// Copyright (c) 2025 PaddlePaddle Authors. 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.


// Ignore CUTLASS warnings about type punning
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
#pragma GCC diagnostic ignored "-Wunused-function"
#pragma once

#include "moe/fused_moe_helper.h"
#include "moe/fused_moe_op.h"
#pragma GCC diagnostic pop

#include "helper.h"
#include <cooperative_groups.h>
namespace cg = cooperative_groups;

template<typename T>
__device__ T warpReduceSum(T val){
    for(int lane_mask = 16; lane_mask > 0; lane_mask /=2){
        val += __shfl_down_sync(0xffffffff, val, lane_mask);
    }
    return val;
}

__global__ void get_expert_token_num(
  int64_t* topk_ids,
  int *out_workspace, // num_experts * 2 + 2
  const int token_num,
  const int moe_topk,
  const int num_experts
) {
  cg::grid_group grid = cg::this_grid();
  constexpr int KNWARPS = 512 / 32;
  __shared__ int warp_sum[KNWARPS * 2];
  int *expert_token_num = out_workspace;
  int *expert_token_num_padded = out_workspace + num_experts;
  int *token_num_all = out_workspace + num_experts * 2;
  int *token_num_all_padded = out_workspace + num_experts * 2 + 1;
  const int global_idx = blockIdx.x * blockDim.x + threadIdx.x;
  for (int i = global_idx; i < num_experts; i += blockDim.x * gridDim.x) {
    expert_token_num[i] = 0;
    expert_token_num_padded[i] = 0;
  }
  grid.sync();
  for (int i = global_idx; i < token_num * moe_topk; i += blockDim.x * gridDim.x) {
    const int topk_idx = topk_ids[i];
    atomicAdd(&expert_token_num[topk_idx], 1);
  }
  grid.sync();
  for (int i = global_idx; i < num_experts; i += blockDim.x * gridDim.x) {
    const int token_num_per_expert = expert_token_num[i];
    if (token_num_per_expert > 0) {
      expert_token_num_padded[i] = 128 - token_num_per_expert % 128 + token_num_per_expert;
    }
  }
  grid.sync();
  if (blockIdx.x == 0) {
    int token_num_now = 0;
    int token_num_padded = 0;
    if (threadIdx.x < num_experts) {
      token_num_now = expert_token_num[threadIdx.x];
      token_num_padded = expert_token_num_padded[threadIdx.x];
    }
    const int laneId = threadIdx.x % 32;
    const int warpId = threadIdx.x / 32;

    int sum = warpReduceSum<int>(token_num_now);
    int sum_padded = warpReduceSum<int>(token_num_padded);
    __syncthreads();
    if (laneId == 0) {
      warp_sum[warpId] = sum;
      warp_sum[warpId + KNWARPS] = sum_padded;
    }
    __syncthreads();
    sum = (threadIdx.x < KNWARPS) ? warp_sum[laneId] : 0;
    sum_padded = (threadIdx.x < KNWARPS) ? warp_sum[laneId + KNWARPS] : 0;
    if (warpId == 0) {
      sum = warpReduceSum<int>(sum);
      sum_padded = warpReduceSum<int>(sum_padded);
    }
    if (threadIdx.x == 0) {
      *token_num_all = sum;
      *token_num_all_padded = sum_padded;
    }
  }
}

std::vector<std::vector<int>> GetExpertTokenNum(
    const paddle::Tensor& topk_ids,
    const int num_experts) {
  const int token_num = topk_ids.dims()[0];
  const int moe_topk = topk_ids.dims()[1];
  auto out_workspace = GetEmptyTensor({num_experts * 2 + 2}, paddle::DataType::INT32, topk_ids.place());
  const int block_size = 512;
  const int grid_size = min(132 * 4, div_up(token_num * moe_topk, block_size));
  int64_t *topk_ids_ptr = const_cast<int64_t*>(topk_ids.data<int64_t>());
  int *out_workspace_ptr = out_workspace.data<int>();
  void* kernel_args[] = {
    (void*)(&topk_ids_ptr),
    (void*)(&out_workspace_ptr),
    (void*)&token_num,
    (void*)&moe_topk,
    (void*)&num_experts
  };
  cudaLaunchCooperativeKernel((void*)get_expert_token_num, dim3(grid_size), dim3(block_size), kernel_args, 0, topk_ids.stream());
  auto out_workspace_host = out_workspace.copy_to(paddle::CPUPlace(), true);
  int *out_workspace_host_ptr = out_workspace_host.data<int>();
  std::vector<int> expert_token_num(out_workspace_host_ptr, out_workspace_host_ptr + num_experts);
  std::vector<int> expert_token_num_padded(out_workspace_host_ptr + num_experts, out_workspace_host_ptr + num_experts * 2);
  std::vector<int> token_num_all(out_workspace_host_ptr + num_experts * 2, out_workspace_host_ptr + num_experts * 2 + 2);
  return {expert_token_num, expert_token_num_padded, token_num_all};
}

