Exemplo n.º 1
0
static void
avx2_test (void)
{
  union256i_w s1, s2, res;
  short res_ref[16];
  int i, j, sign = 1;
  int fail = 0;

  for (i = 0; i < 10; i++)
    {
      for (j = 0; j < 16; j++)
	{
	  s1.a[j] = j * i * sign;
	  s2.a[j] = (i + 2000) * sign;
	  sign = -sign;
	}

      res.x = _mm256_min_epi16 (s1.x, s2.x);

      compute_pminsw256 (s1.a, s2.a, res_ref);

      fail += check_union256i_w (res, res_ref);
    }

  if (fail != 0)
    abort ();
}
Exemplo n.º 2
0
static INLINE __m256i calc_mask_d16_avx2(const __m256i *data_src0,
                                         const __m256i *data_src1,
                                         const __m256i *round_const,
                                         const __m256i *mask_base_16,
                                         const __m256i *clip_diff, int round) {
  const __m256i diffa = _mm256_subs_epu16(*data_src0, *data_src1);
  const __m256i diffb = _mm256_subs_epu16(*data_src1, *data_src0);
  const __m256i diff = _mm256_max_epu16(diffa, diffb);
  const __m256i diff_round =
      _mm256_srli_epi16(_mm256_adds_epu16(diff, *round_const), round);
  const __m256i diff_factor = _mm256_srli_epi16(diff_round, DIFF_FACTOR_LOG2);
  const __m256i diff_mask = _mm256_adds_epi16(diff_factor, *mask_base_16);
  const __m256i diff_clamp = _mm256_min_epi16(diff_mask, *clip_diff);
  return diff_clamp;
}
Exemplo n.º 3
0
void av1_build_compound_diffwtd_mask_highbd_avx2(
    uint8_t *mask, DIFFWTD_MASK_TYPE mask_type, const uint8_t *src0,
    int src0_stride, const uint8_t *src1, int src1_stride, int h, int w,
    int bd) {
  if (w < 16) {
    av1_build_compound_diffwtd_mask_highbd_ssse3(
        mask, mask_type, src0, src0_stride, src1, src1_stride, h, w, bd);
  } else {
    assert(mask_type == DIFFWTD_38 || mask_type == DIFFWTD_38_INV);
    assert(bd >= 8);
    assert((w % 16) == 0);
    const __m256i y0 = _mm256_setzero_si256();
    const __m256i yAOM_BLEND_A64_MAX_ALPHA =
        _mm256_set1_epi16(AOM_BLEND_A64_MAX_ALPHA);
    const int mask_base = 38;
    const __m256i ymask_base = _mm256_set1_epi16(mask_base);
    const uint16_t *ssrc0 = CONVERT_TO_SHORTPTR(src0);
    const uint16_t *ssrc1 = CONVERT_TO_SHORTPTR(src1);
    if (bd == 8) {
      if (mask_type == DIFFWTD_38_INV) {
        for (int i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            __m256i s0 = _mm256_loadu_si256((const __m256i *)&ssrc0[j]);
            __m256i s1 = _mm256_loadu_si256((const __m256i *)&ssrc1[j]);
            __m256i diff = _mm256_srai_epi16(
                _mm256_abs_epi16(_mm256_sub_epi16(s0, s1)), DIFF_FACTOR_LOG2);
            __m256i m = _mm256_min_epi16(
                _mm256_max_epi16(y0, _mm256_add_epi16(diff, ymask_base)),
                yAOM_BLEND_A64_MAX_ALPHA);
            m = _mm256_sub_epi16(yAOM_BLEND_A64_MAX_ALPHA, m);
            m = _mm256_packus_epi16(m, m);
            m = _mm256_permute4x64_epi64(m, _MM_SHUFFLE(0, 0, 2, 0));
            __m128i m0 = _mm256_castsi256_si128(m);
            _mm_storeu_si128((__m128i *)&mask[j], m0);
          }
          ssrc0 += src0_stride;
          ssrc1 += src1_stride;
          mask += w;
        }
      } else {
        for (int i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            __m256i s0 = _mm256_loadu_si256((const __m256i *)&ssrc0[j]);
            __m256i s1 = _mm256_loadu_si256((const __m256i *)&ssrc1[j]);
            __m256i diff = _mm256_srai_epi16(
                _mm256_abs_epi16(_mm256_sub_epi16(s0, s1)), DIFF_FACTOR_LOG2);
