// =================================================================================================
// This file is part of the CLBlast project. The project is licensed under Apache Version 2.0. This
// project loosely follows the Google C++ styleguide and uses a tab-size of two spaces and a max-
// width of 100 characters per line.
//
// Author(s):
//   Cedric Nugteren <www.cedricnugteren.nl>
//
// This file uses the auto-tuner to tune the xgemv OpenCL kernels. Three variants are tuned:
// 1: The full version of the kernel
// 2: The fast version for non-transposed matrices
// 3: The fast version for transposed matrices
//
// =================================================================================================

#include <string>
#include <vector>

#include "utilities/utilities.hpp"
#include "tuning/tuning.hpp"

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

// Settings for this kernel (default command-line arguments)
TunerDefaults XgemvGetTunerDefaults(const int) {
  auto settings = TunerDefaults();
  settings.options = {kArgM, kArgN, kArgAlpha, kArgBeta};
  settings.default_m = 2048;
  settings.default_n = 2048;
  settings.default_num_runs = 4;
  return settings;
}

// Settings for this kernel (general)
template <typename T>
TunerSettings XgemvGetTunerSettings(const int V, const Arguments<T> &args) {
  auto settings = TunerSettings();

  // Identification of the kernel
  settings.kernel_family = (V==1) ? "xgemv" : ((V==2) ? "xgemv_fast" : "xgemv_fast_rot");
  settings.kernel_name = (V==1) ? "Xgemv" : ((V==2) ? "XgemvFast" : "XgemvFastRot");
  settings.sources =
#include "../src/kernels/level2/xgemv.opencl"
#include "../src/kernels/level2/xgemv_fast.opencl"
  ;

  // Buffer sizes
  settings.size_x = args.n;
  settings.size_y = args.m;
  settings.size_a = args.m * args.n;

  // Inputs and outputs IDs (X:0, Y:1, A:2, B:3, C:4, temp:5)
  settings.inputs = {0, 1, 2};
  settings.outputs = {1};

  // Sets the base thread configuration
  settings.global_size = {args.m};
  settings.global_size_ref = settings.global_size;
  settings.local_size = {1};
  settings.local_size_ref = {64};

  // Transforms the thread configuration based on the parameters
  settings.mul_local = {{"WGS"+std::to_string(V)}};
  settings.div_global = (V==1 || V==2) ? TransformVector{{"WPT"+std::to_string(V)}} : TransformVector{};

  // Sets the tuning parameters and their possible values
  if (V==1) {
    settings.parameters = {
      {"WGS"+std::to_string(V), {32, 64, 128, 256}},
      {"WPT"+std::to_string(V), {1, 2, 4}},
    };
  }
  if (V==2) {
    settings.parameters = {
      {"WGS"+std::to_string(V), {16, 32, 64, 128, 256}},
      {"WPT"+std::to_string(V), {1, 2, 4}},
      {"VW"+std::to_string(V), {1, 2, 4, 8}},
    };
  }
  if (V==3) {
    settings.parameters = {
      {"WGS"+std::to_string(V), {16, 32, 64, 128}},
      {"WPT"+std::to_string(V), {1, 2, 4, 8, 16, 32}},
      {"VW"+std::to_string(V), {1, 2, 4, 8}},
    };
  }

  // Describes how to compute the performance metrics
  settings.metric_amount = (args.m*args.n + 2*args.m + args.n) * GetBytes(args.precision);
  settings.performance_unit = "GB/s";

  return settings;
}

// Tests for valid arguments
template <typename T>
void XgemvTestValidArguments(const int, const Arguments<T> &) { }
std::vector<Constraint> XgemvSetConstraints(const int V) {
  auto constraints = std::vector<Constraint>();
  if (V==2 || V==3) {
    auto MultipleOfX = [] (std::vector<size_t> v) { return IsMultiple(v[0], v[1]); };
    constraints.push_back({MultipleOfX, {"WPT"+std::to_string(V), "VW"+std::to_string(V)}});
  }
  if (V==3) {
    auto LargerOrEqual = [] (std::vector<size_t> v) { return v[0] >= v[1]; };
    constraints.push_back({LargerOrEqual, {"WGS"+std::to_string(V), "WPT"+std::to_string(V)}});
  }
  return constraints;
}
template <typename T>
LocalMemSizeInfo XgemvComputeLocalMemSize(const int V) {
  if (V == 1 || V == 2) {
    return {
        [V] (std::vector<size_t> v) -> size_t {
            return GetBytes(PrecisionValue<T>()) * v[0];
        },
        {"WGS" + std::to_string(V)}
    };
  }
  return {
      [V] (std::vector<size_t> v) -> size_t {
          return GetBytes(PrecisionValue<T>()) * (v[0] + v[1] * v[2]);
      },
      {"WGS3", "WPT3", "WGS3"}
  };
}

// Sets the kernel's arguments
template <typename T>
void XgemvSetArguments(const int V, Kernel &kernel, const Arguments<T> &args, std::vector<Buffer<T>>& buffers) {
  auto a_rotated = (V==3) ? 1 : 0;
  kernel.SetArgument(0, static_cast<int>(args.m));
  kernel.SetArgument(1, static_cast<int>(args.n));
  kernel.SetArgument(2, GetRealArg(args.alpha));
  kernel.SetArgument(3, GetRealArg(args.beta));
  kernel.SetArgument(4, a_rotated);
  kernel.SetArgument(5, buffers[2]()); // 2 == A matrix
  kernel.SetArgument(6, 0);
  kernel.SetArgument(7, static_cast<int>(args.m));
  kernel.SetArgument(8, buffers[0]()); // 0 == X vector
  kernel.SetArgument(9, 0);
  kernel.SetArgument(10, 1);
  kernel.SetArgument(11, buffers[1]()); // 1 == Y vector
  kernel.SetArgument(12, 0);
  kernel.SetArgument(13, 1);
  kernel.SetArgument(14, 0); // Conjugate transpose
  kernel.SetArgument(15, 0); // Additional parameter
  kernel.SetArgument(16, 0); // Banded 'kl'
  kernel.SetArgument(17, 0); // Banded 'ku'
}

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