/*************************************************************************
 * Copyright (c) 2022-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 *
 * See LICENSE for license information.
 ************************************************************************/

#include "extensions.h"

std::vector<at::Tensor> layernorm_bwd(const at::Tensor &dz,
                                      const at::Tensor &x,
                                      const at::Tensor &mu,
                                      const at::Tensor &rsigma,
                                      const at::Tensor &gamma,
                                      const int sm_margin,
                                      const bool zero_centered_gamma
) {
    auto dx = at::empty_like(x);
    auto dgamma = at::empty_like(gamma);
    auto dbeta = at::empty_like(gamma);
    transformer_engine::TensorWrapper workspace, barrier, dgamma_part, dbeta_part;

    auto dz_cu      = makeTransformerEngineTensor(dz);
    auto x_cu       = makeTransformerEngineTensor(x);
    auto mu_cu      = makeTransformerEngineTensor(mu);
    auto rsigma_cu  = makeTransformerEngineTensor(rsigma);
    auto gamma_cu   = makeTransformerEngineTensor(gamma);
    auto dx_cu      = makeTransformerEngineTensor(dx);
    auto dgamma_cu  = makeTransformerEngineTensor(dgamma);
    auto dbeta_cu   = makeTransformerEngineTensor(dbeta);

    // This call populates tensors with the required config.
    const auto bwd_fun = zero_centered_gamma ? nvte_layernorm1p_bwd : nvte_layernorm_bwd;
    bwd_fun(dz_cu.data(), x_cu.data(), mu_cu.data(), rsigma_cu.data(), gamma_cu.data(),
            dx_cu.data(), dgamma_cu.data(), dbeta_cu.data(), dgamma_part.data(),
            dbeta_part.data(), at::cuda::getCurrentCUDAStream(),
            at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
            workspace.data(), barrier.data());

    // Alloc space for Tensors.
    auto workspace_data     = allocateSpace(workspace.shape(), workspace.dtype());
    auto barrier_data       = allocateSpace(barrier.shape(), barrier.dtype(), true);
    auto dgamma_part_data   = allocateSpace(dgamma_part.shape(), dgamma_part.dtype());
    auto dbeta_part_data    = allocateSpace(dbeta_part.shape(), dbeta_part.dtype());
    workspace   = makeTransformerEngineTensor(workspace_data.data_ptr(),
                                              workspace.shape(),
                                              workspace.dtype());
    barrier     = makeTransformerEngineTensor(barrier_data.data_ptr(),
                                              barrier.shape(),
                                              barrier.dtype());
    dgamma_part = makeTransformerEngineTensor(dgamma_part_data.data_ptr(),
                                              dgamma_part.shape(),
                                              dgamma_part.dtype());
    dbeta_part  = makeTransformerEngineTensor(dbeta_part_data.data_ptr(),
                                              dbeta_part.shape(),
                                              dbeta_part.dtype());

    // Actual call to bwd kernel.
    bwd_fun(dz_cu.data(), x_cu.data(), mu_cu.data(), rsigma_cu.data(), gamma_cu.data(),
            dx_cu.data(), dgamma_cu.data(), dbeta_cu.data(), dgamma_part.data(),
            dbeta_part.data(), at::cuda::getCurrentCUDAStream(),
            at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
            workspace.data(), barrier.data());

    return { dx, dgamma, dbeta };
}


std::vector<at::Tensor> layernorm_fwd_fp8(const at::Tensor &input,
                                          const at::Tensor &weight,
                                          const at::Tensor &bias,
                                          float eps,
                                          at::Tensor scale,
                                          at::Tensor amax,
                                          at::Tensor scale_inv,
                                          transformer_engine::DType otype,
                                          const int sm_margin,
                                          const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    auto ln_out = at::empty_like(input, at::CUDA(GetATenDType(otype)));
    return layernorm_fwd_fp8_noalloc(input, weight, bias, eps,
                                     scale, ln_out, amax, scale_inv,
                                     otype, sm_margin, zero_centered_gamma);
}


std::vector<at::Tensor> layernorm_fwd_fp8_noalloc(const at::Tensor &input,
                                                  const at::Tensor &weight,
                                                  const at::Tensor &bias,
                                                  float eps,
                                                  at::Tensor scale,
                                                  at::Tensor ln_out,
                                                  at::Tensor amax,
                                                  at::Tensor scale_inv,
                                                  transformer_engine::DType otype,
                                                  const int sm_margin,
                                                  const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    size_t N = static_cast<size_t>(input.size(0));
    size_t H = static_cast<size_t>(input.size(1));

