// Copyright 2021 The libgav1 Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/dsp/intrapred_directional.h"
#include "src/utils/cpu.h"
#if LIBGAV1_TARGETING_SSE4_1
#include <smmintrin.h>
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include "src/dsp/constants.h"
#include "src/dsp/dsp.h"
#include "src/dsp/x86/common_sse4.h"
#include "src/dsp/x86/transpose_sse4.h"
#include "src/utils/common.h"
#include "src/utils/memory.h"
namespace libgav1 {
namespace dsp {
namespace low_bitdepth {
namespace {
//------------------------------------------------------------------------------
// 7.11.2.4. Directional intra prediction process
// Special case: An |xstep| of 64 corresponds to an angle delta of 45, meaning
// upsampling is ruled out. In addition, the bits masked by 0x3F for
// |shift_val| are 0 for all multiples of 64, so the formula
// val = top[top_base_x]*shift + top[top_base_x+1]*(32-shift), reduces to
// val = top[top_base_x+1] << 5, meaning only the second set of pixels is
// involved in the output. Hence |top| is offset by 1.
inline void DirectionalZone1_Step64(uint8_t* dst, ptrdiff_t stride,
const uint8_t* const top, const int width,
const int height) {
ptrdiff_t offset = 1;
if (height == 4) {
memcpy(dst, top + offset, width);
dst += stride;
memcpy(dst, top + offset + 1, width);
dst += stride;
memcpy(dst, top + offset + 2, width);
dst += stride;
memcpy(dst, top + offset + 3, width);
return;
}
int y = 0;
do {
memcpy(dst, top + offset, width);
dst += stride;
memcpy(dst, top + offset + 1, width);
dst += stride;
memcpy(dst, top + offset + 2, width);
dst += stride;
memcpy(dst, top + offset + 3, width);
dst += stride;
memcpy(dst, top + offset + 4, width);
dst += stride;
memcpy(dst, top + offset + 5, width);
dst += stride;
memcpy(dst, top + offset + 6, width);
dst += stride;
memcpy(dst, top + offset + 7, width);
dst += stride;
offset += 8;
y += 8;
} while (y < height);
}
inline void DirectionalZone1_4xH(uint8_t* dst, ptrdiff_t stride,
const uint8_t* const top, const int height,
const int xstep, const bool upsampled) {
const int upsample_shift = static_cast<int>(upsampled);
const int scale_bits = 6 - upsample_shift;
const __m128i max_shift = _mm_set1_epi8(32);
// Downscaling for a weighted average whose weights sum to 32 (max_shift).
const int rounding_bits = 5;
const int max_base_x = (height + 3 /* width - 1 */) << upsample_shift;
const __m128i final_top_val = _mm_set1_epi16(top[max_base_x]);
const __m128i sampler = upsampled ? _mm_set_epi64x(0, 0x0706050403020100)
: _mm_set_epi64x(0, 0x0403030202010100);
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to the top_base_x, it is used to mask values
// that pass the end of |top|. Starting from 1 to simulate "cmpge" which is
// not supported for packed integers.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
// All rows from |min_corner_only_y| down will simply use memcpy. |max_base_x|
// is always greater than |height|, so clipping to 1 is enough to make the
// logic work.
const int xstep_units = std::max(xstep >> scale_bits, 1);
const int min_corner_only_y = std::min(max_base_x / xstep_units, height);
// Rows up to this y-value can be computed without checking for bounds.
int y = 0;
int top_x = xstep;
for (; y < min_corner_only_y; ++y, dst += stride, top_x += xstep) {
const int top_base_x = top_x >> scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
// Load 8 values because we will select the sampled values based on
// |upsampled|.
const __m128i values = LoadLo8(top + top_base_x);
const __m128i sampled_values = _mm_shuffle_epi8(values, sampler);
const __m128i past_max = _mm_cmpgt_epi16(top_index_vect, max_base_x_vect);
__m128i prod = _mm_maddubs_epi16(sampled_values, shifts);
prod = RightShiftWithRounding_U16(prod, rounding_bits);
// Replace pixels from invalid range with top-right corner.
prod = _mm_blendv_epi8(prod, final_top_val, past_max);
Store4(dst, _mm_packus_epi16(prod, prod));
}
// Fill in corner-only rows.
for (; y < height; ++y) {
memset(dst, top[max_base_x], /* width */ 4);
dst += stride;
}
}
// 7.11.2.4 (7) angle < 90
inline void DirectionalZone1_Large(uint8_t* dest, ptrdiff_t stride,
const uint8_t* const top_row,
const int width, const int height,
const int xstep, const bool upsampled) {
const int upsample_shift = static_cast<int>(upsampled);
const __m128i sampler =
upsampled ? _mm_set_epi32(0x0F0E0D0C, 0x0B0A0908, 0x07060504, 0x03020100)
: _mm_set_epi32(0x08070706, 0x06050504, 0x04030302, 0x02010100);
const int scale_bits = 6 - upsample_shift;
const int max_base_x = ((width + height) - 1) << upsample_shift;
const __m128i max_shift = _mm_set1_epi8(32);
// Downscaling for a weighted average whose weights sum to 32 (max_shift).
const int rounding_bits = 5;
const int base_step = 1 << upsample_shift;
const int base_step8 = base_step << 3;
// All rows from |min_corner_only_y| down will simply use memcpy. |max_base_x|
// is always greater than |height|, so clipping to 1 is enough to make the
// logic work.
const int xstep_units = std::max(xstep >> scale_bits, 1);
const int min_corner_only_y = std::min(max_base_x / xstep_units, height);
// Rows up to this y-value can be computed without checking for bounds.
