/*
 * Copyright (c) 2021-2023 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * 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 copies 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
 * IMPLIED, 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 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef ACL_SRC_CPU_KERNELS_FUSE_BATCH_NORMALIZATION_GENERIC_IMPL_H
#define ACL_SRC_CPU_KERNELS_FUSE_BATCH_NORMALIZATION_GENERIC_IMPL_H

#include "arm_compute/core/Helpers.h"

#include "src/core/NEON/wrapper/wrapper.h"

namespace arm_compute
{
namespace cpu
{
template <typename T, bool fused_activation, typename F>
void batch_normalization_nchw(const Window       &window,
                              ITensor            *in,
                              ITensor            *out,
                              const ITensor      *in_mean,
                              const ITensor      *in_var,
                              const ITensor      *in_beta,
                              const ITensor      *in_gamma,
                              float               epsilon,
                              ActivationLayerInfo act_info)
{
    /** SIMD vector tag type. */
    using ExactTagType = typename wrapper::traits::neon_bitvector_tag_t<T, wrapper::traits::BitWidth::W128>;

    const int  window_step_x  = 16 / sizeof(T);
    const auto window_start_x = static_cast<int>(window.x().start());
    const auto window_end_x   = static_cast<int>(window.x().end());

    Window win_to_use = window;
    win_to_use.set(Window::DimX, Window::Dimension(0, 1, 1));

    Iterator input(in, win_to_use);
    Iterator output(out, win_to_use);

    F activation_functor(act_info);

    // Hold information about the current feature map we are iterating.
    // Only compute denominator and constants once per feature map.
    int slice = -1;

    const auto input_mean = reinterpret_cast<const T *>(in_mean->ptr_to_element(Coordinates(0, 0)));
    const auto input_var  = reinterpret_cast<const T *>(in_var->ptr_to_element(Coordinates(0, 0)));
    const auto input_gamma =
        (in_gamma != nullptr) ? reinterpret_cast<const T *>(in_gamma->ptr_to_element(Coordinates(0, 0))) : nullptr;
    const auto input_beta =
        (in_beta != nullptr) ? reinterpret_cast<const T *>(in_beta->ptr_to_element(Coordinates(0, 0))) : nullptr;

    T mean        = static_cast<T>(0);
    T var         = static_cast<T>(0);
    T gamma       = static_cast<T>(1);
    T beta        = static_cast<T>(0);
    T denominator = static_cast<T>(0);

    auto       mean_vec        = wrapper::vdup_n(mean, ExactTagType{});
    auto       var_vec         = wrapper::vdup_n(var, ExactTagType{});
    auto       gamma_vec       = wrapper::vdup_n(gamma, ExactTagType{});
    auto       beta_vec        = wrapper::vdup_n(beta, ExactTagType{});
    auto       denominator_vec = wrapper::vdup_n(denominator, ExactTagType{});
    const auto epsilon_vec     = wrapper::vdup_n(static_cast<T>(epsilon), ExactTagType{});
    execute_window_loop(
        win_to_use,
        [&](const Coordinates &id)
        {
            const auto input_ptr  = reinterpret_cast<const T *>(input.ptr());
            const auto output_ptr = reinterpret_cast<T *>(output.ptr());

            if (slice != id.z())
            {
                mean     = input_mean[id.z()];
                var      = input_var[id.z()];
                mean_vec = wrapper::vdup_n(mean, ExactTagType{});
                var_vec  = wrapper::vdup_n(var, ExactTagType{});
                if (input_gamma != nullptr)
                {
                    gamma     = input_gamma[id.z()];
                    gamma_vec = wrapper::vdup_n(gamma, ExactTagType{});
                }
                if (input_beta != nullptr)
                {
                    beta     = input_beta[id.z()];
                    beta_vec = wrapper::vdup_n(beta, ExactTagType{});
                }

