text: /*
   *  Copyright (c) 2014 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 <assert.h>
  #include <emmintrin.h>  // SSE2
  #include "./vpx_config.h"
  #include "vpx/vpx_integer.h"
  #include "vp9/common/vp9_common.h"
  #include "vp9/common/vp9_idct.h"
  
  // perform 8x8 transpose
  static INLINE void array_transpose_8x8(__m128i *in, __m128i *res) {
    const __m128i tr0_0 = _mm_unpacklo_epi16(in[0], in[1]);
    const __m128i tr0_1 = _mm_unpacklo_epi16(in[2], in[3]);
    const __m128i tr0_2 = _mm_unpackhi_epi16(in[0], in[1]);
    const __m128i tr0_3 = _mm_unpackhi_epi16(in[2], in[3]);
    const __m128i tr0_4 = _mm_unpacklo_epi16(in[4], in[5]);
    const __m128i tr0_5 = _mm_unpacklo_epi16(in[6], in[7]);
    const __m128i tr0_6 = _mm_unpackhi_epi16(in[4], in[5]);
    const __m128i tr0_7 = _mm_unpackhi_epi16(in[6], in[7]);
  
    const __m128i tr1_0 = _mm_unpacklo_epi32(tr0_0, tr0_1);
    const __m128i tr1_1 = _mm_unpacklo_epi32(tr0_4, tr0_5);
    const __m128i tr1_2 = _mm_unpackhi_epi32(tr0_0, tr0_1);
    const __m128i tr1_3 = _mm_unpackhi_epi32(tr0_4, tr0_5);
    const __m128i tr1_4 = _mm_unpacklo_epi32(tr0_2, tr0_3);
    const __m128i tr1_5 = _mm_unpacklo_epi32(tr0_6, tr0_7);
    const __m128i tr1_6 = _mm_unpackhi_epi32(tr0_2, tr0_3);
    const __m128i tr1_7 = _mm_unpackhi_epi32(tr0_6, tr0_7);
  
    res[0] = _mm_unpacklo_epi64(tr1_0, tr1_1);
    res[1] = _mm_unpackhi_epi64(tr1_0, tr1_1);
    res[2] = _mm_unpacklo_epi64(tr1_2, tr1_3);
    res[3] = _mm_unpackhi_epi64(tr1_2, tr1_3);
    res[4] = _mm_unpacklo_epi64(tr1_4, tr1_5);
    res[5] = _mm_unpackhi_epi64(tr1_4, tr1_5);
    res[6] = _mm_unpacklo_epi64(tr1_6, tr1_7);
    res[7] = _mm_unpackhi_epi64(tr1_6, tr1_7);
  }
  
  #define TRANSPOSE_8X4(in0, in1, in2, in3, out0, out1) \
    {                                                     \
      const __m128i tr0_0 = _mm_unpacklo_epi16(in0, in1); \
      const __m128i tr0_1 = _mm_unpacklo_epi16(in2, in3); \
                                                          \
      in0 = _mm_unpacklo_epi32(tr0_0, tr0_1);  /* i1 i0 */  \
      in1 = _mm_unpackhi_epi32(tr0_0, tr0_1);  /* i3 i2 */  \
    }
  
  static INLINE void array_transpose_4X8(__m128i *in, __m128i * out) {
    const __m128i tr0_0 = _mm_unpacklo_epi16(in[0], in[1]);
    const __m128i tr0_1 = _mm_unpacklo_epi16(in[2], in[3]);
    const __m128i tr0_4 = _mm_unpacklo_epi16(in[4], in[5]);
    const __m128i tr0_5 = _mm_unpacklo_epi16(in[6], in[7]);
  
    const __m128i tr1_0 = _mm_unpacklo_epi32(tr0_0, tr0_1);
    const __m128i tr1_2 = _mm_unpackhi_epi32(tr0_0, tr0_1);
    const __m128i tr1_4 = _mm_unpacklo_epi32(tr0_4, tr0_5);
    const __m128i tr1_6 = _mm_unpackhi_epi32(tr0_4, tr0_5);
  
    out[0] = _mm_unpacklo_epi64(tr1_0, tr1_4);
    out[1] = _mm_unpackhi_epi64(tr1_0, tr1_4);
    out[2] = _mm_unpacklo_epi64(tr1_2, tr1_6);
    out[3] = _mm_unpackhi_epi64(tr1_2, tr1_6);
  }
  
  static INLINE void array_transpose_16x16(__m128i *res0, __m128i *res1) {
    __m128i tbuf[8];
    array_transpose_8x8(res0, res0);
    array_transpose_8x8(res1, tbuf);
    array_transpose_8x8(res0 + 8, res1);
    array_transpose_8x8(res1 + 8, res1 + 8);
  
    res0[8] = tbuf[0];
    res0[9] = tbuf[1];
    res0[10] = tbuf[2];
    res0[11] = tbuf[3];
    res0[12] = tbuf[4];
    res0[13] = tbuf[5];
    res0[14] = tbuf[6];
    res0[15] = tbuf[7];
  }
  
