ref: 77c1b9d259149fb53d1c1852786568c4367ae85d
dir: /vpx_dsp/arm/idct4x4_add_neon.c/
/*
* 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/arm/idct_neon.h"
#include "vpx_dsp/arm/mem_neon.h"
#include "vpx_dsp/txfm_common.h"
void vpx_idct4x4_16_add_neon(const tran_low_t *input, uint8_t *dest,
int stride) {
const uint8_t *dst = dest;
uint32x2_t s32 = vdup_n_u32(0);
int16x8_t a[2];
uint8x8_t s, d[2];
uint16x8_t sum[2];
assert(!((intptr_t)dest % sizeof(uint32_t)));
assert(!(stride % sizeof(uint32_t)));
// Rows
a[0] = load_tran_low_to_s16q(input);
a[1] = load_tran_low_to_s16q(input + 8);
transpose_idct4x4_16_bd8(a);
// Columns
a[1] = vcombine_s16(vget_high_s16(a[1]), vget_low_s16(a[1]));
transpose_idct4x4_16_bd8(a);
a[0] = vrshrq_n_s16(a[0], 4);
a[1] = vrshrq_n_s16(a[1], 4);
s = load_u8(dst, stride);
dst += 2 * stride;
// The elements are loaded in reverse order.
s32 = vld1_lane_u32((const uint32_t *)dst, s32, 1);
dst += stride;
s32 = vld1_lane_u32((const uint32_t *)dst, s32, 0);
sum[0] = vaddw_u8(vreinterpretq_u16_s16(a[0]), s);
sum[1] = vaddw_u8(vreinterpretq_u16_s16(a[1]), vreinterpret_u8_u32(s32));
d[0] = vqmovun_s16(vreinterpretq_s16_u16(sum[0]));
d[1] = vqmovun_s16(vreinterpretq_s16_u16(sum[1]));
store_u8(dest, stride, d[0]);
dest += 2 * stride;
// The elements are stored in reverse order.
vst1_lane_u32((uint32_t *)dest, vreinterpret_u32_u8(d[1]), 1);
dest += stride;
vst1_lane_u32((uint32_t *)dest, vreinterpret_u32_u8(d[1]), 0);
}