            __m256i m = _mm256_min_epi16(
                _mm256_max_epi16(y0, _mm256_add_epi16(diff, ymask_base)),
                yAOM_BLEND_A64_MAX_ALPHA);
            m = _mm256_packus_epi16(m, m);
            m = _mm256_permute4x64_epi64(m, _MM_SHUFFLE(0, 0, 2, 0));
            __m128i m0 = _mm256_castsi256_si128(m);
            _mm_storeu_si128((__m128i *)&mask[j], m0);
          }
          ssrc0 += src0_stride;
          ssrc1 += src1_stride;
          mask += w;
        }
      }
    } else {
      const __m128i xshift = xx_set1_64_from_32i(bd - 8 + DIFF_FACTOR_LOG2);
      if (mask_type == DIFFWTD_38_INV) {
        for (int i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            __m256i s0 = _mm256_loadu_si256((const __m256i *)&ssrc0[j]);
            __m256i s1 = _mm256_loadu_si256((const __m256i *)&ssrc1[j]);
            __m256i diff = _mm256_sra_epi16(
                _mm256_abs_epi16(_mm256_sub_epi16(s0, s1)), xshift);
            __m256i m = _mm256_min_epi16(
                _mm256_max_epi16(y0, _mm256_add_epi16(diff, ymask_base)),
                yAOM_BLEND_A64_MAX_ALPHA);
            m = _mm256_sub_epi16(yAOM_BLEND_A64_MAX_ALPHA, m);
            m = _mm256_packus_epi16(m, m);
            m = _mm256_permute4x64_epi64(m, _MM_SHUFFLE(0, 0, 2, 0));
            __m128i m0 = _mm256_castsi256_si128(m);
            _mm_storeu_si128((__m128i *)&mask[j], m0);
          }
          ssrc0 += src0_stride;
          ssrc1 += src1_stride;
          mask += w;
        }
      } else {
        for (int i = 0; i < h; ++i) {
          for (int j = 0; j < w; j += 16) {
            __m256i s0 = _mm256_loadu_si256((const __m256i *)&ssrc0[j]);
            __m256i s1 = _mm256_loadu_si256((const __m256i *)&ssrc1[j]);
            __m256i diff = _mm256_sra_epi16(
                _mm256_abs_epi16(_mm256_sub_epi16(s0, s1)), xshift);
            __m256i m = _mm256_min_epi16(
                _mm256_max_epi16(y0, _mm256_add_epi16(diff, ymask_base)),
                yAOM_BLEND_A64_MAX_ALPHA);
            m = _mm256_packus_epi16(m, m);
            m = _mm256_permute4x64_epi64(m, _MM_SHUFFLE(0, 0, 2, 0));
            __m128i m0 = _mm256_castsi256_si128(m);
            _mm_storeu_si128((__m128i *)&mask[j], m0);
          }
          ssrc0 += src0_stride;
          ssrc1 += src1_stride;
          mask += w;
        }
      }
    }
  }
}
Exemplo n.º 4
0
__m256i test_mm256_min_epi16(__m256i a, __m256i b) {
  // CHECK: @llvm.x86.avx2.pmins.w
  return _mm256_min_epi16(a, b);
}
Exemplo n.º 5
0
__m256i test_mm256_min_epi16(__m256i a, __m256i b) {
  // CHECK-LABEL: test_mm256_min_epi16
  // CHECK:       [[CMP:%.*]] = icmp slt <16 x i16> [[X:%.*]], [[Y:%.*]]
  // CHECK-NEXT:  select <16 x i1> [[CMP]], <16 x i16> [[X]], <16 x i16> [[Y]]
  return _mm256_min_epi16(a, b);
}
static void vpx_filter_block1d16_h8_avx2(const uint8_t *src_ptr,
                                         ptrdiff_t src_pixels_per_line,
                                         uint8_t *output_ptr,
                                         ptrdiff_t output_pitch,
                                         uint32_t output_height,
                                         const int16_t *filter) {
  __m128i filtersReg;
  __m256i addFilterReg64, filt1Reg, filt2Reg, filt3Reg, filt4Reg;
  __m256i firstFilters, secondFilters, thirdFilters, forthFilters;
  __m256i srcRegFilt32b1_1, srcRegFilt32b2_1, srcRegFilt32b2, srcRegFilt32b3;
  __m256i srcReg32b1, srcReg32b2, filtersReg32;
  unsigned int i;
  ptrdiff_t src_stride, dst_stride;

