/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <emmintrin.h>  // SSE2

#include "./vpx_config.h"
#include "./vpx_dsp_rtcd.h"

#include "vpx_ports/mem.h"

typedef void (*getNxMvar_fn_t) (const unsigned char *src, int src_stride,
                                const unsigned char *ref, int ref_stride,
                                unsigned int *sse, int *sum);

unsigned int vpx_get_mb_ss_sse2(const int16_t *src) {
  __m128i vsum = _mm_setzero_si128();
  int i;

  for (i = 0; i < 32; ++i) {
    const __m128i v = _mm_loadu_si128((const __m128i *)src);
    vsum = _mm_add_epi32(vsum, _mm_madd_epi16(v, v));
    src += 8;
  }

  vsum = _mm_add_epi32(vsum, _mm_srli_si128(vsum, 8));
  vsum = _mm_add_epi32(vsum, _mm_srli_si128(vsum, 4));
  return  _mm_cvtsi128_si32(vsum);
}

#define READ64(p, stride, i) \
  _mm_unpacklo_epi8(_mm_cvtsi32_si128(*(const uint32_t *)(p + i * stride)), \
      _mm_cvtsi32_si128(*(const uint32_t *)(p + (i + 1) * stride)))

static void get4x4var_sse2(const uint8_t *src, int src_stride,
                           const uint8_t *ref, int ref_stride,
                           unsigned int *sse, int *sum) {
  const __m128i zero = _mm_setzero_si128();
  const __m128i src0 = _mm_unpacklo_epi8(READ64(src, src_stride, 0), zero);
  const __m128i src1 = _mm_unpacklo_epi8(READ64(src, src_stride, 2), zero);
  const __m128i ref0 = _mm_unpacklo_epi8(READ64(ref, ref_stride, 0), zero);
  const __m128i ref1 = _mm_unpacklo_epi8(READ64(ref, ref_stride, 2), zero);
  const __m128i diff0 = _mm_sub_epi16(src0, ref0);
  const __m128i diff1 = _mm_sub_epi16(src1, ref1);

  // sum
  __m128i vsum = _mm_add_epi16(diff0, diff1);
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 8));
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 4));
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 2));
  *sum = (int16_t)_mm_extract_epi16(vsum, 0);

  // sse
  vsum = _mm_add_epi32(_mm_madd_epi16(diff0, diff0),
                       _mm_madd_epi16(diff1, diff1));
  vsum = _mm_add_epi32(vsum, _mm_srli_si128(vsum, 8));
  vsum = _mm_add_epi32(vsum, _mm_srli_si128(vsum, 4));
  *sse = _mm_cvtsi128_si32(vsum);
}

void vpx_get8x8var_sse2(const uint8_t *src, int src_stride,
                        const uint8_t *ref, int ref_stride,
                        unsigned int *sse, int *sum) {
  const __m128i zero = _mm_setzero_si128();
  __m128i vsum = _mm_setzero_si128();
  __m128i vsse = _mm_setzero_si128();
  int i;

  for (i = 0; i < 8; i += 2) {
    const __m128i src0 = _mm_unpacklo_epi8(_mm_loadl_epi64(
        (const __m128i *)(src + i * src_stride)), zero);
    const __m128i ref0 = _mm_unpacklo_epi8(_mm_loadl_epi64(
        (const __m128i *)(ref + i * ref_stride)), zero);
    const __m128i diff0 = _mm_sub_epi16(src0, ref0);

    const __m128i src1 = _mm_unpacklo_epi8(_mm_loadl_epi64(
        (const __m128i *)(src + (i + 1) * src_stride)), zero);
    const __m128i ref1 = _mm_unpacklo_epi8(_mm_loadl_epi64(
        (const __m128i *)(ref + (i + 1) * ref_stride)), zero);
    const __m128i diff1 = _mm_sub_epi16(src1, ref1);

    vsum = _mm_add_epi16(vsum, diff0);
    vsum = _mm_add_epi16(vsum, diff1);
    vsse = _mm_add_epi32(vsse, _mm_madd_epi16(diff0, diff0));
    vsse = _mm_add_epi32(vsse, _mm_madd_epi16(diff1, diff1));
  }