template <typename T>
__global__ void combine_prmt_back_kernel(
    const T* expanded_permuted_rows,
    T* reduced_unpermuted_output,
    const T* bias,
    const float* dst_weights,
    const int* expanded_source_row_to_expanded_dest_row, // permute_indices_per_token
    const int* expert_for_source_row, // dst_idx
    const int64_t cols,
    const int64_t k,
    const int64_t compute_bias,
    const bool norm_topk_prob,
    const float routed_scaling_factor,
    const int64_t num_rows) {
  static constexpr int VEC_SIZE = sizeof(int4) / sizeof(T);
  AlignedVector<T, VEC_SIZE> load_vec;
  AlignedVector<T, VEC_SIZE> bias_vec;
  AlignedVector<T, VEC_SIZE> res_vec;
  const int cols_int4 = cols / VEC_SIZE;
  for (int original_row = blockIdx.x; original_row < num_rows; original_row += gridDim.x) {
    T* reduced_row_ptr = reduced_unpermuted_output + original_row * cols;
    for (int tid = threadIdx.x; tid < cols_int4; tid += blockDim.x) {
#pragma unroll
      for (int vid = 0; vid < VEC_SIZE; vid++) {
        res_vec[vid] = 0;
      }
      for (int k_idx = 0; k_idx < k; ++k_idx) { // k is num_experts_per_rank
        const int expanded_original_row = original_row + k_idx * num_rows;
        const int expanded_permuted_row =
            expanded_source_row_to_expanded_dest_row[expanded_original_row];
        if (expanded_permuted_row < 0) continue;
        const int64_t k_offset = original_row * k + k_idx;
        const float row_scale = dst_weights[expanded_permuted_row];
        const T* expanded_permuted_rows_row_ptr =
            expanded_permuted_rows + expanded_permuted_row * cols; // prmt后的位置对应的值
        Load<T, VEC_SIZE>(expanded_permuted_rows_row_ptr + tid * VEC_SIZE, &load_vec);
        const int expert_idx = expert_for_source_row[k_offset]; // 当前位置对应的专家
        const T* bias_ptr = bias ? bias + expert_idx * cols : nullptr; // 当前专家对应的down_proj的bias
        if (bias_ptr) {
          Load<T, VEC_SIZE>(bias_ptr + tid * VEC_SIZE, &bias_vec);
#pragma unroll
          for (int vid = 0; vid < VEC_SIZE; vid++) {
            res_vec[vid] += static_cast<T>(
              row_scale * static_cast<float>(load_vec[vid]) +
              static_cast<float>(bias_vec[vid]));
          }
        } else {
#pragma unroll
          for (int vid = 0; vid < VEC_SIZE; vid++) {
            res_vec[vid] += static_cast<T>(
              row_scale * static_cast<float>(load_vec[vid]));
          }
        }
      }
      Store<T, VEC_SIZE>(res_vec, reduced_row_ptr + tid * VEC_SIZE);
    }
  }
}

template <paddle::DataType T>
void MoeCombineKernel(const paddle::Tensor& ffn_out,
                      const paddle::Tensor& expert_scales_float,
                      const paddle::Tensor& permute_indices_per_token,
                      const paddle::Tensor& top_k_indices,
                      const paddle::optional<paddle::Tensor>& down_proj_bias,
                      const bool norm_topk_prob,
                      const float routed_scaling_factor,
                      const int num_rows,
                      const int hidden_size,
                      paddle::Tensor* output) {
    using namespace phi;
    typedef PDTraits<T> traits_;
    typedef typename traits_::DataType DataType_;
    typedef typename traits_::data_t data_t;
    auto stream = ffn_out.stream();
    const int threads = 1024;
    const int gridx = min(132 * 8, num_rows);
    const int num_experts_per_rank = top_k_indices.dims()[1];

    combine_prmt_back_kernel<<<gridx, threads, 0, stream>>>(
        ffn_out.data<data_t>(),
        output->data<data_t>(),
        down_proj_bias ? down_proj_bias->data<data_t>() : nullptr,
        expert_scales_float.data<float>(),
        permute_indices_per_token.data<int32_t>(),
        top_k_indices.data<int>(),
        hidden_size,
        num_experts_per_rank,
        static_cast<int>(1), // compute bias
        norm_topk_prob,
        routed_scaling_factor,
        num_rows);
}

std::vector<paddle::Tensor> EPMoeExpertCombine(
    const paddle::Tensor& ffn_out,
    const paddle::Tensor& expert_scales_float, // dst_weights
    const paddle::Tensor& permute_indices_per_token, // permute_indices_per_token
    const paddle::Tensor& top_k_indices, // dst_indices
    const paddle::optional<paddle::Tensor>& down_proj_bias,
    const bool norm_topk_prob,
    const float routed_scaling_factor) {

    const auto input_type = ffn_out.dtype();
    auto place = ffn_out.place();

    const int num_rows = top_k_indices.dims()[0];
    const int hidden_size = ffn_out.dims()[1];

    auto output = GetEmptyTensor({num_rows, hidden_size}, input_type, place);

    switch (input_type) {
        case paddle::DataType::BFLOAT16:
            MoeCombineKernel<paddle::DataType::BFLOAT16>(
                ffn_out,
                expert_scales_float,
                permute_indices_per_token,
                top_k_indices,
                down_proj_bias,
                norm_topk_prob,
                routed_scaling_factor,
                num_rows,
                hidden_size,
                &output);
            break;
        case paddle::DataType::FLOAT16:
            MoeCombineKernel<paddle::DataType::BFLOAT16>(
                ffn_out,
                expert_scales_float,
                permute_indices_per_token,
                top_k_indices,
                down_proj_bias,
                norm_topk_prob,
                routed_scaling_factor,
                num_rows,
                hidden_size,
                &output);
            break;
        default:
            PD_THROW("Unsupported data type for MoeDispatchKernel");
    }
    return {output};
}