                // Calculate denominator
                denominator_vec = wrapper::vinvsqrt(wrapper::vadd(var_vec, epsilon_vec));
                denominator     = wrapper::vgetlane(denominator_vec, 0);
                slice           = id.z();
            }

            // Perform core calculations using vector operations
            int x = window_start_x;
            for (; x <= (window_end_x - window_step_x); x += window_step_x)
            {
                // Calculate x bar
                const auto numerator = wrapper::vsub(wrapper::vloadq(input_ptr + x), mean_vec);
                const auto x_bar     = wrapper::vmul(numerator, denominator_vec);
                auto       res       = wrapper::vmla(beta_vec, x_bar, gamma_vec);

                // Perform fused activation
                if (fused_activation)
                {
                    activation_functor(res);
                }

                // Store results
                wrapper::vstore(output_ptr + x, res);
            }

            // Compute left-over elements
            for (; x < window_end_x; ++x)
            {
                const T numerator = input_ptr[x] - mean;
                const T x_bar     = numerator * denominator;
                T       res       = beta + x_bar * gamma;

                // Perform fused activation
                if (fused_activation)
                {
                    activation_functor(res);
                }

                // Store results
                *(output_ptr + x) = res;
            }
        },
        input, output);
}

template <typename T>
void fused_batch_normalization_conv(const ITensor *conv_weights,
                                    const ITensor *conv_bias,
                                    ITensor       *fused_weights,
                                    ITensor       *fused_bias,
                                    const ITensor *bn_mean,
                                    const ITensor *bn_var,
                                    const ITensor *bn_beta,
                                    const ITensor *bn_gamma,
                                    float          epsilon,
                                    const Window  &window)
{
    using ScalarType   = T;
    const int size     = 16 / conv_weights->info()->element_size();
    using ExactTagType = typename wrapper::traits::neon_bitvector_tag_t<T, wrapper::traits::BitWidth::W128>;

    const bool run_in_place_weights = (fused_weights == nullptr) || (fused_weights == conv_weights);
    const bool run_in_place_bias    = (fused_bias == nullptr) || (conv_bias != nullptr && fused_bias == conv_bias);

    // Set build options
    Window win = window;
    win.set(Window::DimX, Window::Dimension(0, 1, 1));

    const int  window_step_x  = size;
    const auto window_start_x = static_cast<int>(window.x().start());
    const auto window_end_x   = static_cast<int>(window.x().end());

    Iterator conv_w_in(conv_weights, win);
    Iterator conv_w_out(run_in_place_weights ? conv_weights : fused_weights, win);

    const auto conv_bias_in =
        (conv_bias != nullptr ? reinterpret_cast<ScalarType *>(conv_bias->ptr_to_element(Coordinates(0, 0))) : nullptr);
    auto conv_bias_out =
        (run_in_place_bias ? conv_bias_in
                           : reinterpret_cast<ScalarType *>(fused_bias->ptr_to_element(Coordinates(0, 0))));

    const auto input_mean  = reinterpret_cast<const ScalarType *>(bn_mean->ptr_to_element(Coordinates(0, 0)));
    const auto input_var   = reinterpret_cast<const ScalarType *>(bn_var->ptr_to_element(Coordinates(0, 0)));
    const auto input_gamma = (bn_gamma != nullptr)
                                 ? reinterpret_cast<const ScalarType *>(bn_gamma->ptr_to_element(Coordinates(0, 0)))
                                 : nullptr;
    const auto input_beta  = (bn_beta != nullptr)
                                 ? reinterpret_cast<const ScalarType *>(bn_beta->ptr_to_element(Coordinates(0, 0)))
                                 : nullptr;

    auto       mean_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       var_vec     = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       gamma_vec   = wrapper::vdup_n(ScalarType(1), ExactTagType{});
    auto       beta_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       rvar_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    const auto epsilon_vec = wrapper::vdup_n(ScalarType(epsilon), ExactTagType{});