  // sum
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 8));
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 4));
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 2));
  *sum = (int16_t)_mm_extract_epi16(vsum, 0);

  // sse
  vsse = _mm_add_epi32(vsse, _mm_srli_si128(vsse, 8));
  vsse = _mm_add_epi32(vsse, _mm_srli_si128(vsse, 4));
  *sse = _mm_cvtsi128_si32(vsse);
}

void vpx_get16x16var_sse2(const uint8_t *src, int src_stride,
                          const uint8_t *ref, int ref_stride,
                          unsigned int *sse, int *sum) {
  const __m128i zero = _mm_setzero_si128();
  __m128i vsum = _mm_setzero_si128();
  __m128i vsse = _mm_setzero_si128();
  int i;

  for (i = 0; i < 16; ++i) {
    const __m128i s = _mm_loadu_si128((const __m128i *)src);
    const __m128i r = _mm_loadu_si128((const __m128i *)ref);

    const __m128i src0 = _mm_unpacklo_epi8(s, zero);
    const __m128i ref0 = _mm_unpacklo_epi8(r, zero);
    const __m128i diff0 = _mm_sub_epi16(src0, ref0);

    const __m128i src1 = _mm_unpackhi_epi8(s, zero);
    const __m128i ref1 = _mm_unpackhi_epi8(r, zero);
    const __m128i diff1 = _mm_sub_epi16(src1, ref1);

    vsum = _mm_add_epi16(vsum, diff0);
    vsum = _mm_add_epi16(vsum, diff1);
    vsse = _mm_add_epi32(vsse, _mm_madd_epi16(diff0, diff0));
    vsse = _mm_add_epi32(vsse, _mm_madd_epi16(diff1, diff1));

    src += src_stride;
    ref += ref_stride;
  }

  // sum
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 8));
  vsum = _mm_add_epi16(vsum, _mm_srli_si128(vsum, 4));
  *sum = (int16_t)_mm_extract_epi16(vsum, 0) +
             (int16_t)_mm_extract_epi16(vsum, 1);

  // sse
  vsse = _mm_add_epi32(vsse, _mm_srli_si128(vsse, 8));
  vsse = _mm_add_epi32(vsse, _mm_srli_si128(vsse, 4));
  *sse = _mm_cvtsi128_si32(vsse);
}


static void variance_sse2(const unsigned char *src, int src_stride,
                          const unsigned char *ref, int ref_stride,
                          int w, int h, unsigned int *sse, int *sum,
                          getNxMvar_fn_t var_fn, int block_size) {
  int i, j;

  *sse = 0;
  *sum = 0;

  for (i = 0; i < h; i += block_size) {
    for (j = 0; j < w; j += block_size) {
      unsigned int sse0;
      int sum0;
      var_fn(src + src_stride * i + j, src_stride,
             ref + ref_stride * i + j, ref_stride, &sse0, &sum0);
      *sse += sse0;
      *sum += sum0;
    }
  }
}

unsigned int vpx_variance4x4_sse2(const unsigned char *src, int src_stride,
                                  const unsigned char *ref, int ref_stride,
                                  unsigned int *sse) {
  int sum;
  get4x4var_sse2(src, src_stride, ref, ref_stride, sse, &sum);
  return *sse - ((sum * sum) >> 4);
}

unsigned int vpx_variance8x4_sse2(const uint8_t *src, int src_stride,
                                  const uint8_t *ref, int ref_stride,
                                  unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 8, 4,
                sse, &sum, get4x4var_sse2, 4);
  return *sse - ((sum * sum) >> 5);
}

