text: /**
   * \file dnn/src/arm_common/pooling/do_max_pooling_4x4_nchw44.cpp
   * MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
   *
   * Copyright (c) 2014-2021 Megvii Inc. All rights reserved.
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or
   * implied.
   */
  #include "src/arm_common/pooling/do_pooling_4x4_nchw44.h"
  #include "src/arm_common/pooling/algo.h"
  #include "src/arm_common/simd_macro/marm_neon.h"
  #include "src/common/unroll_macro.h"
  
  namespace megdnn {
  namespace arm_common {
  
  void do_max_pooling_4x4_stride1_int8_nchw44_NEON(
          const int8_t* src, int8_t* dst, size_t IH, size_t IW, size_t OH, size_t OW,
          size_t PH, size_t PW, const WorkspaceBundle& ws) {
      const int8_t* sptr = nullptr;
      size_t IH2, IW2;
      sptr = handle_padding(src, IH, IW, IH2, IW2, PH, PW, ws, true);
      size_t oh = 0;
      for (; oh < OH; ++oh) {
          size_t ih = oh;
          const int8_t* __restrict sptr0 = sptr + (ih + 0) * IW2 * 4;
          const int8_t* __restrict sptr1 = sptr + (ih + 1) * IW2 * 4;
          const int8_t* __restrict sptr2 = sptr + (ih + 2) * IW2 * 4;
          const int8_t* __restrict sptr3 = sptr + (ih + 3) * IW2 * 4;
          int8_t* __restrict dptr = dst + oh * OW * 4;
          size_t ow = 0;
          for (; ow + 3 < OW; ow += 4) {
              int8x16_t src00, src04, max_out, max_tmp0, max_tmp1, max_tmp2, max_tmp3;
              int32x4_t src1234, src2345, src3456;
  
  #define CACULATE_ROW(i)                                                               \
      src00 = vld1q_s8(sptr##i);                                                        \
      src04 = vld1q_s8(sptr##i + 4 * 4);                                                \
      src1234 = vextq_s32(vreinterpretq_s32_s8(src00), vreinterpretq_s32_s8(src04), 1); \
      src2345 = vextq_s32(vreinterpretq_s32_s8(src00), vreinterpretq_s32_s8(src04), 2); \
      src3456 = vextq_s32(vreinterpretq_s32_s8(src00), vreinterpretq_s32_s8(src04), 3); \
      max_tmp##i = vmaxq_s8(src00, vreinterpretq_s8_s32(src1234));                      \
      max_tmp##i = vmaxq_s8(max_tmp##i, vreinterpretq_s8_s32(src2345));                 \
      max_tmp##i = vmaxq_s8(max_tmp##i, vreinterpretq_s8_s32(src3456));
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
              max_out = vmaxq_s8(max_tmp0, max_tmp1);
              max_out = vmaxq_s8(max_out, max_tmp2);
              max_out = vmaxq_s8(max_out, max_tmp3);
  
              vst1q_s8(dptr, max_out);
  
              sptr0 += 16;
              sptr1 += 16;
              sptr2 += 16;
              sptr3 += 16;
              dptr += 16;
  #undef CACULATE_ROW
          }
          for (; ow < OW; ++ow) {
              int8x8_t src01, src23, max_out;
  
  #define CACULATE_ROW(i)           \
      src01 = vld1_s8(sptr##i);     \
      src23 = vld1_s8(sptr##i + 8); \
      int8x8_t max_tmp##i = vmax_s8(src01, src23);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
              max_out = vmax_s8(max_tmp0, max_tmp1);
              max_out = vmax_s8(max_out, max_tmp2);
              max_out = vmax_s8(max_out, max_tmp3);
  
