/* Copyright (c) 2018 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. */

#ifdef POOL_OP

#include "operators/math/pooling.h"
#if defined(__ARM_NEON) || defined(__ARM_NEON__)
#include <arm_neon.h>
#endif  // __ARM_NEON

namespace paddle_mobile {
namespace operators {
namespace math {

#define POOLING3X3_NORMAL_BORDER(start, end)                   \
  for (int w = start; w < end; ++w) {                          \
    const int w_in_start = -padding_w + w * Stride;            \
    const int w_in_end = w_in_start + 3;                       \
    const int w_start = w_in_start > 0 ? w_in_start : 0;       \
    const int w_end = w_in_end < input_w ? w_in_end : input_w; \
    PoolingVal<P> val;                                         \
    for (int h_in = h_start; h_in < h_end; ++h_in) {           \
      for (int w_in = w_start; w_in < w_end; ++w_in) {         \
        val += input[h_in * input_w + w_in];                   \
      }                                                        \
    }                                                          \
    output_ptr[w] = val.Value();                               \
  }

#if defined(__ARM_NEON) || defined(__ARM_NEON__)
template <PoolingType P, int Stride = 1>
struct Pooling3x3ValidColLoadInput {
  inline void operator()(const float *input, const int input_w,
                         const int valid_cols, float32x4x2_t &x0,  // NOLINT
                         float32x4x2_t &x1, float32x4x2_t &x2,     // NOLINT
                         float32x4x2_t &y0) {                      // NOLINT
    float fake_input[3][8];
    if (valid_cols == 1) {
      for (int i = 0; i < 8; ++i, input += input_w) {
        fake_input[0][i] = input[0];
      }
    } else if (valid_cols == 2) {
      for (int i = 0; i < 8; ++i, input += input_w) {
        fake_input[0][i] = input[0];
        fake_input[1][i] = input[1];
      }
    } else {
      for (int i = 0; i < 8; ++i, input += input_w) {
        fake_input[0][i] = input[0];
        fake_input[1][i] = input[1];
        fake_input[2][i] = input[2];
      }
    }
    y0.val[0] = vPoolInitq_f32<P>();
    y0.val[1] = vPoolInitq_f32<P>();
    for (int i = 0; i < valid_cols; ++i) {
      x0.val[0] = vld1q_f32(fake_input[i]);
      x0.val[1] = vld1q_f32(fake_input[i] + 4);
      x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
      x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
      x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
      x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
      y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
      y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
      y0.val[0] = vPoolPreq_f32<P>(x1.val[0], y0.val[0]);
      y0.val[1] = vPoolPreq_f32<P>(x1.val[1], y0.val[1]);
      y0.val[0] = vPoolPreq_f32<P>(x2.val[0], y0.val[0]);
      y0.val[1] = vPoolPreq_f32<P>(x2.val[1], y0.val[1]);
    }
  }
};

template <PoolingType P>
struct Pooling3x3ValidColLoadInput<P, 2> {
  inline void operator()(const float *input, const int input_w,
                         const int valid_cols, float32x4x2_t &x0,  // NOLINT
                         float32x4x2_t &x1, float32x4x2_t &x2,     // NOLINT
                         float32x4x2_t &y0) {                      // NOLINT
    float fake_input[3][13];
    if (valid_cols == 1) {
      for (int i = 0; i < 13; ++i, input += input_w) {
        fake_input[0][i] = input[0];
      }
    } else if (valid_cols == 2) {
      for (int i = 0; i < 13; ++i, input += input_w) {
        fake_input[0][i] = input[0];
        fake_input[1][i] = input[1];
      }
    } else {
      for (int i = 0; i < 13; ++i, input += input_w) {
        fake_input[0][i] = input[0];
        fake_input[1][i] = input[1];
        fake_input[2][i] = input[2];
      }
    }
    for (int i = 0; i < valid_cols; ++i) {
      x0 = vld2q_f32(fake_input[i]);
      x1 = vld2q_f32(fake_input[i] + 8);
      x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
      x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
      x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
      x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
      x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
      x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
      y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
      y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
    }
  }
};

template <PoolingType P, int Stride = 1>
struct Pooling3x3NormalRowLoadInput {
  inline void operator()(const float *input, float32x4x2_t &x0,  // NOLINT
                         float32x4x2_t &x1, float32x4x2_t &x2,   // NOLINT
                         float32x4x2_t &y0) {                    // NOLINT
    x0.val[0] = vld1q_f32(input);
    x0.val[1] = vld1q_f32(input + 4);
    x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
    x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
    x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
    x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
    y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
    y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
    y0.val[0] = vPoolPreq_f32<P>(x1.val[0], y0.val[0]);
    y0.val[1] = vPoolPreq_f32<P>(x1.val[1], y0.val[1]);
    y0.val[0] = vPoolPreq_f32<P>(x2.val[0], y0.val[0]);
    y0.val[1] = vPoolPreq_f32<P>(x2.val[1], y0.val[1]);
  }
};

