OpenJij/OpenJij

//    Copyright 2023 Jij Inc.
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at

//        http://www.apache.org/licenses/LICENSE-2.0

//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.

#pragma once

#ifdef USE_CUDA

#include "openjij/system/gpu/chimera_cuda/kernel.hpp"
#include "openjij/system/gpu/chimera_gpu_classical.hpp"
#include "openjij/system/gpu/chimera_gpu_transverse.hpp"
#include "openjij/utility/random.hpp"
#include "openjij/utility/schedule_list.hpp"

namespace openjij {
namespace updater {

/**
 * @brief GPU algorithm using cuda
 *
 * @tparam System type of system
 */
template <typename System> struct GPU;

/**
 * @brief GPU algorithm for chimera transverse model
 *
 */
template <typename FloatType, std::size_t rows_per_block,
          std::size_t cols_per_block, std::size_t trotters_per_block>
struct GPU<system::ChimeraTransverseGPU<FloatType, rows_per_block,
                                        cols_per_block, trotters_per_block>> {

  /**
   * @brief Chimera Transverse type
   */
  using QIsing =
      system::ChimeraTransverseGPU<FloatType, rows_per_block, cols_per_block,
                                   trotters_per_block>;
  /**
   *
   * @brief operate GPU monte carlo in a chimera transverse ising system
   *
   * @param system object of a chimera transverse system
   * @param random_number_engine random number engine
   * @param parameter parameter object including inverse temperature
   * \f\beta:=(k_B T)^{-1}\f
   *
   * @return energy difference \f\Delta E\f
   */
  template <curandRngType_t rng_type>
  inline static void update(
      QIsing &system,
      utility::cuda::CurandWrapper<FloatType, rng_type> &random_number_engine,
      const utility::TransverseFieldUpdaterParameter &parameter) {

    // generate uniform random sequence
    random_number_engine.generate_uniform(system.info.rows * system.info.cols *
                                              system.info.trotters *
                                              system.info.chimera_unitsize,
                                          system.dev_random);
    // do metropolis
    system::chimera_cuda::metropolis_interface<
        FloatType, rows_per_block, cols_per_block, trotters_per_block>(
        0, system.spin.get(), system.dev_random.get(),
        system.interaction.J_out_p.get(), system.interaction.J_out_n.get(),
        system.interaction.J_in_04.get(), system.interaction.J_in_15.get(),
        system.interaction.J_in_26.get(), system.interaction.J_in_37.get(),
        system.interaction.h.get(), system.info, system.grid, system.block,
        parameter.beta, system.gamma, parameter.s);

    // generate uniform random sequence
    random_number_engine.generate_uniform(system.info.rows * system.info.cols *
                                              system.info.trotters *
                                              system.info.chimera_unitsize,
                                          system.dev_random);
    // do metropolis
    system::chimera_cuda::metropolis_interface<
        FloatType, rows_per_block, cols_per_block, trotters_per_block>(
        1, system.spin.get(), system.dev_random.get(),
        system.interaction.J_out_p.get(), system.interaction.J_out_n.get(),
        system.interaction.J_in_04.get(), system.interaction.J_in_15.get(),
        system.interaction.J_in_26.get(), system.interaction.J_in_37.get(),
        system.interaction.h.get(), system.info, system.grid, system.block,
        parameter.beta, system.gamma, parameter.s);
  }
};

/**
 * @brief GPU algorithm for chimera classical model
 *
 */
template <typename FloatType, std::size_t rows_per_block,
          std::size_t cols_per_block>
struct GPU<
    system::ChimeraClassicalGPU<FloatType, rows_per_block, cols_per_block>> {

  /**
   * @brief Chimera Classical type
   */
  using CIsing =
      system::ChimeraClassicalGPU<FloatType, rows_per_block, cols_per_block>;
  /**
   *
   * @brief operate GPU monte carlo in a chimera classical ising system
   *
   * @param system object of a chimera transverse system
   * @param random_number_engine random number engine
   * @param parameter parameter object including inverse temperature
   * \f\beta:=(k_B T)^{-1}\f
   *
   * @return energy difference \f\Delta E\f
   */
  template <curandRngType_t rng_type>
  inline static void update(
      CIsing &system,
      utility::cuda::CurandWrapper<FloatType, rng_type> &random_number_engine,
      const utility::ClassicalUpdaterParameter &parameter) {

    // cast to chimera transverse field system with single trotter slice.
    return GPU<typename CIsing::Base>::update(
        system, random_number_engine,
        utility::TransverseFieldUpdaterParameter(parameter.beta, 1));
  }
};

} // namespace updater
} // namespace openjij

#endif