ref: 264a7ecfd8ed4938378928deb4233c187562dbe5
dir: /vpx_dsp/x86/post_proc_sse2.c/
/*
* Copyright (c) 2018 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 <stdio.h>
#include "./vpx_dsp_rtcd.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/x86/mem_sse2.h"
extern const int16_t vpx_rv[];
void vpx_mbpost_proc_down_sse2(unsigned char *dst, int pitch, int rows,
int cols, int flimit) {
int col;
const __m128i zero = _mm_setzero_si128();
const __m128i f = _mm_set1_epi32(flimit);
DECLARE_ALIGNED(16, int16_t, above_context[8 * 8]);
// 8 columns are processed at a time.
// If rows is less than 8 the bottom border extension fails.
assert(cols % 8 == 0);
assert(rows >= 8);
for (col = 0; col < cols; col += 8) {
int row, i;
__m128i s = _mm_loadl_epi64((__m128i *)dst);
__m128i sum, sumsq_0, sumsq_1;
__m128i tmp_0, tmp_1;
__m128i below_context;
s = _mm_unpacklo_epi8(s, zero);
for (i = 0; i < 8; ++i) {
_mm_store_si128((__m128i *)above_context + i, s);
}
// sum *= 9
sum = _mm_slli_epi16(s, 3);
sum = _mm_add_epi16(s, sum);
// sum^2 * 9 == (sum * 9) * sum
tmp_0 = _mm_mullo_epi16(sum, s);
tmp_1 = _mm_mulhi_epi16(sum, s);
sumsq_0 = _mm_unpacklo_epi16(tmp_0, tmp_1);
sumsq_1 = _mm_unpackhi_epi16(tmp_0, tmp_1);
// Prime sum/sumsq
for (i = 1; i <= 6; ++i) {
__m128i a = _mm_loadl_epi64((__m128i *)(dst + i * pitch));
a = _mm_unpacklo_epi8(a, zero);
sum = _mm_add_epi16(sum, a);
a = _mm_mullo_epi16(a, a);
sumsq_0 = _mm_add_epi32(sumsq_0, _mm_unpacklo_epi16(a, zero));
sumsq_1 = _mm_add_epi32(sumsq_1, _mm_unpackhi_epi16(a, zero));
}
for (row = 0; row < rows + 8; row++) {
const __m128i above =
_mm_load_si128((__m128i *)above_context + (row & 7));
__m128i this_row = _mm_loadl_epi64((__m128i *)(dst + row * pitch));
__m128i above_sq, below_sq;
__m128i mask_0, mask_1;
__m128i multmp_0, multmp_1;
__m128i rv;
__m128i out;
this_row = _mm_unpacklo_epi8(this_row, zero);
if (row + 7 < rows) {
// Instead of copying the end context we just stop loading when we get
// to the last one.
below_context = _mm_loadl_epi64((__m128i *)(dst + (row + 7) * pitch));
below_context = _mm_unpacklo_epi8(below_context, zero);
}
sum = _mm_sub_epi16(sum, above);
sum = _mm_add_epi16(sum, below_context);
// context^2 fits in 16 bits. Don't need to mulhi and combine. Just zero
// extend. Unfortunately we can't do below_sq - above_sq in 16 bits
// because x86 does not have unpack with sign extension.
above_sq = _mm_mullo_epi16(above, above);
sumsq_0 = _mm_sub_epi32(sumsq_0, _mm_unpacklo_epi16(above_sq, zero));
sumsq_1 = _mm_sub_epi32(sumsq_1, _mm_unpackhi_epi16(above_sq, zero));
below_sq = _mm_mullo_epi16(below_context, below_context);
sumsq_0 = _mm_add_epi32(sumsq_0, _mm_unpacklo_epi16(below_sq, zero));
sumsq_1 = _mm_add_epi32(sumsq_1, _mm_unpackhi_epi16(below_sq, zero));
// sumsq * 16 - sumsq == sumsq * 15
mask_0 = _mm_slli_epi32(sumsq_0, 4);
mask_0 = _mm_sub_epi32(mask_0, sumsq_0);
mask_1 = _mm_slli_epi32(sumsq_1, 4);
mask_1 = _mm_sub_epi32(mask_1, sumsq_1);
multmp_0 = _mm_mullo_epi16(sum, sum);
multmp_1 = _mm_mulhi_epi16(sum, sum);
mask_0 = _mm_sub_epi32(mask_0, _mm_unpacklo_epi16(multmp_0, multmp_1));
mask_1 = _mm_sub_epi32(mask_1, _mm_unpackhi_epi16(multmp_0, multmp_1));
// mask - f gives a negative value when mask < f
mask_0 = _mm_sub_epi32(mask_0, f);
mask_1 = _mm_sub_epi32(mask_1, f);
// Shift the sign bit down to create a mask
mask_0 = _mm_srai_epi32(mask_0, 31);
mask_1 = _mm_srai_epi32(mask_1, 31);
mask_0 = _mm_packs_epi32(mask_0, mask_1);
rv = _mm_loadu_si128((__m128i const *)(vpx_rv + (row & 127)));
mask_1 = _mm_add_epi16(rv, sum);
mask_1 = _mm_add_epi16(mask_1, this_row);
mask_1 = _mm_srai_epi16(mask_1, 4);
mask_1 = _mm_and_si128(mask_0, mask_1);
mask_0 = _mm_andnot_si128(mask_0, this_row);
out = _mm_or_si128(mask_1, mask_0);
_mm_storel_epi64((__m128i *)(dst + row * pitch),
_mm_packus_epi16(out, zero));
_mm_store_si128((__m128i *)above_context + ((row + 8) & 7), this_row);
}
dst += 8;
}
}