/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include <immintrin.h>

#include <qnnpack/q8gemm.h>


void q8gemm_ukernel_4x4c2__sse2(
    size_t mr,
    size_t nr,
    size_t k,
    const uint8_t* restrict a,
    size_t a_stride,
    const void* restrict w,
    uint8_t* restrict c,
    size_t c_stride,
    const union qnnp_conv_quantization_params quantization_params[RESTRICT_STATIC 1])
{
  __m128i vacc0x0123 = _mm_loadu_si128((const __m128i*) w);
  __m128i vacc1x0123 = vacc0x0123;
  __m128i vacc2x0123 = vacc0x0123;
  __m128i vacc3x0123 = vacc0x0123;
  w = (const void*) ((uintptr_t) w + 16);

  const uint8_t* a0 = a;
  const uint8_t* a1 = (const uint8_t*) ((uintptr_t) a0 + a_stride);
  if (mr < 2) {
    a1 = a0;
  }
  const uint8_t* a2 = (const uint8_t*) ((uintptr_t) a1 + a_stride);
  if (mr <= 2) {
    a2 = a1;
  }
  const uint8_t* a3 = (const uint8_t*) ((uintptr_t) a2 + a_stride);
  if (mr != 4) {
    a3 = a2;
  }

  const __m128i vb_zero_point = _mm_load_si128((const __m128i*) quantization_params->sse2.kernel_zero_point);
  const __m128i vzero = _mm_setzero_si128();
  for (; k >= 8; k -= 8) {
    const __m128i va0 = _mm_loadl_epi64((const __m128i*) a0);
    const __m128i vxa0 = _mm_unpacklo_epi8(va0, vzero);
    a0 += 8;
    const __m128i va1 = _mm_loadl_epi64((const __m128i*) a1);
    const __m128i vxa1 = _mm_unpacklo_epi8(va1, vzero);
    a1 += 8;
    const __m128i va2 = _mm_loadl_epi64((const __m128i*) a2);
    const __m128i vxa2 = _mm_unpacklo_epi8(va2, vzero);
    a2 += 8;
    const __m128i va3 = _mm_loadl_epi64((const __m128i*) a3);
    const __m128i vxa3 = _mm_unpacklo_epi8(va3, vzero);
    a3 += 8;

    const __m128i vb0 = _mm_loadl_epi64((const __m128i*) w);
    const __m128i vxb0 = _mm_sub_epi16(_mm_unpacklo_epi8(vb0, vzero), vb_zero_point);

    vacc0x0123 = _mm_add_epi32(vacc0x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc1x0123 = _mm_add_epi32(vacc1x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc2x0123 = _mm_add_epi32(vacc2x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc3x0123 = _mm_add_epi32(vacc3x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));

    const __m128i vb1 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 8));
    const __m128i vxb1 = _mm_sub_epi16(_mm_unpacklo_epi8(vb1, vzero), vb_zero_point);

    vacc0x0123 = _mm_add_epi32(vacc0x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
    vacc1x0123 = _mm_add_epi32(vacc1x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
    vacc2x0123 = _mm_add_epi32(vacc2x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
    vacc3x0123 = _mm_add_epi32(vacc3x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));

    const __m128i vb2 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 16));
    const __m128i vxb2 = _mm_sub_epi16(_mm_unpacklo_epi8(vb2, vzero), vb_zero_point);

    vacc0x0123 = _mm_add_epi32(vacc0x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
    vacc1x0123 = _mm_add_epi32(vacc1x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
    vacc2x0123 = _mm_add_epi32(vacc2x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
    vacc3x0123 = _mm_add_epi32(vacc3x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));

    const __m128i vb3 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 24));
    const __m128i vxb3 = _mm_sub_epi16(_mm_unpacklo_epi8(vb3, vzero), vb_zero_point);
    w = (const void*) ((uintptr_t) w + 32);

    vacc0x0123 = _mm_add_epi32(vacc0x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
    vacc1x0123 = _mm_add_epi32(vacc1x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
    vacc2x0123 = _mm_add_epi32(vacc2x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
    vacc3x0123 = _mm_add_epi32(vacc3x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
  }
  if (k != 0) {
    const size_t a_predecrement = 8 - k;
    const __m128i va_shift = _mm_cvtsi32_si128(8 * a_predecrement);

