/* NiuTrans.Tensor - an open-source tensor library
 * Copyright (C) 2017, Natural Language Processing Lab, Northeastern University.
 * All rights reserved.
 *
 * 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.
 */

/*
* $Created by: XIAO Tong (email: xiaotong@mail.neu.edu.cn) 2018-04-25
*/

#ifndef __HARDTANH_CUH__
#define __HARDTANH_CUH__

#include "../XTensor.h"

namespace nts{ // namespace nts(NiuTrans.Tensor)

#ifdef USE_CUDA

/* 
rectify function 
y =  1    if x > 1
     x    if -1 <= x <= 1
    -1    if x < -1
*/
void _CudaHardTanH(const XTensor * input, XTensor * output);

/* de/dx (Cuda version) */
void _CudaHardTanHBackward(XTensor * y, XTensor * x, 
                           XTensor * dedy, XTensor * dedx);

#endif // USE_CUDA

} // namespace nts(NiuTrans.Tensor)

#endif // __HARDTANH_CUH__