unsigned int vpx_variance4x8_sse2(const uint8_t *src, int src_stride,
                                  const uint8_t *ref, int ref_stride,
                                  unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 4, 8,
                sse, &sum, get4x4var_sse2, 4);
  return *sse - ((sum * sum) >> 5);
}

unsigned int vpx_variance8x8_sse2(const unsigned char *src, int src_stride,
                                  const unsigned char *ref, int ref_stride,
                                  unsigned int *sse) {
  int sum;
  vpx_get8x8var_sse2(src, src_stride, ref, ref_stride, sse, &sum);
  return *sse - ((sum * sum) >> 6);
}

unsigned int vpx_variance16x8_sse2(const unsigned char *src, int src_stride,
                                   const unsigned char *ref, int ref_stride,
                                   unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 16, 8,
                sse, &sum, vpx_get8x8var_sse2, 8);
  return *sse - ((sum * sum) >> 7);
}

unsigned int vpx_variance8x16_sse2(const unsigned char *src, int src_stride,
                                   const unsigned char *ref, int ref_stride,
                                   unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 8, 16,
                sse, &sum, vpx_get8x8var_sse2, 8);
  return *sse - ((sum * sum) >> 7);
}

unsigned int vpx_variance16x16_sse2(const unsigned char *src, int src_stride,
                                    const unsigned char *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  vpx_get16x16var_sse2(src, src_stride, ref, ref_stride, sse, &sum);
  return *sse - (((uint32_t)((int64_t)sum * sum)) >> 8);
}

unsigned int vpx_variance32x32_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 32, 32,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 10);
}

unsigned int vpx_variance32x16_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 32, 16,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 9);
}

unsigned int vpx_variance16x32_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 16, 32,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 9);
}

unsigned int vpx_variance64x64_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 64, 64,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 12);
}

unsigned int vpx_variance64x32_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 64, 32,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 11);
}

unsigned int vpx_variance32x64_sse2(const uint8_t *src, int src_stride,
                                    const uint8_t *ref, int ref_stride,
                                    unsigned int *sse) {
  int sum;
  variance_sse2(src, src_stride, ref, ref_stride, 32, 64,
                sse, &sum, vpx_get16x16var_sse2, 16);
  return *sse - (((int64_t)sum * sum) >> 11);
}

unsigned int vpx_mse8x8_sse2(const uint8_t *src, int src_stride,
                             const uint8_t *ref, int ref_stride,
                             unsigned int *sse) {
  vpx_variance8x8_sse2(src, src_stride, ref, ref_stride, sse);
  return *sse;
}

unsigned int vpx_mse8x16_sse2(const uint8_t *src, int src_stride,
                              const uint8_t *ref, int ref_stride,
                              unsigned int *sse) {
  vpx_variance8x16_sse2(src, src_stride, ref, ref_stride, sse);
  return *sse;
}

unsigned int vpx_mse16x8_sse2(const uint8_t *src, int src_stride,
                              const uint8_t *ref, int ref_stride,
                              unsigned int *sse) {
  vpx_variance16x8_sse2(src, src_stride, ref, ref_stride, sse);
  return *sse;
}

unsigned int vpx_mse16x16_sse2(const uint8_t *src, int src_stride,
                               const uint8_t *ref, int ref_stride,
                               unsigned int *sse) {
  vpx_variance16x16_sse2(src, src_stride, ref, ref_stride, sse);
  return *sse;
}

// The 2 unused parameters are place holders for PIC enabled build.
// These definitions are for functions defined in subpel_variance.asm
#define DECL(w, opt) \
  int vpx_sub_pixel_variance##w##xh_##opt(const uint8_t *src, \
                                          ptrdiff_t src_stride, \
                                          int x_offset, int y_offset, \
                                          const uint8_t *dst, \
                                          ptrdiff_t dst_stride, \
                                          int height, unsigned int *sse, \
                                          void *unused0, void *unused)
#define DECLS(opt1, opt2) \
  DECL(4, opt1); \
  DECL(8, opt1); \
  DECL(16, opt1)