    const __m128i va0 = _mm_srl_epi64(_mm_loadl_epi64((const __m128i*) (a0 - a_predecrement)), va_shift);
    const __m128i vxa0 = _mm_unpacklo_epi8(va0, vzero);
    const __m128i va1 = _mm_srl_epi64(_mm_loadl_epi64((const __m128i*) (a1 - a_predecrement)), va_shift);
    const __m128i vxa1 = _mm_unpacklo_epi8(va1, vzero);
    const __m128i va2 = _mm_srl_epi64(_mm_loadl_epi64((const __m128i*) (a2 - a_predecrement)), va_shift);
    const __m128i vxa2 = _mm_unpacklo_epi8(va2, vzero);
    const __m128i va3 = _mm_srl_epi64(_mm_loadl_epi64((const __m128i*) (a3 - a_predecrement)), va_shift);
    const __m128i vxa3 = _mm_unpacklo_epi8(va3, vzero);

    const __m128i vb0 = _mm_loadl_epi64((const __m128i*) w);
    const __m128i vxb0 = _mm_sub_epi16(_mm_unpacklo_epi8(vb0, vzero), vb_zero_point);

    vacc0x0123 = _mm_add_epi32(vacc0x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc1x0123 = _mm_add_epi32(vacc1x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc2x0123 = _mm_add_epi32(vacc2x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));
    vacc3x0123 = _mm_add_epi32(vacc3x0123,
      _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(0, 0, 0, 0)), vxb0));

    if (k > 2) {
      const __m128i vb1 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 8));
      const __m128i vxb1 = _mm_sub_epi16(_mm_unpacklo_epi8(vb1, vzero), vb_zero_point);

      vacc0x0123 = _mm_add_epi32(vacc0x0123,
        _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
      vacc1x0123 = _mm_add_epi32(vacc1x0123,
        _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
      vacc2x0123 = _mm_add_epi32(vacc2x0123,
        _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));
      vacc3x0123 = _mm_add_epi32(vacc3x0123,
        _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(1, 1, 1, 1)), vxb1));

      if (k > 4) {
        const __m128i vb2 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 16));
        const __m128i vxb2 = _mm_sub_epi16(_mm_unpacklo_epi8(vb2, vzero), vb_zero_point);

        vacc0x0123 = _mm_add_epi32(vacc0x0123,
          _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
        vacc1x0123 = _mm_add_epi32(vacc1x0123,
          _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
        vacc2x0123 = _mm_add_epi32(vacc2x0123,
          _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));
        vacc3x0123 = _mm_add_epi32(vacc3x0123,
          _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(2, 2, 2, 2)), vxb2));

        if (k > 6) {
          const __m128i vb3 = _mm_loadl_epi64((const __m128i*) ((uintptr_t) w + 24));
          const __m128i vxb3 = _mm_sub_epi16(_mm_unpacklo_epi8(vb3, vzero), vb_zero_point);

          vacc0x0123 = _mm_add_epi32(vacc0x0123,
            _mm_madd_epi16(_mm_shuffle_epi32(vxa0, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
          vacc1x0123 = _mm_add_epi32(vacc1x0123,
            _mm_madd_epi16(_mm_shuffle_epi32(vxa1, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
          vacc2x0123 = _mm_add_epi32(vacc2x0123,
            _mm_madd_epi16(_mm_shuffle_epi32(vxa2, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
          vacc3x0123 = _mm_add_epi32(vacc3x0123,
            _mm_madd_epi16(_mm_shuffle_epi32(vxa3, _MM_SHUFFLE(3, 3, 3, 3)), vxb3));
        }
      }
    }
  }

  const __m128i vmultiplier = _mm_load_si128((const __m128i*) quantization_params->sse2.multiplier);
  const __m128i vrounding = _mm_load_si128((const __m128i*) quantization_params->sse2.rounding);

  const __m128i vnmask0x0123 = _mm_cmpgt_epi32(_mm_setzero_si128(), vacc0x0123);
  const __m128i vnmask1x0123 = _mm_cmpgt_epi32(_mm_setzero_si128(), vacc1x0123);
  const __m128i vnmask2x0123 = _mm_cmpgt_epi32(_mm_setzero_si128(), vacc2x0123);
  const __m128i vnmask3x0123 = _mm_cmpgt_epi32(_mm_setzero_si128(), vacc3x0123);