template <PoolingType P>
struct Pooling3x3NormalRowLoadInput<P, 2> {
  inline void operator()(const float *input, float32x4x2_t &x0,  // NOLINT
                         float32x4x2_t &x1, float32x4x2_t &x2,   // NOLINT
                         float32x4x2_t &y0) {                    // NOLINT
    x0 = vld2q_f32(input);
    x1 = vld2q_f32(input + 8);
    x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
    x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
    x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
    x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
    x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
    x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
    y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
    y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
  }
};
#endif  // __ARM_NEON__

template <PoolingType P, int Stride>
inline void Pooling3x3ValidCol(const float *input, const int h_output,
                               const int h_output_end, const int w_output,
                               const int input_h, const int input_w,
                               const int padding_h, const int padding_w,
                               const int output_w, float *output) {
  const int w_in_start = -padding_w + w_output * Stride;
  const int w_in_end = w_in_start + 3;
  const int w_start = w_in_start > 0 ? w_in_start : 0;
  const int w_end = w_in_end < input_w ? w_in_end : input_w;
  int remain_start = h_output;
#if defined(__ARM_NEON) || defined(__ARM_NEON__)
  int output_tiles = (h_output_end - h_output) / 6;
  remain_start = h_output + output_tiles * 6;
  int input_h_start = h_output * Stride - padding_h;
  size_t input_offset = input_h_start * input_w + w_start;
  size_t output_offset = h_output * output_w + w_output;
  int valid_cols = w_end - w_start;
  Pooling3x3ValidColLoadInput<P, Stride> PoolingCompute;
  float32x4x2_t x0, x1, x2, y0;
  float32x4_t avg = vdupq_n_f32(1.f / (3 * valid_cols));
  for (int h = 0; h < output_tiles * 6; h += 6) {
    float *output0 = output + output_offset;
    float *output1 = output0 + output_w;
    float *output2 = output1 + output_w;
    float *output3 = output2 + output_w;
    float *output4 = output3 + output_w;
    float *output5 = output4 + output_w;
    y0.val[0] = vPoolInitq_f32<P>();
    y0.val[1] = vPoolInitq_f32<P>();
    PoolingCompute(input + input_offset, input_w, valid_cols, x0, x1, x2, y0);
    y0.val[0] = vPoolPostq_f32<P>(y0.val[0], avg);
    y0.val[1] = vPoolPostq_f32<P>(y0.val[1], avg);
    vst1q_lane_f32(output0, y0.val[0], 0);
    vst1q_lane_f32(output1, y0.val[0], 1);
    vst1q_lane_f32(output2, y0.val[0], 2);
    vst1q_lane_f32(output3, y0.val[0], 3);
    vst1q_lane_f32(output4, y0.val[1], 0);
    vst1q_lane_f32(output5, y0.val[1], 1);
    input_offset += 6 * Stride * input_w;
    output_offset += 6 * output_w;
  }
#endif
  for (int h = remain_start; h < h_output_end; ++h) {
    PoolingVal<P> val;
    const int h_in_start = -padding_h + h * Stride;
    for (int i = 0; i < 3; ++i) {
      for (int w_in = w_start; w_in < w_end; ++w_in) {
        val += input[(h_in_start + i) * input_w + w_in];
      }
    }
    output[h * output_w + w_output] = val.Value();
  }
}

template <PoolingType P, int Stride>
inline void Pooling3x3NormalRow(const float *input, const int h_output,
                                const int input_h, const int input_w,
                                const int padding_h, const int padding_w,
                                const int output_w, float *output) {
  const int h_in_start = -padding_h + h_output * Stride;
  const int h_in_end = h_in_start + 3;
  const int h_start = h_in_start > 0 ? h_in_start : 0;
  const int h_end = h_in_end < input_h ? h_in_end : input_h;

  int valid_w_start = (padding_w + Stride - 1) / Stride;
  int valid_w_end = (input_w - 3) / Stride + 1 + valid_w_start;