const int max_no_corner_y = std::min(
LeftShift((max_base_x - (base_step * width)), scale_bits) / xstep,
height);
// No need to check for exceeding |max_base_x| in the first loop.
int y = 0;
int top_x = xstep;
for (; y < max_no_corner_y; ++y, dest += stride, top_x += xstep) {
int top_base_x = top_x >> scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
int x = 0;
do {
const __m128i top_vals = LoadUnaligned16(top_row + top_base_x);
__m128i vals = _mm_shuffle_epi8(top_vals, sampler);
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
StoreLo8(dest + x, _mm_packus_epi16(vals, vals));
top_base_x += base_step8;
x += 8;
} while (x < width);
}
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to the top_base_x, it is used to mask values
// that pass the end of |top|. Starting from 1 to simulate "cmpge" which is
// not supported for packed integers.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
const __m128i final_top_val = _mm_set1_epi16(top_row[max_base_x]);
const __m128i base_step8_vect = _mm_set1_epi16(base_step8);
for (; y < min_corner_only_y; ++y, dest += stride, top_x += xstep) {
int top_base_x = top_x >> scale_bits;
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
int x = 0;
const int min_corner_only_x =
std::min(width, ((max_base_x - top_base_x) >> upsample_shift) + 7) & ~7;
for (; x < min_corner_only_x;
x += 8, top_base_x += base_step8,
top_index_vect = _mm_add_epi16(top_index_vect, base_step8_vect)) {
const __m128i past_max = _mm_cmpgt_epi16(top_index_vect, max_base_x_vect);
// Assuming a buffer zone of 8 bytes at the end of top_row, this prevents
// reading out of bounds. If all indices are past max and we don't need to
// use the loaded bytes at all, |top_base_x| becomes 0. |top_base_x| will
// reset for the next |y|.
top_base_x &= ~_mm_cvtsi128_si32(past_max);
const __m128i top_vals = LoadUnaligned16(top_row + top_base_x);
__m128i vals = _mm_shuffle_epi8(top_vals, sampler);
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
vals = _mm_blendv_epi8(vals, final_top_val, past_max);
StoreLo8(dest + x, _mm_packus_epi16(vals, vals));
}
// Corner-only section of the row.
memset(dest + x, top_row[max_base_x], width - x);
}
// Fill in corner-only rows.
for (; y < height; ++y) {
memset(dest, top_row[max_base_x], width);
dest += stride;
}
}
// 7.11.2.4 (7) angle < 90
inline void DirectionalZone1_SSE4_1(uint8_t* dest, ptrdiff_t stride,
const uint8_t* const top_row,
const int width, const int height,
const int xstep, const bool upsampled) {
const int upsample_shift = static_cast<int>(upsampled);
if (xstep == 64) {
DirectionalZone1_Step64(dest, stride, top_row, width, height);
return;
}
if (width == 4) {
DirectionalZone1_4xH(dest, stride, top_row, height, xstep, upsampled);
return;
}
if (width >= 32) {
DirectionalZone1_Large(dest, stride, top_row, width, height, xstep,
upsampled);
return;
}
const __m128i sampler =
upsampled ? _mm_set_epi32(0x0F0E0D0C, 0x0B0A0908, 0x07060504, 0x03020100)
: _mm_set_epi32(0x08070706, 0x06050504, 0x04030302, 0x02010100);
const int scale_bits = 6 - upsample_shift;
const int max_base_x = ((width + height) - 1) << upsample_shift;
const __m128i max_shift = _mm_set1_epi8(32);
// Downscaling for a weighted average whose weights sum to 32 (max_shift).
const int rounding_bits = 5;
const int base_step = 1 << upsample_shift;
const int base_step8 = base_step << 3;
// No need to check for exceeding |max_base_x| in the loops.
if (((xstep * height) >> scale_bits) + base_step * width < max_base_x) {
int top_x = xstep;
int y = 0;
do {
int top_base_x = top_x >> scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
int x = 0;
do {
const __m128i top_vals = LoadUnaligned16(top_row + top_base_x);
__m128i vals = _mm_shuffle_epi8(top_vals, sampler);
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
StoreLo8(dest + x, _mm_packus_epi16(vals, vals));
top_base_x += base_step8;
x += 8;
} while (x < width);
dest += stride;
top_x += xstep;
} while (++y < height);
return;
}
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to the top_base_x, it is used to mask values
// that pass the end of |top|. Starting from 1 to simulate "cmpge" which is
// not supported for packed integers.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
const __m128i final_top_val = _mm_set1_epi16(top_row[max_base_x]);
const __m128i base_step8_vect = _mm_set1_epi16(base_step8);
int top_x = xstep;
int y = 0;
do {
int top_base_x = top_x >> scale_bits;
if (top_base_x >= max_base_x) {
for (int i = y; i < height; ++i) {
memset(dest, top_row[max_base_x], width);
dest += stride;
}
return;
}
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
int x = 0;
for (; x < width - 8;
x += 8, top_base_x += base_step8,
top_index_vect = _mm_add_epi16(top_index_vect, base_step8_vect)) {
const __m128i past_max = _mm_cmpgt_epi16(top_index_vect, max_base_x_vect);
// Assuming a buffer zone of 8 bytes at the end of top_row, this prevents
// reading out of bounds. If all indices are past max and we don't need to
// use the loaded bytes at all, |top_base_x| becomes 0. |top_base_x| will
// reset for the next |y|.