  // create a register with 0,64,0,64,0,64,0,64,0,64,0,64,0,64,0,64
  addFilterReg64 = _mm256_set1_epi32((int)0x0400040u);
  filtersReg = _mm_loadu_si128((const __m128i *)filter);
  // converting the 16 bit (short) to 8 bit (byte) and have the same data
  // in both lanes of 128 bit register.
  filtersReg =_mm_packs_epi16(filtersReg, filtersReg);
  // have the same data in both lanes of a 256 bit register
  filtersReg32 = MM256_BROADCASTSI128_SI256(filtersReg);

  // duplicate only the first 16 bits (first and second byte)
  // across 256 bit register
  firstFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x100u));
  // duplicate only the second 16 bits (third and forth byte)
  // across 256 bit register
  secondFilters = _mm256_shuffle_epi8(filtersReg32,
                  _mm256_set1_epi16(0x302u));
  // duplicate only the third 16 bits (fifth and sixth byte)
  // across 256 bit register
  thirdFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x504u));
  // duplicate only the forth 16 bits (seventh and eighth byte)
  // across 256 bit register
  forthFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x706u));

  filt1Reg = _mm256_load_si256((__m256i const *)filt1_global_avx2);
  filt2Reg = _mm256_load_si256((__m256i const *)filt2_global_avx2);
  filt3Reg = _mm256_load_si256((__m256i const *)filt3_global_avx2);
  filt4Reg = _mm256_load_si256((__m256i const *)filt4_global_avx2);

  // multiple the size of the source and destination stride by two
  src_stride = src_pixels_per_line << 1;
  dst_stride = output_pitch << 1;
  for (i = output_height; i > 1; i-=2) {
    // load the 2 strides of source
    srcReg32b1 = _mm256_castsi128_si256(
                 _mm_loadu_si128((const __m128i *)(src_ptr - 3)));
    srcReg32b1 = _mm256_inserti128_si256(srcReg32b1,
                 _mm_loadu_si128((const __m128i *)
                 (src_ptr+src_pixels_per_line-3)), 1);

    // filter the source buffer
    srcRegFilt32b1_1= _mm256_shuffle_epi8(srcReg32b1, filt1Reg);
    srcRegFilt32b2= _mm256_shuffle_epi8(srcReg32b1, filt4Reg);

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt32b1_1 = _mm256_maddubs_epi16(srcRegFilt32b1_1, firstFilters);
    srcRegFilt32b2 = _mm256_maddubs_epi16(srcRegFilt32b2, forthFilters);

    // add and saturate the results together
    srcRegFilt32b1_1 = _mm256_adds_epi16(srcRegFilt32b1_1, srcRegFilt32b2);

    // filter the source buffer
    srcRegFilt32b3= _mm256_shuffle_epi8(srcReg32b1, filt2Reg);
    srcRegFilt32b2= _mm256_shuffle_epi8(srcReg32b1, filt3Reg);

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt32b3 = _mm256_maddubs_epi16(srcRegFilt32b3, secondFilters);
    srcRegFilt32b2 = _mm256_maddubs_epi16(srcRegFilt32b2, thirdFilters);

