text: /*
   * Copyright (c) 2018, Alliance for Open Media. All rights reserved
   *
   * This source code is subject to the terms of the BSD 2 Clause License and
   * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   * was not distributed with this source code in the LICENSE file, you can
   * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   * Media Patent License 1.0 was not distributed with this source code in the
  s * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
   */
  
  #include <xmmintrin.h>
  
  #include "EbDefinitions.h"
  #include "fft_common.h"
  
  static INLINE void transpose4x4(const float *A, float *B, const int32_t lda,
      const int32_t ldb) {
      __m128 row1 = _mm_load_ps(&A[0 * lda]);
      __m128 row2 = _mm_load_ps(&A[1 * lda]);
      __m128 row3 = _mm_load_ps(&A[2 * lda]);
      __m128 row4 = _mm_load_ps(&A[3 * lda]);
      _MM_TRANSPOSE4_PS(row1, row2, row3, row4);
      _mm_store_ps(&B[0 * ldb], row1);
      _mm_store_ps(&B[1 * ldb], row2);
      _mm_store_ps(&B[2 * ldb], row3);
      _mm_store_ps(&B[3 * ldb], row4);
  }
  
  void aom_transpose_float_sse2(const float *A, float *B, int32_t n) {
      for (int32_t y = 0; y < n; y += 4) {
          for (int32_t x = 0; x < n; x += 4)
              transpose4x4(A + y * n + x, B + x * n + y, n, n);
      }
  }
  
  void aom_fft_unpack_2d_output_sse2(const float *packed, float *output, int32_t n) {
      const int32_t n2 = n / 2;
      output[0] = packed[0];
      output[1] = 0;
      output[2 * (n2 * n)] = packed[n2 * n];
      output[2 * (n2 * n) + 1] = 0;
  
      output[2 * n2] = packed[n2];
      output[2 * n2 + 1] = 0;
      output[2 * (n2 * n + n2)] = packed[n2 * n + n2];
      output[2 * (n2 * n + n2) + 1] = 0;
  
      for (int32_t c = 1; c < n2; ++c) {
          output[2 * (0 * n + c)] = packed[c];
          output[2 * (0 * n + c) + 1] = packed[c + n2];
          output[2 * (n2 * n + c) + 0] = packed[n2 * n + c];
          output[2 * (n2 * n + c) + 1] = packed[n2 * n + c + n2];
      }
      for (int32_t r = 1; r < n2; ++r) {
          output[2 * (r * n + 0)] = packed[r * n];
          output[2 * (r * n + 0) + 1] = packed[(r + n2) * n];
          output[2 * (r * n + n2) + 0] = packed[r * n + n2];
          output[2 * (r * n + n2) + 1] = packed[(r + n2) * n + n2];
  
          for (int32_t c = 1; c < AOMMIN(n2, 4); ++c) {
              output[2 * (r * n + c)] =
                  packed[r * n + c] - packed[(r + n2) * n + c + n2];
              output[2 * (r * n + c) + 1] =
                  packed[(r + n2) * n + c] + packed[r * n + c + n2];
          }
  
          for (int32_t c = 4; c < n2; c += 4) {
              __m128 real1 = _mm_load_ps(packed + r * n + c);
              __m128 real2 = _mm_load_ps(packed + (r + n2) * n + c + n2);
              __m128 imag1 = _mm_load_ps(packed + (r + n2) * n + c);
              __m128 imag2 = _mm_load_ps(packed + r * n + c + n2);
              real1 = _mm_sub_ps(real1, real2);
              imag1 = _mm_add_ps(imag1, imag2);
              _mm_store_ps(output + 2 * (r * n + c), _mm_unpacklo_ps(real1, imag1));
              _mm_store_ps(output + 2 * (r * n + c + 2), _mm_unpackhi_ps(real1, imag1));
          }
  
          int32_t r2 = r + n2;
          int32_t r3 = n - r2;
          output[2 * (r2 * n + 0)] = packed[r3 * n];
          output[2 * (r2 * n + 0) + 1] = -packed[(r3 + n2) * n];
          output[2 * (r2 * n + n2)] = packed[r3 * n + n2];
          output[2 * (r2 * n + n2) + 1] = -packed[(r3 + n2) * n + n2];
          for (int32_t c = 1; c < AOMMIN(4, n2); ++c) {
              output[2 * (r2 * n + c)] =
                  packed[r3 * n + c] + packed[(r3 + n2) * n + c + n2];
              output[2 * (r2 * n + c) + 1] =
                  -packed[(r3 + n2) * n + c] + packed[r3 * n + c + n2];
          }
          for (int32_t c = 4; c < n2; c += 4) {
              __m128 real1 = _mm_load_ps(packed + r3 * n + c);
              __m128 real2 = _mm_load_ps(packed + (r3 + n2) * n + c + n2);
              __m128 imag1 = _mm_load_ps(packed + (r3 + n2) * n + c);
              __m128 imag2 = _mm_load_ps(packed + r3 * n + c + n2);
              real1 = _mm_add_ps(real1, real2);
              imag1 = _mm_sub_ps(imag2, imag1);
              _mm_store_ps(output + 2 * (r2 * n + c), _mm_unpacklo_ps(real1, imag1));
              _mm_store_ps(output + 2 * (r2 * n + c + 2),
                  _mm_unpackhi_ps(real1, imag1));
          }
      }
  }
  
  // Generate definitions for 1d transforms using float and __mm128
  GEN_FFT_4(static INLINE void, sse2, float, __m128, _mm_load_ps, _mm_store_ps,
      _mm_set1_ps, _mm_add_ps, _mm_sub_ps);
  
  void aom_fft4x4_float_sse2(const float *input, float *temp, float *output) {
      aom_fft_2d_gen(input, temp, output, 4, aom_fft1d_4_sse2,
          aom_transpose_float_sse2, aom_fft_unpack_2d_output_sse2, 4);
  }
  
  // Generate definitions for 1d inverse transforms using float and mm128
  GEN_IFFT_4(static INLINE void, sse2, float, __m128, _mm_load_ps, _mm_store_ps,
      _mm_set1_ps, _mm_add_ps, _mm_sub_ps);
  
  void aom_ifft4x4_float_sse2(const float *input, float *temp, float *output) {
      aom_ifft_2d_gen(input, temp, output, 4, aom_fft1d_4_float, aom_fft1d_4_sse2,
          aom_ifft1d_4_sse2, aom_transpose_float_sse2, 4);
  }
  