top_base_x &= ~_mm_cvtsi128_si32(past_max);
const __m128i top_vals = LoadUnaligned16(top_row + top_base_x);
__m128i vals = _mm_shuffle_epi8(top_vals, sampler);
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
vals = _mm_blendv_epi8(vals, final_top_val, past_max);
StoreLo8(dest + x, _mm_packus_epi16(vals, vals));
}
const __m128i past_max = _mm_cmpgt_epi16(top_index_vect, max_base_x_vect);
__m128i vals;
if (upsampled) {
vals = LoadUnaligned16(top_row + top_base_x);
} else {
const __m128i top_vals = LoadLo8(top_row + top_base_x);
vals = _mm_shuffle_epi8(top_vals, sampler);
vals = _mm_insert_epi8(vals, top_row[top_base_x + 8], 15);
}
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
vals = _mm_blendv_epi8(vals, final_top_val, past_max);
StoreLo8(dest + x, _mm_packus_epi16(vals, vals));
dest += stride;
top_x += xstep;
} while (++y < height);
}
void DirectionalIntraPredictorZone1_SSE4_1(void* const dest, ptrdiff_t stride,
const void* const top_row,
const int width, const int height,
const int xstep,
const bool upsampled_top) {
const auto* const top_ptr = static_cast<const uint8_t*>(top_row);
auto* dst = static_cast<uint8_t*>(dest);
DirectionalZone1_SSE4_1(dst, stride, top_ptr, width, height, xstep,
upsampled_top);
}
template <bool upsampled>
inline void DirectionalZone3_4x4(uint8_t* dest, ptrdiff_t stride,
const uint8_t* const left_column,
const int base_left_y, const int ystep) {
// For use in the non-upsampled case.
const __m128i sampler = _mm_set_epi64x(0, 0x0403030202010100);
const int upsample_shift = static_cast<int>(upsampled);
const int scale_bits = 6 - upsample_shift;
const __m128i max_shift = _mm_set1_epi8(32);
// Downscaling for a weighted average whose weights sum to 32 (max_shift).
const int rounding_bits = 5;
__m128i result_block[4];
for (int x = 0, left_y = base_left_y; x < 4; x++, left_y += ystep) {
const int left_base_y = left_y >> scale_bits;
const int shift_val = ((left_y << upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
__m128i vals;
if (upsampled) {
vals = LoadLo8(left_column + left_base_y);
} else {
const __m128i top_vals = LoadLo8(left_column + left_base_y);
vals = _mm_shuffle_epi8(top_vals, sampler);
}
vals = _mm_maddubs_epi16(vals, shifts);
vals = RightShiftWithRounding_U16(vals, rounding_bits);
result_block[x] = _mm_packus_epi16(vals, vals);
}
const __m128i result = Transpose4x4_U8(result_block);
// This is result_row0.
Store4(dest, result);
dest += stride;
const int result_row1 = _mm_extract_epi32(result, 1);
memcpy(dest, &result_row1, sizeof(result_row1));
dest += stride;
const int result_row2 = _mm_extract_epi32(result, 2);
memcpy(dest, &result_row2, sizeof(result_row2));
dest += stride;
const int result_row3 = _mm_extract_epi32(result, 3);
memcpy(dest, &result_row3, sizeof(result_row3));
}
template <bool upsampled, int height>
inline void DirectionalZone3_8xH(uint8_t* dest, ptrdiff_t stride,
const uint8_t* const left_column,
const int base_left_y, const int ystep) {
// For use in the non-upsampled case.
const __m128i sampler =
_mm_set_epi64x(0x0807070606050504, 0x0403030202010100);
const int upsample_shift = static_cast<int>(upsampled);
const int scale_bits = 6 - upsample_shift;
const __m128i max_shift = _mm_set1_epi8(32);
// Downscaling for a weighted average whose weights sum to 32 (max_shift).
const int rounding_bits = 5;
__m128i result_block[8];
for (int x = 0, left_y = base_left_y; x < 8; x++, left_y += ystep) {
const int left_base_y = left_y >> scale_bits;
const int shift_val = (LeftShift(left_y, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi8(shift_val);
const __m128i opposite_shift = _mm_sub_epi8(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi8(opposite_shift, shift);
__m128i vals;
if (upsampled) {
vals = LoadUnaligned16(left_column + left_base_y);
} else {
const __m128i top_vals = LoadUnaligned16(left_column + left_base_y);
vals = _mm_shuffle_epi8(top_vals, sampler);
}
vals = _mm_maddubs_epi16(vals, shifts);
result_block[x] = RightShiftWithRounding_U16(vals, rounding_bits);
}
Transpose8x8_U16(result_block, result_block);
for (int y = 0; y < height; ++y) {
StoreLo8(dest, _mm_packus_epi16(result_block[y], result_block[y]));
dest += stride;
}
}
// 7.11.2.4 (9) angle > 180
void DirectionalIntraPredictorZone3_SSE4_1(void* dest, ptrdiff_t stride,
const void* const left_column,
const int width, const int height,
const int ystep,
const bool upsampled) {
const auto* const left_ptr = static_cast<const uint8_t*>(left_column);
auto* dst = static_cast<uint8_t*>(dest);
const int upsample_shift = static_cast<int>(upsampled);
if (width == 4 || height == 4) {
const ptrdiff_t stride4 = stride << 2;
if (upsampled) {
int left_y = ystep;
int x = 0;
do {
uint8_t* dst_x = dst + x;
int y = 0;
do {
DirectionalZone3_4x4<true>(
dst_x, stride, left_ptr + (y << upsample_shift), left_y, ystep);
dst_x += stride4;
y += 4;
} while (y < height);
left_y += ystep << 2;
x += 4;
} while (x < width);
} else {
int left_y = ystep;
int x = 0;
do {
uint8_t* dst_x = dst + x;
int y = 0;
do {
DirectionalZone3_4x4<false>(dst_x, stride, left_ptr + y, left_y,
ystep);
dst_x += stride4;
y += 4;
} while (y < height);
left_y += ystep << 2;
x += 4;
} while (x < width);
}
return;
}
const ptrdiff_t stride8 = stride << 3;
if (upsampled) {
int left_y = ystep;
int x = 0;
do {
uint8_t* dst_x = dst + x;
int y = 0;
do {
DirectionalZone3_8xH<true, 8>(
dst_x, stride, left_ptr + (y << upsample_shift), left_y, ystep);
dst_x += stride8;
y += 8;
} while (y < height);
left_y += ystep << 3;
x += 8;
} while (x < width);
} else {
int left_y = ystep;
int x = 0;
do {
uint8_t* dst_x = dst + x;
int y = 0;
do {
DirectionalZone3_8xH<false, 8>(
dst_x, stride, left_ptr + (y << upsample_shift), left_y, ystep);
dst_x += stride8;
y += 8;
} while (y < height);
left_y += ystep << 3;
x += 8;
} while (x < width);
}
}
//------------------------------------------------------------------------------
// Directional Zone 2 Functions
// 7.11.2.4 (8)
// DirectionalBlend* selectively overwrites the values written by
// DirectionalZone2FromLeftCol*. |zone_bounds| has one 16-bit index for each
// row.
