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fwd_txfm_impl_sse2.h (24059B)


      1 /*
      2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
      3 *
      4 * This source code is subject to the terms of the BSD 2 Clause License and
      5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6 * was not distributed with this source code in the LICENSE file, you can
      7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8 * Media Patent License 1.0 was not distributed with this source code in the
      9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10 */
     11 
     12 #include <emmintrin.h>  // SSE2
     13 
     14 #include "config/aom_dsp_rtcd.h"
     15 
     16 #include "aom_dsp/txfm_common.h"
     17 #include "aom_dsp/x86/fwd_txfm_sse2.h"
     18 #include "aom_dsp/x86/txfm_common_sse2.h"
     19 #include "aom_ports/mem.h"
     20 
     21 // TODO(jingning) The high bit-depth functions need rework for performance.
     22 // After we properly fix the high bit-depth function implementations, this
     23 // file's dependency should be substantially simplified.
     24 #if DCT_HIGH_BIT_DEPTH
     25 #define ADD_EPI16 _mm_adds_epi16
     26 #define SUB_EPI16 _mm_subs_epi16
     27 
     28 #else
     29 #define ADD_EPI16 _mm_add_epi16
     30 #define SUB_EPI16 _mm_sub_epi16
     31 #endif
     32 
     33 #if defined(FDCT4x4_2D_HELPER)
     34 static void FDCT4x4_2D_HELPER(const int16_t *input, int stride, __m128i *in0,
     35                              __m128i *in1) {
     36  // Constants
     37  // These are the coefficients used for the multiplies.
     38  // In the comments, pN means cos(N pi /64) and mN is -cos(N pi /64),
     39  // where cospi_N_64 = cos(N pi /64)
     40  const __m128i k__cospi_A =
     41      octa_set_epi16(cospi_16_64, cospi_16_64, cospi_16_64, cospi_16_64,
     42                     cospi_16_64, -cospi_16_64, cospi_16_64, -cospi_16_64);
     43  const __m128i k__cospi_B =
     44      octa_set_epi16(cospi_16_64, -cospi_16_64, cospi_16_64, -cospi_16_64,
     45                     cospi_16_64, cospi_16_64, cospi_16_64, cospi_16_64);
     46  const __m128i k__cospi_C =
     47      octa_set_epi16(cospi_8_64, cospi_24_64, cospi_8_64, cospi_24_64,
     48                     cospi_24_64, -cospi_8_64, cospi_24_64, -cospi_8_64);
     49  const __m128i k__cospi_D =
     50      octa_set_epi16(cospi_24_64, -cospi_8_64, cospi_24_64, -cospi_8_64,
     51                     cospi_8_64, cospi_24_64, cospi_8_64, cospi_24_64);
     52  const __m128i k__cospi_E =
     53      octa_set_epi16(cospi_16_64, cospi_16_64, cospi_16_64, cospi_16_64,
     54                     cospi_16_64, cospi_16_64, cospi_16_64, cospi_16_64);
     55  const __m128i k__cospi_F =
     56      octa_set_epi16(cospi_16_64, -cospi_16_64, cospi_16_64, -cospi_16_64,
     57                     cospi_16_64, -cospi_16_64, cospi_16_64, -cospi_16_64);
     58  const __m128i k__cospi_G =
     59      octa_set_epi16(cospi_8_64, cospi_24_64, cospi_8_64, cospi_24_64,
     60                     -cospi_8_64, -cospi_24_64, -cospi_8_64, -cospi_24_64);
     61  const __m128i k__cospi_H =
     62      octa_set_epi16(cospi_24_64, -cospi_8_64, cospi_24_64, -cospi_8_64,
     63                     -cospi_24_64, cospi_8_64, -cospi_24_64, cospi_8_64);
     64 
     65  const __m128i k__DCT_CONST_ROUNDING = _mm_set1_epi32(DCT_CONST_ROUNDING);
     66  // This second rounding constant saves doing some extra adds at the end
     67  const __m128i k__DCT_CONST_ROUNDING2 =
     68      _mm_set1_epi32(DCT_CONST_ROUNDING + (DCT_CONST_ROUNDING << 1));
     69  const int DCT_CONST_BITS2 = DCT_CONST_BITS + 2;
     70  const __m128i k__nonzero_bias_a = _mm_setr_epi16(0, 1, 1, 1, 1, 1, 1, 1);
     71  const __m128i k__nonzero_bias_b = _mm_setr_epi16(1, 0, 0, 0, 0, 0, 0, 0);
     72 
     73  // Load inputs.