template <typename T, typename OutT, int NUM_EXPERTS_PER_RANK = 8, int RoundType = 1>
__global__ void permute_x_kernel(const T *src_x,
                                 const int64_t *topk_idx,
                                 const float *topk_weights,
                                 const int *token_nums_per_expert,
                                 const float *up_gate_proj_in_scale,
                                 const int moe_topk,
                                 const int num_rows,
                                 const int token_nums_this_rank,
                                 const int hidden_size,
                                 OutT *permute_x, // [token_nums_this_rank, hidden_size]
                                 int *permute_indices_per_token, // [moe_topk, num_rows]
                                 float *dst_weights, // [token_nums_this_rank]
                                 int *dst_indices,
                                 int *cumsum_idx_gpu,
                                 int64_t *token_nums_per_expert_cumsum,
                                 int64_t *expert_idx_per_token,
                                 float max_bound = 127.0,
                                 float min_bound = -127.0) { // [num_rows, moe_topk]
    const int src_token_idx = blockIdx.x;
    const int tid = threadIdx.x;
    constexpr int vec_size = sizeof(int4) / sizeof(T);
    __shared__ int write_idx; // cumsum start idx
    __shared__ int token_nums_per_expert_cum[NUM_EXPERTS_PER_RANK];
    AlignedVector<T, vec_size> src_vec;
    AlignedVector<OutT, vec_size> res_vec;
    if (tid == 0) {
      int sum_now = 0;
      for (int i = 0; i < NUM_EXPERTS_PER_RANK; i++) {
        sum_now += token_nums_per_expert[i];
        token_nums_per_expert_cum[i] = sum_now;
        if (blockIdx.x == 0) {
          token_nums_per_expert_cumsum[i] = sum_now;
        }
      }
    }
    __syncthreads();
    const int hidden_size_int4 = hidden_size / vec_size;
    for (int s_token_idx = src_token_idx; s_token_idx < num_rows; s_token_idx += gridDim.x) {
        const int64_t *topk_idx_now = topk_idx + s_token_idx * moe_topk;
#pragma unroll
        for (int expert_idx = 0; expert_idx < moe_topk; expert_idx++) {
          int expert_now = static_cast<int>(topk_idx_now[expert_idx]);
          if (expert_now == -1) continue;
          const int dst_chunk_start_idx = expert_now == 0 ? 0 : token_nums_per_expert_cum[expert_now - 1];
          if (tid == 0) {
            const int offset_now = atomicAdd(cumsum_idx_gpu + expert_now, 1);
            write_idx = offset_now;
          }
          __syncthreads();
          const int token_offset_now = write_idx;
          const int dst_token_idx = dst_chunk_start_idx + token_offset_now;
          permute_indices_per_token[expert_now * num_rows + s_token_idx] = dst_token_idx;
          dst_weights[dst_token_idx] = topk_weights[s_token_idx * moe_topk + expert_idx];
          dst_indices[s_token_idx * NUM_EXPERTS_PER_RANK + expert_now] = expert_now;
          // cp x
          for (int v_id = tid; v_id < hidden_size_int4; v_id += blockDim.x) {
            Load<T, vec_size>(&src_x[s_token_idx * hidden_size + v_id * vec_size], &src_vec);
            if (up_gate_proj_in_scale) {
              for (int i = 0; i < vec_size; i++) {
                float quant_value = max_bound * up_gate_proj_in_scale[expert_now] * static_cast<float>(src_vec[i]);
                if (RoundType == 0) {
                  res_vec[i] = static_cast<OutT>(ClipFunc<float>(rint(quant_value), min_bound, max_bound));
                } else {
                  res_vec[i] = static_cast<OutT>(round(quant_value));
                }
              }
            } else {
              for (int i = 0; i < vec_size; i++) {
                res_vec[i] = static_cast<OutT>(src_vec[i]);
              }
            }
            Store<OutT, vec_size>(res_vec, &permute_x[dst_token_idx * hidden_size + v_id * vec_size]);
          }
          expert_idx_per_token[dst_token_idx] = expert_now;
        }
    }
}

template <paddle::DataType T>
void EPMoeDispatchKernel(const paddle::Tensor& input,
                         const paddle::Tensor& topk_ids,
                         const paddle::Tensor& topk_weights,
                         const paddle::Tensor& token_nums_per_expert,
                         const paddle::optional<paddle::Tensor>& up_gate_proj_in_scale,
                         const std::string& moe_quant_type,
                         const int moe_topk,
                         const int num_rows,
                         const int token_nums_this_rank,
                         const int hidden_size,
                         const int num_experts_per_rank,
                         paddle::Tensor* permute_input,
                         paddle::Tensor* permute_indices_per_token,
                         paddle::Tensor* dst_weights,
                         paddle::Tensor* dst_indices,
                         paddle::Tensor* cumsum_idx_gpu,
                         paddle::Tensor* token_nums_per_expert_cumsum,
                         paddle::Tensor* expert_idx_per_token) {
  using namespace phi;

