/* ************************************************************************
 * Copyright (C) 2016-2023 Advanced Micro Devices, Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell cop-
 * ies of the Software, and to permit persons to whom the Software is furnished
 * to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IM-
 * PLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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 * CTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * ************************************************************************ */

#include "check_numerics_vector.hpp"
#include "handle.hpp"
#include "rocblas_swap.hpp"

template <typename T>
__forceinline__ __device__ __host__ void rocblas_swap_vals(T* __restrict__ x, T* __restrict__ y)
{
    T tmp = *y;
    *y    = *x;
    *x    = tmp;
}

template <rocblas_int NB, typename UPtr>
ROCBLAS_KERNEL(NB)
rocblas_swap_kernel(rocblas_int    n,
                    UPtr           xa,
                    rocblas_stride offsetx,
                    rocblas_int    incx,
                    rocblas_stride stridex,
                    UPtr           ya,
                    rocblas_stride offsety,
                    rocblas_int    incy,
                    rocblas_stride stridey)
{
    auto*   x   = load_ptr_batch(xa, blockIdx.y, offsetx, stridex);
    auto*   y   = load_ptr_batch(ya, blockIdx.y, offsety, stridey);
    int64_t tid = blockIdx.x * blockDim.x + threadIdx.x;

    if(tid < n)
    {
        rocblas_swap_vals(x + tid * incx, y + tid * incy);
    }
}

//! @brief Optimized kernel for the floating points.
//!
template <rocblas_int NB, typename UPtr>
ROCBLAS_KERNEL(NB)
rocblas_sswap_2_kernel(rocblas_int n,
                       UPtr __restrict__ xa,
                       rocblas_stride offsetx,
                       rocblas_stride stridex,
                       UPtr __restrict__ ya,
                       rocblas_stride offsety,
                       rocblas_stride stridey)
{
    int64_t tid = (blockIdx.x * blockDim.x + threadIdx.x) * 2;
    auto*   x   = load_ptr_batch(xa, blockIdx.y, offsetx, stridex);
    auto*   y   = load_ptr_batch(ya, blockIdx.y, offsety, stridey);
    if(tid < n - 1)
    {
        for(int j = 0; j < 2; ++j)
        {
            rocblas_swap_vals(x + tid + j, y + tid + j);
        }
    }
    if(n % 2 != 0 && tid == n - 1)
    {
        rocblas_swap_vals(x + tid, y + tid);
    }
}

template <rocblas_int NB, typename T>
rocblas_status rocblas_swap_template(rocblas_handle handle,
                                     rocblas_int    n,
                                     T              x,
                                     rocblas_stride offsetx,
                                     rocblas_int    incx,
                                     rocblas_stride stridex,
                                     T              y,
                                     rocblas_stride offsety,
                                     rocblas_int    incy,
                                     rocblas_stride stridey,
                                     rocblas_int    batch_count)
{
    // Quick return if possible.
    if(n <= 0 || batch_count <= 0)
        return rocblas_status_success;

    static constexpr bool using_rocblas_float
        = std::is_same_v<T, rocblas_float*> || std::is_same_v<T, rocblas_float* const*>;

    if(!using_rocblas_float || incx != 1 || incy != 1)
    {
        // in case of negative inc shift pointer to end of data for negative indexing tid*inc
        int64_t shiftx = incx < 0 ? offsetx - int64_t(incx) * (n - 1) : offsetx;
        int64_t shifty = incy < 0 ? offsety - int64_t(incy) * (n - 1) : offsety;

        dim3 blocks((n - 1) / NB + 1, batch_count);
        dim3 threads(NB);

        hipLaunchKernelGGL((rocblas_swap_kernel<NB>),
                           blocks,
                           threads,
                           0,
                           handle->get_stream(),
                           n,
                           x,
                           shiftx,
                           incx,
                           stridex,
                           y,
                           shifty,
                           incy,
                           stridey);
    }
    else
    {
        // Kernel function for improving the performance of SSWAP when incx==1 and incy==1
        int64_t shiftx = offsetx - 0;
        int64_t shifty = offsety - 0;

        int  blocks = 1 + ((n - 1) / (NB * 2));
        dim3 grid(blocks, batch_count);
        dim3 threads(NB);

        hipLaunchKernelGGL((rocblas_sswap_2_kernel<NB>),
                           grid,
                           threads,
                           0,
                           handle->get_stream(),
                           n,
                           x,
                           shiftx,
                           stridex,
                           y,
                           shifty,
                           stridey);
    }
    return rocblas_status_success;
}