DECLS(sse2, sse2);
DECLS(ssse3, ssse3);
#undef DECLS
#undef DECL

#define FN(w, h, wf, wlog2, hlog2, opt, cast_prod, cast) \
unsigned int vpx_sub_pixel_variance##w##x##h##_##opt(const uint8_t *src, \
                                                     int src_stride, \
                                                     int x_offset, \
                                                     int y_offset, \
                                                     const uint8_t *dst, \
                                                     int dst_stride, \
                                                     unsigned int *sse_ptr) { \
  unsigned int sse; \
  int se = vpx_sub_pixel_variance##wf##xh_##opt(src, src_stride, x_offset, \
                                                y_offset, dst, dst_stride, \
                                                h, &sse, NULL, NULL); \
  if (w > wf) { \
    unsigned int sse2; \
    int se2 = vpx_sub_pixel_variance##wf##xh_##opt(src + 16, src_stride, \
                                                   x_offset, y_offset, \
                                                   dst + 16, dst_stride, \
                                                   h, &sse2, NULL, NULL); \
    se += se2; \
    sse += sse2; \
    if (w > wf * 2) { \
      se2 = vpx_sub_pixel_variance##wf##xh_##opt(src + 32, src_stride, \
                                                 x_offset, y_offset, \
                                                 dst + 32, dst_stride, \
                                                 h, &sse2, NULL, NULL); \
      se += se2; \
      sse += sse2; \
      se2 = vpx_sub_pixel_variance##wf##xh_##opt(src + 48, src_stride, \
                                                 x_offset, y_offset, \
                                                 dst + 48, dst_stride, \
                                                 h, &sse2, NULL, NULL); \
      se += se2; \
      sse += sse2; \
    } \
  } \
  *sse_ptr = sse; \
  return sse - (cast_prod (cast se * se) >> (wlog2 + hlog2)); \
}

#define FNS(opt1, opt2) \
FN(64, 64, 16, 6, 6, opt1, (int64_t), (int64_t)); \
FN(64, 32, 16, 6, 5, opt1, (int64_t), (int64_t)); \
FN(32, 64, 16, 5, 6, opt1, (int64_t), (int64_t)); \
FN(32, 32, 16, 5, 5, opt1, (int64_t), (int64_t)); \
FN(32, 16, 16, 5, 4, opt1, (int64_t), (int64_t)); \
FN(16, 32, 16, 4, 5, opt1, (int64_t), (int64_t)); \
FN(16, 16, 16, 4, 4, opt1, (uint32_t), (int64_t)); \
FN(16,  8, 16, 4, 3, opt1, (int32_t), (int32_t)); \
FN(8,  16,  8, 3, 4, opt1, (int32_t), (int32_t)); \
FN(8,   8,  8, 3, 3, opt1, (int32_t), (int32_t)); \
FN(8,   4,  8, 3, 2, opt1, (int32_t), (int32_t)); \
FN(4,   8,  4, 2, 3, opt1, (int32_t), (int32_t)); \
FN(4,   4,  4, 2, 2, opt1, (int32_t), (int32_t))

FNS(sse2, sse2);
FNS(ssse3, ssse3);

#undef FNS
#undef FN

// The 2 unused parameters are place holders for PIC enabled build.
#define DECL(w, opt) \
int vpx_sub_pixel_avg_variance##w##xh_##opt(const uint8_t *src, \
                                            ptrdiff_t src_stride, \
                                            int x_offset, int y_offset, \
                                            const uint8_t *dst, \
                                            ptrdiff_t dst_stride, \
                                            const uint8_t *sec, \
                                            ptrdiff_t sec_stride, \
                                            int height, unsigned int *sse, \
                                            void *unused0, void *unused)
#define DECLS(opt1, opt2) \
DECL(4, opt1); \
DECL(8, opt1); \
DECL(16, opt1)