     74  *in0 = _mm_loadl_epi64((const __m128i *)(input + 0 * stride));
     75  *in1 = _mm_loadl_epi64((const __m128i *)(input + 1 * stride));
     76  *in1 = _mm_unpacklo_epi64(
     77      *in1, _mm_loadl_epi64((const __m128i *)(input + 2 * stride)));
     78  *in0 = _mm_unpacklo_epi64(
     79      *in0, _mm_loadl_epi64((const __m128i *)(input + 3 * stride)));
     80  // in0 = [i0 i1 i2 i3 iC iD iE iF]
     81  // in1 = [i4 i5 i6 i7 i8 i9 iA iB]
     82  // multiply by 16 to give some extra precision
     83  *in0 = _mm_slli_epi16(*in0, 4);
     84  *in1 = _mm_slli_epi16(*in1, 4);
     85  // if (i == 0 && input[0]) input[0] += 1;
     86  // add 1 to the upper left pixel if it is non-zero, which helps reduce
     87  // the round-trip error
     88  {
     89    // The mask will only contain whether the first value is zero, all
     90    // other comparison will fail as something shifted by 4 (above << 4)
     91    // can never be equal to one. To increment in the non-zero case, we
     92    // add the mask and one for the first element:
     93    //   - if zero, mask = -1, v = v - 1 + 1 = v
     94    //   - if non-zero, mask = 0, v = v + 0 + 1 = v + 1
     95    __m128i mask = _mm_cmpeq_epi16(*in0, k__nonzero_bias_a);
     96    *in0 = _mm_add_epi16(*in0, mask);
     97    *in0 = _mm_add_epi16(*in0, k__nonzero_bias_b);
     98  }
     99  // There are 4 total stages, alternating between an add/subtract stage
    100  // followed by an multiply-and-add stage.
    101  {
    102    // Stage 1: Add/subtract
    103 
    104    // in0 = [i0 i1 i2 i3 iC iD iE iF]
    105    // in1 = [i4 i5 i6 i7 i8 i9 iA iB]
    106    const __m128i r0 = _mm_unpacklo_epi16(*in0, *in1);
    107    const __m128i r1 = _mm_unpackhi_epi16(*in0, *in1);
    108    // r0 = [i0 i4 i1 i5 i2 i6 i3 i7]
    109    // r1 = [iC i8 iD i9 iE iA iF iB]
    110    const __m128i r2 = _mm_shuffle_epi32(r0, 0xB4);
    111    const __m128i r3 = _mm_shuffle_epi32(r1, 0xB4);
    112    // r2 = [i0 i4 i1 i5 i3 i7 i2 i6]
    113    // r3 = [iC i8 iD i9 iF iB iE iA]
    114 
    115    const __m128i t0 = _mm_add_epi16(r2, r3);
    116    const __m128i t1 = _mm_sub_epi16(r2, r3);
    117    // t0 = [a0 a4 a1 a5 a3 a7 a2 a6]
    118    // t1 = [aC a8 aD a9 aF aB aE aA]
    119 
    120    // Stage 2: multiply by constants (which gets us into 32 bits).