  typedef PDTraits<T> traits_;
  typedef typename traits_::DataType DataType_;
  typedef typename traits_::data_t data_t;

  auto stream = input.stream();
  auto place = input.place();
  const int gridx = min(132 * 8, num_rows);
  if (moe_quant_type == "w4a8") {
    if (num_experts_per_rank == 8) {
      permute_x_kernel<data_t, int8_t, 8><<<gridx, 512, 0, stream>>>(
        input.data<data_t>(),
        topk_ids.data<int64_t>(),
        topk_weights.data<float>(),
        token_nums_per_expert.data<int>(),
        up_gate_proj_in_scale ? up_gate_proj_in_scale.get().data<float>() : nullptr,
        moe_topk,
        num_rows,
        token_nums_this_rank,
        hidden_size,
        permute_input->data<int8_t>(),
        permute_indices_per_token->data<int>(),
        dst_weights->data<float>(),
        dst_indices->data<int>(),
        cumsum_idx_gpu->data<int>(),
        token_nums_per_expert_cumsum->data<int64_t>(),
        expert_idx_per_token->data<int64_t>(),
        127.0,
        -127.0
      );
    } else if (num_experts_per_rank == 16) {
      permute_x_kernel<data_t, int8_t, 16><<<gridx, 512, 0, stream>>>(
        input.data<data_t>(),
        topk_ids.data<int64_t>(),
        topk_weights.data<float>(),
        token_nums_per_expert.data<int>(),
        up_gate_proj_in_scale ? up_gate_proj_in_scale.get().data<float>() : nullptr,
        moe_topk,
        num_rows,
        token_nums_this_rank,
        hidden_size,
        permute_input->data<int8_t>(),
        permute_indices_per_token->data<int>(),
        dst_weights->data<float>(),
        dst_indices->data<int>(),
        cumsum_idx_gpu->data<int>(),
        token_nums_per_expert_cumsum->data<int64_t>(),
        expert_idx_per_token->data<int64_t>(),
        127.0,
        -127.0
      );
    }
  } else {
    if (num_experts_per_rank == 8) {
      permute_x_kernel<data_t, data_t, 8><<<gridx, 512, 0, stream>>>(
        input.data<data_t>(),
        topk_ids.data<int64_t>(),
        topk_weights.data<float>(),
        token_nums_per_expert.data<int>(),
        up_gate_proj_in_scale ? up_gate_proj_in_scale.get().data<float>() : nullptr,
        moe_topk,
        num_rows,
        token_nums_this_rank,
        hidden_size,
        permute_input->data<data_t>(),
        permute_indices_per_token->data<int>(),
        dst_weights->data<float>(),
        dst_indices->data<int>(),
        cumsum_idx_gpu->data<int>(),
        token_nums_per_expert_cumsum->data<int64_t>(),
        expert_idx_per_token->data<int64_t>(),
        127.0,
        -127.0
      );
    } else if (num_experts_per_rank == 16) {
      permute_x_kernel<data_t, data_t, 16><<<gridx, 512, 0, stream>>>(
        input.data<data_t>(),
        topk_ids.data<int64_t>(),
        topk_weights.data<float>(),
        token_nums_per_expert.data<int>(),
        up_gate_proj_in_scale ? up_gate_proj_in_scale.get().data<float>() : nullptr,
        moe_topk,
        num_rows,
        token_nums_this_rank,
        hidden_size,
        permute_input->data<data_t>(),
        permute_indices_per_token->data<int>(),
        dst_weights->data<float>(),
        dst_indices->data<int>(),
        cumsum_idx_gpu->data<int>(),
        token_nums_per_expert_cumsum->data<int64_t>(),
        expert_idx_per_token->data<int64_t>(),
        127.0,
        -127.0
      );
    }
  }
}


std::vector<paddle::Tensor> EPMoeExpertDispatch(
    const paddle::Tensor& input,
    const paddle::Tensor& topk_ids,
    const paddle::Tensor& topk_weights,
    const paddle::optional<paddle::Tensor>& up_gate_proj_in_scale,
    const std::vector<int>& token_nums_per_expert,
    const int token_nums_this_rank,
    const std::string& moe_quant_type) {
  const auto input_type = input.dtype();
  const int moe_topk = topk_ids.dims()[1];
  auto place = input.place();
  int token_rows = 0;
  auto input_dims = input.dims();

  if (input_dims.size() == 3) {
    token_rows = input_dims[0] * input_dims[1];
  } else {
    token_rows = input_dims[0];
  }
  const int num_rows = token_rows;
  const int hidden_size = input.dims()[input_dims.size() - 1];
  const int num_experts_per_rank = token_nums_per_expert.size();