    auto mean                = ScalarType(0.0);
    auto var                 = ScalarType(0.0);
    auto gamma               = ScalarType(1.0);
    auto beta                = ScalarType(0.0);
    auto conv_bias_in_scalar = ScalarType(0.0);
    execute_window_loop(
        win,
        [&](const Coordinates &id)
        {
            var = input_var[id[3]];
            if (input_gamma != nullptr)
            {
                gamma = input_gamma[id[3]];
            }

            if ((id[0] == 0) && (id[1] == 0) && (id[2] == 0))
            {
                if (input_beta != nullptr)
                {
                    beta     = input_beta[id[3]];
                    beta_vec = wrapper::vdup_n(beta, ExactTagType{});
                }

                // Construct vectors
                mean     = input_mean[id[3]];
                mean_vec = wrapper::vdup_n(mean, ExactTagType{});

                if (conv_bias_in != nullptr)
                {
                    conv_bias_in_scalar = conv_bias_in[id[3]];
                }
                auto conv_bias_tmp_scalar = (conv_bias_in_scalar - mean) / std::sqrt(var + ScalarType(epsilon));
                conv_bias_out[id[3]]      = (conv_bias_tmp_scalar * gamma) + beta;
            }

            int  x              = window_start_x;
            auto conv_w_in_ptr  = reinterpret_cast<const ScalarType *>(conv_w_in.ptr());
            auto conv_w_out_ptr = reinterpret_cast<ScalarType *>(conv_w_out.ptr());
            var_vec             = wrapper::vdup_n(var, ExactTagType{});
            gamma_vec           = wrapper::vdup_n(gamma, ExactTagType{});
            rvar_vec            = wrapper::vinvsqrt(wrapper::vadd(var_vec, epsilon_vec));

            for (; x <= (window_end_x - window_step_x); x += window_step_x)
            {
                auto wn = wrapper::vloadq(conv_w_in_ptr + x);
                wn      = wrapper::vmul(wn, rvar_vec);
                wn      = wrapper::vmul(wn, gamma_vec);

                // Store results
                wrapper::vstore(conv_w_out_ptr + x, wn);
            }

            // Compute left-over elements
            for (; x < window_end_x; ++x)
            {
                *(conv_w_out_ptr + x) = *(conv_w_in_ptr + x) / std::sqrt(var + ScalarType(epsilon)) * gamma;
            }
        },
        conv_w_in, conv_w_out);
}
template <typename T>
void fused_batch_normalization_dwc_nchw(const ITensor *dwc_weights,
                                        const ITensor *dwc_bias,
                                        ITensor       *fused_weights,
                                        ITensor       *fused_bias,
                                        const ITensor *bn_mean,
                                        const ITensor *bn_var,
                                        const ITensor *bn_beta,
                                        const ITensor *bn_gamma,
                                        float          epsilon,
                                        const Window  &window)
{
    using ScalarType   = T;
    const int size     = 16 / dwc_weights->info()->element_size();
    using ExactTagType = typename wrapper::traits::neon_bitvector_tag_t<T, wrapper::traits::BitWidth::W128>;

    const bool run_in_place_weights = (fused_weights == nullptr) || (fused_weights == dwc_weights);
    const bool run_in_place_bias    = (fused_bias == nullptr) || (dwc_bias != nullptr && fused_bias == dwc_bias);

    // Set build options
    Window win = window;
    win.set(Window::DimX, Window::Dimension(0, 1, 1));

    const int  window_step_x  = size;
    const auto window_start_x = static_cast<int>(window.x().start());
    const auto window_end_x   = static_cast<int>(window.x().end());