    121    // The constants needed here are:
    122    // k__cospi_A = [p16 p16 p16 p16 p16 m16 p16 m16]
    123    // k__cospi_B = [p16 m16 p16 m16 p16 p16 p16 p16]
    124    // k__cospi_C = [p08 p24 p08 p24 p24 m08 p24 m08]
    125    // k__cospi_D = [p24 m08 p24 m08 p08 p24 p08 p24]
    126    const __m128i u0 = _mm_madd_epi16(t0, k__cospi_A);
    127    const __m128i u2 = _mm_madd_epi16(t0, k__cospi_B);
    128    const __m128i u1 = _mm_madd_epi16(t1, k__cospi_C);
    129    const __m128i u3 = _mm_madd_epi16(t1, k__cospi_D);
    130    // Then add and right-shift to get back to 16-bit range
    131    const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
    132    const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
    133    const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
    134    const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
    135    const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
    136    const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
    137    const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
    138    const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
    139    // w0 = [b0 b1 b7 b6]
    140    // w1 = [b8 b9 bF bE]
    141    // w2 = [b4 b5 b3 b2]
    142    // w3 = [bC bD bB bA]
    143    const __m128i x0 = _mm_packs_epi32(w0, w1);
    144    const __m128i x1 = _mm_packs_epi32(w2, w3);
    145 
    146    // x0 = [b0 b1 b7 b6 b8 b9 bF bE]
    147    // x1 = [b4 b5 b3 b2 bC bD bB bA]
    148    *in0 = _mm_shuffle_epi32(x0, 0xD8);
    149    *in1 = _mm_shuffle_epi32(x1, 0x8D);
    150    // in0 = [b0 b1 b8 b9 b7 b6 bF bE]
    151    // in1 = [b3 b2 bB bA b4 b5 bC bD]
    152  }
    153  {
    154    // vertical DCTs finished. Now we do the horizontal DCTs.
    155    // Stage 3: Add/subtract
    156 
    157    const __m128i t0 = ADD_EPI16(*in0, *in1);
    158    const __m128i t1 = SUB_EPI16(*in0, *in1);
    159 
    160    // Stage 4: multiply by constants (which gets us into 32 bits).
    161    {
    162      // The constants needed here are:
    163      // k__cospi_E = [p16 p16 p16 p16 p16 p16 p16 p16]
    164      // k__cospi_F = [p16 m16 p16 m16 p16 m16 p16 m16]
    165      // k__cospi_G = [p08 p24 p08 p24 m08 m24 m08 m24]
    166      // k__cospi_H = [p24 m08 p24 m08 m24 p08 m24 p08]
    167      const __m128i u0 = _mm_madd_epi16(t0, k__cospi_E);
    168      const __m128i u1 = _mm_madd_epi16(t0, k__cospi_F);
    169      const __m128i u2 = _mm_madd_epi16(t1, k__cospi_G);
    170      const __m128i u3 = _mm_madd_epi16(t1, k__cospi_H);
    171      // Then add and right-shift to get back to 16-bit range
    172      // but this combines the final right-shift as well to save operations
    173      // This unusual rounding operations is to maintain bit-accurate
    174      // compatibility with the c version of this function which has two
    175      // rounding steps in a row.
    176      const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING2);
    177      const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING2);
    178      const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING2);
    179      const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING2);
    180      const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS2);
    181      const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS2);
    182      const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS2);
    183      const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS2);
    184      *in0 = _mm_packs_epi32(w0, w2);
    185      *in1 = _mm_packs_epi32(w1, w3);
    186    }
    187  }
    188 }
    189 #endif  // defined(FDCT4x4_2D_HELPER)
    190 
    191 #if defined(FDCT4x4_2D)
    192 void FDCT4x4_2D(const int16_t *input, tran_low_t *output, int stride) {
    193  // This 2D transform implements 4 vertical 1D transforms followed
    194  // by 4 horizontal 1D transforms.  The multiplies and adds are as given
    195  // by Chen, Smith and Fralick ('77).  The commands for moving the data
    196  // around have been minimized by hand.
    197  // For the purposes of the comments, the 16 inputs are referred to at i0
    198  // through iF (in raster order), intermediate variables are a0, b0, c0
    199  // through f, and correspond to the in-place computations mapped to input
    200  // locations.  The outputs, o0 through oF are labeled according to the
    201  // output locations.
    202  __m128i in0, in1;
    203  FDCT4x4_2D_HELPER(input, stride, &in0, &in1);
    204 
    205  // Post-condition (v + 1) >> 2 is now incorporated into previous
    206  // add and right-shift commands.  Only 2 store instructions needed
    207  // because we are using the fact that 1/3 are stored just after 0/2.