  #define store(i) *(dptr + i) = std::max(max_out[i], max_out[i + 4]);
              UNROLL_CALL_NOWRAPPER(4, store)
  #undef store
  #undef CACULATE_ROW
              sptr0 += 4;
              sptr1 += 4;
              sptr2 += 4;
              sptr3 += 4;
              dptr += 4;
          }
      }
  }
  void do_max_pooling_4x4_stride2_int8_nchw44_NEON(
          const int8_t* src, int8_t* dst, size_t IH, size_t IW, size_t OH, size_t OW,
          size_t PH, size_t PW, const WorkspaceBundle& ws) {
      const int8_t* sptr = nullptr;
      size_t IH2, IW2;
      sptr = handle_padding(src, IH, IW, IH2, IW2, PH, PW, ws, true);
      size_t oh = 0;
      for (; oh < OH; ++oh) {
          size_t ih = oh << 1;
          const int8_t* __restrict sptr0 = sptr + (ih + 0) * IW2 * 4;
          const int8_t* __restrict sptr1 = sptr + (ih + 1) * IW2 * 4;
          const int8_t* __restrict sptr2 = sptr + (ih + 2) * IW2 * 4;
          const int8_t* __restrict sptr3 = sptr + (ih + 3) * IW2 * 4;
          int8_t* __restrict dptr = dst + oh * OW * 4;
          size_t ow = 0;
          for (; ow + 3 < OW; ow += 4) {
              int8x16_t src00, src04, max_tmp0, max_tmp1, max_tmp2, max_tmp3;
              int32x4_t src0246, src1357, src2468, src3579, src08, src09;
              int32x4x2_t src_tmp;
  #define CACULATE_ROW(i)                                                             \
      src00 = vld1q_s8(sptr##i);                                                      \
      src04 = vld1q_s8(sptr##i + 4 * 4);                                              \
      src08 = vld1q_dup_s32(reinterpret_cast<const int32_t*>(sptr##i + 4 * 8));       \
      src09 = vld1q_dup_s32(reinterpret_cast<const int32_t*>(sptr##i + 4 * 9));       \
      src_tmp = vuzpq_s32(vreinterpretq_s32_s8(src00), vreinterpretq_s32_s8(src04));  \
      src0246 = src_tmp.val[0];                                                       \
      src1357 = src_tmp.val[1];                                                       \
      src2468 = vextq_s32(src0246, src08, 1);                                         \
      src3579 = vextq_s32(src1357, src09, 1);                                         \
      max_tmp##i =                                                                    \
              vmaxq_s8(vreinterpretq_s8_s32(src0246), vreinterpretq_s8_s32(src1357)); \
      max_tmp##i = vmaxq_s8(max_tmp##i, vreinterpretq_s8_s32(src2468));               \
      max_tmp##i = vmaxq_s8(max_tmp##i, vreinterpretq_s8_s32(src3579));
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
              int8x16_t max_out = vmaxq_s8(max_tmp0, max_tmp1);
              max_out = vmaxq_s8(max_out, max_tmp2);
              max_out = vmaxq_s8(max_out, max_tmp3);
  
              vst1q_s8(dptr, max_out);
  
              sptr0 += 32;
              sptr1 += 32;
              sptr2 += 32;
              sptr3 += 32;
              dptr += 16;
  #undef CACULATE_ROW
          }
          for (; ow < OW; ++ow) {
              int8x8_t src01, src23, max_out;
  
  #define CACULATE_ROW(i)           \
      src01 = vld1_s8(sptr##i);     \
      src23 = vld1_s8(sptr##i + 8); \
      int8x8_t max_tmp##i = vmax_s8(src01, src23);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
              max_out = vmax_s8(max_tmp0, max_tmp1);
              max_out = vmax_s8(max_out, max_tmp2);
              max_out = vmax_s8(max_out, max_tmp3);
  