  const __m128i vabsacc0x0123 = _mm_sub_epi32(_mm_xor_si128(vacc0x0123, vnmask0x0123), vnmask0x0123);
  const __m128i vabsacc1x0123 = _mm_sub_epi32(_mm_xor_si128(vacc1x0123, vnmask1x0123), vnmask1x0123);
  const __m128i vabsacc2x0123 = _mm_sub_epi32(_mm_xor_si128(vacc2x0123, vnmask2x0123), vnmask2x0123);
  const __m128i vabsacc3x0123 = _mm_sub_epi32(_mm_xor_si128(vacc3x0123, vnmask3x0123), vnmask3x0123);

  const __m128i vabsacc0x1032 = _mm_shuffle_epi32(vabsacc0x0123, _MM_SHUFFLE(2, 3, 0, 1));
  const __m128i vabsacc1x1032 = _mm_shuffle_epi32(vabsacc1x0123, _MM_SHUFFLE(2, 3, 0, 1));
  const __m128i vabsacc2x1032 = _mm_shuffle_epi32(vabsacc2x0123, _MM_SHUFFLE(2, 3, 0, 1));
  const __m128i vabsacc3x1032 = _mm_shuffle_epi32(vabsacc3x0123, _MM_SHUFFLE(2, 3, 0, 1));

  const __m128i vabsprod0x02 = _mm_mul_epu32(vabsacc0x0123, vmultiplier);
  const __m128i vabsprod1x02 = _mm_mul_epu32(vabsacc1x0123, vmultiplier);
  const __m128i vabsprod2x02 = _mm_mul_epu32(vabsacc2x0123, vmultiplier);
  const __m128i vabsprod3x02 = _mm_mul_epu32(vabsacc3x0123, vmultiplier);

  const __m128i vnmask0x02 = _mm_shuffle_epi32(vnmask0x0123, _MM_SHUFFLE(2, 2, 0, 0));
  const __m128i vnmask1x02 = _mm_shuffle_epi32(vnmask1x0123, _MM_SHUFFLE(2, 2, 0, 0));
  const __m128i vnmask2x02 = _mm_shuffle_epi32(vnmask2x0123, _MM_SHUFFLE(2, 2, 0, 0));
  const __m128i vnmask3x02 = _mm_shuffle_epi32(vnmask3x0123, _MM_SHUFFLE(2, 2, 0, 0));

  const __m128i vprod0x02 = _mm_sub_epi64(_mm_xor_si128(vabsprod0x02, vnmask0x02), vnmask0x02);
  const __m128i vprod1x02 = _mm_sub_epi64(_mm_xor_si128(vabsprod1x02, vnmask1x02), vnmask1x02);
  const __m128i vprod2x02 = _mm_sub_epi64(_mm_xor_si128(vabsprod2x02, vnmask2x02), vnmask2x02);
  const __m128i vprod3x02 = _mm_sub_epi64(_mm_xor_si128(vabsprod3x02, vnmask3x02), vnmask3x02);

  const __m128i vq31prod0x02 = _mm_srli_epi64(_mm_add_epi64(vprod0x02, vrounding), 31);
  const __m128i vq31prod1x02 = _mm_srli_epi64(_mm_add_epi64(vprod1x02, vrounding), 31);
  const __m128i vq31prod2x02 = _mm_srli_epi64(_mm_add_epi64(vprod2x02, vrounding), 31);
  const __m128i vq31prod3x02 = _mm_srli_epi64(_mm_add_epi64(vprod3x02, vrounding), 31);

  const __m128i vabsprod0x13 = _mm_mul_epu32(vabsacc0x1032, vmultiplier);
  const __m128i vabsprod1x13 = _mm_mul_epu32(vabsacc1x1032, vmultiplier);
  const __m128i vabsprod2x13 = _mm_mul_epu32(vabsacc2x1032, vmultiplier);
  const __m128i vabsprod3x13 = _mm_mul_epu32(vabsacc3x1032, vmultiplier);