    // add and saturate the results together
    srcRegFilt32b1_1 = _mm256_adds_epi16(srcRegFilt32b1_1,
                       _mm256_min_epi16(srcRegFilt32b3, srcRegFilt32b2));

    // reading 2 strides of the next 16 bytes
    // (part of it was being read by earlier read)
    srcReg32b2 = _mm256_castsi128_si256(
                 _mm_loadu_si128((const __m128i *)(src_ptr + 5)));
    srcReg32b2 = _mm256_inserti128_si256(srcReg32b2,
                 _mm_loadu_si128((const __m128i *)
                 (src_ptr+src_pixels_per_line+5)), 1);

    // add and saturate the results together
    srcRegFilt32b1_1 = _mm256_adds_epi16(srcRegFilt32b1_1,
                       _mm256_max_epi16(srcRegFilt32b3, srcRegFilt32b2));

    // filter the source buffer
    srcRegFilt32b2_1 = _mm256_shuffle_epi8(srcReg32b2, filt1Reg);
    srcRegFilt32b2 = _mm256_shuffle_epi8(srcReg32b2, filt4Reg);

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt32b2_1 = _mm256_maddubs_epi16(srcRegFilt32b2_1, firstFilters);
    srcRegFilt32b2 = _mm256_maddubs_epi16(srcRegFilt32b2, forthFilters);

    // add and saturate the results together
    srcRegFilt32b2_1 = _mm256_adds_epi16(srcRegFilt32b2_1, srcRegFilt32b2);

    // filter the source buffer
    srcRegFilt32b3= _mm256_shuffle_epi8(srcReg32b2, filt2Reg);
    srcRegFilt32b2= _mm256_shuffle_epi8(srcReg32b2, filt3Reg);

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt32b3 = _mm256_maddubs_epi16(srcRegFilt32b3, secondFilters);
    srcRegFilt32b2 = _mm256_maddubs_epi16(srcRegFilt32b2, thirdFilters);

    // add and saturate the results together
    srcRegFilt32b2_1 = _mm256_adds_epi16(srcRegFilt32b2_1,
                       _mm256_min_epi16(srcRegFilt32b3, srcRegFilt32b2));
    srcRegFilt32b2_1 = _mm256_adds_epi16(srcRegFilt32b2_1,
                       _mm256_max_epi16(srcRegFilt32b3, srcRegFilt32b2));


    srcRegFilt32b1_1 = _mm256_adds_epi16(srcRegFilt32b1_1, addFilterReg64);

    srcRegFilt32b2_1 = _mm256_adds_epi16(srcRegFilt32b2_1, addFilterReg64);

    // shift by 7 bit each 16 bit
    srcRegFilt32b1_1 = _mm256_srai_epi16(srcRegFilt32b1_1, 7);
    srcRegFilt32b2_1 = _mm256_srai_epi16(srcRegFilt32b2_1, 7);

    // shrink to 8 bit each 16 bits, the first lane contain the first
    // convolve result and the second lane contain the second convolve
    // result
    srcRegFilt32b1_1 = _mm256_packus_epi16(srcRegFilt32b1_1,
                                           srcRegFilt32b2_1);

    src_ptr+=src_stride;

    // save 16 bytes
    _mm_store_si128((__m128i*)output_ptr,
    _mm256_castsi256_si128(srcRegFilt32b1_1));

    // save the next 16 bits
    _mm_store_si128((__m128i*)(output_ptr+output_pitch),
    _mm256_extractf128_si256(srcRegFilt32b1_1, 1));
    output_ptr+=dst_stride;
  }

  // if the number of strides is odd.
  // process only 16 bytes
  if (i > 0) {
    __m128i srcReg1, srcReg2, srcRegFilt1_1, srcRegFilt2_1;
    __m128i srcRegFilt2, srcRegFilt3;

    srcReg1 = _mm_loadu_si128((const __m128i *)(src_ptr - 3));

