ref: fe8cce2e36ff22d5426afe3271f9c7e32d8dc9ac
dir: /vpx_dsp/x86/avg_pred_sse2.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 <assert.h>
#include <emmintrin.h>
#include "./vpx_dsp_rtcd.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/x86/mem_sse2.h"
void vpx_comp_avg_pred_sse2(uint8_t *comp_pred, const uint8_t *pred, int width,
int height, const uint8_t *ref, int ref_stride) {
/* comp_pred and pred must be 16 byte aligned. */
assert(((intptr_t)comp_pred & 0xf) == 0);
assert(((intptr_t)pred & 0xf) == 0);
if (width > 8) {
int x, y;
for (y = 0; y < height; ++y) {
for (x = 0; x < width; x += 16) {
const __m128i p = _mm_load_si128((const __m128i *)(pred + x));
const __m128i r = _mm_loadu_si128((const __m128i *)(ref + x));
const __m128i avg = _mm_avg_epu8(p, r);
_mm_store_si128((__m128i *)(comp_pred + x), avg);
}
comp_pred += width;
pred += width;
ref += ref_stride;
}
} else { // width must be 4 or 8.
int i;
// Process 16 elements at a time. comp_pred and pred have width == stride
// and therefore live in contigious memory. 4*4, 4*8, 8*4, 8*8, and 8*16 are
// all divisible by 16 so just ref needs to be massaged when loading.
for (i = 0; i < width * height; i += 16) {
const __m128i p = _mm_load_si128((const __m128i *)pred);
__m128i r;
__m128i avg;
if (width == ref_stride) {
r = _mm_loadu_si128((const __m128i *)ref);
ref += 16;
} else if (width == 4) {
r = _mm_set_epi32(loadu_uint32(ref + 3 * ref_stride),
loadu_uint32(ref + 2 * ref_stride),
loadu_uint32(ref + ref_stride), loadu_uint32(ref));
ref += 4 * ref_stride;
} else {
const __m128i r_0 = _mm_loadl_epi64((const __m128i *)ref);
assert(width == 8);
r = _mm_castps_si128(_mm_loadh_pi(_mm_castsi128_ps(r_0),
(const __m64 *)(ref + ref_stride)));
ref += 2 * ref_stride;
}
avg = _mm_avg_epu8(p, r);
_mm_store_si128((__m128i *)comp_pred, avg);
pred += 16;
comp_pred += 16;
}
}
}