  const __m128i vnmask0x13 = _mm_shuffle_epi32(vnmask0x0123, _MM_SHUFFLE(3, 3, 1, 1));
  const __m128i vnmask1x13 = _mm_shuffle_epi32(vnmask1x0123, _MM_SHUFFLE(3, 3, 1, 1));
  const __m128i vnmask2x13 = _mm_shuffle_epi32(vnmask2x0123, _MM_SHUFFLE(3, 3, 1, 1));
  const __m128i vnmask3x13 = _mm_shuffle_epi32(vnmask3x0123, _MM_SHUFFLE(3, 3, 1, 1));

  const __m128i vprod0x13 = _mm_sub_epi64(_mm_xor_si128(vabsprod0x13, vnmask0x13), vnmask0x13);
  const __m128i vprod1x13 = _mm_sub_epi64(_mm_xor_si128(vabsprod1x13, vnmask1x13), vnmask1x13);
  const __m128i vprod2x13 = _mm_sub_epi64(_mm_xor_si128(vabsprod2x13, vnmask2x13), vnmask2x13);
  const __m128i vprod3x13 = _mm_sub_epi64(_mm_xor_si128(vabsprod3x13, vnmask3x13), vnmask3x13);

  const __m128i vq31prod0x13 = _mm_srli_epi64(_mm_add_epi64(vprod0x13, vrounding), 31);
  const __m128i vq31prod1x13 = _mm_srli_epi64(_mm_add_epi64(vprod1x13, vrounding), 31);
  const __m128i vq31prod2x13 = _mm_srli_epi64(_mm_add_epi64(vprod2x13, vrounding), 31);
  const __m128i vq31prod3x13 = _mm_srli_epi64(_mm_add_epi64(vprod3x13, vrounding), 31);

  const __m128i vq31prod0x0213 = _mm_castps_si128(_mm_shuffle_ps(
      _mm_castsi128_ps(vq31prod0x02), _mm_castsi128_ps(vq31prod0x13), _MM_SHUFFLE(2, 0, 2, 0)));
  const __m128i vq31prod1x0213 = _mm_castps_si128(_mm_shuffle_ps(
      _mm_castsi128_ps(vq31prod1x02), _mm_castsi128_ps(vq31prod1x13), _MM_SHUFFLE(2, 0, 2, 0)));
  const __m128i vq31prod2x0213 = _mm_castps_si128(_mm_shuffle_ps(
      _mm_castsi128_ps(vq31prod2x02), _mm_castsi128_ps(vq31prod2x13), _MM_SHUFFLE(2, 0, 2, 0)));
  const __m128i vq31prod3x0213 = _mm_castps_si128(_mm_shuffle_ps(
      _mm_castsi128_ps(vq31prod3x02), _mm_castsi128_ps(vq31prod3x13), _MM_SHUFFLE(2, 0, 2, 0)));

  const __m128i vq31prod0x0123 = _mm_shuffle_epi32(vq31prod0x0213, _MM_SHUFFLE(3, 1, 2, 0));
  const __m128i vq31prod1x0123 = _mm_shuffle_epi32(vq31prod1x0213, _MM_SHUFFLE(3, 1, 2, 0));
  const __m128i vq31prod2x0123 = _mm_shuffle_epi32(vq31prod2x0213, _MM_SHUFFLE(3, 1, 2, 0));
  const __m128i vq31prod3x0123 = _mm_shuffle_epi32(vq31prod3x0213, _MM_SHUFFLE(3, 1, 2, 0));

  const __m128i vremainder_mask = _mm_load_si128((const __m128i*) quantization_params->sse2.remainder_mask);
  
  const __m128i vrem0x0123 =
    _mm_add_epi32(_mm_and_si128(vq31prod0x0123, vremainder_mask), _mm_cmpgt_epi32(_mm_setzero_si128(), vq31prod0x0123));
  const __m128i vrem1x0123 =
    _mm_add_epi32(_mm_and_si128(vq31prod1x0123, vremainder_mask), _mm_cmpgt_epi32(_mm_setzero_si128(), vq31prod1x0123));
  const __m128i vrem2x0123 =
    _mm_add_epi32(_mm_and_si128(vq31prod2x0123, vremainder_mask), _mm_cmpgt_epi32(_mm_setzero_si128(), vq31prod2x0123));
  const __m128i vrem3x0123 =
    _mm_add_epi32(_mm_and_si128(vq31prod3x0123, vremainder_mask), _mm_cmpgt_epi32(_mm_setzero_si128(), vq31prod3x0123));

