text: /*******************************************************************************
   * Copyright (c) 2015-2018 Skymind, Inc.
   *
   * This program and the accompanying materials are made available under the
   * terms of the Apache License, Version 2.0 which is available at
   * https://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.
   *
   * SPDX-License-Identifier: Apache-2.0
   ******************************************************************************/
  
  //
  // Created by raver119 on 21.11.17.
  //
  
  #ifndef LIBND4J_DATATYPECONVERSIONS_H
  #define LIBND4J_DATATYPECONVERSIONS_H
  
  #include <system/pointercast.h>
  #include <helpers/logger.h>
  #include <system/op_boilerplate.h>
  #include <array/DataType.h>
  #include <types/float16.h>
  #include <helpers/BitwiseUtils.h>
  #include <loops/type_conversions.h>
  #include <system/dll.h>
  #include <execution/Threads.h>
  
  namespace sd {
      template <typename T>
      class ND4J_EXPORT DataTypeConversions {
      private:
          template <typename T2>
          static FORCEINLINE void rconv(bool isBe, bool canKeep, T *buffer, Nd4jLong length, void *src) {
              if (std::is_same<T, T2>::value && canKeep) {
                  memcpy(buffer, src, length * sizeof(T));
              } else {
                  auto tmp = new T2[length];
                  memcpy(tmp, src, length * sizeof(T2));
  
  
  #if __GNUC__ <= 4
                  if (!canKeep)
                                  for (Nd4jLong e = 0; e < length; e++)
                                      buffer[e] = BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              else
                                  TypeCast::convertGeneric<T2, T>(nullptr, tmp, length, buffer);
  #else
                  auto func = PRAGMA_THREADS_FOR {
                      for (auto e = start; e < stop; e++)
                          buffer[e] = canKeep ? static_cast<T>(tmp[e]) : BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                  };
  
                  samediff::Threads::parallel_for(func, 0, length);
  #endif
  
                  delete[] tmp;
              }
          }
  
      public:
          static FORCEINLINE void convertType(void* vbuffer, void* src, DataType dataType, ByteOrder order, Nd4jLong length) {
              auto buffer = reinterpret_cast<T *>(vbuffer);
              bool isBe = BitwiseUtils::isBE();
              bool canKeep = (isBe && order == ByteOrder::BE) || (!isBe && order == ByteOrder::LE);
  
              switch (dataType) {
                  case BOOL: {
                          DataTypeConversions<T>::template rconv<bool>(isBe, canKeep, buffer, length, src);
                      }
                      break;
                  case UINT8: {
                      DataTypeConversions<T>::template rconv<uint8_t>(isBe, canKeep, buffer, length, src);
                      }
                      break;
                  case INT8: {
                      DataTypeConversions<T>::template rconv<int8_t>(isBe, canKeep, buffer, length, src);
                      }
                      break;
                  case INT16: {
                      DataTypeConversions<T>::template rconv<int16_t>(isBe, canKeep, buffer, length, src);
                      }
                      break;
                  case INT32: {
                          DataTypeConversions<T>::template rconv<int>(isBe, canKeep, buffer, length, src);
                      }
                      break;
                  case INT64: {
                      DataTypeConversions<T>::template rconv<Nd4jLong>(isBe, canKeep, buffer, length, src);
                  }
                      break;
                  case FLOAT32: {
                          if (std::is_same<T, float>::value && canKeep) {
                              memcpy(buffer, src, length * sizeof(T));
                          } else {
                              auto tmp = new float[length];
                              memcpy(tmp, src, length * sizeof(float));
  
  
  #if __GNUC__ <= 4
                              if (!canKeep)
                                  for (Nd4jLong e = 0; e < length; e++)
                                      buffer[e] = BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              else
                                  TypeCast::convertGeneric<float, T>(nullptr, tmp, length, buffer);
  #else
                              auto func = PRAGMA_THREADS_FOR {
                                  for (auto e = start; e < stop; e++)
                                      buffer[e] = canKeep ? static_cast<T>(tmp[e]) : BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              };
  
                              samediff::Threads::parallel_for(func, 0, length);
  #endif
  
                              delete[] tmp;
                          }
                      }
                      break;
                  case DOUBLE: {
                          if (std::is_same<T, double>::value && canKeep) {
                              memcpy(buffer, src, length * sizeof(T));
                          } else {
                              auto tmp = new double[length];
                              memcpy(tmp, src, length * sizeof(double));
  
  #if __GNUC__ <= 4
                              if (!canKeep)
                                  for (Nd4jLong e = 0; e < length; e++)
                                      buffer[e] = BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              else
                                  TypeCast::convertGeneric<double, T>(nullptr, tmp, length, buffer);
  
  
  #else
                              auto func = PRAGMA_THREADS_FOR {
                                  for (auto e = start; e < stop; e++)
                                      buffer[e] = canKeep ? static_cast<T>(tmp[e]) : BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              };
  
                              samediff::Threads::parallel_for(func, 0, length);
  #endif
                              delete[] tmp;
                          }
                      }
                      break;
                  case HALF: {
  
                          if (std::is_same<T, float16>::value && canKeep) {
                              memcpy(buffer, src, length * sizeof(T));
                          } else {
                              auto tmp = new float16[length];
                              memcpy(tmp, src, length * sizeof(float16));
  
  #if __GNUC__ <= 4
                              if (!canKeep)
                                  for (Nd4jLong e = 0; e < length; e++)
                                      buffer[e] = BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              else
                                  TypeCast::convertGeneric<float16, T>(nullptr, tmp, length, buffer);
  #else
                              auto func = PRAGMA_THREADS_FOR {
                                  for (auto e = start; e < stop; e++)
                                      buffer[e] = canKeep ? static_cast<T>(tmp[e]) : BitwiseUtils::swap_bytes<T>(static_cast<T>(tmp[e]));
                              };
  
                              samediff::Threads::parallel_for(func, 0, length);
  #endif
                              delete[] tmp;
                          }
                      }
                      break;
                  default: {
                      nd4j_printf("Unsupported DataType requested: [%i]\n", static_cast<int>(dataType));
                      throw std::runtime_error("Unsupported DataType");
                  }
              }
          }
      };
  }
  
  
  
  #endif //LIBND4J_DATATYPECONVERSIONS_H
  