    208  storeu_output(&in0, output + 0 * 4);
    209  storeu_output(&in1, output + 2 * 4);
    210 }
    211 #endif  // defined(FDCT4x4_2D)
    212 
    213 #if defined(FDCT4x4_2D_LP)
    214 void FDCT4x4_2D_LP(const int16_t *input, int16_t *output, int stride) {
    215  __m128i in0, in1;
    216  FDCT4x4_2D_HELPER(input, stride, &in0, &in1);
    217  _mm_storeu_si128((__m128i *)(output + 0 * 4), in0);
    218  _mm_storeu_si128((__m128i *)(output + 2 * 4), in1);
    219 }
    220 #endif  // defined(FDCT4x4_2D_LP)
    221 
    222 #if CONFIG_INTERNAL_STATS
    223 void FDCT8x8_2D(const int16_t *input, tran_low_t *output, int stride) {
    224  int pass;
    225  // Constants
    226  //    When we use them, in one case, they are all the same. In all others
    227  //    it's a pair of them that we need to repeat four times. This is done
    228  //    by constructing the 32 bit constant corresponding to that pair.
    229  const __m128i k__cospi_p16_p16 = _mm_set1_epi16((int16_t)cospi_16_64);
    230  const __m128i k__cospi_p16_m16 = pair_set_epi16(cospi_16_64, -cospi_16_64);
    231  const __m128i k__cospi_p24_p08 = pair_set_epi16(cospi_24_64, cospi_8_64);
    232  const __m128i k__cospi_m08_p24 = pair_set_epi16(-cospi_8_64, cospi_24_64);
    233  const __m128i k__cospi_p28_p04 = pair_set_epi16(cospi_28_64, cospi_4_64);
    234  const __m128i k__cospi_m04_p28 = pair_set_epi16(-cospi_4_64, cospi_28_64);
    235  const __m128i k__cospi_p12_p20 = pair_set_epi16(cospi_12_64, cospi_20_64);
    236  const __m128i k__cospi_m20_p12 = pair_set_epi16(-cospi_20_64, cospi_12_64);
    237  const __m128i k__DCT_CONST_ROUNDING = _mm_set1_epi32(DCT_CONST_ROUNDING);
    238 #if DCT_HIGH_BIT_DEPTH
    239  int overflow;
    240 #endif
    241  // Load input
    242  __m128i in0 = _mm_load_si128((const __m128i *)(input + 0 * stride));
    243  __m128i in1 = _mm_load_si128((const __m128i *)(input + 1 * stride));
    244  __m128i in2 = _mm_load_si128((const __m128i *)(input + 2 * stride));
    245  __m128i in3 = _mm_load_si128((const __m128i *)(input + 3 * stride));
    246  __m128i in4 = _mm_load_si128((const __m128i *)(input + 4 * stride));
    247  __m128i in5 = _mm_load_si128((const __m128i *)(input + 5 * stride));
    248  __m128i in6 = _mm_load_si128((const __m128i *)(input + 6 * stride));
    249  __m128i in7 = _mm_load_si128((const __m128i *)(input + 7 * stride));
    250  // Pre-condition input (shift by two)
    251  in0 = _mm_slli_epi16(in0, 2);
    252  in1 = _mm_slli_epi16(in1, 2);
    253  in2 = _mm_slli_epi16(in2, 2);
    254  in3 = _mm_slli_epi16(in3, 2);
    255  in4 = _mm_slli_epi16(in4, 2);
    256  in5 = _mm_slli_epi16(in5, 2);
    257  in6 = _mm_slli_epi16(in6, 2);
    258  in7 = _mm_slli_epi16(in7, 2);
    259 
    260  // We do two passes, first the columns, then the rows. The results of the
    261  // first pass are transposed so that the same column code can be reused. The
    262  // results of the second pass are also transposed so that the rows (processed
    263  // as columns) are put back in row positions.
    264  for (pass = 0; pass < 2; pass++) {
    265    // To store results of each pass before the transpose.