  auto permute_input = GetEmptyTensor(
    {token_nums_this_rank, hidden_size},
    moe_quant_type == "w4a8" ? paddle::DataType::INT8 : input_type,
    place);
  auto num_experts_per_rank_tensor = GetEmptyTensor(
    {num_experts_per_rank},
    paddle::DataType::INT32,
    place);
  auto expert_idx_per_token = GetEmptyTensor(
    {token_nums_this_rank}, paddle::DataType::INT64, place);
  cudaMemcpyAsync(num_experts_per_rank_tensor.data<int>(), token_nums_per_expert.data(), num_experts_per_rank * sizeof(int), cudaMemcpyHostToDevice, input.stream());
  // cudaMemcpy(num_experts_per_rank_tensor.data<int>(), token_nums_per_expert.data(), num_experts_per_rank * sizeof(int), cudaMemcpyHostToDevice);
  auto token_nums_per_expert_cumsum = GetEmptyTensor({num_experts_per_rank}, paddle::DataType::INT64, place);
  auto dst_weights = GetEmptyTensor({token_nums_this_rank}, paddle::DataType::FLOAT32, place);
  auto dst_indices = GetEmptyTensor({num_rows, num_experts_per_rank}, paddle::DataType::INT32, place);
  auto permute_indices_per_token = paddle::full({num_experts_per_rank, num_rows}, -1, paddle::DataType::INT32, place);
  auto cumsum_idx_gpu = paddle::full({num_experts_per_rank}, 0, paddle::DataType::INT32, place);


  switch (input_type) {
    case paddle::DataType::BFLOAT16:
      EPMoeDispatchKernel<paddle::DataType::BFLOAT16>(input,
                                                      topk_ids,
                                                      topk_weights,
                                                      num_experts_per_rank_tensor,
                                                      up_gate_proj_in_scale,
                                                      moe_quant_type,
                                                      moe_topk,
                                                      num_rows,
                                                      token_nums_this_rank,
                                                      hidden_size,
                                                      num_experts_per_rank,
                                                      &permute_input,
                                                      &permute_indices_per_token,
                                                      &dst_weights,
                                                      &dst_indices,
                                                      &cumsum_idx_gpu,
                                                      &token_nums_per_expert_cumsum,
                                                      &expert_idx_per_token);
      break;
    case paddle::DataType::FLOAT16:
      EPMoeDispatchKernel<paddle::DataType::FLOAT16>(input,
                                                     topk_ids,
                                                     topk_weights,
                                                     num_experts_per_rank_tensor,
                                                     up_gate_proj_in_scale,
                                                     moe_quant_type,
                                                     moe_topk,
                                                     num_rows,
                                                     token_nums_this_rank,
                                                     hidden_size,
                                                     num_experts_per_rank,
                                                     &permute_input,
                                                     &permute_indices_per_token,
                                                     &dst_weights,
                                                     &dst_indices,
                                                     &cumsum_idx_gpu,
                                                     &token_nums_per_expert_cumsum,
                                                     &expert_idx_per_token);
      break;
    default:
      PD_THROW("Unsupported data type for EPMoeDispatchKernel");
  }
  return {permute_input,
          permute_indices_per_token,
          token_nums_per_expert_cumsum,
          dst_weights,
          dst_indices,
          cumsum_idx_gpu,
          expert_idx_per_token};
}


std::vector<std::vector<int64_t>> EPMoeExpertDispatchInferShape(
    const std::vector<int64_t>& input_shape,
    const std::vector<int64_t>& topk_ids_shape,
    const std::vector<int64_t>& topk_weights_shape,
    const paddle::optional<std::vector<int64_t>>& up_gate_proj_in_scale_dtype,
    const std::vector<int>& token_nums_per_expert,
    const int token_nums_this_rank) {
  int token_rows = -1;
  int moe_topk = topk_ids_shape[1];
  if (input_shape.size() == 3) {
    token_rows = input_shape[0] * input_shape[1];
  } else {
    token_rows = input_shape[0];
  }
  const int expert_num = token_nums_per_expert.size(); // 本地专家个数
  const int num_rows = token_rows;
  const int hidden_size = input_shape[input_shape.size() - 1];

  return {{token_nums_this_rank, hidden_size},
          {expert_num, num_rows},
          {expert_num},
          {token_nums_this_rank},
          {num_rows, expert_num},
          {expert_num},
          {token_nums_this_rank}}; // dst_idx per expert
}

std::vector<paddle::DataType> EPMoeExpertDispatchInferDtype(
    const paddle::DataType& input_dtype,
    const paddle::DataType& topk_ids_dtype,
    const paddle::DataType& topk_weights_dtype,
    const std::vector<int>& token_nums_per_expert,
    const int token_nums_this_rank,
    const std::string& moe_quant_type) {
  return {moe_quant_type == "w4a8" ? paddle::DataType::INT8 : input_dtype,
          paddle::DataType::INT32,
          paddle::DataType::INT64,
          paddle::DataType::FLOAT32,
          paddle::DataType::INT32,
          paddle::DataType::INT32,
          paddle::DataType::INT64};
}