  static INLINE void load_buffer_8x16(const int16_t *input, __m128i *in) {
    in[0]  = _mm_load_si128((const __m128i *)(input + 0 * 16));
    in[1]  = _mm_load_si128((const __m128i *)(input + 1 * 16));
    in[2]  = _mm_load_si128((const __m128i *)(input + 2 * 16));
    in[3]  = _mm_load_si128((const __m128i *)(input + 3 * 16));
    in[4]  = _mm_load_si128((const __m128i *)(input + 4 * 16));
    in[5]  = _mm_load_si128((const __m128i *)(input + 5 * 16));
    in[6]  = _mm_load_si128((const __m128i *)(input + 6 * 16));
    in[7]  = _mm_load_si128((const __m128i *)(input + 7 * 16));
  
    in[8]  = _mm_load_si128((const __m128i *)(input + 8 * 16));
    in[9]  = _mm_load_si128((const __m128i *)(input + 9 * 16));
    in[10]  = _mm_load_si128((const __m128i *)(input + 10 * 16));
    in[11]  = _mm_load_si128((const __m128i *)(input + 11 * 16));
    in[12]  = _mm_load_si128((const __m128i *)(input + 12 * 16));
    in[13]  = _mm_load_si128((const __m128i *)(input + 13 * 16));
    in[14]  = _mm_load_si128((const __m128i *)(input + 14 * 16));
    in[15]  = _mm_load_si128((const __m128i *)(input + 15 * 16));
  }
  
  #define RECON_AND_STORE(dest, in_x) \
    {                                                     \
       __m128i d0 = _mm_loadl_epi64((__m128i *)(dest)); \
        d0 = _mm_unpacklo_epi8(d0, zero); \
        d0 = _mm_add_epi16(in_x, d0); \
        d0 = _mm_packus_epi16(d0, d0); \
        _mm_storel_epi64((__m128i *)(dest), d0); \
        dest += stride; \
    }
  
  static INLINE void write_buffer_8x16(uint8_t *dest, __m128i *in, int stride) {
    const __m128i final_rounding = _mm_set1_epi16(1<<5);
    const __m128i zero = _mm_setzero_si128();
    // Final rounding and shift
    in[0] = _mm_adds_epi16(in[0], final_rounding);
    in[1] = _mm_adds_epi16(in[1], final_rounding);
    in[2] = _mm_adds_epi16(in[2], final_rounding);
    in[3] = _mm_adds_epi16(in[3], final_rounding);
    in[4] = _mm_adds_epi16(in[4], final_rounding);
    in[5] = _mm_adds_epi16(in[5], final_rounding);
    in[6] = _mm_adds_epi16(in[6], final_rounding);
    in[7] = _mm_adds_epi16(in[7], final_rounding);
    in[8] = _mm_adds_epi16(in[8], final_rounding);
    in[9] = _mm_adds_epi16(in[9], final_rounding);
    in[10] = _mm_adds_epi16(in[10], final_rounding);
    in[11] = _mm_adds_epi16(in[11], final_rounding);
    in[12] = _mm_adds_epi16(in[12], final_rounding);
    in[13] = _mm_adds_epi16(in[13], final_rounding);
    in[14] = _mm_adds_epi16(in[14], final_rounding);
    in[15] = _mm_adds_epi16(in[15], final_rounding);
  
    in[0] = _mm_srai_epi16(in[0], 6);
    in[1] = _mm_srai_epi16(in[1], 6);
    in[2] = _mm_srai_epi16(in[2], 6);
    in[3] = _mm_srai_epi16(in[3], 6);
    in[4] = _mm_srai_epi16(in[4], 6);
    in[5] = _mm_srai_epi16(in[5], 6);
    in[6] = _mm_srai_epi16(in[6], 6);
    in[7] = _mm_srai_epi16(in[7], 6);
    in[8] = _mm_srai_epi16(in[8], 6);
    in[9] = _mm_srai_epi16(in[9], 6);
    in[10] = _mm_srai_epi16(in[10], 6);
    in[11] = _mm_srai_epi16(in[11], 6);
    in[12] = _mm_srai_epi16(in[12], 6);
    in[13] = _mm_srai_epi16(in[13], 6);
    in[14] = _mm_srai_epi16(in[14], 6);
    in[15] = _mm_srai_epi16(in[15], 6);
  
    RECON_AND_STORE(dest, in[0]);
    RECON_AND_STORE(dest, in[1]);
    RECON_AND_STORE(dest, in[2]);
    RECON_AND_STORE(dest, in[3]);
    RECON_AND_STORE(dest, in[4]);
    RECON_AND_STORE(dest, in[5]);
    RECON_AND_STORE(dest, in[6]);
    RECON_AND_STORE(dest, in[7]);
    RECON_AND_STORE(dest, in[8]);
    RECON_AND_STORE(dest, in[9]);
    RECON_AND_STORE(dest, in[10]);
    RECON_AND_STORE(dest, in[11]);
    RECON_AND_STORE(dest, in[12]);
    RECON_AND_STORE(dest, in[13]);
    RECON_AND_STORE(dest, in[14]);
    RECON_AND_STORE(dest, in[15]);
  }
  