    DType itype = GetTransformerEngineDType(input.scalar_type());

    auto mu = at::empty({static_cast<int64_t>(N)}, at::CUDA(at::kFloat));
    auto rsigma = at::empty({static_cast<int64_t>(N)}, at::CUDA(at::kFloat));
    auto input_cu     = makeTransformerEngineTensor(input);
    auto gamma_cu     = makeTransformerEngineTensor(weight);
    auto beta_cu      = makeTransformerEngineTensor(bias);
    auto z_cu         = makeTransformerEngineTensor(ln_out.data_ptr(), {N, H}, otype,
                                                    getDataPtr(amax), getDataPtr(scale),
                                                    getDataPtr(scale_inv));
    auto mu_cu        = makeTransformerEngineTensor(mu);
    auto rsigma_cu    = makeTransformerEngineTensor(rsigma);
    transformer_engine::TensorWrapper workspace, barrier;

    // This call populates workspace and barrier tensors with the required config
    const auto func = zero_centered_gamma ? nvte_layernorm1p_fwd : nvte_layernorm_fwd;
    func(input_cu.data(), gamma_cu.data(), beta_cu.data(), eps, z_cu.data(),
         mu_cu.data(), rsigma_cu.data(), at::cuda::getCurrentCUDAStream(),
         at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
         workspace.data(), barrier.data());

    // Fill workspace and barrier
    auto workspace_data = allocateSpace(workspace.shape(),
                                        workspace.dtype());
    auto barrier_data = allocateSpace(barrier.shape(),
                                      barrier.dtype(),
                                      true);
    workspace = makeTransformerEngineTensor(workspace_data.data_ptr(),
                                            workspace.shape(),
                                            workspace.dtype());
    barrier   = makeTransformerEngineTensor(barrier_data.data_ptr(),
                                            barrier.shape(),
                                            barrier.dtype());

    // Actual call to fwd kernel
    func(input_cu.data(), gamma_cu.data(), beta_cu.data(), eps, z_cu.data(),
         mu_cu.data(), rsigma_cu.data(), at::cuda::getCurrentCUDAStream(),
         at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
         workspace.data(), barrier.data());

    return {ln_out, mu, rsigma};
}


at::Tensor layernorm_fwd_fp8_inf(const at::Tensor &input,
                                 const at::Tensor &weight,
                                 const at::Tensor &bias,
                                 float eps,
                                 at::Tensor scale,
                                 at::Tensor amax,
                                 at::Tensor scale_inv,
                                 transformer_engine::DType otype,
                                 const int sm_margin,
                                 const bool zero_centered_gamma
) {
    // This is a specialized version of layernorm_fwd_fp8, optimized for inference,
    // which only returns the normalized output.
    std::vector<at::Tensor> out = layernorm_fwd_fp8(
      input, weight, bias, eps, scale, amax, scale_inv, otype, sm_margin, zero_centered_gamma);
    return out[0];
}


std::vector<at::Tensor> layernorm_fwd(const at::Tensor &input,
                                      const at::Tensor &weight,
                                      const at::Tensor &bias,
                                      float eps,
                                      const int sm_margin,
                                      const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    DType itype = GetTransformerEngineDType(input.scalar_type());
    auto ln_out = at::empty_like(input, at::CUDA(GetATenDType(itype)));

    return layernorm_fwd_noalloc(input, weight, bias, ln_out, eps,
                                 sm_margin, zero_centered_gamma);
}


std::vector<at::Tensor> layernorm_fwd_noalloc(const at::Tensor &input,
                                              const at::Tensor &weight,
                                              const at::Tensor &bias,
                                              at::Tensor ln_out,
                                              float eps,
                                              const int sm_margin,
                                              const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    DType itype = GetTransformerEngineDType(input.scalar_type());