DECLS(sse2, sse2);
DECLS(ssse3, ssse3);
#undef DECL
#undef DECLS

#define FN(w, h, wf, wlog2, hlog2, opt, cast_prod, cast) \
unsigned int vpx_sub_pixel_avg_variance##w##x##h##_##opt(const uint8_t *src, \
                                                         int src_stride, \
                                                         int x_offset, \
                                                         int y_offset, \
                                                         const uint8_t *dst, \
                                                         int dst_stride, \
                                                         unsigned int *sseptr, \
                                                         const uint8_t *sec) { \
  unsigned int sse; \
  int se = vpx_sub_pixel_avg_variance##wf##xh_##opt(src, src_stride, x_offset, \
                                                    y_offset, dst, dst_stride, \
                                                    sec, w, h, &sse, NULL, \
                                                    NULL); \
  if (w > wf) { \
    unsigned int sse2; \
    int se2 = vpx_sub_pixel_avg_variance##wf##xh_##opt(src + 16, src_stride, \
                                                       x_offset, y_offset, \
                                                       dst + 16, dst_stride, \
                                                       sec + 16, w, h, &sse2, \
                                                       NULL, NULL); \
    se += se2; \
    sse += sse2; \
    if (w > wf * 2) { \
      se2 = vpx_sub_pixel_avg_variance##wf##xh_##opt(src + 32, src_stride, \
                                                     x_offset, y_offset, \
                                                     dst + 32, dst_stride, \
                                                     sec + 32, w, h, &sse2, \
                                                     NULL, NULL); \
      se += se2; \
      sse += sse2; \
      se2 = vpx_sub_pixel_avg_variance##wf##xh_##opt(src + 48, src_stride, \
                                                     x_offset, y_offset, \
                                                     dst + 48, dst_stride, \
                                                     sec + 48, w, h, &sse2, \
                                                     NULL, NULL); \
      se += se2; \
      sse += sse2; \
    } \
  } \
  *sseptr = sse; \
  return sse - (cast_prod (cast se * se) >> (wlog2 + hlog2)); \
}

#define FNS(opt1, opt2) \
FN(64, 64, 16, 6, 6, opt1, (int64_t), (int64_t)); \
FN(64, 32, 16, 6, 5, opt1, (int64_t), (int64_t)); \
FN(32, 64, 16, 5, 6, opt1, (int64_t), (int64_t)); \
FN(32, 32, 16, 5, 5, opt1, (int64_t), (int64_t)); \
FN(32, 16, 16, 5, 4, opt1, (int64_t), (int64_t)); \
FN(16, 32, 16, 4, 5, opt1, (int64_t), (int64_t)); \
FN(16, 16, 16, 4, 4, opt1, (uint32_t), (int64_t)); \
FN(16,  8, 16, 4, 3, opt1, (uint32_t), (int32_t)); \
FN(8,  16,  8, 3, 4, opt1, (uint32_t), (int32_t)); \
FN(8,   8,  8, 3, 3, opt1, (uint32_t), (int32_t)); \
FN(8,   4,  8, 3, 2, opt1, (uint32_t), (int32_t)); \
FN(4,   8,  4, 2, 3, opt1, (uint32_t), (int32_t)); \
FN(4,   4,  4, 2, 2, opt1, (uint32_t), (int32_t))

FNS(sse2, sse);
FNS(ssse3, ssse3);