template <int y_selector>
inline void DirectionalBlend4_SSE4_1(uint8_t* dest,
const __m128i& dest_index_vect,
const __m128i& vals,
const __m128i& zone_bounds) {
const __m128i max_dest_x_vect = _mm_shufflelo_epi16(zone_bounds, y_selector);
const __m128i use_left = _mm_cmplt_epi16(dest_index_vect, max_dest_x_vect);
const __m128i original_vals = _mm_cvtepu8_epi16(Load4(dest));
const __m128i blended_vals = _mm_blendv_epi8(vals, original_vals, use_left);
Store4(dest, _mm_packus_epi16(blended_vals, blended_vals));
}
inline void DirectionalBlend8_SSE4_1(uint8_t* dest,
const __m128i& dest_index_vect,
const __m128i& vals,
const __m128i& zone_bounds,
const __m128i& bounds_selector) {
const __m128i max_dest_x_vect =
_mm_shuffle_epi8(zone_bounds, bounds_selector);
const __m128i use_left = _mm_cmplt_epi16(dest_index_vect, max_dest_x_vect);
const __m128i original_vals = _mm_cvtepu8_epi16(LoadLo8(dest));
const __m128i blended_vals = _mm_blendv_epi8(vals, original_vals, use_left);
StoreLo8(dest, _mm_packus_epi16(blended_vals, blended_vals));
}
constexpr int kDirectionalWeightBits = 5;
// |source| is packed with 4 or 8 pairs of 8-bit values from left or top.
// |shifts| is named to match the specification, with 4 or 8 pairs of (32 -
// shift) and shift. Shift is guaranteed to be between 0 and 32.
inline __m128i DirectionalZone2FromSource_SSE4_1(const uint8_t* const source,
const __m128i& shifts,
const __m128i& sampler) {
const __m128i src_vals = LoadUnaligned16(source);
__m128i vals = _mm_shuffle_epi8(src_vals, sampler);
vals = _mm_maddubs_epi16(vals, shifts);
return RightShiftWithRounding_U16(vals, kDirectionalWeightBits);
}
// Because the source values "move backwards" as the row index increases, the
// indices derived from ystep are generally negative. This is accommodated by
// making sure the relative indices are within [-15, 0] when the function is
// called, and sliding them into the inclusive range [0, 15], relative to a
// lower base address.
constexpr int kPositiveIndexOffset = 15;
template <bool upsampled>
inline void DirectionalZone2FromLeftCol_4x4_SSE4_1(
uint8_t* dst, ptrdiff_t stride, const uint8_t* const left_column_base,
__m128i left_y) {
const int upsample_shift = static_cast<int>(upsampled);
const int scale_bits = 6 - upsample_shift;
const __m128i max_shifts = _mm_set1_epi8(32);
const __m128i shift_mask = _mm_set1_epi32(0x003F003F);
const __m128i index_increment = _mm_cvtsi32_si128(0x01010101);
const __m128i positive_offset = _mm_set1_epi8(kPositiveIndexOffset);
// Left_column and sampler are both offset by 15 so the indices are always
// positive.
const uint8_t* left_column = left_column_base - kPositiveIndexOffset;
for (int y = 0; y < 4; dst += stride, ++y) {
__m128i offset_y = _mm_srai_epi16(left_y, scale_bits);
offset_y = _mm_packs_epi16(offset_y, offset_y);
const __m128i adjacent = _mm_add_epi8(offset_y, index_increment);
__m128i sampler = _mm_unpacklo_epi8(offset_y, adjacent);
// Slide valid |offset_y| indices from range [-15, 0] to [0, 15] so they
// can work as shuffle indices. Some values may be out of bounds, but their
// pred results will be masked over by top prediction.