  float *output_ptr = output + h_output * output_w;
  // border left
  POOLING3X3_NORMAL_BORDER(0, valid_w_start)
  // middle
  int remain_start = valid_w_start;
#if defined(__ARM_NEON) || defined(__ARM_NEON__)
  int output_tiles = (valid_w_end - valid_w_start) / 6;
  remain_start = valid_w_start + output_tiles * 6;
  Pooling3x3NormalRowLoadInput<P, Stride> PoolingCompute;
  float32x4x2_t x0, x1, x2, y0;
  float32x4_t post = vdupq_n_f32(1.f / (3 * (h_end - h_start)));
  for (int w = 0; w < output_tiles * 6; w += 6) {
    int output_offset = valid_w_start + w;
    int input_w_offset = output_offset * Stride - padding_w;
    y0.val[0] = vPoolInitq_f32<P>();
    y0.val[1] = vPoolInitq_f32<P>();
    for (int h_in = h_start; h_in < h_end; ++h_in) {
      PoolingCompute(input + h_in * input_w + input_w_offset, x0, x1, x2, y0);
    }
    y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
    y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
    vst1q_f32(output_ptr + output_offset, y0.val[0]);
    vst1_f32(output_ptr + output_offset + 4, vget_low_f32(y0.val[1]));
  }
#endif  // __ARM_NEON__
  for (int w = remain_start; w < valid_w_end; ++w) {
    PoolingVal<P> val;
    int input_start = -padding_w + w * Stride;
    for (int h_in = h_start; h_in < h_end; ++h_in) {
      for (int j = 0; j < 3; ++j) {
        val += input[h_in * input_w + j + input_start];
      }
    }
    output_ptr[w] = val.Value();
  }
  // border right
  POOLING3X3_NORMAL_BORDER(valid_w_end, output_w)
}

template <PoolingType P>
struct Pooling3x3<P, 1> {
  inline void operator()(const framework::Tensor &input,
                         const std::vector<int> &paddings,
                         framework::Tensor *output) {
    const float *input_data = input.data<float>();
    float *output_data = output->mutable_data<float>();
    int input_h = input.dims()[2];
    int input_w = input.dims()[3];
    int output_h = output->dims()[2];
    int output_w = output->dims()[3];
    int padding_h = paddings[0];
    int padding_w = paddings[1];
    int image_size = input_h * input_w;
    int out_image_size = output_h * output_w;
    int valid_h_start = padding_h;
    int valid_h = input_h - 2;
    int valid_h_end = valid_h_start + valid_h;
    int valid_w_start = padding_w;
    int valid_w = input_w - 2;
    int valid_w_end = valid_w_start + valid_w;
    float avg = 1.f / 9;

    #pragma omp parallel for collapse(2)
    for (int batch = 0; batch < output->dims()[0]; ++batch) {
      for (int c = 0; c < output->dims()[1]; ++c) {
        int channel = batch * output->dims()[1] + c;
        const float *input_ptr = input_data + channel * image_size;
        float *output_ptr = output_data + channel * out_image_size;
        // top
        for (int h = 0; h < valid_h_start; ++h) {
          Pooling3x3NormalRow<P, 1>(input_ptr, h, input_h, input_w, padding_h,
                                    padding_w, output_w, output_ptr);
        }
        // left
        for (int w = 0; w < valid_w_start; ++w) {
          Pooling3x3ValidCol<P, 1>(input_ptr, valid_h_start, valid_h_end, w,
                                   input_h, input_w, padding_h, padding_w,
                                   output_w, output_ptr);
        }
        // right
        for (int w = valid_w_end; w < output_w; ++w) {
          Pooling3x3ValidCol<P, 1>(input_ptr, valid_h_start, valid_h_end, w,
                                   input_h, input_w, padding_h, padding_w,
                                   output_w, output_ptr);
        }
        // bottom
        for (int h = valid_h_end; h < output_h; ++h) {
          Pooling3x3NormalRow<P, 1>(input_ptr, h, input_h, input_w, padding_h,
                                    padding_w, output_w, output_ptr);
        }
        // valid
        int output_w_tiles = valid_w / 6;
        int output_w_remain = valid_w - output_w_tiles * 6;
        for (int h = valid_h_start; h < valid_h_end - 3; h += 4) {
          const float *input_ptr0 = input_ptr + (h - padding_h) * input_w;
          const float *input_ptr1 = input_ptr0 + input_w;
          const float *input_ptr2 = input_ptr1 + input_w;
          const float *input_ptr3 = input_ptr2 + input_w;
          const float *input_ptr4 = input_ptr3 + input_w;
          const float *input_ptr5 = input_ptr4 + input_w;
          float *output_ptr0 = output_ptr + h * output_w + valid_w_start;
          float *output_ptr1 = output_ptr0 + output_w;
          float *output_ptr2 = output_ptr1 + output_w;
          float *output_ptr3 = output_ptr2 + output_w;
          int remain = output_w_remain;
#if defined(__ARM_NEON__) || defined(__ARM_NEON)
          float32x4x2_t x0, x1, x2;
          float32x4x2_t y0, y1, y2;
          float32x4_t post = vdupq_n_f32(1.f / 9);
          for (int loop = 0; loop < output_w_tiles; ++loop) {
            x0.val[0] = vld1q_f32(input_ptr0);
            x0.val[1] = vld1q_f32(input_ptr0 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);