    // filter the source buffer
    srcRegFilt1_1 = _mm_shuffle_epi8(srcReg1,
                    _mm256_castsi256_si128(filt1Reg));
    srcRegFilt2 = _mm_shuffle_epi8(srcReg1,
                  _mm256_castsi256_si128(filt4Reg));

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt1_1 = _mm_maddubs_epi16(srcRegFilt1_1,
                    _mm256_castsi256_si128(firstFilters));
    srcRegFilt2 = _mm_maddubs_epi16(srcRegFilt2,
                  _mm256_castsi256_si128(forthFilters));

    // add and saturate the results together
    srcRegFilt1_1 = _mm_adds_epi16(srcRegFilt1_1, srcRegFilt2);

    // filter the source buffer
    srcRegFilt3= _mm_shuffle_epi8(srcReg1,
                 _mm256_castsi256_si128(filt2Reg));
    srcRegFilt2= _mm_shuffle_epi8(srcReg1,
                 _mm256_castsi256_si128(filt3Reg));

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt3 = _mm_maddubs_epi16(srcRegFilt3,
                  _mm256_castsi256_si128(secondFilters));
    srcRegFilt2 = _mm_maddubs_epi16(srcRegFilt2,
                  _mm256_castsi256_si128(thirdFilters));

    // add and saturate the results together
    srcRegFilt1_1 = _mm_adds_epi16(srcRegFilt1_1,
                    _mm_min_epi16(srcRegFilt3, srcRegFilt2));

    // reading the next 16 bytes
    // (part of it was being read by earlier read)
    srcReg2 = _mm_loadu_si128((const __m128i *)(src_ptr + 5));

    // add and saturate the results together
    srcRegFilt1_1 = _mm_adds_epi16(srcRegFilt1_1,
                    _mm_max_epi16(srcRegFilt3, srcRegFilt2));

    // filter the source buffer
    srcRegFilt2_1 = _mm_shuffle_epi8(srcReg2,
                    _mm256_castsi256_si128(filt1Reg));
    srcRegFilt2 = _mm_shuffle_epi8(srcReg2,
                  _mm256_castsi256_si128(filt4Reg));

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt2_1 = _mm_maddubs_epi16(srcRegFilt2_1,
                    _mm256_castsi256_si128(firstFilters));
    srcRegFilt2 = _mm_maddubs_epi16(srcRegFilt2,
                  _mm256_castsi256_si128(forthFilters));

    // add and saturate the results together
    srcRegFilt2_1 = _mm_adds_epi16(srcRegFilt2_1, srcRegFilt2);

    // filter the source buffer
    srcRegFilt3 = _mm_shuffle_epi8(srcReg2,
                  _mm256_castsi256_si128(filt2Reg));
    srcRegFilt2 = _mm_shuffle_epi8(srcReg2,
                  _mm256_castsi256_si128(filt3Reg));

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt3 = _mm_maddubs_epi16(srcRegFilt3,
                  _mm256_castsi256_si128(secondFilters));
    srcRegFilt2 = _mm_maddubs_epi16(srcRegFilt2,
                  _mm256_castsi256_si128(thirdFilters));

    // add and saturate the results together
    srcRegFilt2_1 = _mm_adds_epi16(srcRegFilt2_1,
                    _mm_min_epi16(srcRegFilt3, srcRegFilt2));
    srcRegFilt2_1 = _mm_adds_epi16(srcRegFilt2_1,
                    _mm_max_epi16(srcRegFilt3, srcRegFilt2));


    srcRegFilt1_1 = _mm_adds_epi16(srcRegFilt1_1,
                    _mm256_castsi256_si128(addFilterReg64));

    srcRegFilt2_1 = _mm_adds_epi16(srcRegFilt2_1,
                    _mm256_castsi256_si128(addFilterReg64));

    // shift by 7 bit each 16 bit
    srcRegFilt1_1 = _mm_srai_epi16(srcRegFilt1_1, 7);
    srcRegFilt2_1 = _mm_srai_epi16(srcRegFilt2_1, 7);