    266    __m128i res0, res1, res2, res3, res4, res5, res6, res7;
    267    // Add/subtract
    268    const __m128i q0 = ADD_EPI16(in0, in7);
    269    const __m128i q1 = ADD_EPI16(in1, in6);
    270    const __m128i q2 = ADD_EPI16(in2, in5);
    271    const __m128i q3 = ADD_EPI16(in3, in4);
    272    const __m128i q4 = SUB_EPI16(in3, in4);
    273    const __m128i q5 = SUB_EPI16(in2, in5);
    274    const __m128i q6 = SUB_EPI16(in1, in6);
    275    const __m128i q7 = SUB_EPI16(in0, in7);
    276 #if DCT_HIGH_BIT_DEPTH
    277    if (pass == 1) {
    278      overflow =
    279          check_epi16_overflow_x8(&q0, &q1, &q2, &q3, &q4, &q5, &q6, &q7);
    280      if (overflow) {
    281        aom_highbd_fdct8x8_c(input, output, stride);
    282        return;
    283      }
    284    }
    285 #endif  // DCT_HIGH_BIT_DEPTH
    286    // Work on first four results
    287    {
    288      // Add/subtract
    289      const __m128i r0 = ADD_EPI16(q0, q3);
    290      const __m128i r1 = ADD_EPI16(q1, q2);
    291      const __m128i r2 = SUB_EPI16(q1, q2);
    292      const __m128i r3 = SUB_EPI16(q0, q3);
    293 #if DCT_HIGH_BIT_DEPTH
    294      overflow = check_epi16_overflow_x4(&r0, &r1, &r2, &r3);
    295      if (overflow) {
    296        aom_highbd_fdct8x8_c(input, output, stride);
    297        return;
    298      }
    299 #endif  // DCT_HIGH_BIT_DEPTH
    300      // Interleave to do the multiply by constants which gets us into 32bits
    301      {
    302        const __m128i t0 = _mm_unpacklo_epi16(r0, r1);
    303        const __m128i t1 = _mm_unpackhi_epi16(r0, r1);
    304        const __m128i t2 = _mm_unpacklo_epi16(r2, r3);
    305        const __m128i t3 = _mm_unpackhi_epi16(r2, r3);
    306        const __m128i u0 = _mm_madd_epi16(t0, k__cospi_p16_p16);
    307        const __m128i u1 = _mm_madd_epi16(t1, k__cospi_p16_p16);
    308        const __m128i u2 = _mm_madd_epi16(t0, k__cospi_p16_m16);
    309        const __m128i u3 = _mm_madd_epi16(t1, k__cospi_p16_m16);
    310        const __m128i u4 = _mm_madd_epi16(t2, k__cospi_p24_p08);
    311        const __m128i u5 = _mm_madd_epi16(t3, k__cospi_p24_p08);
    312        const __m128i u6 = _mm_madd_epi16(t2, k__cospi_m08_p24);
    313        const __m128i u7 = _mm_madd_epi16(t3, k__cospi_m08_p24);
    314        // dct_const_round_shift
    315        const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
    316        const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
    317        const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
    318        const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
    319        const __m128i v4 = _mm_add_epi32(u4, k__DCT_CONST_ROUNDING);
    320        const __m128i v5 = _mm_add_epi32(u5, k__DCT_CONST_ROUNDING);
    321        const __m128i v6 = _mm_add_epi32(u6, k__DCT_CONST_ROUNDING);
    322        const __m128i v7 = _mm_add_epi32(u7, k__DCT_CONST_ROUNDING);
    323        const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
    324        const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
    325        const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
    326        const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
    327        const __m128i w4 = _mm_srai_epi32(v4, DCT_CONST_BITS);
    328        const __m128i w5 = _mm_srai_epi32(v5, DCT_CONST_BITS);