  #define store(i) *(dptr + i) = std::max(max_out[i], max_out[i + 4]);
              UNROLL_CALL_NOWRAPPER(4, store)
  #undef store
  #undef CACULATE_ROW
              sptr0 += 8;
              sptr1 += 8;
              sptr2 += 8;
              sptr3 += 8;
              dptr += 4;
          }
      }
  }
  
  void do_avg_pooling_4x4_stride1_int8_nchw44_NEON(
          const int8_t* src, int8_t* dst, size_t IH, size_t IW, size_t OH, size_t OW,
          size_t PH, size_t PW, const WorkspaceBundle& ws) {
      int16_t filter_size = 16;
      const int8_t* sptr = nullptr;
      size_t IH2, IW2;
      sptr = handle_padding(src, IH, IW, IH2, IW2, PH, PW, ws, false);
      size_t oh = 0;
      for (; oh < OH; ++oh) {
          size_t ih = oh;
          const int8_t* __restrict sptr0 = sptr + (ih + 0) * IW2 * 4;
          const int8_t* __restrict sptr1 = sptr + (ih + 1) * IW2 * 4;
          const int8_t* __restrict sptr2 = sptr + (ih + 2) * IW2 * 4;
          const int8_t* __restrict sptr3 = sptr + (ih + 3) * IW2 * 4;
          int8_t* __restrict dptr = dst + oh * OW * 4;
          size_t ow = 0;
          for (; ow + 3 < OW; ow += 4) {
              int16x8_t src01, src23, src12, src34, src45, src56;
              int16x8_t sum01 = vdupq_n_s16(0);
              int16x8_t sum23 = vdupq_n_s16(0);
  
  #define CACULATE_ROW(i)                      \
      src01 = vmovl_s8(vld1_s8(sptr##i));      \
      src23 = vmovl_s8(vld1_s8(sptr##i + 8));  \
      src12 = vmovl_s8(vld1_s8(sptr##i + 4));  \
      src34 = vmovl_s8(vld1_s8(sptr##i + 12)); \
      src45 = vmovl_s8(vld1_s8(sptr##i + 16)); \
      src56 = vmovl_s8(vld1_s8(sptr##i + 20)); \
      sum01 = vaddq_s16(sum01, src01);         \
      sum01 = vaddq_s16(sum01, src12);         \
      sum01 = vaddq_s16(sum01, src23);         \
      sum01 = vaddq_s16(sum01, src34);         \
      sum23 = vaddq_s16(sum23, src23);         \
      sum23 = vaddq_s16(sum23, src34);         \
      sum23 = vaddq_s16(sum23, src45);         \
      sum23 = vaddq_s16(sum23, src56);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
  #define sum_define(i) int16_t sum##i;
              UNROLL_CALL_NOWRAPPER(8, sum_define)
  
  #define sum01_avg(i)                                                            \
      sum##i = vgetq_lane_s16(sum01, i) > 0                                       \
                     ? (vgetq_lane_s16(sum01, i) + filter_size / 2) / filter_size \
                     : (vgetq_lane_s16(sum01, i) - filter_size / 2) / filter_size;
  #define sum23_avg(i)                                                            \
      sum##i = vgetq_lane_s16(sum23, i) > 0                                       \
                     ? (vgetq_lane_s16(sum23, i) + filter_size / 2) / filter_size \
                     : (vgetq_lane_s16(sum23, i) - filter_size / 2) / filter_size;
  #define store_sum01(i) *(dptr + i) = static_cast<int8_t>(sum##i);
  #define store_sum23(i) *(dptr + i + 8) = static_cast<int8_t>(sum##i);
  
              UNROLL_CALL_NOWRAPPER(8, sum01_avg)
              UNROLL_CALL_NOWRAPPER(8, store_sum01)
  
              UNROLL_CALL_NOWRAPPER(8, sum23_avg)
              UNROLL_CALL_NOWRAPPER(8, store_sum23)
  
              sptr0 += 16;
              sptr1 += 16;
              sptr2 += 16;
              sptr3 += 16;
              dptr += 16;
  
  #undef store_sum01
  #undef store_sum23
  #undef sum01_avg
  #undef sum23_avg
  #undef sum_define
  #undef CACULATE_ROW
          }
          for (; ow < OW; ++ow) {
              int16x8_t src01, src23, sum01;
              sum01 = vdupq_n_s16(0);
  