    return layernorm_fwd_fp8_noalloc(input, weight, bias, eps, at::Tensor(),
                                     ln_out, at::Tensor(), at::Tensor(),
                                     itype, sm_margin, zero_centered_gamma);
}


at::Tensor layernorm_fwd_inf(const at::Tensor &input,
                             const at::Tensor &weight,
                             const at::Tensor &bias,
                             float eps,
                             const int sm_margin,
                             const bool zero_centered_gamma
) {
    // This is a specialized version of layernorm_fwd, optimized for inference,
    // which only returns the normalized output.
    std::vector<at::Tensor> out = layernorm_fwd(input, weight, bias, eps, sm_margin,
                                                zero_centered_gamma);
    return out[0];
}

std::vector<at::Tensor> rmsnorm_bwd(const at::Tensor &dz,
                                    const at::Tensor &x,
                                    const at::Tensor &rsigma,
                                    const at::Tensor &gamma,
                                    const int sm_margin,
                                    const bool zero_centered_gamma
) {
    auto dx = at::empty_like(x);
    auto dgamma = at::empty_like(gamma);
    transformer_engine::TensorWrapper workspace, barrier, dgamma_part;

    auto dz_cu      = makeTransformerEngineTensor(dz);
    auto x_cu       = makeTransformerEngineTensor(x);
    auto rsigma_cu  = makeTransformerEngineTensor(rsigma);
    auto gamma_cu   = makeTransformerEngineTensor(gamma);
    auto dx_cu      = makeTransformerEngineTensor(dx);
    auto dgamma_cu  = makeTransformerEngineTensor(dgamma);

    // This call populates tensors with the required config.
    const auto bwd_fun = zero_centered_gamma ? nvte_rmsnorm1p_bwd : nvte_rmsnorm_bwd;
    bwd_fun(dz_cu.data(), x_cu.data(), rsigma_cu.data(), gamma_cu.data(),
            dx_cu.data(), dgamma_cu.data(), dgamma_part.data(),
            at::cuda::getCurrentCUDAStream(),
            at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
            workspace.data(), barrier.data());

    // Alloc space for Tensors.
    auto workspace_data     = allocateSpace(workspace.shape(), workspace.dtype());
    auto barrier_data       = allocateSpace(barrier.shape(), barrier.dtype(), true);
    auto dgamma_part_data   = allocateSpace(dgamma_part.shape(), dgamma_part.dtype());
    workspace   = makeTransformerEngineTensor(workspace_data.data_ptr(),
                                              workspace.shape(),
                                              workspace.dtype());
    barrier     = makeTransformerEngineTensor(barrier_data.data_ptr(),
                                              barrier.shape(),
                                              barrier.dtype());
    dgamma_part = makeTransformerEngineTensor(dgamma_part_data.data_ptr(),
                                              dgamma_part.shape(),
                                              dgamma_part.dtype());

    // Actual call to bwd kernel.
    bwd_fun(dz_cu.data(), x_cu.data(), rsigma_cu.data(), gamma_cu.data(),
            dx_cu.data(), dgamma_cu.data(), dgamma_part.data(),
            at::cuda::getCurrentCUDAStream(),
            at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
            workspace.data(), barrier.data());

    return { dx, dgamma };
}


std::vector<at::Tensor> rmsnorm_fwd_fp8(const at::Tensor &input,
                                        const at::Tensor &weight,
                                        float eps,
                                        at::Tensor scale,
                                        at::Tensor amax,
                                        at::Tensor scale_inv,
                                        transformer_engine::DType otype,
                                        const int sm_margin,
                                        const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    auto ln_out = at::empty_like(input, at::CUDA(GetATenDType(otype)));
    return rmsnorm_fwd_fp8_noalloc(input, weight, eps,
                                   scale, ln_out, amax, scale_inv,
                                   otype, sm_margin, zero_centered_gamma);
}


std::vector<at::Tensor> rmsnorm_fwd_fp8_noalloc(const at::Tensor &input,
                                                const at::Tensor &weight,
                                                float eps,
                                                at::Tensor scale,
                                                at::Tensor ln_out,
                                                at::Tensor amax,
                                                at::Tensor scale_inv,
                                                transformer_engine::DType otype,
                                                const int sm_margin,
                                                const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    size_t N = static_cast<size_t>(input.size(0));
    size_t H = static_cast<size_t>(input.size(1));