    // shrink to 8 bit each 16 bits, the first lane contain the first
    // convolve result and the second lane contain the second convolve
    // result
    srcRegFilt1_1 = _mm_packus_epi16(srcRegFilt1_1, srcRegFilt2_1);

    // save 16 bytes
    _mm_store_si128((__m128i*)output_ptr, srcRegFilt1_1);
  }
}
static void vpx_filter_block1d16_v8_avx2(const uint8_t *src_ptr,
                                         ptrdiff_t src_pitch,
                                         uint8_t *output_ptr,
                                         ptrdiff_t out_pitch,
                                         uint32_t output_height,
                                         const int16_t *filter) {
  __m128i filtersReg;
  __m256i addFilterReg64;
  __m256i srcReg32b1, srcReg32b2, srcReg32b3, srcReg32b4, srcReg32b5;
  __m256i srcReg32b6, srcReg32b7, srcReg32b8, srcReg32b9, srcReg32b10;
  __m256i srcReg32b11, srcReg32b12, filtersReg32;
  __m256i firstFilters, secondFilters, thirdFilters, forthFilters;
  unsigned int i;
  ptrdiff_t src_stride, dst_stride;

  // create a register with 0,64,0,64,0,64,0,64,0,64,0,64,0,64,0,64
  addFilterReg64 = _mm256_set1_epi32((int)0x0400040u);
  filtersReg = _mm_loadu_si128((const __m128i *)filter);
  // converting the 16 bit (short) to  8 bit (byte) and have the
  // same data in both lanes of 128 bit register.
  filtersReg =_mm_packs_epi16(filtersReg, filtersReg);
  // have the same data in both lanes of a 256 bit register
  filtersReg32 = MM256_BROADCASTSI128_SI256(filtersReg);

  // duplicate only the first 16 bits (first and second byte)
  // across 256 bit register
  firstFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x100u));
  // duplicate only the second 16 bits (third and forth byte)
  // across 256 bit register
  secondFilters = _mm256_shuffle_epi8(filtersReg32,
                  _mm256_set1_epi16(0x302u));
  // duplicate only the third 16 bits (fifth and sixth byte)
  // across 256 bit register
  thirdFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x504u));
  // duplicate only the forth 16 bits (seventh and eighth byte)
  // across 256 bit register
  forthFilters = _mm256_shuffle_epi8(filtersReg32,
                 _mm256_set1_epi16(0x706u));

  // multiple the size of the source and destination stride by two
  src_stride = src_pitch << 1;
  dst_stride = out_pitch << 1;

  // load 16 bytes 7 times in stride of src_pitch
  srcReg32b1 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr)));
  srcReg32b2 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch)));
  srcReg32b3 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 2)));
  srcReg32b4 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 3)));
  srcReg32b5 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 4)));
  srcReg32b6 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 5)));
  srcReg32b7 = _mm256_castsi128_si256(
               _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 6)));

  // have each consecutive loads on the same 256 register
  srcReg32b1 = _mm256_inserti128_si256(srcReg32b1,
               _mm256_castsi256_si128(srcReg32b2), 1);
  srcReg32b2 = _mm256_inserti128_si256(srcReg32b2,
               _mm256_castsi256_si128(srcReg32b3), 1);
  srcReg32b3 = _mm256_inserti128_si256(srcReg32b3,
               _mm256_castsi256_si128(srcReg32b4), 1);
  srcReg32b4 = _mm256_inserti128_si256(srcReg32b4,
               _mm256_castsi256_si128(srcReg32b5), 1);
  srcReg32b5 = _mm256_inserti128_si256(srcReg32b5,
               _mm256_castsi256_si128(srcReg32b6), 1);
  srcReg32b6 = _mm256_inserti128_si256(srcReg32b6,
               _mm256_castsi256_si128(srcReg32b7), 1);

  // merge every two consecutive registers except the last one
  srcReg32b10 = _mm256_unpacklo_epi8(srcReg32b1, srcReg32b2);
  srcReg32b1 = _mm256_unpackhi_epi8(srcReg32b1, srcReg32b2);