  #define CACULATE_ROW(i)                     \
      src01 = vmovl_s8(vld1_s8(sptr##i));     \
      src23 = vmovl_s8(vld1_s8(sptr##i + 8)); \
      sum01 = vaddq_s16(sum01, src01);        \
      sum01 = vaddq_s16(sum01, src23);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
  #define do_acc(i) \
      int16_t sum##i = vgetq_lane_s16(sum01, i) + vgetq_lane_s16(sum01, i + 4);
  #define do_avg(i)                                                  \
      sum##i = sum##i > 0 ? (sum##i + filter_size / 2) / filter_size \
                          : (sum##i - filter_size / 2) / filter_size;
  #define store(i) *(dptr + i) = static_cast<int8_t>(sum##i);
  
              UNROLL_CALL_NOWRAPPER(4, do_acc)
              UNROLL_CALL_NOWRAPPER(4, do_avg)
              UNROLL_CALL_NOWRAPPER(4, store)
  
  #undef store
  #undef do_avg
  #undef do_acc
  #undef CACULATE_ROW
  
              sptr0 += 4;
              sptr1 += 4;
              sptr2 += 4;
              sptr3 += 4;
              dptr += 4;
          }
      }
  }
  void do_avg_pooling_4x4_stride2_int8_nchw44_NEON(
          const int8_t* src, int8_t* dst, size_t IH, size_t IW, size_t OH, size_t OW,
          size_t PH, size_t PW, const WorkspaceBundle& ws) {
      int16_t filter_size = 16;
      const int8_t* sptr = nullptr;
      size_t IH2, IW2;
      sptr = handle_padding(src, IH, IW, IH2, IW2, PH, PW, ws, false);
      size_t oh = 0;
      for (; oh < OH; ++oh) {
          size_t ih = oh << 1;
          const int8_t* sptr0 = sptr + (ih + 0) * IW2 * 4;
          const int8_t* sptr1 = sptr + (ih + 1) * IW2 * 4;
          const int8_t* sptr2 = sptr + (ih + 2) * IW2 * 4;
          const int8_t* sptr3 = sptr + (ih + 3) * IW2 * 4;
          int8_t* __restrict dptr = dst + oh * OW * 4;
          size_t ow = 0;
          for (; ow + 3 < OW; ow += 4) {
              int32x4x2_t src_tmp;
              int8x16_t src00, src04;
              int16x8_t src02, src13, src57, src24, src68, src35, src79, src46;
              int32x4_t src08, src09, src0246, src1357, src2468, src3579;
              int16x8_t sum01 = vdupq_n_s16(0);
              int16x8_t sum23 = vdupq_n_s16(0);
  
  #define CACULATE_ROW(i)                                                            \
      src00 = vld1q_s8(sptr##i);                                                     \
      src04 = vld1q_s8(sptr##i + 4 * 4);                                             \
      src08 = vld1q_dup_s32(reinterpret_cast<const int32_t*>(sptr##i + 4 * 8));      \
      src09 = vld1q_dup_s32(reinterpret_cast<const int32_t*>(sptr##i + 4 * 9));      \
      src_tmp = vuzpq_s32(vreinterpretq_s32_s8(src00), vreinterpretq_s32_s8(src04)); \
      src0246 = src_tmp.val[0];                                                      \
      src1357 = src_tmp.val[1];                                                      \
      src2468 = vextq_s32(src0246, src08, 1);                                        \
      src3579 = vextq_s32(src1357, src09, 1);                                        \
      src02 = vmovl_s8(vget_low_s8(vreinterpretq_s8_s32(src0246)));                  \
      src46 = vmovl_s8(vget_high_s8(vreinterpretq_s8_s32(src0246)));                 \
      src13 = vmovl_s8(vget_low_s8(vreinterpretq_s8_s32(src1357)));                  \
      src57 = vmovl_s8(vget_high_s8(vreinterpretq_s8_s32(src1357)));                 \
      src24 = vmovl_s8(vget_low_s8(vreinterpretq_s8_s32(src2468)));                  \
      src68 = vmovl_s8(vget_high_s8(vreinterpretq_s8_s32(src2468)));                 \
      src35 = vmovl_s8(vget_low_s8(vreinterpretq_s8_s32(src3579)));                  \
      src79 = vmovl_s8(vget_high_s8(vreinterpretq_s8_s32(src3579)));                 \
      sum01 = vaddq_s16(sum01, src02);                                               \
      sum01 = vaddq_s16(sum01, src13);                                               \
      sum01 = vaddq_s16(sum01, src24);                                               \
      sum01 = vaddq_s16(sum01, src35);                                               \
      sum23 = vaddq_s16(sum23, src46);                                               \
      sum23 = vaddq_s16(sum23, src57);                                               \
      sum23 = vaddq_s16(sum23, src68);                                               \
      sum23 = vaddq_s16(sum23, src79);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
  #define sum_define(i) int16_t sum##i;
              UNROLL_CALL_NOWRAPPER(8, sum_define)
  