#undef FNS
#undef FN

void vpx_upsampled_pred_sse2(uint8_t *comp_pred,
                             int width, int height,
                             const uint8_t *ref,  int ref_stride) {
    int i, j;
    int stride = ref_stride << 3;

    if (width >= 16) {
      // read 16 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 16) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i s2 = _mm_loadu_si128((const __m128i *)(ref + 32));
          __m128i s3 = _mm_loadu_si128((const __m128i *)(ref + 48));
          __m128i s4 = _mm_loadu_si128((const __m128i *)(ref + 64));
          __m128i s5 = _mm_loadu_si128((const __m128i *)(ref + 80));
          __m128i s6 = _mm_loadu_si128((const __m128i *)(ref + 96));
          __m128i s7 = _mm_loadu_si128((const __m128i *)(ref + 112));
          __m128i t0, t1, t2, t3;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          t1 = _mm_unpacklo_epi8(s2, s3);
          s3 = _mm_unpackhi_epi8(s2, s3);
          t2 = _mm_unpacklo_epi8(s4, s5);
          s5 = _mm_unpackhi_epi8(s4, s5);
          t3 = _mm_unpacklo_epi8(s6, s7);
          s7 = _mm_unpackhi_epi8(s6, s7);

          s0 = _mm_unpacklo_epi8(t0, s1);
          s2 = _mm_unpacklo_epi8(t1, s3);
          s4 = _mm_unpacklo_epi8(t2, s5);
          s6 = _mm_unpacklo_epi8(t3, s7);
          s0 = _mm_unpacklo_epi32(s0, s2);
          s4 = _mm_unpacklo_epi32(s4, s6);
          s0 = _mm_unpacklo_epi64(s0, s4);

          _mm_storeu_si128((__m128i *)(comp_pred), s0);
          comp_pred += 16;
          ref += 16 * 8;
        }
        ref += stride - (width << 3);
      }
    } else if (width >= 8) {
      // read 8 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 8) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i s2 = _mm_loadu_si128((const __m128i *)(ref + 32));
          __m128i s3 = _mm_loadu_si128((const __m128i *)(ref + 48));
          __m128i t0, t1;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          t1 = _mm_unpacklo_epi8(s2, s3);
          s3 = _mm_unpackhi_epi8(s2, s3);

          s0 = _mm_unpacklo_epi8(t0, s1);
          s2 = _mm_unpacklo_epi8(t1, s3);
          s0 = _mm_unpacklo_epi32(s0, s2);

          _mm_storel_epi64((__m128i *)(comp_pred), s0);
          comp_pred += 8;
          ref += 8 * 8;
        }
        ref += stride - (width << 3);
      }
    } else {
      // read 4 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 4) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i t0;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          s0 = _mm_unpacklo_epi8(t0, s1);

          *(int *)comp_pred = _mm_cvtsi128_si32(s0);
          comp_pred += 4;
          ref += 4 * 8;
        }
        ref += stride - (width << 3);
      }
    }
}

void vpx_comp_avg_upsampled_pred_sse2(uint8_t *comp_pred, const uint8_t *pred,
                                      int width, int height,
                                      const uint8_t *ref,  int ref_stride) {
    const __m128i zero = _mm_set1_epi16(0);
    const __m128i one = _mm_set1_epi16(1);
    int i, j;
    int stride = ref_stride << 3;

    if (width >= 16) {
      // read 16 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 16) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i s2 = _mm_loadu_si128((const __m128i *)(ref + 32));
          __m128i s3 = _mm_loadu_si128((const __m128i *)(ref + 48));
          __m128i s4 = _mm_loadu_si128((const __m128i *)(ref + 64));
          __m128i s5 = _mm_loadu_si128((const __m128i *)(ref + 80));
          __m128i s6 = _mm_loadu_si128((const __m128i *)(ref + 96));
          __m128i s7 = _mm_loadu_si128((const __m128i *)(ref + 112));
          __m128i p0 = _mm_loadu_si128((const __m128i *)pred);
          __m128i p1;
          __m128i t0, t1, t2, t3;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          t1 = _mm_unpacklo_epi8(s2, s3);
          s3 = _mm_unpackhi_epi8(s2, s3);
          t2 = _mm_unpacklo_epi8(s4, s5);
          s5 = _mm_unpackhi_epi8(s4, s5);
          t3 = _mm_unpacklo_epi8(s6, s7);
          s7 = _mm_unpackhi_epi8(s6, s7);