sampler = _mm_add_epi8(sampler, positive_offset);
__m128i shifts = _mm_srli_epi16(
_mm_and_si128(_mm_slli_epi16(left_y, upsample_shift), shift_mask), 1);
shifts = _mm_packus_epi16(shifts, shifts);
const __m128i opposite_shifts = _mm_sub_epi8(max_shifts, shifts);
shifts = _mm_unpacklo_epi8(opposite_shifts, shifts);
const __m128i vals = DirectionalZone2FromSource_SSE4_1(
left_column + (y << upsample_shift), shifts, sampler);
Store4(dst, _mm_packus_epi16(vals, vals));
}
}
template <bool upsampled>
inline void DirectionalZone2FromLeftCol_8x8_SSE4_1(
uint8_t* dst, ptrdiff_t stride, const uint8_t* const left_column,
__m128i left_y) {
const int upsample_shift = static_cast<int>(upsampled);
const int scale_bits = 6 - upsample_shift;
const __m128i max_shifts = _mm_set1_epi8(32);
const __m128i shift_mask = _mm_set1_epi32(0x003F003F);
const __m128i index_increment = _mm_set1_epi8(1);
const __m128i denegation = _mm_set1_epi8(kPositiveIndexOffset);
for (int y = 0; y < 8; dst += stride, ++y) {
__m128i offset_y = _mm_srai_epi16(left_y, scale_bits);
offset_y = _mm_packs_epi16(offset_y, offset_y);
const __m128i adjacent = _mm_add_epi8(offset_y, index_increment);
// Offset the relative index because ystep is negative in Zone 2 and shuffle
// indices must be nonnegative.
__m128i sampler = _mm_unpacklo_epi8(offset_y, adjacent);
sampler = _mm_add_epi8(sampler, denegation);
__m128i shifts = _mm_srli_epi16(
_mm_and_si128(_mm_slli_epi16(left_y, upsample_shift), shift_mask), 1);
shifts = _mm_packus_epi16(shifts, shifts);
const __m128i opposite_shifts = _mm_sub_epi8(max_shifts, shifts);
shifts = _mm_unpacklo_epi8(opposite_shifts, shifts);
// The specification adds (y << 6) to left_y, which is subject to
// upsampling, but this puts sampler indices out of the 0-15 range. It is
// equivalent to offset the source address by (y << upsample_shift) instead.
const __m128i vals = DirectionalZone2FromSource_SSE4_1(
left_column - kPositiveIndexOffset + (y << upsample_shift), shifts,
sampler);
StoreLo8(dst, _mm_packus_epi16(vals, vals));
}
}
// |zone_bounds| is an epi16 of the relative x index at which base >= -(1 <<
// upsampled_top), for each row. When there are 4 values, they can be duplicated
// with a non-register shuffle mask.
// |shifts| is one pair of weights that applies throughout a given row.
template <bool upsampled_top>
inline void DirectionalZone1Blend_4x4(
uint8_t* dest, const uint8_t* const top_row, ptrdiff_t stride,
__m128i sampler, const __m128i& zone_bounds, const __m128i& shifts,
const __m128i& dest_index_x, int top_x, const int xstep) {
const int upsample_shift = static_cast<int>(upsampled_top);
const int scale_bits_x = 6 - upsample_shift;
top_x -= xstep;
int top_base_x = (top_x >> scale_bits_x);
const __m128i vals0 = DirectionalZone2FromSource_SSE4_1(
top_row + top_base_x, _mm_shufflelo_epi16(shifts, 0x00), sampler);
DirectionalBlend4_SSE4_1<0x00>(dest, dest_index_x, vals0, zone_bounds);
top_x -= xstep;
dest += stride;
top_base_x = (top_x >> scale_bits_x);
const __m128i vals1 = DirectionalZone2FromSource_SSE4_1(
top_row + top_base_x, _mm_shufflelo_epi16(shifts, 0x55), sampler);
DirectionalBlend4_SSE4_1<0x55>(dest, dest_index_x, vals1, zone_bounds);
top_x -= xstep;
dest += stride;
top_base_x = (top_x >> scale_bits_x);
const __m128i vals2 = DirectionalZone2FromSource_SSE4_1(
top_row + top_base_x, _mm_shufflelo_epi16(shifts, 0xAA), sampler);
DirectionalBlend4_SSE4_1<0xAA>(dest, dest_index_x, vals2, zone_bounds);
top_x -= xstep;
dest += stride;
top_base_x = (top_x >> scale_bits_x);
const __m128i vals3 = DirectionalZone2FromSource_SSE4_1(
top_row + top_base_x, _mm_shufflelo_epi16(shifts, 0xFF), sampler);
DirectionalBlend4_SSE4_1<0xFF>(dest, dest_index_x, vals3, zone_bounds);
}
template <bool upsampled_top, int height>
inline void DirectionalZone1Blend_8xH(
uint8_t* dest, const uint8_t* const top_row, ptrdiff_t stride,
__m128i sampler, const __m128i& zone_bounds, const __m128i& shifts,
const __m128i& dest_index_x, int top_x, const int xstep) {
const int upsample_shift = static_cast<int>(upsampled_top);
const int scale_bits_x = 6 - upsample_shift;
__m128i y_selector = _mm_set1_epi32(0x01000100);
const __m128i index_increment = _mm_set1_epi32(0x02020202);
for (int y = 0; y < height; ++y,
y_selector = _mm_add_epi8(y_selector, index_increment),
dest += stride) {
top_x -= xstep;
const int top_base_x = top_x >> scale_bits_x;
const __m128i vals = DirectionalZone2FromSource_SSE4_1(
top_row + top_base_x, _mm_shuffle_epi8(shifts, y_selector), sampler);
DirectionalBlend8_SSE4_1(dest, dest_index_x, vals, zone_bounds, y_selector);
}
}
template <bool shuffle_left_column, bool upsampled_left, bool upsampled_top>
inline void DirectionalZone2_8xH(
uint8_t* LIBGAV1_RESTRICT const dst, const ptrdiff_t stride,
const uint8_t* LIBGAV1_RESTRICT const top_row,
const uint8_t* LIBGAV1_RESTRICT const left_column, const int height,
const int xstep, const int ystep, const int x, const int left_offset,
const __m128i& xstep_for_shift, const __m128i& xstep_bounds_base,
const __m128i& left_y) {
const int upsample_left_shift = static_cast<int>(upsampled_left);
const int upsample_top_shift = static_cast<int>(upsampled_top);
// Loop incrementers for moving by block (8x8). This function handles blocks
// with height 4 as well. They are calculated in one pass so these variables
// do not get used.