            x0.val[0] = vld1q_f32(input_ptr1);
            x0.val[1] = vld1q_f32(input_ptr1 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(y1.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(y1.val[1], y0.val[1]);

            x0.val[0] = vld1q_f32(input_ptr2);
            x0.val[1] = vld1q_f32(input_ptr2 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            y2.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y2.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(y2.val[0], y1.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(y2.val[1], y1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(y2.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(y2.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr0, y0.val[0]);
            vst1_f32(output_ptr0 + 4, vget_low_f32(y0.val[1]));

            x0.val[0] = vld1q_f32(input_ptr3);
            x0.val[1] = vld1q_f32(input_ptr3 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(y0.val[0], y1.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(y0.val[1], y1.val[1]);
            y2.val[0] = vPoolPreq_f32<P>(y0.val[0], y2.val[0]);
            y2.val[1] = vPoolPreq_f32<P>(y0.val[1], y2.val[1]);
            y1.val[0] = vPoolPostq_f32<P>(y1.val[0], post);
            y1.val[1] = vPoolPostq_f32<P>(y1.val[1], post);
            vst1q_f32(output_ptr1, y1.val[0]);
            vst1_f32(output_ptr1 + 4, vget_low_f32(y1.val[1]));

            x0.val[0] = vld1q_f32(input_ptr4);
            x0.val[1] = vld1q_f32(input_ptr4 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
            y2.val[0] = vPoolPreq_f32<P>(x0.val[0], y2.val[0]);
            y2.val[1] = vPoolPreq_f32<P>(x0.val[1], y2.val[1]);
            y2.val[0] = vPoolPostq_f32<P>(y2.val[0], post);
            y2.val[1] = vPoolPostq_f32<P>(y2.val[1], post);
            vst1q_f32(output_ptr2, y2.val[0]);
            vst1_f32(output_ptr2 + 4, vget_low_f32(y2.val[1]));

            x0.val[0] = vld1q_f32(input_ptr5);
            x0.val[1] = vld1q_f32(input_ptr5 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr3, y0.val[0]);
            vst1_f32(output_ptr3 + 4, vget_low_f32(y0.val[1]));

            input_ptr0 += 6;
            input_ptr1 += 6;
            input_ptr2 += 6;
            input_ptr3 += 6;
            input_ptr4 += 6;
            input_ptr5 += 6;
            output_ptr0 += 6;
            output_ptr1 += 6;
            output_ptr2 += 6;
            output_ptr3 += 6;
          }
          // remain width
          if (remain >= 4) {
            x0.val[0] = vld1q_f32(input_ptr0);
            x0.val[1] = vld1q_f32(input_ptr0 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);

            x0.val[0] = vld1q_f32(input_ptr1);
            x0.val[1] = vld1q_f32(input_ptr1 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(y1.val[0], y0.val[0]);

            x0.val[0] = vld1q_f32(input_ptr2);
            x0.val[1] = vld1q_f32(input_ptr2 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            y2.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[0] = vPoolPreq_f32<P>(y2.val[0], y1.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(y2.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr0, y0.val[0]);

            x0.val[0] = vld1q_f32(input_ptr3);
            x0.val[1] = vld1q_f32(input_ptr3 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[0] = vPoolPreq_f32<P>(y0.val[0], y1.val[0]);
            y2.val[0] = vPoolPreq_f32<P>(y0.val[0], y2.val[0]);
            y1.val[0] = vPoolPostq_f32<P>(y1.val[0], post);
            vst1q_f32(output_ptr1, y1.val[0]);

            x0.val[0] = vld1q_f32(input_ptr4);
            x0.val[1] = vld1q_f32(input_ptr4 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y2.val[0] = vPoolPreq_f32<P>(x0.val[0], y2.val[0]);
            y2.val[0] = vPoolPostq_f32<P>(y2.val[0], post);
            vst1q_f32(output_ptr2, y2.val[0]);

            x0.val[0] = vld1q_f32(input_ptr5);
            x0.val[1] = vld1q_f32(input_ptr5 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr3, y0.val[0]);

