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hybrid_fwd_txfm_neon.c (2283B)


      1 /*
      2 * Copyright (c) 2020, 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 <arm_neon.h>
     13 
     14 #include "aom_dsp/txfm_common.h"
     15 #include "config/av1_rtcd.h"
     16 
     17 static void transpose4x4(int16x8_t in[2], int16x4_t out[4]) {
     18  int32x4x2_t b0 =
     19      vtrnq_s32(vreinterpretq_s32_s16(in[0]), vreinterpretq_s32_s16(in[1]));
     20  int16x4x2_t c0 = vtrn_s16(vreinterpret_s16_s32(vget_low_s32(b0.val[0])),
     21                            vreinterpret_s16_s32(vget_high_s32(b0.val[0])));
     22  int16x4x2_t c1 = vtrn_s16(vreinterpret_s16_s32(vget_low_s32(b0.val[1])),
     23                            vreinterpret_s16_s32(vget_high_s32(b0.val[1])));
     24  out[0] = c0.val[0];
     25  out[1] = c0.val[1];
     26  out[2] = c1.val[0];
     27  out[3] = c1.val[1];
     28 }
     29 
     30 void av1_fwht4x4_neon(const int16_t *input, tran_low_t *output, int stride) {
     31  // Load the 4x4 source in transposed form.
     32  int16x4_t a1, b1, c1, d1, e;
     33  a1 = vld1_s16(&input[0]);
     34  b1 = vld1_s16(&input[1 * stride]);
     35  c1 = vld1_s16(&input[2 * stride]);
     36  d1 = vld1_s16(&input[3 * stride]);
     37 
     38  // WHT.
     39 
     40  // Row transforms.
     41  a1 = vadd_s16(a1, b1);
     42  d1 = vsub_s16(d1, c1);
     43  e = vhsub_s16(a1, d1);
     44  b1 = vsub_s16(e, b1);
     45  c1 = vsub_s16(e, c1);
     46  a1 = vsub_s16(a1, c1);
     47  d1 = vadd_s16(d1, b1);
     48 
     49  int16x8_t x[2];
     50  x[0] = vcombine_s16(a1, c1);
     51  x[1] = vcombine_s16(d1, b1);
     52 
     53  int16x4_t s[4];
     54  transpose4x4(x, s);
     55 
     56  a1 = s[0];
     57  b1 = s[1];
     58  c1 = s[2];
     59  d1 = s[3];
     60 
     61  // Row transforms.
     62  a1 = vadd_s16(a1, b1);
     63  d1 = vsub_s16(d1, c1);
     64  e = vhsub_s16(a1, d1);
     65  b1 = vsub_s16(e, b1);
     66  c1 = vsub_s16(e, c1);
     67  a1 = vsub_s16(a1, c1);
     68  d1 = vadd_s16(d1, b1);
     69 
     70  vst1q_s32(&output[0], vshll_n_s16(a1, UNIT_QUANT_SHIFT));
     71  vst1q_s32(&output[4], vshll_n_s16(c1, UNIT_QUANT_SHIFT));
     72  vst1q_s32(&output[8], vshll_n_s16(d1, UNIT_QUANT_SHIFT));
     73  vst1q_s32(&output[12], vshll_n_s16(b1, UNIT_QUANT_SHIFT));
     74 }