const ptrdiff_t stride8 = stride << 3;
const int xstep8 = xstep << 3;
const __m128i xstep8_vect = _mm_set1_epi16(xstep8);
// Cover 8x4 case.
const int min_height = (height == 4) ? 4 : 8;
// The first stage, before the first y-loop, covers blocks that are only
// computed from the top row. The second stage, comprising two y-loops, covers
// blocks that have a mixture of values computed from top or left. The final
// stage covers blocks that are only computed from the left.
uint8_t* dst_x = dst + x;
// Round down to the nearest multiple of 8 (or 4, if height is 4).
const int max_top_only_y =
std::min(((x + 1) << 6) / xstep, height) & ~(min_height - 1);
DirectionalZone1_4xH(dst_x, stride, top_row + (x << upsample_top_shift),
max_top_only_y, -xstep, upsampled_top);
DirectionalZone1_4xH(dst_x + 4, stride,
top_row + ((x + 4) << upsample_top_shift),
max_top_only_y, -xstep, upsampled_top);
if (max_top_only_y == height) return;
const __m128i max_shift = _mm_set1_epi8(32);
const __m128i shift_mask = _mm_set1_epi32(0x003F003F);
const __m128i dest_index_x =
_mm_set_epi32(0x00070006, 0x00050004, 0x00030002, 0x00010000);
const __m128i sampler_top =
upsampled_top
? _mm_set_epi32(0x0F0E0D0C, 0x0B0A0908, 0x07060504, 0x03020100)
: _mm_set_epi32(0x08070706, 0x06050504, 0x04030302, 0x02010100);
int y = max_top_only_y;
dst_x += stride * y;
const int xstep_y = xstep * y;
const __m128i xstep_y_vect = _mm_set1_epi16(xstep_y);
// All rows from |min_left_only_y| down for this set of columns, only need
// |left_column| to compute.
const int min_left_only_y =
Align(std::min(((x + 8) << 6) / xstep, height), 8);
__m128i xstep_bounds = _mm_add_epi16(xstep_bounds_base, xstep_y_vect);
__m128i xstep_for_shift_y = _mm_sub_epi16(xstep_for_shift, xstep_y_vect);
int top_x = -xstep_y;
const auto base_left_y = static_cast<int16_t>(_mm_extract_epi16(left_y, 0));
for (; y < min_left_only_y;
y += 8, dst_x += stride8,
xstep_bounds = _mm_add_epi16(xstep_bounds, xstep8_vect),
xstep_for_shift_y = _mm_sub_epi16(xstep_for_shift_y, xstep8_vect),
top_x -= xstep8) {
// Pick up from the last y-value, using the 10% slower but secure method for
// left prediction.
if (shuffle_left_column) {
DirectionalZone2FromLeftCol_8x8_SSE4_1<upsampled_left>(
dst_x, stride,
left_column + ((left_offset + y) << upsample_left_shift), left_y);
} else {
DirectionalZone3_8xH<upsampled_left, 8>(
dst_x, stride,
left_column + ((left_offset + y) << upsample_left_shift), base_left_y,
-ystep);
}
__m128i shifts = _mm_srli_epi16(
_mm_and_si128(_mm_slli_epi16(xstep_for_shift_y, upsample_top_shift),
shift_mask),
1);
shifts = _mm_packus_epi16(shifts, shifts);
__m128i opposite_shifts = _mm_sub_epi8(max_shift, shifts);
shifts = _mm_unpacklo_epi8(opposite_shifts, shifts);
__m128i xstep_bounds_off = _mm_srai_epi16(xstep_bounds, 6);
DirectionalZone1Blend_8xH<upsampled_top, 8>(
dst_x, top_row + (x << upsample_top_shift), stride, sampler_top,
xstep_bounds_off, shifts, dest_index_x, top_x, xstep);
}
// Loop over y for left_only rows.
for (; y < height; y += 8, dst_x += stride8) {
DirectionalZone3_8xH<upsampled_left, 8>(
dst_x, stride, left_column + ((left_offset + y) << upsample_left_shift),
base_left_y, -ystep);
}
}
// 7.11.2.4 (8) 90 < angle > 180
// The strategy for this function is to know how many blocks can be processed
// with just pixels from |top_ptr|, then handle mixed blocks, then handle only
// blocks that take from |left_ptr|. Additionally, a fast index-shuffle
// approach is used for pred values from |left_column| in sections that permit
// it.
template <bool upsampled_left, bool upsampled_top>
inline void DirectionalZone2_SSE4_1(void* dest, ptrdiff_t stride,
const uint8_t* const top_row,
const uint8_t* const left_column,
const int width, const int height,
const int xstep, const int ystep) {
auto* dst = static_cast<uint8_t*>(dest);
const int upsample_top_shift = static_cast<int>(upsampled_top);
// All columns from |min_top_only_x| to the right will only need |top_row|
// to compute. This assumes minimum |xstep| is 3.
const int min_top_only_x = std::min((height * xstep) >> 6, width);
// Accumulate xstep across 8 rows.