    329        const __m128i w6 = _mm_srai_epi32(v6, DCT_CONST_BITS);
    330        const __m128i w7 = _mm_srai_epi32(v7, DCT_CONST_BITS);
    331        // Combine
    332        res0 = _mm_packs_epi32(w0, w1);
    333        res4 = _mm_packs_epi32(w2, w3);
    334        res2 = _mm_packs_epi32(w4, w5);
    335        res6 = _mm_packs_epi32(w6, w7);
    336 #if DCT_HIGH_BIT_DEPTH
    337        overflow = check_epi16_overflow_x4(&res0, &res4, &res2, &res6);
    338        if (overflow) {
    339          aom_highbd_fdct8x8_c(input, output, stride);
    340          return;
    341        }
    342 #endif  // DCT_HIGH_BIT_DEPTH
    343      }
    344    }
    345    // Work on next four results
    346    {
    347      // Interleave to do the multiply by constants which gets us into 32bits
    348      const __m128i d0 = _mm_unpacklo_epi16(q6, q5);
    349      const __m128i d1 = _mm_unpackhi_epi16(q6, q5);
    350      const __m128i e0 = _mm_madd_epi16(d0, k__cospi_p16_m16);
    351      const __m128i e1 = _mm_madd_epi16(d1, k__cospi_p16_m16);
    352      const __m128i e2 = _mm_madd_epi16(d0, k__cospi_p16_p16);
    353      const __m128i e3 = _mm_madd_epi16(d1, k__cospi_p16_p16);
    354      // dct_const_round_shift
    355      const __m128i f0 = _mm_add_epi32(e0, k__DCT_CONST_ROUNDING);
    356      const __m128i f1 = _mm_add_epi32(e1, k__DCT_CONST_ROUNDING);
    357      const __m128i f2 = _mm_add_epi32(e2, k__DCT_CONST_ROUNDING);
    358      const __m128i f3 = _mm_add_epi32(e3, k__DCT_CONST_ROUNDING);
    359      const __m128i s0 = _mm_srai_epi32(f0, DCT_CONST_BITS);
    360      const __m128i s1 = _mm_srai_epi32(f1, DCT_CONST_BITS);
    361      const __m128i s2 = _mm_srai_epi32(f2, DCT_CONST_BITS);
    362      const __m128i s3 = _mm_srai_epi32(f3, DCT_CONST_BITS);
    363      // Combine
    364      const __m128i r0 = _mm_packs_epi32(s0, s1);
    365      const __m128i r1 = _mm_packs_epi32(s2, s3);
    366 #if DCT_HIGH_BIT_DEPTH
    367      overflow = check_epi16_overflow_x2(&r0, &r1);
    368      if (overflow) {
    369        aom_highbd_fdct8x8_c(input, output, stride);
    370        return;
    371      }
    372 #endif  // DCT_HIGH_BIT_DEPTH
    373      {
    374        // Add/subtract
    375        const __m128i x0 = ADD_EPI16(q4, r0);
    376        const __m128i x1 = SUB_EPI16(q4, r0);
    377        const __m128i x2 = SUB_EPI16(q7, r1);
    378        const __m128i x3 = ADD_EPI16(q7, r1);
    379 #if DCT_HIGH_BIT_DEPTH
    380        overflow = check_epi16_overflow_x4(&x0, &x1, &x2, &x3);
    381        if (overflow) {
    382          aom_highbd_fdct8x8_c(input, output, stride);
    383          return;
    384        }
    385 #endif  // DCT_HIGH_BIT_DEPTH
    386        // Interleave to do the multiply by constants which gets us into 32bits
    387        {
    388          const __m128i t0 = _mm_unpacklo_epi16(x0, x3);
    389          const __m128i t1 = _mm_unpackhi_epi16(x0, x3);
    390          const __m128i t2 = _mm_unpacklo_epi16(x1, x2);
    391          const __m128i t3 = _mm_unpackhi_epi16(x1, x2);
    392          const __m128i u0 = _mm_madd_epi16(t0, k__cospi_p28_p04);
    393          const __m128i u1 = _mm_madd_epi16(t1, k__cospi_p28_p04);
    394          const __m128i u2 = _mm_madd_epi16(t0, k__cospi_m04_p28);
    395          const __m128i u3 = _mm_madd_epi16(t1, k__cospi_m04_p28);
    396          const __m128i u4 = _mm_madd_epi16(t2, k__cospi_p12_p20);