            input_ptr0 += 4;
            input_ptr1 += 4;
            input_ptr2 += 4;
            input_ptr3 += 4;
            input_ptr4 += 4;
            input_ptr5 += 4;
            output_ptr0 += 4;
            output_ptr1 += 4;
            output_ptr2 += 4;
            output_ptr3 += 4;
            remain -= 4;
          }
#endif  // __ARM_NEON__
          for (int r = 0; r < remain; ++r) {
            float m0 = PoolPre<P>(input_ptr0[r], input_ptr0[r + 1]);
            m0 = PoolPre<P>(m0, input_ptr0[r + 2]);
            float m1 = PoolPre<P>(input_ptr1[r], input_ptr1[r + 1]);
            m1 = PoolPre<P>(m1, input_ptr1[r + 2]);
            float m2 = PoolPre<P>(input_ptr2[r], input_ptr2[r + 1]);
            m2 = PoolPre<P>(m2, input_ptr2[r + 2]);
            float m3 = PoolPre<P>(input_ptr3[r], input_ptr3[r + 1]);
            m3 = PoolPre<P>(m3, input_ptr3[r + 2]);
            float m4 = PoolPre<P>(input_ptr4[r], input_ptr4[r + 1]);
            m4 = PoolPre<P>(m4, input_ptr4[r + 2]);
            float m5 = PoolPre<P>(input_ptr5[r], input_ptr5[r + 1]);
            m5 = PoolPre<P>(m5, input_ptr5[r + 2]);

            m0 = PoolPre<P>(PoolPre<P>(m0, m1), m2);
            m1 = PoolPre<P>(PoolPre<P>(m1, m2), m3);
            m2 = PoolPre<P>(PoolPre<P>(m2, m3), m4);
            m3 = PoolPre<P>(PoolPre<P>(m3, m4), m5);
            output_ptr0[r] = PoolPost<P>(m0, avg);
            output_ptr1[r] = PoolPost<P>(m1, avg);
            output_ptr2[r] = PoolPost<P>(m2, avg);
            output_ptr3[r] = PoolPost<P>(m3, avg);
          }
        }
        // remain height
        int start_h = valid_h_start + (valid_h & 0xFFFC);
        for (int h = start_h; h < valid_h_end; ++h) {
          const float *input_ptr0 = input_ptr + (h - padding_h) * input_w;
          const float *input_ptr1 = input_ptr0 + input_w;
          const float *input_ptr2 = input_ptr1 + input_w;
          float *output_ptr0 = output_ptr + h * output_w + valid_w_start;
          int remain = output_w_remain;
#if defined(__ARM_NEON__) || defined(__ARM_NEON)
          float32x4x2_t x0, x1, x2, y0;
          float32x4_t post = vdupq_n_f32(1.f / 9);
          for (int loop = 0; loop < output_w_tiles; ++loop) {
            x0.val[0] = vld1q_f32(input_ptr0);
            x0.val[1] = vld1q_f32(input_ptr0 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);

            x0.val[0] = vld1q_f32(input_ptr1);
            x0.val[1] = vld1q_f32(input_ptr1 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);

            x0.val[0] = vld1q_f32(input_ptr2);
            x0.val[1] = vld1q_f32(input_ptr2 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x1.val[1] = vextq_f32(x0.val[1], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x2.val[1] = vextq_f32(x0.val[1], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr0, y0.val[0]);
            vst1_f32(output_ptr0 + 4, vget_low_f32(y0.val[1]));

            input_ptr0 += 6;
            input_ptr1 += 6;
            input_ptr2 += 6;
            output_ptr0 += 6;
          }
          // remain width
          if (remain >= 4) {
            x0.val[0] = vld1q_f32(input_ptr0);
            x0.val[1] = vld1q_f32(input_ptr0 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);

            x0.val[0] = vld1q_f32(input_ptr1);
            x0.val[1] = vld1q_f32(input_ptr1 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);

            x0.val[0] = vld1q_f32(input_ptr2);
            x0.val[1] = vld1q_f32(input_ptr2 + 4);
            x1.val[0] = vextq_f32(x0.val[0], x0.val[1], 1);
            x2.val[0] = vextq_f32(x0.val[0], x0.val[1], 2);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x1.val[0]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr0, y0.val[0]);

