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 <arm_neon.h>
  #include <assert.h>
  
  #include "./vpx_dsp_rtcd.h"
  #include "vpx_dsp/inv_txfm.h"
  
  static INLINE void idct4x4_1_add_kernel(uint8_t **dest, const int stride,
                                          const int16x8_t res,
                                          uint32x2_t *const d) {
    uint16x8_t a;
    uint8x8_t b;
    *d = vld1_lane_u32((const uint32_t *)*dest, *d, 0);
    *d = vld1_lane_u32((const uint32_t *)(*dest + stride), *d, 1);
    a = vaddw_u8(vreinterpretq_u16_s16(res), vreinterpret_u8_u32(*d));
    b = vqmovun_s16(vreinterpretq_s16_u16(a));
    vst1_lane_u32((uint32_t *)*dest, vreinterpret_u32_u8(b), 0);
    *dest += stride;
    vst1_lane_u32((uint32_t *)*dest, vreinterpret_u32_u8(b), 1);
    *dest += stride;
  }
  
  void vpx_idct4x4_1_add_neon(const tran_low_t *input, uint8_t *dest,
                              int stride) {
    const int16_t out0 = WRAPLOW(dct_const_round_shift(input[0] * cospi_16_64));
    const int16_t out1 = WRAPLOW(dct_const_round_shift(out0 * cospi_16_64));
    const int16_t a1 = ROUND_POWER_OF_TWO(out1, 4);
    const int16x8_t dc = vdupq_n_s16(a1);
    uint32x2_t d = vdup_n_u32(0);
  
    assert(!((intptr_t)dest % sizeof(uint32_t)));
    assert(!(stride % sizeof(uint32_t)));
  
    idct4x4_1_add_kernel(&dest, stride, dc, &d);
    idct4x4_1_add_kernel(&dest, stride, dc, &d);
  }
  