PD_BUILD_STATIC_OP(ep_moe_expert_dispatch)
    .Inputs({"input", "topk_ids", "topk_weights",
             paddle::Optional("up_gate_proj_in_scale")})
    .Outputs({"permute_input",
              "permute_indices_per_token",
              "token_nums_per_expert_cumsum",
              "dst_weights",
              "dst_indices",
              "cumsum_idx_gpu",
              "expert_idx_per_token"})
    .Attrs({
      "token_nums_per_expert: std::vector<int>",
      "token_nums_this_rank: int",
      "moe_quant_type: std::string"
      })
    .SetKernelFn(PD_KERNEL(EPMoeExpertDispatch))
    .SetInferShapeFn(PD_INFER_SHAPE(EPMoeExpertDispatchInferShape))
    .SetInferDtypeFn(PD_INFER_DTYPE(EPMoeExpertDispatchInferDtype));


template <typename T, int NUM_EXPERTS_PER_RANK = 8>
__global__ void permute_x_fp8_kernel(const T *src_x,
                                     const float *scale,
                                     const int64_t *topk_idx,
                                     const float *topk_weights,
                                     const int *token_nums_per_expert,
                                     const int *token_nums_per_expert_padded,
                                     const int moe_topk,
                                     const int num_rows,
                                     const int token_nums_this_rank,
                                     const int token_nums_this_rank_padded,
                                     const int64_t hidden_size,
                                     T *permute_x, // [token_nums_this_rank, hidden_size]
                                     float *permute_scale,
                                     int *permute_indices_per_token, // [moe_topk, num_rows]
                                     float *dst_weights, // [token_nums_this_rank]
                                     int *dst_indices,
                                     int *cumsum_idx_gpu,
                                     int64_t *token_nums_per_expert_cumsum,
                                     int64_t *token_nums_per_expert_padded_cumsum,
                                     int *m_indices) { // [num_rows, moe_topk]
    const int64_t src_token_idx = blockIdx.x;
    const int tid = threadIdx.x;
    constexpr int vec_size = sizeof(int4) / sizeof(T);
    constexpr int scale_vec_size = sizeof(int4) / sizeof(float);
    __shared__ int write_idx; // cumsum start idx
    __shared__ int token_nums_per_expert_cum[NUM_EXPERTS_PER_RANK];
    if (tid == 0) {
      int sum_now = 0;
      int sum_now_padded = 0;
      for (int i = 0; i < NUM_EXPERTS_PER_RANK; i++) {
        sum_now += token_nums_per_expert[i];
        sum_now_padded += token_nums_per_expert_padded[i];
        token_nums_per_expert_cum[i] = sum_now_padded;
        if (blockIdx.x == 0) {
          token_nums_per_expert_cumsum[i] = sum_now;
          token_nums_per_expert_padded_cumsum[i] = sum_now_padded;
        }
      }
    }
    __syncthreads();
    const int hidden_size_int4 = hidden_size / vec_size;
    const int hidden_size_scale = hidden_size / 128;
    const int hidden_size_scale_int4 = hidden_size_scale / scale_vec_size;
    const int token_nums_feed_to_ffn = token_nums_per_expert_cum[NUM_EXPERTS_PER_RANK-1];
    // prmt
    for (int64_t s_token_idx = src_token_idx; s_token_idx < token_nums_feed_to_ffn; s_token_idx += gridDim.x) {

      // the m_indices[s_token_idx] must be a value `i` in [0, NUM_EXPERTS_PER_RANK)
      // here we parallel wo find the `i` we want.
      for (int i = threadIdx.x; i < NUM_EXPERTS_PER_RANK; i+= blockDim.x) {
        const int start_idx = i == 0 ? 0 : token_nums_per_expert_cum[i - 1];
        const int end_idx = token_nums_per_expert_cum[i];
        if (s_token_idx >= start_idx && s_token_idx < end_idx) {
          if ((s_token_idx - start_idx) < token_nums_per_expert[i]) m_indices[s_token_idx] = i;
          break;
        }
      }

      if (s_token_idx < num_rows) {
        const int64_t *topk_idx_now = topk_idx + s_token_idx * moe_topk;
#pragma unroll
        for (int expert_idx = 0; expert_idx < moe_topk; expert_idx++) {
          int expert_now = static_cast<int>(topk_idx_now[expert_idx]);
          if (expert_now == -1) continue;
          const int dst_chunk_start_idx = expert_now == 0 ? 0 : token_nums_per_expert_cum[expert_now - 1];
          if (tid == 0) {
            const int offset_now = atomicAdd(cumsum_idx_gpu + expert_now, 1);
            write_idx = offset_now;
          }
          __syncthreads();
          const int token_offset_now = write_idx;
          const int64_t dst_token_idx = dst_chunk_start_idx + token_offset_now;
          permute_indices_per_token[expert_now * num_rows + s_token_idx] = dst_token_idx;
          dst_weights[dst_token_idx] = topk_weights[s_token_idx * moe_topk + expert_idx];
          // m_indices[dst_token_idx] = expert_now; // not need?
          dst_indices[s_token_idx * NUM_EXPERTS_PER_RANK + expert_now] = expert_now;
          // cp x
          for (int64_t v_id = tid; v_id < hidden_size_int4; v_id += blockDim.x) {
              *(reinterpret_cast<int4*>(permute_x + dst_token_idx * hidden_size) + v_id) = *(reinterpret_cast<const int4*>(src_x + s_token_idx * hidden_size) + v_id);
          }
          // cp scale
          for (int v_id = tid; v_id < hidden_size_scale_int4; v_id += blockDim.x) {
              *(reinterpret_cast<int4*>(permute_scale + dst_token_idx * hidden_size_scale) + v_id) = *(reinterpret_cast<const int4*>(scale + s_token_idx * hidden_size_scale) + v_id);
          }
        }
      }
    }
}