  // save
  srcReg32b11 = _mm256_unpacklo_epi8(srcReg32b3, srcReg32b4);

  // save
  srcReg32b3 = _mm256_unpackhi_epi8(srcReg32b3, srcReg32b4);

  // save
  srcReg32b2 = _mm256_unpacklo_epi8(srcReg32b5, srcReg32b6);

  // save
  srcReg32b5 = _mm256_unpackhi_epi8(srcReg32b5, srcReg32b6);


  for (i = output_height; i > 1; i-=2) {
     // load the last 2 loads of 16 bytes and have every two
     // consecutive loads in the same 256 bit register
     srcReg32b8 = _mm256_castsi128_si256(
     _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 7)));
     srcReg32b7 = _mm256_inserti128_si256(srcReg32b7,
     _mm256_castsi256_si128(srcReg32b8), 1);
     srcReg32b9 = _mm256_castsi128_si256(
     _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 8)));
     srcReg32b8 = _mm256_inserti128_si256(srcReg32b8,
     _mm256_castsi256_si128(srcReg32b9), 1);

     // merge every two consecutive registers
     // save
     srcReg32b4 = _mm256_unpacklo_epi8(srcReg32b7, srcReg32b8);
     srcReg32b7 = _mm256_unpackhi_epi8(srcReg32b7, srcReg32b8);

     // multiply 2 adjacent elements with the filter and add the result
     srcReg32b10 = _mm256_maddubs_epi16(srcReg32b10, firstFilters);
     srcReg32b6 = _mm256_maddubs_epi16(srcReg32b4, forthFilters);

     // add and saturate the results together
     srcReg32b10 = _mm256_adds_epi16(srcReg32b10, srcReg32b6);

     // multiply 2 adjacent elements with the filter and add the result
     srcReg32b8 = _mm256_maddubs_epi16(srcReg32b11, secondFilters);
     srcReg32b12 = _mm256_maddubs_epi16(srcReg32b2, thirdFilters);

     // add and saturate the results together
     srcReg32b10 = _mm256_adds_epi16(srcReg32b10,
                   _mm256_min_epi16(srcReg32b8, srcReg32b12));
     srcReg32b10 = _mm256_adds_epi16(srcReg32b10,
                   _mm256_max_epi16(srcReg32b8, srcReg32b12));

     // multiply 2 adjacent elements with the filter and add the result
     srcReg32b1 = _mm256_maddubs_epi16(srcReg32b1, firstFilters);
     srcReg32b6 = _mm256_maddubs_epi16(srcReg32b7, forthFilters);

     srcReg32b1 = _mm256_adds_epi16(srcReg32b1, srcReg32b6);

     // multiply 2 adjacent elements with the filter and add the result
     srcReg32b8 = _mm256_maddubs_epi16(srcReg32b3, secondFilters);
     srcReg32b12 = _mm256_maddubs_epi16(srcReg32b5, thirdFilters);

     // add and saturate the results together
     srcReg32b1 = _mm256_adds_epi16(srcReg32b1,
                  _mm256_min_epi16(srcReg32b8, srcReg32b12));
     srcReg32b1 = _mm256_adds_epi16(srcReg32b1,
                  _mm256_max_epi16(srcReg32b8, srcReg32b12));

     srcReg32b10 = _mm256_adds_epi16(srcReg32b10, addFilterReg64);
     srcReg32b1 = _mm256_adds_epi16(srcReg32b1, addFilterReg64);

     // shift by 7 bit each 16 bit
     srcReg32b10 = _mm256_srai_epi16(srcReg32b10, 7);
     srcReg32b1 = _mm256_srai_epi16(srcReg32b1, 7);

     // shrink to 8 bit each 16 bits, the first lane contain the first
     // convolve result and the second lane contain the second convolve
     // result
     srcReg32b1 = _mm256_packus_epi16(srcReg32b10, srcReg32b1);

     src_ptr+=src_stride;

     // save 16 bytes
     _mm_store_si128((__m128i*)output_ptr,
     _mm256_castsi256_si128(srcReg32b1));