    Iterator dwc_w_in(dwc_weights, win);
    Iterator dwc_w_out(run_in_place_weights ? dwc_weights : fused_weights, win);

    const auto dwc_bias_in =
        (dwc_bias != nullptr ? reinterpret_cast<ScalarType *>(dwc_bias->ptr_to_element(Coordinates(0, 0))) : nullptr);
    auto dwc_bias_out =
        (run_in_place_bias ? dwc_bias_in
                           : reinterpret_cast<ScalarType *>(fused_bias->ptr_to_element(Coordinates(0, 0))));

    const auto input_mean  = reinterpret_cast<const ScalarType *>(bn_mean->ptr_to_element(Coordinates(0, 0)));
    const auto input_var   = reinterpret_cast<const ScalarType *>(bn_var->ptr_to_element(Coordinates(0, 0)));
    const auto input_gamma = (bn_gamma != nullptr)
                                 ? reinterpret_cast<const ScalarType *>(bn_gamma->ptr_to_element(Coordinates(0, 0)))
                                 : nullptr;
    const auto input_beta  = (bn_beta != nullptr)
                                 ? reinterpret_cast<const ScalarType *>(bn_beta->ptr_to_element(Coordinates(0, 0)))
                                 : nullptr;

    auto       mean_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       var_vec     = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       gamma_vec   = wrapper::vdup_n(ScalarType(1), ExactTagType{});
    auto       beta_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    auto       rvar_vec    = wrapper::vdup_n(ScalarType(0), ExactTagType{});
    const auto epsilon_vec = wrapper::vdup_n(ScalarType(epsilon), ExactTagType{});

    auto mean               = ScalarType(0.0);
    auto var                = ScalarType(0.0);
    auto gamma              = ScalarType(1.0);
    auto beta               = ScalarType(0.0);
    auto dwc_bias_in_scalar = ScalarType(0.0);
    execute_window_loop(
        win,
        [&](const Coordinates &id)
        {
            var = input_var[id[2]];
            if (input_gamma != nullptr)
            {
                gamma = input_gamma[id[2]];
            }

            if (id[1] == 0)
            {
                mean = input_mean[id[2]];

                // Construct vectors
                mean_vec = wrapper::vdup_n(mean, ExactTagType{});
                if (input_beta != nullptr)
                {
                    beta     = input_beta[id[2]];
                    beta_vec = wrapper::vdup_n(beta, ExactTagType{});
                }

                if (dwc_bias_in != nullptr)
                {
                    dwc_bias_in_scalar = dwc_bias_in[id[2]];
                }

                auto dwc_bias_tmp_scalar = (dwc_bias_in_scalar - mean) / std::sqrt(var + ScalarType(epsilon));
                dwc_bias_out[id[2]]      = (dwc_bias_tmp_scalar * gamma) + beta;
            }

            int  x             = window_start_x;
            auto dwc_w_in_ptr  = reinterpret_cast<const ScalarType *>(dwc_w_in.ptr());
            auto dwc_w_out_ptr = reinterpret_cast<ScalarType *>(dwc_w_out.ptr());
            var_vec            = wrapper::vdup_n(var, ExactTagType{});
            gamma_vec          = wrapper::vdup_n(gamma, ExactTagType{});
            rvar_vec           = wrapper::vinvsqrt(wrapper::vadd(var_vec, epsilon_vec));

            for (; x <= (window_end_x - window_step_x); x += window_step_x)
            {
                auto wn = wrapper::vloadq(dwc_w_in_ptr + x);
                wn      = wrapper::vmul(wn, rvar_vec);
                wn      = wrapper::vmul(wn, gamma_vec);

                // Store results
                wrapper::vstore(dwc_w_out_ptr + x, wn);
            }

            // Compute left-over elements
            for (; x < window_end_x; ++x)
            {
                *(dwc_w_out_ptr + x) = *(dwc_w_in_ptr + x) / std::sqrt(var + ScalarType(epsilon)) * gamma;
            }
        },
        dwc_w_in, dwc_w_out);
}

} // namespace cpu
} // namespace arm_compute
#endif // ACL_SRC_CPU_KERNELS_FUSE_BATCH_NORMALIZATION_GENERIC_IMPL_H