    397          const __m128i u5 = _mm_madd_epi16(t3, k__cospi_p12_p20);
    398          const __m128i u6 = _mm_madd_epi16(t2, k__cospi_m20_p12);
    399          const __m128i u7 = _mm_madd_epi16(t3, k__cospi_m20_p12);
    400          // dct_const_round_shift
    401          const __m128i v0 = _mm_add_epi32(u0, k__DCT_CONST_ROUNDING);
    402          const __m128i v1 = _mm_add_epi32(u1, k__DCT_CONST_ROUNDING);
    403          const __m128i v2 = _mm_add_epi32(u2, k__DCT_CONST_ROUNDING);
    404          const __m128i v3 = _mm_add_epi32(u3, k__DCT_CONST_ROUNDING);
    405          const __m128i v4 = _mm_add_epi32(u4, k__DCT_CONST_ROUNDING);
    406          const __m128i v5 = _mm_add_epi32(u5, k__DCT_CONST_ROUNDING);
    407          const __m128i v6 = _mm_add_epi32(u6, k__DCT_CONST_ROUNDING);
    408          const __m128i v7 = _mm_add_epi32(u7, k__DCT_CONST_ROUNDING);
    409          const __m128i w0 = _mm_srai_epi32(v0, DCT_CONST_BITS);
    410          const __m128i w1 = _mm_srai_epi32(v1, DCT_CONST_BITS);
    411          const __m128i w2 = _mm_srai_epi32(v2, DCT_CONST_BITS);
    412          const __m128i w3 = _mm_srai_epi32(v3, DCT_CONST_BITS);
    413          const __m128i w4 = _mm_srai_epi32(v4, DCT_CONST_BITS);
    414          const __m128i w5 = _mm_srai_epi32(v5, DCT_CONST_BITS);
    415          const __m128i w6 = _mm_srai_epi32(v6, DCT_CONST_BITS);
    416          const __m128i w7 = _mm_srai_epi32(v7, DCT_CONST_BITS);
    417          // Combine
    418          res1 = _mm_packs_epi32(w0, w1);
    419          res7 = _mm_packs_epi32(w2, w3);
    420          res5 = _mm_packs_epi32(w4, w5);
    421          res3 = _mm_packs_epi32(w6, w7);
    422 #if DCT_HIGH_BIT_DEPTH
    423          overflow = check_epi16_overflow_x4(&res1, &res7, &res5, &res3);
    424          if (overflow) {
    425            aom_highbd_fdct8x8_c(input, output, stride);
    426            return;
    427          }
    428 #endif  // DCT_HIGH_BIT_DEPTH
    429        }
    430      }
    431    }
    432    // Transpose the 8x8.
    433    {
    434      // 00 01 02 03 04 05 06 07
    435      // 10 11 12 13 14 15 16 17
    436      // 20 21 22 23 24 25 26 27
    437      // 30 31 32 33 34 35 36 37
    438      // 40 41 42 43 44 45 46 47
    439      // 50 51 52 53 54 55 56 57
    440      // 60 61 62 63 64 65 66 67
    441      // 70 71 72 73 74 75 76 77
    442      const __m128i tr0_0 = _mm_unpacklo_epi16(res0, res1);
    443      const __m128i tr0_1 = _mm_unpacklo_epi16(res2, res3);
    444      const __m128i tr0_2 = _mm_unpackhi_epi16(res0, res1);
    445      const __m128i tr0_3 = _mm_unpackhi_epi16(res2, res3);
    446      const __m128i tr0_4 = _mm_unpacklo_epi16(res4, res5);
    447      const __m128i tr0_5 = _mm_unpacklo_epi16(res6, res7);
    448      const __m128i tr0_6 = _mm_unpackhi_epi16(res4, res5);
    449      const __m128i tr0_7 = _mm_unpackhi_epi16(res6, res7);
    450      // 00 10 01 11 02 12 03 13
    451      // 20 30 21 31 22 32 23 33
    452      // 04 14 05 15 06 16 07 17
    453      // 24 34 25 35 26 36 27 37
    454      // 40 50 41 51 42 52 43 53
    455      // 60 70 61 71 62 72 63 73
    456      // 54 54 55 55 56 56 57 57
    457      // 64 74 65 75 66 76 67 77
    458      const __m128i tr1_0 = _mm_unpacklo_epi32(tr0_0, tr0_1);
    459      const __m128i tr1_1 = _mm_unpacklo_epi32(tr0_2, tr0_3);