     // save the next 16 bits
     _mm_store_si128((__m128i*)(output_ptr+out_pitch),
     _mm256_extractf128_si256(srcReg32b1, 1));

     output_ptr+=dst_stride;

     // save part of the registers for next strides
     srcReg32b10 = srcReg32b11;
     srcReg32b1 = srcReg32b3;
     srcReg32b11 = srcReg32b2;
     srcReg32b3 = srcReg32b5;
     srcReg32b2 = srcReg32b4;
     srcReg32b5 = srcReg32b7;
     srcReg32b7 = srcReg32b9;
  }
  if (i > 0) {
    __m128i srcRegFilt1, srcRegFilt3, srcRegFilt4, srcRegFilt5;
    __m128i srcRegFilt6, srcRegFilt7, srcRegFilt8;
    // load the last 16 bytes
    srcRegFilt8 = _mm_loadu_si128((const __m128i *)(src_ptr + src_pitch * 7));

    // merge the last 2 results together
    srcRegFilt4 = _mm_unpacklo_epi8(
                  _mm256_castsi256_si128(srcReg32b7), srcRegFilt8);
    srcRegFilt7 = _mm_unpackhi_epi8(
                  _mm256_castsi256_si128(srcReg32b7), srcRegFilt8);

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt1 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b10),
                  _mm256_castsi256_si128(firstFilters));
    srcRegFilt4 = _mm_maddubs_epi16(srcRegFilt4,
                  _mm256_castsi256_si128(forthFilters));
    srcRegFilt3 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b1),
                  _mm256_castsi256_si128(firstFilters));
    srcRegFilt7 = _mm_maddubs_epi16(srcRegFilt7,
                  _mm256_castsi256_si128(forthFilters));

    // add and saturate the results together
    srcRegFilt1 = _mm_adds_epi16(srcRegFilt1, srcRegFilt4);
    srcRegFilt3 = _mm_adds_epi16(srcRegFilt3, srcRegFilt7);


    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt4 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b11),
                  _mm256_castsi256_si128(secondFilters));
    srcRegFilt5 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b3),
                  _mm256_castsi256_si128(secondFilters));

    // multiply 2 adjacent elements with the filter and add the result
    srcRegFilt6 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b2),
                  _mm256_castsi256_si128(thirdFilters));
    srcRegFilt7 = _mm_maddubs_epi16(_mm256_castsi256_si128(srcReg32b5),
                  _mm256_castsi256_si128(thirdFilters));

    // add and saturate the results together
    srcRegFilt1 = _mm_adds_epi16(srcRegFilt1,
                  _mm_min_epi16(srcRegFilt4, srcRegFilt6));
    srcRegFilt3 = _mm_adds_epi16(srcRegFilt3,
                  _mm_min_epi16(srcRegFilt5, srcRegFilt7));

    // add and saturate the results together
    srcRegFilt1 = _mm_adds_epi16(srcRegFilt1,
                  _mm_max_epi16(srcRegFilt4, srcRegFilt6));
    srcRegFilt3 = _mm_adds_epi16(srcRegFilt3,
                  _mm_max_epi16(srcRegFilt5, srcRegFilt7));


    srcRegFilt1 = _mm_adds_epi16(srcRegFilt1,
                  _mm256_castsi256_si128(addFilterReg64));
    srcRegFilt3 = _mm_adds_epi16(srcRegFilt3,
                  _mm256_castsi256_si128(addFilterReg64));

    // shift by 7 bit each 16 bit
    srcRegFilt1 = _mm_srai_epi16(srcRegFilt1, 7);
    srcRegFilt3 = _mm_srai_epi16(srcRegFilt3, 7);

    // shrink to 8 bit each 16 bits, the first lane contain the first
    // convolve result and the second lane contain the second convolve
    // result
    srcRegFilt1 = _mm_packus_epi16(srcRegFilt1, srcRegFilt3);

    // save 16 bytes
    _mm_store_si128((__m128i*)output_ptr, srcRegFilt1);
  }
}