  const __m128i vremainder_threshold = _mm_load_si128((const __m128i*) quantization_params->sse2.remainder_threshold);
  const __m128i vshift = _mm_load_si128((const __m128i*) quantization_params->sse2.shift);

  vacc0x0123 = 
    _mm_sub_epi32(_mm_sra_epi32(vq31prod0x0123, vshift), _mm_cmpgt_epi32(vrem0x0123, vremainder_threshold));
  vacc1x0123 = 
    _mm_sub_epi32(_mm_sra_epi32(vq31prod1x0123, vshift), _mm_cmpgt_epi32(vrem1x0123, vremainder_threshold));
  vacc2x0123 = 
    _mm_sub_epi32(_mm_sra_epi32(vq31prod2x0123, vshift), _mm_cmpgt_epi32(vrem2x0123, vremainder_threshold));
  vacc3x0123 = 
    _mm_sub_epi32(_mm_sra_epi32(vq31prod3x0123, vshift), _mm_cmpgt_epi32(vrem3x0123, vremainder_threshold));

  const __m128i voutput_zero_point = _mm_load_si128((const __m128i*) quantization_params->sse2.output_zero_point);
  const __m128i vacc01x0123 = _mm_adds_epi16(_mm_packs_epi32(vacc0x0123, vacc1x0123), voutput_zero_point);
  const __m128i vacc23x0123 = _mm_adds_epi16(_mm_packs_epi32(vacc2x0123, vacc3x0123), voutput_zero_point);
  __m128i vout = _mm_packus_epi16(vacc01x0123, vacc23x0123);
  vout = _mm_min_epu8(vout, _mm_load_si128((const __m128i*) quantization_params->sse2.output_max));
  vout = _mm_max_epu8(vout, _mm_load_si128((const __m128i*) quantization_params->sse2.output_min));

  uint8_t* c0 = c;
  uint8_t* c1 = (uint8_t*) ((uintptr_t) c0 + c_stride);
  if (mr < 2) {
    c1 = c0;
  }
  uint8_t* c2 = (uint8_t*) ((uintptr_t) c1 + c_stride);
  if (mr <= 2) {
    c2 = c1;
  }
  uint8_t* c3 = (uint8_t*) ((uintptr_t) c2 + c_stride);
  if (mr != 4) {
    c3 = c2;
  }
  if (nr == 4) {
    *((uint32_t*) c0) = (uint32_t) _mm_cvtsi128_si32(vout);
    *((uint32_t*) c1) = (uint32_t) _mm_cvtsi128_si32(_mm_srli_epi64(vout, 32));
    *((uint32_t*) c2) = (uint32_t) _mm_cvtsi128_si32(_mm_unpackhi_epi32(vout, vout));
    *((uint32_t*) c3) = (uint32_t) _mm_cvtsi128_si32(_mm_srli_si128(vout, 12));
  } else {
    if (nr >= 2) {
      *((uint16_t*) c0) = (uint16_t) _mm_extract_epi16(vout, 0);
      c0 += 2;
      *((uint16_t*) c1) = (uint16_t) _mm_extract_epi16(vout, 2);
      c1 += 2;
      *((uint16_t*) c2) = (uint16_t) _mm_extract_epi16(vout, 4);
      c2 += 2;
      *((uint16_t*) c3) = (uint16_t) _mm_extract_epi16(vout, 6);
      c3 += 2;
      vout = _mm_srli_epi32(vout, 16);
      nr -= 2;
    }
    if (nr != 0) {
      *((uint8_t*) c0) = (uint8_t) _mm_cvtsi128_si32(vout);
      *((uint8_t*) c1) = (uint8_t) _mm_extract_epi16(vout, 2);
      *((uint8_t*) c2) = (uint8_t) _mm_extract_epi16(vout, 4);
      *((uint8_t*) c3) = (uint8_t) _mm_extract_epi16(vout, 6);
    }
  }
}