            input_ptr0 += 4;
            input_ptr1 += 4;
            input_ptr2 += 4;
            output_ptr0 += 4;
            remain -= 4;
          }
#endif  // __ARM_NEON__
          for (int r = 0; r < remain; ++r) {
            float m0 = PoolPre<P>(input_ptr0[r], input_ptr0[r + 1]);
            m0 = PoolPre<P>(m0, input_ptr0[r + 2]);
            float m1 = PoolPre<P>(input_ptr1[r], input_ptr1[r + 1]);
            m1 = PoolPre<P>(m1, input_ptr1[r + 2]);
            float m2 = PoolPre<P>(input_ptr2[r], input_ptr2[r + 1]);
            m2 = PoolPre<P>(m2, input_ptr2[r + 2]);

            m0 = PoolPre<P>(PoolPre<P>(m0, m1), m2);
            output_ptr0[r] = PoolPost<P>(m0, avg);
          }
        }
      }
    }
  }
};

template <PoolingType P>
struct Pooling3x3<P, 2> {
  inline void operator()(const framework::Tensor &input,
                         const std::vector<int> &paddings,
                         framework::Tensor *output) {
    const float *input_data = input.data<float>();
    float *output_data = output->mutable_data<float>();
    int input_h = input.dims()[2];
    int input_w = input.dims()[3];
    int output_h = output->dims()[2];
    int output_w = output->dims()[3];
    int padding_h = paddings[0];
    int padding_w = paddings[1];
    int image_size = input_h * input_w;
    int out_image_size = output_h * output_w;
    int valid_h_start = (padding_h + 1) / 2;
    int valid_h = (input_h - 3) / 2 + 1;
    int valid_h_end = valid_h_start + valid_h;
    int valid_w_start = (padding_w + 1) / 2;
    int valid_w = (input_w - 3) / 2 + 1;
    int valid_w_end = valid_w_start + valid_w;
    float avg = 1.f / 9;

    #pragma omp parallel for collapse(2)
    for (int batch = 0; batch < output->dims()[0]; ++batch) {
      for (int c = 0; c < output->dims()[1]; ++c) {
        int channel = batch * output->dims()[1] + c;
        const float *input_ptr = input_data + channel * image_size;
        float *output_ptr = output_data + channel * out_image_size;
        // top
        for (int h = 0; h < valid_h_start; ++h) {
          Pooling3x3NormalRow<P, 2>(input_ptr, h, input_h, input_w, padding_h,
                                    padding_w, output_w, output_ptr);
        }
        // left
        for (int w = 0; w < valid_w_start; ++w) {
          Pooling3x3ValidCol<P, 2>(input_ptr, valid_h_start, valid_h_end, w,
                                   input_h, input_w, padding_h, padding_w,
                                   output_w, output_ptr);
        }
        // right
        for (int w = valid_w_end; w < output_w; ++w) {
          Pooling3x3ValidCol<P, 2>(input_ptr, valid_h_start, valid_h_end, w,
                                   input_h, input_w, padding_h, padding_w,
                                   output_w, output_ptr);
        }
        // bottom
        for (int h = valid_h_end; h < output_h; ++h) {
          Pooling3x3NormalRow<P, 2>(input_ptr, h, input_h, input_w, padding_h,
                                    padding_w, output_w, output_ptr);
        }
        // valid
        int input_w_start = 2 * valid_w_start - padding_w;
        int output_w_tiles = valid_w / 6;
        int output_w_remain = valid_w - output_w_tiles * 6;
        for (int h = valid_h_start; h < valid_h_end - 2; h += 3) {
          size_t offset = (2 * h - padding_h) * input_w + input_w_start;
          const float *input_ptr0 = input_ptr + offset;
          const float *input_ptr1 = input_ptr0 + input_w;
          const float *input_ptr2 = input_ptr1 + input_w;
          const float *input_ptr3 = input_ptr2 + input_w;
          const float *input_ptr4 = input_ptr3 + input_w;
          const float *input_ptr5 = input_ptr4 + input_w;
          const float *input_ptr6 = input_ptr5 + input_w;
          float *output_ptr0 = output_ptr + h * output_w + valid_w_start;
          float *output_ptr1 = output_ptr0 + output_w;
          float *output_ptr2 = output_ptr1 + output_w;
          int remain = output_w_remain;
#if defined(__ARM_NEON__) || defined(__ARM_NEON)
          float32x4x2_t x0, x1, x2;
          float32x4x2_t y0, y1, y2;
          float32x4_t post = vdupq_n_f32(1.f / 9);
          for (int loop = 0; loop < output_w_tiles; ++loop) {
            x0 = vld2q_f32(input_ptr0);
            x1 = vld2q_f32(input_ptr0 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);

            x0 = vld2q_f32(input_ptr1);
            x1 = vld2q_f32(input_ptr1 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);