template <typename T>
rocblas_status rocblas_swap_check_numerics(const char*    function_name,
                                           rocblas_handle handle,
                                           rocblas_int    n,
                                           T              x,
                                           rocblas_stride offset_x,
                                           rocblas_int    inc_x,
                                           rocblas_stride stride_x,
                                           T              y,
                                           rocblas_stride offset_y,
                                           rocblas_int    inc_y,
                                           rocblas_stride stride_y,
                                           rocblas_int    batch_count,
                                           const int      check_numerics,
                                           bool           is_input)
{
    rocblas_status check_numerics_status
        = rocblas_internal_check_numerics_vector_template(function_name,
                                                          handle,
                                                          n,
                                                          x,
                                                          offset_x,
                                                          inc_x,
                                                          stride_x,
                                                          batch_count,
                                                          check_numerics,
                                                          is_input);
    if(check_numerics_status != rocblas_status_success)
        return check_numerics_status;

    check_numerics_status = rocblas_internal_check_numerics_vector_template(function_name,
                                                                            handle,
                                                                            n,
                                                                            y,
                                                                            offset_y,
                                                                            inc_y,
                                                                            stride_y,
                                                                            batch_count,
                                                                            check_numerics,
                                                                            is_input);

    return check_numerics_status;
}

// Instantiations below will need to be manually updated to match any change in
// template parameters in the files swap*.cpp

// clang-format off
#ifdef INSTANTIATE_SWAP_TEMPLATE
#error INSTANTIATE_SWAP_TEMPLATE already defined
#endif

#define INSTANTIATE_SWAP_TEMPLATE(NB_, T_)                                            \
template rocblas_status rocblas_swap_template<NB_, T_>(rocblas_handle handle,         \
                                                       rocblas_int    n,              \
                                                       T_             x,              \
                                                       rocblas_stride offsetx,        \
                                                       rocblas_int    incx,           \
                                                       rocblas_stride stridex,        \
                                                       T_             y,              \
                                                       rocblas_stride offsety,        \
                                                       rocblas_int    incy,           \
                                                       rocblas_stride stridey,        \
                                                       rocblas_int    batch_count = 1);
INSTANTIATE_SWAP_TEMPLATE(256, float*)
INSTANTIATE_SWAP_TEMPLATE(256, double*)
INSTANTIATE_SWAP_TEMPLATE(256, rocblas_float_complex*)
INSTANTIATE_SWAP_TEMPLATE(256, rocblas_double_complex*)

INSTANTIATE_SWAP_TEMPLATE(256, float* const*)
INSTANTIATE_SWAP_TEMPLATE(256, double* const*)
INSTANTIATE_SWAP_TEMPLATE(256, rocblas_float_complex* const*)
INSTANTIATE_SWAP_TEMPLATE(256, rocblas_double_complex* const*)

#undef INSTANTIATE_SWAP_TEMPLATE

#ifdef INSTANTIATE_SWAP_CHECK_NUMERICS
#error INSTANTIATE_SWAP_CHECK_NUMERICS already defined
#endif

#define INSTANTIATE_SWAP_CHECK_NUMERICS(T_)                                            \
template rocblas_status rocblas_swap_check_numerics<T_>(const char*    function_name,  \
                                                        rocblas_handle handle,         \
                                                        rocblas_int    n,              \
                                                        T_             x,              \
                                                        rocblas_stride offset_x,       \
                                                        rocblas_int    inc_x,          \
                                                        rocblas_stride stride_x,       \
                                                        T_             y,              \
                                                        rocblas_stride offset_y,       \
                                                        rocblas_int    inc_y,          \
                                                        rocblas_stride stride_y,       \
                                                        rocblas_int    batch_count,    \
                                                        const int      check_numerics, \
                                                        bool           is_input);

INSTANTIATE_SWAP_CHECK_NUMERICS(float*)
INSTANTIATE_SWAP_CHECK_NUMERICS(double*)
INSTANTIATE_SWAP_CHECK_NUMERICS(rocblas_float_complex*)
INSTANTIATE_SWAP_CHECK_NUMERICS(rocblas_double_complex*)

INSTANTIATE_SWAP_CHECK_NUMERICS(float* const*)
INSTANTIATE_SWAP_CHECK_NUMERICS(double* const*)
INSTANTIATE_SWAP_CHECK_NUMERICS(rocblas_float_complex* const*)
INSTANTIATE_SWAP_CHECK_NUMERICS(rocblas_double_complex* const*)

#undef INSTANTIATE_SWAP_CHECK_NUMERICS
// clang-format on