const __m128i xstep_dup = _mm_set1_epi16(-xstep);
const __m128i increments = _mm_set_epi16(8, 7, 6, 5, 4, 3, 2, 1);
const __m128i xstep_for_shift = _mm_mullo_epi16(xstep_dup, increments);
// Offsets the original zone bound value to simplify x < (y+1)*xstep/64 -1
const __m128i scaled_one = _mm_set1_epi16(-64);
__m128i xstep_bounds_base =
(xstep == 64) ? _mm_sub_epi16(scaled_one, xstep_for_shift)
: _mm_sub_epi16(_mm_set1_epi16(-1), xstep_for_shift);
const int left_base_increment = ystep >> 6;
const int ystep_remainder = ystep & 0x3F;
const int ystep8 = ystep << 3;
const int left_base_increment8 = ystep8 >> 6;
const int ystep_remainder8 = ystep8 & 0x3F;
const __m128i increment_left8 = _mm_set1_epi16(-ystep_remainder8);
// If the 64 scaling is regarded as a decimal point, the first value of the
// left_y vector omits the portion which is covered under the left_column
// offset. Following values need the full ystep as a relative offset.
const __m128i ystep_init = _mm_set1_epi16(-ystep_remainder);
const __m128i ystep_dup = _mm_set1_epi16(-ystep);
const __m128i dest_index_x =
_mm_set_epi32(0x00070006, 0x00050004, 0x00030002, 0x00010000);
__m128i left_y = _mm_mullo_epi16(ystep_dup, dest_index_x);
left_y = _mm_add_epi16(ystep_init, left_y);
// Analysis finds that, for most angles (ystep < 132), all segments that use
// both top_row and left_column can compute from left_column using byte
// shuffles from a single vector. For steeper angles, the shuffle is also
// fully reliable when x >= 32.
const int shuffle_left_col_x = (ystep < 132) ? 0 : 32;
const int min_shuffle_x = std::min(min_top_only_x, shuffle_left_col_x);
const __m128i increment_top8 = _mm_set1_epi16(8 << 6);
int x = 0;
for (int left_offset = -left_base_increment; x < min_shuffle_x;
x += 8,
xstep_bounds_base = _mm_sub_epi16(xstep_bounds_base, increment_top8),
// Watch left_y because it can still get big.
left_y = _mm_add_epi16(left_y, increment_left8),
left_offset -= left_base_increment8) {
DirectionalZone2_8xH<false, upsampled_left, upsampled_top>(
dst, stride, top_row, left_column, height, xstep, ystep, x, left_offset,
xstep_for_shift, xstep_bounds_base, left_y);
}
for (int left_offset = -left_base_increment; x < min_top_only_x;
x += 8,
xstep_bounds_base = _mm_sub_epi16(xstep_bounds_base, increment_top8),
// Watch left_y because it can still get big.
left_y = _mm_add_epi16(left_y, increment_left8),
left_offset -= left_base_increment8) {
DirectionalZone2_8xH<true, upsampled_left, upsampled_top>(
dst, stride, top_row, left_column, height, xstep, ystep, x, left_offset,
xstep_for_shift, xstep_bounds_base, left_y);
}
for (; x < width; x += 4) {
DirectionalZone1_4xH(dst + x, stride, top_row + (x << upsample_top_shift),
height, -xstep, upsampled_top);
}
}
template <bool upsampled_left, bool upsampled_top>
inline void DirectionalZone2_4_SSE4_1(void* dest, ptrdiff_t stride,
const uint8_t* const top_row,
const uint8_t* const left_column,
const int width, const int height,
const int xstep, const int ystep) {
auto* dst = static_cast<uint8_t*>(dest);
const int upsample_left_shift = static_cast<int>(upsampled_left);
const int upsample_top_shift = static_cast<int>(upsampled_top);
const __m128i max_shift = _mm_set1_epi8(32);
const ptrdiff_t stride4 = stride << 2;
const __m128i dest_index_x = _mm_set_epi32(0, 0, 0x00030002, 0x00010000);
const __m128i sampler_top =
upsampled_top
? _mm_set_epi32(0x0F0E0D0C, 0x0B0A0908, 0x07060504, 0x03020100)
: _mm_set_epi32(0x08070706, 0x06050504, 0x04030302, 0x02010100);
// All columns from |min_top_only_x| to the right will only need |top_row| to
// compute.
assert(xstep >= 3);
const int min_top_only_x = std::min((height * xstep) >> 6, width);
const int xstep4 = xstep << 2;
const __m128i xstep4_vect = _mm_set1_epi16(xstep4);
const __m128i xstep_dup = _mm_set1_epi16(-xstep);
const __m128i increments = _mm_set_epi32(0, 0, 0x00040003, 0x00020001);
__m128i xstep_for_shift = _mm_mullo_epi16(xstep_dup, increments);
const __m128i scaled_one = _mm_set1_epi16(-64);
// Offsets the original zone bound value to simplify x < (y+1)*xstep/64 -1
__m128i xstep_bounds_base =
(xstep == 64) ? _mm_sub_epi16(scaled_one, xstep_for_shift)
: _mm_sub_epi16(_mm_set1_epi16(-1), xstep_for_shift);
const int left_base_increment = ystep >> 6;
const int ystep_remainder = ystep & 0x3F;
const int ystep4 = ystep << 2;
const int left_base_increment4 = ystep4 >> 6;
// This is guaranteed to be less than 64, but accumulation may bring it past
// 64 for higher x values.
const int ystep_remainder4 = ystep4 & 0x3F;
const __m128i increment_left4 = _mm_set1_epi16(-ystep_remainder4);
const __m128i increment_top4 = _mm_set1_epi16(4 << 6);
// If the 64 scaling is regarded as a decimal point, the first value of the
// left_y vector omits the portion which will go into the left_column offset.