  #define sum01_avg(i)                                                            \
      sum##i = vgetq_lane_s16(sum01, i) > 0                                       \
                     ? (vgetq_lane_s16(sum01, i) + filter_size / 2) / filter_size \
                     : (vgetq_lane_s16(sum01, i) - filter_size / 2) / filter_size;
  #define sum23_avg(i)                                                            \
      sum##i = vgetq_lane_s16(sum23, i) > 0                                       \
                     ? (vgetq_lane_s16(sum23, i) + filter_size / 2) / filter_size \
                     : (vgetq_lane_s16(sum23, i) - filter_size / 2) / filter_size;
  #define store_sum01(i) *(dptr + i) = static_cast<int8_t>(sum##i);
  #define store_sum23(i) *(dptr + i + 8) = static_cast<int8_t>(sum##i);
  
              UNROLL_CALL_NOWRAPPER(8, sum01_avg)
              UNROLL_CALL_NOWRAPPER(8, store_sum01)
  
              UNROLL_CALL_NOWRAPPER(8, sum23_avg)
              UNROLL_CALL_NOWRAPPER(8, store_sum23)
  
              sptr0 += 32;
              sptr1 += 32;
              sptr2 += 32;
              sptr3 += 32;
              dptr += 16;
  
  #undef store_sum01
  #undef store_sum23
  #undef sum01_avg
  #undef sum23_avg
  #undef sum_define
  #undef CACULATE_ROW
          }
          for (; ow < OW; ++ow) {
              int8x8_t src001, src023;
              int16x8_t src01, src23, sum01;
              sum01 = vdupq_n_s16(0);
  
  #define CACULATE_ROW(i)              \
      src001 = vld1_s8(sptr##i);       \
      src023 = vld1_s8(sptr##i + 8);   \
      src01 = vmovl_s8(src001);        \
      src23 = vmovl_s8(src023);        \
      sum01 = vaddq_s16(sum01, src01); \
      sum01 = vaddq_s16(sum01, src23);
  
              UNROLL_CALL_NOWRAPPER(4, CACULATE_ROW)
  
  #define do_acc(i) \
      int16_t sum##i = vgetq_lane_s16(sum01, i) + vgetq_lane_s16(sum01, i + 4);
  #define do_avg(i)                                                  \
      sum##i = sum##i > 0 ? (sum##i + filter_size / 2) / filter_size \
                          : (sum##i - filter_size / 2) / filter_size;
  #define store(i) *(dptr + i) = static_cast<int8_t>(sum##i);
  
              UNROLL_CALL_NOWRAPPER(4, do_acc)
              UNROLL_CALL_NOWRAPPER(4, do_avg)
              UNROLL_CALL_NOWRAPPER(4, store)
  
  #undef store
  #undef do_avg
  #undef do_acc
  #undef CACULATE_ROW
              sptr0 += 8;
              sptr1 += 8;
              sptr2 += 8;
              sptr3 += 8;
              dptr += 4;
          }
      }
  }
  
  }  // namespace arm_common
  }  // namespace megdnn
     // vim: syntax=cpp.doxygen
  