void EPMoeDispatchFP8Kernel(const paddle::Tensor& input,
                            const paddle::Tensor& scale,
                            const paddle::Tensor& topk_ids,
                            const paddle::Tensor& topk_weights,
                            const paddle::Tensor& token_nums_per_expert,
                            const paddle::Tensor& token_nums_per_expert_padded,
                            const int moe_topk,
                            const int num_rows,
                            const int token_nums_this_rank,
                            const int token_nums_this_rank_padded,
                            const int hidden_size,
                            const int num_experts_per_rank,
                            paddle::Tensor* permute_input,
                            paddle::Tensor* permute_scale,
                            paddle::Tensor* permute_indices_per_token,
                            paddle::Tensor* dst_weights,
                            paddle::Tensor* dst_indices,
                            paddle::Tensor* cumsum_idx_gpu,
                            paddle::Tensor* token_nums_per_expert_cumsum,
                            paddle::Tensor* token_nums_per_expert_padded_cumsum,
                            paddle::Tensor* m_indices) {
  auto stream = input.stream();
  auto place = input.place();
  // const int gridx = min(132 * 8, num_rows);
  const int gridx = 132 * 8;
  if (num_experts_per_rank == 8) {
    permute_x_fp8_kernel<phi::dtype::float8_e4m3fn, 8><<<gridx, 512, 0, stream>>>(
      input.data<phi::dtype::float8_e4m3fn>(),
      scale.data<float>(),
      topk_ids.data<int64_t>(),
      topk_weights.data<float>(),
      token_nums_per_expert.data<int>(),
      token_nums_per_expert_padded.data<int>(),
      moe_topk,
      num_rows,
      token_nums_this_rank,
      token_nums_this_rank_padded,
      hidden_size,
      permute_input->data<phi::dtype::float8_e4m3fn>(),
      permute_scale->data<float>(),
      permute_indices_per_token->data<int>(),
      dst_weights->data<float>(),
      dst_indices->data<int>(),
      cumsum_idx_gpu->data<int>(),
      token_nums_per_expert_cumsum->data<int64_t>(),
      token_nums_per_expert_padded_cumsum->data<int64_t>(),
      m_indices->data<int>()
    );
  } else if (num_experts_per_rank == 9) {
    permute_x_fp8_kernel<phi::dtype::float8_e4m3fn, 9><<<gridx, 512, 0, stream>>>(
      input.data<phi::dtype::float8_e4m3fn>(),
      scale.data<float>(),
      topk_ids.data<int64_t>(),
      topk_weights.data<float>(),
      token_nums_per_expert.data<int>(),
      token_nums_per_expert_padded.data<int>(),
      moe_topk,
      num_rows,
      token_nums_this_rank,
      token_nums_this_rank_padded,
      hidden_size,
      permute_input->data<phi::dtype::float8_e4m3fn>(),
      permute_scale->data<float>(),
      permute_indices_per_token->data<int>(),
      dst_weights->data<float>(),
      dst_indices->data<int>(),
      cumsum_idx_gpu->data<int>(),
      token_nums_per_expert_cumsum->data<int64_t>(),
      token_nums_per_expert_padded_cumsum->data<int64_t>(),
      m_indices->data<int>()
    );
  } else if (num_experts_per_rank == 16) {
    permute_x_fp8_kernel<phi::dtype::float8_e4m3fn, 16><<<gridx, 512, 0, stream>>>(
      input.data<phi::dtype::float8_e4m3fn>(),
      scale.data<float>(),
      topk_ids.data<int64_t>(),
      topk_weights.data<float>(),
      token_nums_per_expert.data<int>(),
      token_nums_per_expert_padded.data<int>(),
      moe_topk,
      num_rows,
      token_nums_this_rank,
      token_nums_this_rank_padded,
      hidden_size,
      permute_input->data<phi::dtype::float8_e4m3fn>(),
      permute_scale->data<float>(),
      permute_indices_per_token->data<int>(),
      dst_weights->data<float>(),
      dst_indices->data<int>(),
      cumsum_idx_gpu->data<int>(),
      token_nums_per_expert_cumsum->data<int64_t>(),
      token_nums_per_expert_padded_cumsum->data<int64_t>(),
      m_indices->data<int>()
    );
  } else if (num_experts_per_rank == 64) {
    permute_x_fp8_kernel<phi::dtype::float8_e4m3fn, 64><<<gridx, 512, 0, stream>>>(
      input.data<phi::dtype::float8_e4m3fn>(),
      scale.data<float>(),
      topk_ids.data<int64_t>(),
      topk_weights.data<float>(),
      token_nums_per_expert.data<int>(),
      token_nums_per_expert_padded.data<int>(),
      moe_topk,
      num_rows,
      token_nums_this_rank,
      token_nums_this_rank_padded,
      hidden_size,
      permute_input->data<phi::dtype::float8_e4m3fn>(),
      permute_scale->data<float>(),
      permute_indices_per_token->data<int>(),
      dst_weights->data<float>(),
      dst_indices->data<int>(),
      cumsum_idx_gpu->data<int>(),
      token_nums_per_expert_cumsum->data<int64_t>(),
      token_nums_per_expert_padded_cumsum->data<int64_t>(),
      m_indices->data<int>()
    );
  } else if (num_experts_per_rank == 128) {
    permute_x_fp8_kernel<phi::dtype::float8_e4m3fn, 128><<<gridx, 512, 0, stream>>>(
      input.data<phi::dtype::float8_e4m3fn>(),
      scale.data<float>(),
      topk_ids.data<int64_t>(),
      topk_weights.data<float>(),
      token_nums_per_expert.data<int>(),
      token_nums_per_expert_padded.data<int>(),
      moe_topk,
      num_rows,
      token_nums_this_rank,
      token_nums_this_rank_padded,
      hidden_size,
      permute_input->data<phi::dtype::float8_e4m3fn>(),
      permute_scale->data<float>(),
      permute_indices_per_token->data<int>(),
      dst_weights->data<float>(),
      dst_indices->data<int>(),
      cumsum_idx_gpu->data<int>(),
      token_nums_per_expert_cumsum->data<int64_t>(),
      token_nums_per_expert_padded_cumsum->data<int64_t>(),
      m_indices->data<int>()
    );
  } else {
    PD_THROW("Not dispatching this num_experts_per_rank(", num_experts_per_rank, ") for EPMoeDispatchFP8Kernel");
  }
}