    460      const __m128i tr1_2 = _mm_unpackhi_epi32(tr0_0, tr0_1);
    461      const __m128i tr1_3 = _mm_unpackhi_epi32(tr0_2, tr0_3);
    462      const __m128i tr1_4 = _mm_unpacklo_epi32(tr0_4, tr0_5);
    463      const __m128i tr1_5 = _mm_unpacklo_epi32(tr0_6, tr0_7);
    464      const __m128i tr1_6 = _mm_unpackhi_epi32(tr0_4, tr0_5);
    465      const __m128i tr1_7 = _mm_unpackhi_epi32(tr0_6, tr0_7);
    466      // 00 10 20 30 01 11 21 31
    467      // 40 50 60 70 41 51 61 71
    468      // 02 12 22 32 03 13 23 33
    469      // 42 52 62 72 43 53 63 73
    470      // 04 14 24 34 05 15 21 36
    471      // 44 54 64 74 45 55 61 76
    472      // 06 16 26 36 07 17 27 37
    473      // 46 56 66 76 47 57 67 77
    474      in0 = _mm_unpacklo_epi64(tr1_0, tr1_4);
    475      in1 = _mm_unpackhi_epi64(tr1_0, tr1_4);
    476      in2 = _mm_unpacklo_epi64(tr1_2, tr1_6);
    477      in3 = _mm_unpackhi_epi64(tr1_2, tr1_6);
    478      in4 = _mm_unpacklo_epi64(tr1_1, tr1_5);
    479      in5 = _mm_unpackhi_epi64(tr1_1, tr1_5);
    480      in6 = _mm_unpacklo_epi64(tr1_3, tr1_7);
    481      in7 = _mm_unpackhi_epi64(tr1_3, tr1_7);
    482      // 00 10 20 30 40 50 60 70
    483      // 01 11 21 31 41 51 61 71
    484      // 02 12 22 32 42 52 62 72
    485      // 03 13 23 33 43 53 63 73
    486      // 04 14 24 34 44 54 64 74
    487      // 05 15 25 35 45 55 65 75
    488      // 06 16 26 36 46 56 66 76
    489      // 07 17 27 37 47 57 67 77
    490    }
    491  }
    492  // Post-condition output and store it
    493  {
    494    // Post-condition (division by two)
    495    //    division of two 16 bits signed numbers using shifts
    496    //    n / 2 = (n - (n >> 15)) >> 1
    497    const __m128i sign_in0 = _mm_srai_epi16(in0, 15);
    498    const __m128i sign_in1 = _mm_srai_epi16(in1, 15);
    499    const __m128i sign_in2 = _mm_srai_epi16(in2, 15);
    500    const __m128i sign_in3 = _mm_srai_epi16(in3, 15);
    501    const __m128i sign_in4 = _mm_srai_epi16(in4, 15);
    502    const __m128i sign_in5 = _mm_srai_epi16(in5, 15);
    503    const __m128i sign_in6 = _mm_srai_epi16(in6, 15);
    504    const __m128i sign_in7 = _mm_srai_epi16(in7, 15);
    505    in0 = _mm_sub_epi16(in0, sign_in0);
    506    in1 = _mm_sub_epi16(in1, sign_in1);
    507    in2 = _mm_sub_epi16(in2, sign_in2);
    508    in3 = _mm_sub_epi16(in3, sign_in3);
    509    in4 = _mm_sub_epi16(in4, sign_in4);
    510    in5 = _mm_sub_epi16(in5, sign_in5);
    511    in6 = _mm_sub_epi16(in6, sign_in6);
    512    in7 = _mm_sub_epi16(in7, sign_in7);
    513    in0 = _mm_srai_epi16(in0, 1);
    514    in1 = _mm_srai_epi16(in1, 1);
    515    in2 = _mm_srai_epi16(in2, 1);
    516    in3 = _mm_srai_epi16(in3, 1);
    517    in4 = _mm_srai_epi16(in4, 1);
    518    in5 = _mm_srai_epi16(in5, 1);
    519    in6 = _mm_srai_epi16(in6, 1);
    520    in7 = _mm_srai_epi16(in7, 1);
    521    // store results
    522    store_output(&in0, (output + 0 * 8));
    523    store_output(&in1, (output + 1 * 8));
    524    store_output(&in2, (output + 2 * 8));
    525    store_output(&in3, (output + 3 * 8));
    526    store_output(&in4, (output + 4 * 8));
    527    store_output(&in5, (output + 5 * 8));
    528    store_output(&in6, (output + 6 * 8));
    529    store_output(&in7, (output + 7 * 8));
    530  }
    531 }
    532 #endif  // CONFIG_INTERNAL_STATS
    533 
    534 #undef ADD_EPI16
    535 #undef SUB_EPI16