ref: 35e98a70ba65d82f0b94df3f5e453a3a9f0d6365
dir: /vpx_dsp/ppc/deblock_vsx.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 "./vpx_dsp_rtcd.h"
#include "vpx_dsp/ppc/types_vsx.h"
extern const int16_t vpx_rv[];
static const uint8x16_t load_merge = { 0x00, 0x02, 0x04, 0x06, 0x08, 0x0A,
0x0C, 0x0E, 0x18, 0x19, 0x1A, 0x1B,
0x1C, 0x1D, 0x1E, 0x1F };
static const uint8x16_t mask_merge = { 0x00, 0x01, 0x10, 0x11, 0x04, 0x05,
0x14, 0x15, 0x08, 0x09, 0x18, 0x19,
0x0C, 0x0D, 0x1C, 0x1D };
void vpx_mbpost_proc_down_vsx(uint8_t *dst, int pitch, int rows, int cols,
int flimit) {
int col, row, i;
int16x8_t window[16];
const int32x4_t lim = vec_splats(flimit);
// 8 columns are processed at a time.
assert(cols % 8 == 0);
// If rows is less than 8 the bottom border extension fails.
assert(rows >= 8);
for (col = 0; col < cols; col += 8) {
// The sum is signed and requires at most 13 bits.
// (8 bits + sign) * 15 (4 bits)
int16x8_t r1, sum;
// The sum of squares requires at most 20 bits.
// (16 bits + sign) * 15 (4 bits)
int32x4_t sumsq_even, sumsq_odd;
r1 = unpack_to_s16_h(vec_vsx_ld(0, dst));
// Fill sliding window with first row.
for (i = 0; i <= 8; i++) {
window[i] = r1;
}
// First 9 rows of the sliding window are the same.
// sum = r1 * 9
sum = vec_mladd(r1, vec_splats((int16_t)9), vec_zeros_s16);
// sumsq = r1 * r1 * 9
sumsq_even = vec_mule(sum, r1);
sumsq_odd = vec_mulo(sum, r1);
// Fill the next 6 rows of the sliding window with rows 2 to 7.
for (i = 1; i <= 6; ++i) {
const int16x8_t next_row = unpack_to_s16_h(vec_vsx_ld(i * pitch, dst));
window[i + 8] = next_row;
sum = vec_add(sum, next_row);
sumsq_odd = vec_add(sumsq_odd, vec_mulo(next_row, next_row));
sumsq_even = vec_add(sumsq_even, vec_mule(next_row, next_row));
}
for (row = 0; row < rows; row++) {
int32x4_t d15_even, d15_odd, d0_even, d0_odd;
int32x4_t sumsq_odd_scaled, sumsq_even_scaled;
int32x4_t thres_odd, thres_even;
bool32x4_t mask_odd, mask_even;
bool16x8_t mask;
int16x8_t filtered, masked;
uint8x16_t out;
const int16x8_t rv = vec_vsx_ld(0, vpx_rv + (row & 127));
// Move the sliding window
if (row + 7 < rows) {
window[15] = unpack_to_s16_h(vec_vsx_ld((row + 7) * pitch, dst));
} else {
window[15] = window[14];
}
// C: sum += s[7 * pitch] - s[-8 * pitch];
sum = vec_add(sum, vec_sub(window[15], window[0]));
// C: sumsq += s[7 * pitch] * s[7 * pitch] - s[-8 * pitch] * s[-8 *
// pitch];
// Optimization Note: Caching a squared-window for odd and even is
// slower than just repeating the multiplies.
d15_odd = vec_mulo(window[15], window[15]);
d15_even = vec_mule(window[15], window[15]);
d0_odd = vec_mulo(window[0], window[0]);
d0_even = vec_mule(window[0], window[0]);
sumsq_odd = vec_add(sumsq_odd, vec_sub(d15_odd, d0_odd));
sumsq_even = vec_add(sumsq_even, vec_sub(d15_even, d0_even));
// C: sumsq * 15 - sum * sum
sumsq_odd_scaled = vec_mul(sumsq_odd, vec_splats((int32_t)15));
sumsq_even_scaled = vec_mul(sumsq_even, vec_splats((int32_t)15));
thres_odd = vec_sub(sumsq_odd_scaled, vec_mulo(sum, sum));
thres_even = vec_sub(sumsq_even_scaled, vec_mule(sum, sum));
// C: (vpx_rv[(r & 127) + (c & 7)] + sum + s[0]) >> 4
filtered = vec_add(vec_add(rv, sum), window[8]);
filtered = vec_sra(filtered, vec_splats((uint16_t)4));
mask_odd = vec_cmplt(thres_odd, lim);
mask_even = vec_cmplt(thres_even, lim);
mask = vec_perm((bool16x8_t)mask_even, (bool16x8_t)mask_odd, mask_merge);
masked = vec_sel(window[8], filtered, mask);
// TODO(ltrudeau) If cols % 16 == 0, we could just process 16 per
// iteration
out = vec_perm((uint8x16_t)masked, vec_vsx_ld(0, dst + row * pitch),
load_merge);
vec_vsx_st(out, 0, dst + row * pitch);
// Optimization Note: Turns out that the following loop is faster than
// using pointers to manage the sliding window.
for (i = 1; i < 16; i++) {
window[i - 1] = window[i];
}
}
dst += 8;
}
}