            x0 = vld2q_f32(input_ptr2);
            x1 = vld2q_f32(input_ptr2 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(y1.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(y1.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr0, y0.val[0]);
            vst1_f32(output_ptr0 + 4, vget_low_f32(y0.val[1]));

            x0 = vld2q_f32(input_ptr3);
            x1 = vld2q_f32(input_ptr3 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], y1.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(x0.val[1], y1.val[1]);

            x0 = vld2q_f32(input_ptr4);
            x1 = vld2q_f32(input_ptr4 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(y0.val[0], y1.val[0]);
            y1.val[1] = vPoolPreq_f32<P>(y0.val[1], y1.val[1]);
            y1.val[0] = vPoolPostq_f32<P>(y1.val[0], post);
            y1.val[1] = vPoolPostq_f32<P>(y1.val[1], post);
            vst1q_f32(output_ptr1, y1.val[0]);
            vst1_f32(output_ptr1 + 4, vget_low_f32(y1.val[1]));

            x0 = vld2q_f32(input_ptr5);
            x1 = vld2q_f32(input_ptr5 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);

            x0 = vld2q_f32(input_ptr6);
            x1 = vld2q_f32(input_ptr6 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr2, y0.val[0]);
            vst1_f32(output_ptr2 + 4, vget_low_f32(y0.val[1]));

            input_ptr0 += 12;
            input_ptr1 += 12;
            input_ptr2 += 12;
            input_ptr3 += 12;
            input_ptr4 += 12;
            input_ptr5 += 12;
            input_ptr6 += 12;
            output_ptr0 += 6;
            output_ptr1 += 6;
            output_ptr2 += 6;
          }
          // remain width
          if (remain >= 4) {
            x0 = vld2q_f32(input_ptr0);
            x1.val[0] = vdupq_n_f32(input_ptr0[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);

            x0 = vld2q_f32(input_ptr1);
            x1.val[0] = vdupq_n_f32(input_ptr1[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);

            x0 = vld2q_f32(input_ptr2);
            x1.val[0] = vdupq_n_f32(input_ptr2[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(y1.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr0, y0.val[0]);

            x0 = vld2q_f32(input_ptr3);
            x1.val[0] = vdupq_n_f32(input_ptr3[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[0] = vPoolPreq_f32<P>(x0.val[0], y1.val[0]);

            x0 = vld2q_f32(input_ptr4);
            x1.val[0] = vdupq_n_f32(input_ptr4[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y1.val[0] = vPoolPreq_f32<P>(y0.val[0], y1.val[0]);
            y1.val[0] = vPoolPostq_f32<P>(y1.val[0], post);
            vst1q_f32(output_ptr1, y1.val[0]);

            x0 = vld2q_f32(input_ptr5);
            x1.val[0] = vdupq_n_f32(input_ptr5[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);

            x0 = vld2q_f32(input_ptr6);
            x1.val[0] = vdupq_n_f32(input_ptr6[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr2, y0.val[0]);

            input_ptr0 += 8;
            input_ptr1 += 8;
            input_ptr2 += 8;
            input_ptr3 += 8;
            input_ptr4 += 8;
            input_ptr5 += 8;
            input_ptr6 += 8;
            output_ptr0 += 4;
            output_ptr1 += 4;
            output_ptr2 += 4;
            remain -= 4;
          }
#endif  // __ARM_NEON__
          for (int r = 0; r < remain; ++r) {
            float m0 = PoolPre<P>(input_ptr0[2 * r], input_ptr0[2 * r + 1]);
            m0 = PoolPre<P>(m0, input_ptr0[2 * r + 2]);
            float m1 = PoolPre<P>(input_ptr1[2 * r], input_ptr1[2 * r + 1]);
            m1 = PoolPre<P>(m1, input_ptr1[2 * r + 2]);
            float m2 = PoolPre<P>(input_ptr2[2 * r], input_ptr2[2 * r + 1]);
            m2 = PoolPre<P>(m2, input_ptr2[2 * r + 2]);
            float m3 = PoolPre<P>(input_ptr3[2 * r], input_ptr3[2 * r + 1]);
            m3 = PoolPre<P>(m3, input_ptr3[2 * r + 2]);
            float m4 = PoolPre<P>(input_ptr4[2 * r], input_ptr4[2 * r + 1]);
            m4 = PoolPre<P>(m4, input_ptr4[2 * r + 2]);
            float m5 = PoolPre<P>(input_ptr5[2 * r], input_ptr5[2 * r + 1]);
            m5 = PoolPre<P>(m5, input_ptr5[2 * r + 2]);
            float m6 = PoolPre<P>(input_ptr6[2 * r], input_ptr6[2 * r + 1]);
            m6 = PoolPre<P>(m6, input_ptr6[2 * r + 2]);

