/**
 * Copyright (c) 2024 Huawei Technologies Co., Ltd.
 * This file is a part of the CANN Open Software.
 * Licensed under CANN Open Software License Agreement Version 1.0 (the "License").
 * Please refer to the License for details. You may not use this file except in compliance with the License.
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE.
 * See LICENSE in the root of the software repository for the full text of the License.
 */

/*!
 * \file cos.h
 * \brief Defines a series of interface used to do elementwise math cos calculation.
 * Formula: cos(x) = (-1)^k*sin(x0 + π/2), sin(x) = xP(x)
 * The Cos function does not have an elementary function expression, first normalize (x0 + π/2) to [-π/2, π/2]
 * and then calculating by function approximation.
 * k=round(x/π + 1/2), x0=x-kπ, x0 belongs to [-π, 0], (x0 + π/2) belongs to [-π/2, π/2]
 * π=π_0+π_1+π_2+π_3+π_4 achieve final precision compensation.
 * Final solution：
 *   k = round(x * invpi + 1/2)
 *   x -= k * pi_0
 *   x -= k * pi_1
 *   x = x + COS_PI_DOWN
 *   x -= k * pi_2
 *   x -= k * pi_3
 *   x -= k * pi_4
 *   x = x + COS_PI_RESDOWN_ADDS_NEG
 *   P(x) = (((x^2 * R0 + R1) * x^2 + R2) * x^2 + R3) * x^2 + 1.0
 *   COS_PI_DOWN = 1.57079637050628662109375
 *   COS_PI_RESDOWN_ADDS_NEG = -0.00000004371139000189375
 *   R0 = 2.604926501e-6
 *   R1 = -0.0001980894471
 *   R2 = 0.008333049340
 *   R3 = -0.1666665792
 */
#ifndef LIB_MATH_COS_H
#define LIB_MATH_COS_H

#if __CCE_AICORE__ == 200 || __CCE_AICORE__ == 220

#include "kernel_tensor.h"
#include "../../impl/math/cos/cos_common_impl.h"

namespace AscendC {
#pragma begin_pipe(V)
/*!
 * \ingroup Cos
 * \brief compute Cos elementwisely
 * \tparam T: half/float
 * \tparam isReuseSource: whether allows API to modify source data, usually for performance reason, only support
 * float input data type
 * \param [out] dstTensor: output LocalTensor
 * \param [in] srcTensor: input LocalTensor
 * \param [in] sharedTmpBuffer: extra temporary shared space used for intermediate values among calculation process,
 * whose required space size should refer to corresponding tiling API, which is defined at cos_tiling.h.
 * Generally, the more space you allocate, the better performance you will achieve, and the performance
 * reaches peak when buffer size is maximum(calculated by tiling function). Moreover, it is not guaranteed
 * that the shared space will be cleared after usage, the data could be anything.
 * \note src/dst Tensor must be 32B align, and it doesn't allow src/dst/sharedTmpBuffer tensor address overlap.
 * Input data valid range should be [-65504, 65504]
 */
template <typename T, bool isReuseSource = false>
__aicore__ inline void Cos(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor,
    const LocalTensor<uint8_t>& sharedTmpBuffer)
{
    Cos<T, isReuseSource>(dstTensor, srcTensor, sharedTmpBuffer, srcTensor.GetSize());
}

/*!
 * \ingroup Cos
 * \brief compute Cos elementwisely
 * \tparam T: half/float
 * \tparam isReuseSource: whether allows API to modify source data, usually for performance reason
 * \param [out] dstTensor: output LocalTensor
 * \param [in] srcTensor: input LocalTensor
 * \param [in] sharedTmpBuffer: extra temporary shared space used for intermediate values among calculation process,
 * whose required space size should refer to corresponding tiling API, which is defined at cos_tiling.h.
 * Generally, the more space you allocate, the better performance you will achieve, and the performance
 * reaches peak when buffer size is maximum(calculated by tiling function). Moreover, it is not guaranteed
 * that the shared space will be cleared after usage, the data could be anything.
 * \param [in] calCount: the number of elements to be processed.
 * \note src/dst Tensor must be 32B align, and it doesn't allow src/dst/sharedTmpBuffer tensor address overlap.
 * Input data valid range should be [-65504, 65504]
 */
template<typename T, bool isReuseSource = false>
__aicore__ inline void Cos(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor,
    const LocalTensor<uint8_t>& sharedTmpBuffer, const uint32_t calCount)
{
    CosImpl(dstTensor, srcTensor, sharedTmpBuffer, calCount);
}

/*!
 * \ingroup Cos
 * \brief compute Cos elementwisely
 * \tparam T: half/float
 * \tparam isReuseSource: whether allows API to modify source data, usually for performance reason
 * \param [out] dstTensor: output LocalTensor
 * \param [in] srcTensor: input LocalTensor
 * \note src/dst Tensor must be 32B align, and it doesn't allow src/dst/sharedTmpBuffer tensor address overlap.
 * Input data valid range should be [-65504, 65504]
 */
template <typename T, bool isReuseSource = false>
__aicore__ inline void Cos(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor)
{
    Cos<T, isReuseSource>(dstTensor, srcTensor, srcTensor.GetSize());
}

/*!
 * \ingroup Cos
 * \brief compute Cos elementwisely
 * \tparam T: half/float
 * \tparam isReuseSource: whether allows API to modify source data, usually for performance reason
 * \param [out] dstTensor: output LocalTensor
 * \param [in] srcTensor: input LocalTensor
 * \param [in] calCount: the number of elements to be processed.
 * \note src/dst Tensor must be 32B align, and it doesn't allow src/dst/sharedTmpBuffer tensor address overlap.
 * Input data valid range should be [-65504, 65504]
 */
template<typename T, bool isReuseSource = false>
__aicore__ inline void Cos(const LocalTensor<T>& dstTensor, const LocalTensor<T>& srcTensor,
    const uint32_t calCount)
{
    CosImpl(dstTensor, srcTensor, calCount);
}

#pragma end_pipe
}  // namespace AscendC

#endif

#endif  // LIB_MATH_COS_H