    DType itype = GetTransformerEngineDType(input.scalar_type());

    auto rsigma = at::empty({static_cast<int64_t>(N)}, at::CUDA(at::kFloat));
    auto input_cu     = makeTransformerEngineTensor(input);
    auto gamma_cu     = makeTransformerEngineTensor(weight);
    auto z_cu         = makeTransformerEngineTensor(ln_out.data_ptr(), {N, H}, otype,
                                                    getDataPtr(amax), getDataPtr(scale),
                                                    getDataPtr(scale_inv));
    auto rsigma_cu    = makeTransformerEngineTensor(rsigma);
    transformer_engine::TensorWrapper workspace, barrier;

    // This call populates workspace and barrier tensors with the required config
    const auto func = zero_centered_gamma ? nvte_rmsnorm1p_fwd : nvte_rmsnorm_fwd;
    func(input_cu.data(), gamma_cu.data(), eps, z_cu.data(),
         rsigma_cu.data(), at::cuda::getCurrentCUDAStream(),
         at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
         workspace.data(), barrier.data());

    // Fill workspace and barrier
    auto workspace_data = allocateSpace(workspace.shape(),
                                        workspace.dtype());
    auto barrier_data = allocateSpace(barrier.shape(),
                                      barrier.dtype(),
                                      true);
    workspace = makeTransformerEngineTensor(workspace_data.data_ptr(),
                                            workspace.shape(),
                                            workspace.dtype());
    barrier   = makeTransformerEngineTensor(barrier_data.data_ptr(),
                                            barrier.shape(),
                                            barrier.dtype());

    // Actual call to fwd kernel
    func(input_cu.data(), gamma_cu.data(), eps, z_cu.data(),
         rsigma_cu.data(), at::cuda::getCurrentCUDAStream(),
         at::cuda::getCurrentDeviceProperties()->multiProcessorCount - sm_margin,
         workspace.data(), barrier.data());

    return {ln_out, rsigma};
}


at::Tensor rmsnorm_fwd_fp8_inf(const at::Tensor &input,
                               const at::Tensor &weight,
                               float eps,
                               at::Tensor scale,
                               at::Tensor amax,
                               at::Tensor scale_inv,
                               transformer_engine::DType otype,
                               const int sm_margin,
                               const bool zero_centered_gamma
) {
    // This is a specialized version of rmsnorm_fwd_fp8, optimized for inference,
    // which only returns the normalized output.
    std::vector<at::Tensor> out = rmsnorm_fwd_fp8(
      input, weight, eps, scale, amax, scale_inv, otype, sm_margin, zero_centered_gamma);
    return out[0];
}


std::vector<at::Tensor> rmsnorm_fwd(const at::Tensor &input,
                                    const at::Tensor &weight,
                                    float eps,
                                    const int sm_margin,
                                    const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    DType itype = GetTransformerEngineDType(input.scalar_type());
    auto ln_out = at::empty_like(input, at::CUDA(GetATenDType(itype)));

    return rmsnorm_fwd_noalloc(input, weight, ln_out, eps,
                               sm_margin, zero_centered_gamma);
}


std::vector<at::Tensor> rmsnorm_fwd_noalloc(const at::Tensor &input,
                                            const at::Tensor &weight,
                                            at::Tensor ln_out,
                                            float eps,
                                            const int sm_margin,
                                            const bool zero_centered_gamma
) {
    using namespace transformer_engine;

    DType itype = GetTransformerEngineDType(input.scalar_type());

    return rmsnorm_fwd_fp8_noalloc(input, weight, eps, at::Tensor(),
                                   ln_out, at::Tensor(), at::Tensor(),
                                   itype, sm_margin, zero_centered_gamma);
}


at::Tensor rmsnorm_fwd_inf(const at::Tensor &input,
                           const at::Tensor &weight,
                           float eps,
                           const int sm_margin,
                           const bool zero_centered_gamma
) {
    // This is a specialized version of rmsnorm_fwd, optimized for inference,
    // which only returns the normalized output.
    std::vector<at::Tensor> out = rmsnorm_fwd(input, weight, eps, sm_margin, zero_centered_gamma);
    return out[0];
}