          s0 = _mm_unpacklo_epi8(t0, s1);
          s2 = _mm_unpacklo_epi8(t1, s3);
          s4 = _mm_unpacklo_epi8(t2, s5);
          s6 = _mm_unpacklo_epi8(t3, s7);

          s0 = _mm_unpacklo_epi32(s0, s2);
          s4 = _mm_unpacklo_epi32(s4, s6);
          s0 = _mm_unpacklo_epi8(s0, zero);
          s4 = _mm_unpacklo_epi8(s4, zero);

          p1 = _mm_unpackhi_epi8(p0, zero);
          p0 = _mm_unpacklo_epi8(p0, zero);
          p0 = _mm_adds_epu16(s0, p0);
          p1 = _mm_adds_epu16(s4, p1);
          p0 = _mm_adds_epu16(p0, one);
          p1 = _mm_adds_epu16(p1, one);

          p0 = _mm_srli_epi16(p0, 1);
          p1 = _mm_srli_epi16(p1, 1);
          p0 = _mm_packus_epi16(p0, p1);

          _mm_storeu_si128((__m128i *)(comp_pred), p0);
          comp_pred += 16;
          pred += 16;
          ref += 16 * 8;
        }
        ref += stride - (width << 3);
      }
    } else if (width >= 8) {
      // read 8 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 8) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i s2 = _mm_loadu_si128((const __m128i *)(ref + 32));
          __m128i s3 = _mm_loadu_si128((const __m128i *)(ref + 48));
          __m128i p0 = _mm_loadl_epi64((const __m128i *)pred);
          __m128i t0, t1;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          t1 = _mm_unpacklo_epi8(s2, s3);
          s3 = _mm_unpackhi_epi8(s2, s3);

          s0 = _mm_unpacklo_epi8(t0, s1);
          s2 = _mm_unpacklo_epi8(t1, s3);
          s0 = _mm_unpacklo_epi32(s0, s2);
          s0 = _mm_unpacklo_epi8(s0, zero);

          p0 = _mm_unpacklo_epi8(p0, zero);
          p0 = _mm_adds_epu16(s0, p0);
          p0 = _mm_adds_epu16(p0, one);
          p0 = _mm_srli_epi16(p0, 1);
          p0 = _mm_packus_epi16(p0, zero);

          _mm_storel_epi64((__m128i *)(comp_pred), p0);
          comp_pred += 8;
          pred += 8;
          ref += 8 * 8;
        }
        ref += stride - (width << 3);
      }
    } else {
      // read 4 points at one time
      for (i = 0; i < height; i++) {
        for (j = 0; j < width; j+= 4) {
          __m128i s0 = _mm_loadu_si128((const __m128i *)ref);
          __m128i s1 = _mm_loadu_si128((const __m128i *)(ref + 16));
          __m128i p0 = _mm_cvtsi32_si128(*(const uint32_t *)pred);
          __m128i t0;

          t0 = _mm_unpacklo_epi8(s0, s1);
          s1 = _mm_unpackhi_epi8(s0, s1);
          s0 = _mm_unpacklo_epi8(t0, s1);
          s0 = _mm_unpacklo_epi8(s0, zero);

          p0 = _mm_unpacklo_epi8(p0, zero);
          p0 = _mm_adds_epu16(s0, p0);
          p0 = _mm_adds_epu16(p0, one);
          p0 = _mm_srli_epi16(p0, 1);
          p0 = _mm_packus_epi16(p0, zero);

          *(int *)comp_pred = _mm_cvtsi128_si32(p0);
          comp_pred += 4;
          pred += 4;
          ref += 4 * 8;
        }
        ref += stride - (width << 3);
      }
    }
}