shithub: libvpx

ref: c2044fda1d00421ddab27c9fd80383546a8ba844
dir: /vpx_dsp/arm/fdct_partial_neon.c/

/*
 *  Copyright (c) 2017 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 <arm_neon.h>

#include "./vpx_dsp_rtcd.h"
#include "./vpx_config.h"
#include "vpx_dsp/arm/mem_neon.h"

static INLINE int32_t sum_int16x8(const int16x8_t a) {
  const int32x4_t b = vpaddlq_s16(a);
  const int64x2_t c = vpaddlq_s32(b);
  const int32x2_t d = vadd_s32(vreinterpret_s32_s64(vget_low_s64(c)),
                               vreinterpret_s32_s64(vget_high_s64(c)));
  return vget_lane_s32(d, 0);
}

void vpx_fdct4x4_1_neon(const int16_t *input, tran_low_t *output, int stride) {
  int16x4_t a0, a1, a2, a3;
  int16x8_t b0, b1;
  int16x8_t c;

  a0 = vld1_s16(input);
  input += stride;
  a1 = vld1_s16(input);
  input += stride;
  a2 = vld1_s16(input);
  input += stride;
  a3 = vld1_s16(input);

  b0 = vcombine_s16(a0, a1);
  b1 = vcombine_s16(a2, a3);

  c = vaddq_s16(b0, b1);

  output[0] = (tran_low_t)(sum_int16x8(c) << 1);
  output[1] = 0;
}

void vpx_fdct8x8_1_neon(const int16_t *input, tran_low_t *output, int stride) {
  int r;
  int16x8_t sum = vld1q_s16(&input[0]);
  for (r = 1; r < 8; ++r) {
    const int16x8_t input_00 = vld1q_s16(&input[r * stride]);
    sum = vaddq_s16(sum, input_00);
  }

  output[0] = (tran_low_t)sum_int16x8(sum);
  output[1] = 0;
}

void vpx_fdct16x16_1_neon(const int16_t *input, tran_low_t *output,
                          int stride) {
  int r;
  int16x8_t left = vld1q_s16(input);
  int16x8_t right = vld1q_s16(input + 8);
  input += stride;
  for (r = 1; r < 16; ++r) {
    const int16x8_t a = vld1q_s16(input);
    const int16x8_t b = vld1q_s16(input + 8);
    input += stride;
    left = vaddq_s16(left, a);
    right = vaddq_s16(right, b);
  }

  output[0] = (tran_low_t)((sum_int16x8(left) + sum_int16x8(right)) >> 1);
  output[1] = 0;
}

void vpx_fdct32x32_1_neon(const int16_t *input, tran_low_t *output,
                          int stride) {
  int r;
  int16x8_t a0 = vld1q_s16(input);
  int16x8_t a1 = vld1q_s16(input + 8);
  int16x8_t a2 = vld1q_s16(input + 16);
  int16x8_t a3 = vld1q_s16(input + 24);
  input += stride;
  for (r = 1; r < 32; ++r) {
    const int16x8_t b0 = vld1q_s16(input);
    const int16x8_t b1 = vld1q_s16(input + 8);
    const int16x8_t b2 = vld1q_s16(input + 16);
    const int16x8_t b3 = vld1q_s16(input + 24);
    input += stride;
    a0 = vaddq_s16(a0, b0);
    a1 = vaddq_s16(a1, b1);
    a2 = vaddq_s16(a2, b2);
    a3 = vaddq_s16(a3, b3);
  }

  // TODO(johannkoenig): sum and shift the values in neon registers.
  output[0] = (tran_low_t)(
      (sum_int16x8(a0) + sum_int16x8(a1) + sum_int16x8(a2) + sum_int16x8(a3)) >>
      3);
  output[1] = 0;
}