            m0 = PoolPre<P>(PoolPre<P>(m0, m1), m2);
            m1 = PoolPre<P>(PoolPre<P>(m2, m3), m4);
            m2 = PoolPre<P>(PoolPre<P>(m4, m5), m6);
            output_ptr0[r] = PoolPost<P>(m0, avg);
            output_ptr1[r] = PoolPost<P>(m1, avg);
            output_ptr2[r] = PoolPost<P>(m2, avg);
          }
        }
        // remain height
        int start_h = valid_h_start + valid_h / 3 * 3;
        for (int h = start_h; h < valid_h_end; ++h) {
          size_t offset = (2 * h - padding_h) * input_w + input_w_start;
          const float *input_ptr0 = input_ptr + offset;
          const float *input_ptr1 = input_ptr0 + input_w;
          const float *input_ptr2 = input_ptr1 + input_w;
          float *output_ptr0 = output_ptr + h * output_w + valid_w_start;
          int remain = output_w_remain;
#if defined(__ARM_NEON__) || defined(__ARM_NEON)
          float32x4x2_t x0, x1, x2, y0;
          float32x4_t post = vdupq_n_f32(1.f / 9);
          for (int loop = 0; loop < output_w_tiles; ++loop) {
            x0 = vld2q_f32(input_ptr0);
            x1 = vld2q_f32(input_ptr0 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);

            x0 = vld2q_f32(input_ptr1);
            x1 = vld2q_f32(input_ptr1 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);

            x0 = vld2q_f32(input_ptr2);
            x1 = vld2q_f32(input_ptr2 + 8);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x2.val[1] = vextq_f32(x1.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[1] = vPoolPreq_f32<P>(x1.val[0], x1.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            x0.val[1] = vPoolPreq_f32<P>(x0.val[1], x2.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[1] = vPoolPreq_f32<P>(x0.val[1], y0.val[1]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            y0.val[1] = vPoolPostq_f32<P>(y0.val[1], post);
            vst1q_f32(output_ptr0, y0.val[0]);
            vst1_f32(output_ptr0 + 4, vget_low_f32(y0.val[1]));

            input_ptr0 += 12;
            input_ptr1 += 12;
            input_ptr2 += 12;
            output_ptr0 += 6;
          }
          // remain width
          if (remain >= 4) {
            x0 = vld2q_f32(input_ptr0);
            x1.val[0] = vdupq_n_f32(input_ptr0[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);

            x0 = vld2q_f32(input_ptr1);
            x1.val[0] = vdupq_n_f32(input_ptr1[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);

            x0 = vld2q_f32(input_ptr2);
            x1.val[0] = vdupq_n_f32(input_ptr2[8]);
            x2.val[0] = vextq_f32(x0.val[0], x1.val[0], 1);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x0.val[1]);
            x0.val[0] = vPoolPreq_f32<P>(x0.val[0], x2.val[0]);
            y0.val[0] = vPoolPreq_f32<P>(x0.val[0], y0.val[0]);
            y0.val[0] = vPoolPostq_f32<P>(y0.val[0], post);
            vst1q_f32(output_ptr0, y0.val[0]);

            input_ptr0 += 8;
            input_ptr1 += 8;
            input_ptr2 += 8;
            output_ptr0 += 4;
            remain -= 4;
          }
#endif  // __ARM_NEON__
          for (int r = 0; r < remain; ++r) {
            float m0 = PoolPre<P>(input_ptr0[2 * r], input_ptr0[2 * r + 1]);
            m0 = PoolPre<P>(m0, input_ptr0[2 * r + 2]);
            float m1 = PoolPre<P>(input_ptr1[2 * r], input_ptr1[2 * r + 1]);
            m1 = PoolPre<P>(m1, input_ptr1[2 * r + 2]);
            float m2 = PoolPre<P>(input_ptr2[2 * r], input_ptr2[2 * r + 1]);
            m2 = PoolPre<P>(m2, input_ptr2[2 * r + 2]);

            m0 = PoolPre<P>(PoolPre<P>(m0, m1), m2);
            output_ptr0[r] = PoolPost<P>(m0, avg);
          }
        }
      }
    }
  }
};

template struct Pooling3x3<Max, 1>;
template struct Pooling3x3<Avg, 1>;
template struct Pooling3x3<Max, 2>;
template struct Pooling3x3<Avg, 2>;

}  // namespace math
}  // namespace operators
}  // namespace paddle_mobile

#endif  // POOL_OP