ref: 6585fc753660873951a5fb4b037aca65a9faded2
dir: /vpx_dsp/arm/subtract_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_config.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/arm/mem_neon.h"
void vpx_subtract_block_neon(int rows, int cols, int16_t *diff,
ptrdiff_t diff_stride, const uint8_t *src,
ptrdiff_t src_stride, const uint8_t *pred,
ptrdiff_t pred_stride) {
int r = rows, c;
if (cols > 16) {
do {
for (c = 0; c < cols; c += 32) {
const uint8x16_t s0 = vld1q_u8(&src[c + 0]);
const uint8x16_t s1 = vld1q_u8(&src[c + 16]);
const uint8x16_t p0 = vld1q_u8(&pred[c + 0]);
const uint8x16_t p1 = vld1q_u8(&pred[c + 16]);
const uint16x8_t d0 = vsubl_u8(vget_low_u8(s0), vget_low_u8(p0));
const uint16x8_t d1 = vsubl_u8(vget_high_u8(s0), vget_high_u8(p0));
const uint16x8_t d2 = vsubl_u8(vget_low_u8(s1), vget_low_u8(p1));
const uint16x8_t d3 = vsubl_u8(vget_high_u8(s1), vget_high_u8(p1));
vst1q_s16(&diff[c + 0], vreinterpretq_s16_u16(d0));
vst1q_s16(&diff[c + 8], vreinterpretq_s16_u16(d1));
vst1q_s16(&diff[c + 16], vreinterpretq_s16_u16(d2));
vst1q_s16(&diff[c + 24], vreinterpretq_s16_u16(d3));
}
diff += diff_stride;
pred += pred_stride;
src += src_stride;
} while (--r);
} else if (cols > 8) {
do {
const uint8x16_t s = vld1q_u8(&src[0]);
const uint8x16_t p = vld1q_u8(&pred[0]);
const uint16x8_t d0 = vsubl_u8(vget_low_u8(s), vget_low_u8(p));
const uint16x8_t d1 = vsubl_u8(vget_high_u8(s), vget_high_u8(p));
vst1q_s16(&diff[0], vreinterpretq_s16_u16(d0));
vst1q_s16(&diff[8], vreinterpretq_s16_u16(d1));
diff += diff_stride;
pred += pred_stride;
src += src_stride;
} while (--r);
} else if (cols > 4) {
do {
const uint8x8_t s = vld1_u8(&src[0]);
const uint8x8_t p = vld1_u8(&pred[0]);
const uint16x8_t v_diff = vsubl_u8(s, p);
vst1q_s16(&diff[0], vreinterpretq_s16_u16(v_diff));
diff += diff_stride;
pred += pred_stride;
src += src_stride;
} while (--r);
} else {
assert(cols == 4);
do {
const uint8x8_t s = load_unaligned_u8(src, (int)src_stride);
const uint8x8_t p = load_unaligned_u8(pred, (int)pred_stride);
const uint16x8_t d = vsubl_u8(s, p);
vst1_s16(diff + 0 * diff_stride, vreinterpret_s16_u16(vget_low_u16(d)));
vst1_s16(diff + 1 * diff_stride, vreinterpret_s16_u16(vget_high_u16(d)));
diff += 2 * diff_stride;
pred += 2 * pred_stride;
src += 2 * src_stride;
r -= 2;
} while (r);
}
}