std::vector<paddle::Tensor> EPMoeExpertDispatchFP8(
    const paddle::Tensor& input,
    const paddle::Tensor& scale,
    const paddle::Tensor& topk_ids,
    const paddle::Tensor& topk_weights,
    const paddle::Tensor& num_experts_per_rank_tensor,
    const paddle::Tensor& num_experts_per_rank_padded_tensor,
    const bool use_in_ep,
    const int token_nums_this_rank_padded) {
  const auto input_type = input.dtype();
  const int moe_topk = topk_ids.dims()[1];
  auto place = input.place();
  int token_rows = 0;
  auto input_dims = input.dims();

  if (input_dims.size() == 3) {
    token_rows = input_dims[0] * input_dims[1];
  } else {
    token_rows = input_dims[0];
  }
  const int num_rows = token_rows;
  const int hidden_size = input.dims()[input_dims.size() - 1];
  const int num_experts_per_rank = num_experts_per_rank_tensor.dims()[0];

  int32_t token_nums_feed_to_ffn = use_in_ep ? token_nums_this_rank_padded : token_rows * moe_topk + num_experts_per_rank * (128-1);

  auto permute_input = GetEmptyTensor(
    {token_nums_feed_to_ffn, hidden_size},
    input_type,
    place);
  auto permute_scale = GetEmptyTensor(
    {token_nums_feed_to_ffn, hidden_size / 128},
    paddle::DataType::FLOAT32,
    place);

  auto m_indices = paddle::full({token_nums_feed_to_ffn}, -1, paddle::DataType::INT32, place);
  auto token_nums_per_expert_cumsum = GetEmptyTensor({num_experts_per_rank}, paddle::DataType::INT64, place);
  auto token_nums_per_expert_padded_cumsum = GetEmptyTensor({num_experts_per_rank}, paddle::DataType::INT64, place);
  auto dst_weights = GetEmptyTensor({token_nums_feed_to_ffn}, paddle::DataType::FLOAT32, place);
  auto dst_indices = GetEmptyTensor({num_rows, num_experts_per_rank}, paddle::DataType::INT32, place);
  auto permute_indices_per_token = paddle::full({num_experts_per_rank, num_rows}, -1, paddle::DataType::INT32, place);
  auto cumsum_idx_gpu = paddle::full({num_experts_per_rank}, 0, paddle::DataType::INT32, place);

  EPMoeDispatchFP8Kernel(input,
                        scale,
                        topk_ids,
                        topk_weights,
                        num_experts_per_rank_tensor,
                        num_experts_per_rank_padded_tensor,
                        moe_topk,
                        num_rows,
                        -1,
                        -1,
                        hidden_size,
                        num_experts_per_rank,
                        &permute_input,
                        &permute_scale,
                        &permute_indices_per_token,
                        &dst_weights,
                        &dst_indices,
                        &cumsum_idx_gpu,
                        &token_nums_per_expert_cumsum,
                        &token_nums_per_expert_padded_cumsum,
                        &m_indices);
  return {permute_input,
          permute_scale,
          permute_indices_per_token,
          token_nums_per_expert_cumsum,
          token_nums_per_expert_padded_cumsum,
          dst_weights,
          dst_indices,
          cumsum_idx_gpu,
          m_indices};
}

PD_BUILD_STATIC_OP(ep_moe_expert_dispatch_fp8)
    .Inputs({"input", "scale", "topk_ids", "topk_weights", "num_experts_per_rank_tensor", "num_experts_per_rank_padded_tensor"})
    .Outputs({"permute_input",
              "permute_scale",
              "permute_indices_per_token",
              "token_nums_per_expert_cumsum",
              "token_nums_per_expert_padded_cumsum",
              "dst_weights",
              "dst_indices",
              "cumsum_idx_gpu",
              "m_indices"})
    .Attrs({"use_in_ep:bool", "token_nums_this_rank_padded:int"})
    .SetKernelFn(PD_KERNEL(EPMoeExpertDispatchFP8));
