/*
 *  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 <arm_neon.h>

#include "./vpx_config.h"
#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/arm/idct_neon.h"
#include "vpx_dsp/arm/mem_neon.h"
#include "vpx_dsp/arm/transpose_neon.h"
#include "vpx_dsp/txfm_common.h"

static INLINE void idct8x8_add8x1(const int16x8_t a, uint8_t **const dest,
                                  const int stride) {
  const uint8x8_t s = vld1_u8(*dest);
  const int16x8_t res = vrshrq_n_s16(a, 5);
  const uint16x8_t q = vaddw_u8(vreinterpretq_u16_s16(res), s);
  const uint8x8_t d = vqmovun_s16(vreinterpretq_s16_u16(q));
  vst1_u8(*dest, d);
  *dest += stride;
}

static INLINE void add8x8(int16x8_t *const out, uint8_t *dest,
                          const int stride) {
  idct8x8_add8x1(out[0], &dest, stride);
  idct8x8_add8x1(out[1], &dest, stride);
  idct8x8_add8x1(out[2], &dest, stride);
  idct8x8_add8x1(out[3], &dest, stride);
  idct8x8_add8x1(out[4], &dest, stride);
  idct8x8_add8x1(out[5], &dest, stride);
  idct8x8_add8x1(out[6], &dest, stride);
  idct8x8_add8x1(out[7], &dest, stride);
}

void vpx_idct8x8_64_add_neon(const tran_low_t *input, uint8_t *dest,
                             int stride) {
  const int16x8_t cospis = vld1q_s16(kCospi);
  const int16x4_t cospis0 = vget_low_s16(cospis);   // cospi 0, 8, 16, 24
  const int16x4_t cospis1 = vget_high_s16(cospis);  // cospi 4, 12, 20, 28
  int16x8_t a[8];

  a[0] = load_tran_low_to_s16q(input);
  a[1] = load_tran_low_to_s16q(input + 8);
  a[2] = load_tran_low_to_s16q(input + 16);
  a[3] = load_tran_low_to_s16q(input + 24);
  a[4] = load_tran_low_to_s16q(input + 32);
  a[5] = load_tran_low_to_s16q(input + 40);
  a[6] = load_tran_low_to_s16q(input + 48);
  a[7] = load_tran_low_to_s16q(input + 56);

  idct8x8_64_1d_bd8(cospis0, cospis1, a);
  idct8x8_64_1d_bd8(cospis0, cospis1, a);
  add8x8(a, dest, stride);
}

void vpx_idct8x8_12_add_neon(const tran_low_t *input, uint8_t *dest,
                             int stride) {
  const int16x8_t cospis = vld1q_s16(kCospi);
  const int16x8_t cospisd = vaddq_s16(cospis, cospis);
  const int16x4_t cospis0 = vget_low_s16(cospis);     // cospi 0, 8, 16, 24
  const int16x4_t cospisd0 = vget_low_s16(cospisd);   // doubled 0, 8, 16, 24
  const int16x4_t cospisd1 = vget_high_s16(cospisd);  // doubled 4, 12, 20, 28
  int16x4_t a[8];
  int16x8_t b[8];

  a[0] = load_tran_low_to_s16d(input);
  a[1] = load_tran_low_to_s16d(input + 8);
  a[2] = load_tran_low_to_s16d(input + 16);
  a[3] = load_tran_low_to_s16d(input + 24);

  idct8x8_12_pass1_bd8(cospis0, cospisd0, cospisd1, a);
  idct8x8_12_pass2_bd8(cospis0, cospisd0, cospisd1, a, b);
  add8x8(b, dest, stride);
}