SetArgument(4, temp_buffer1());
  kernel1.SetArgument(5, temp_buffer2());

  // Event waiting list
  auto eventWaitList = std::vector<Event>();

  // Launches the main kernel
  auto global1 = std::vector<size_t>{db_["WGS1"] * temp_size};
  auto local1 = std::vector<size_t>{db_["WGS1"]};
  auto kernelEvent = Event();
  RunKernel(kernel1, queue_, device_, global1, local1, kernelEvent.pointer());
  eventWaitList.push_back(kernelEvent);

  // Sets the arguments for the epilogue kernel
  kernel2.SetArgument(0, temp_buffer1());
  kernel2.SetArgument(1, temp_buffer2());
  kernel2.SetArgument(2, imax_buffer());
  kernel2.SetArgument(3, static_cast<int>(imax_offset));

  // Launches the epilogue kernel
  auto global2 = std::vector<size_t>{db_["WGS2"]};
  auto local2 = std::vector<size_t>{db_["WGS2"]};
  RunKernel(kernel2, queue_, device_, global2, local2, event_, eventWaitList);
}

// =================================================================================================

// Compiles the templated class
template class Xamax<half>;
template class Xamax<float>;
template class Xamax<double>;
template class Xamax<float2>;
template class Xamax<double2>;

// =================================================================================================
}  // namespace clblast