// Following values need the full ystep as a relative offset.
const __m128i ystep_init = _mm_set1_epi16(-ystep_remainder);
const __m128i ystep_dup = _mm_set1_epi16(-ystep);
__m128i left_y = _mm_mullo_epi16(ystep_dup, dest_index_x);
left_y = _mm_add_epi16(ystep_init, left_y);
const __m128i shift_mask = _mm_set1_epi32(0x003F003F);
int x = 0;
// Loop over x for columns with a mixture of sources.
for (int left_offset = -left_base_increment; x < min_top_only_x; x += 4,
xstep_bounds_base = _mm_sub_epi16(xstep_bounds_base, increment_top4),
left_y = _mm_add_epi16(left_y, increment_left4),
left_offset -= left_base_increment4) {
uint8_t* dst_x = dst + x;
// Round down to the nearest multiple of 4.
const int max_top_only_y = std::min((x << 6) / xstep, height) & ~3;
DirectionalZone1_4xH(dst_x, stride, top_row + (x << upsample_top_shift),
max_top_only_y, -xstep, upsampled_top);
int y = max_top_only_y;
dst_x += stride * y;
const int xstep_y = xstep * y;
const __m128i xstep_y_vect = _mm_set1_epi16(xstep_y);
// All rows from |min_left_only_y| down for this set of columns, only need
// |left_column| to compute. Rounded up to the nearest multiple of 4.
const int min_left_only_y = std::min(((x + 4) << 6) / xstep, height);
__m128i xstep_bounds = _mm_add_epi16(xstep_bounds_base, xstep_y_vect);
__m128i xstep_for_shift_y = _mm_sub_epi16(xstep_for_shift, xstep_y_vect);
int top_x = -xstep_y;
// Loop over y for mixed rows.
for (; y < min_left_only_y;
y += 4, dst_x += stride4,
xstep_bounds = _mm_add_epi16(xstep_bounds, xstep4_vect),
xstep_for_shift_y = _mm_sub_epi16(xstep_for_shift_y, xstep4_vect),
top_x -= xstep4) {
DirectionalZone2FromLeftCol_4x4_SSE4_1<upsampled_left>(
dst_x, stride,
left_column + ((left_offset + y) * (1 << upsample_left_shift)),
left_y);
__m128i shifts = _mm_srli_epi16(
_mm_and_si128(_mm_slli_epi16(xstep_for_shift_y, upsample_top_shift),
shift_mask),
1);
shifts = _mm_packus_epi16(shifts, shifts);
const __m128i opposite_shifts = _mm_sub_epi8(max_shift, shifts);
shifts = _mm_unpacklo_epi8(opposite_shifts, shifts);
const __m128i xstep_bounds_off = _mm_srai_epi16(xstep_bounds, 6);
DirectionalZone1Blend_4x4<upsampled_top>(
dst_x, top_row + (x << upsample_top_shift), stride, sampler_top,
xstep_bounds_off, shifts, dest_index_x, top_x, xstep);
}
// Loop over y for left-only rows, if any.
for (; y < height; y += 4, dst_x += stride4) {
DirectionalZone2FromLeftCol_4x4_SSE4_1<upsampled_left>(
dst_x, stride,
left_column + ((left_offset + y) << upsample_left_shift), left_y);
}
}
// Loop over top-only columns, if any.
for (; x < width; x += 4) {
DirectionalZone1_4xH(dst + x, stride, top_row + (x << upsample_top_shift),
height, -xstep, upsampled_top);
}
}
void DirectionalIntraPredictorZone2_SSE4_1(void* const dest, ptrdiff_t stride,
const void* const top_row,
const void* const left_column,
const int width, const int height,
const int xstep, const int ystep,
const bool upsampled_top,
const bool upsampled_left) {
// Increasing the negative buffer for this function allows more rows to be
// processed at a time without branching in an inner loop to check the base.
uint8_t top_buffer[288];
uint8_t left_buffer[288];
memcpy(top_buffer + 128, static_cast<const uint8_t*>(top_row) - 16, 160);
memcpy(left_buffer + 128, static_cast<const uint8_t*>(left_column) - 16, 160);
const uint8_t* top_ptr = top_buffer + 144;
const uint8_t* left_ptr = left_buffer + 144;
if (width == 4 || height == 4) {
if (upsampled_left) {
if (upsampled_top) {
DirectionalZone2_4_SSE4_1<true, true>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
} else {
DirectionalZone2_4_SSE4_1<true, false>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
}
} else {
if (upsampled_top) {
DirectionalZone2_4_SSE4_1<false, true>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
} else {
DirectionalZone2_4_SSE4_1<false, false>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
}
}
return;
}
if (upsampled_left) {
if (upsampled_top) {
DirectionalZone2_SSE4_1<true, true>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
} else {
DirectionalZone2_SSE4_1<true, false>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
}
} else {
if (upsampled_top) {
DirectionalZone2_SSE4_1<false, true>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
} else {
DirectionalZone2_SSE4_1<false, false>(dest, stride, top_ptr, left_ptr,
width, height, xstep, ystep);
}
}
}
void Init8bpp() {
Dsp* const dsp = dsp_internal::GetWritableDspTable(kBitdepth8);
assert(dsp != nullptr);
static_cast<void>(dsp);
#if DSP_ENABLED_8BPP_SSE4_1(DirectionalIntraPredictorZone1)
dsp->directional_intra_predictor_zone1 =
DirectionalIntraPredictorZone1_SSE4_1;
#endif
#if DSP_ENABLED_8BPP_SSE4_1(DirectionalIntraPredictorZone2)
dsp->directional_intra_predictor_zone2 =
DirectionalIntraPredictorZone2_SSE4_1;
#endif
#if DSP_ENABLED_8BPP_SSE4_1(DirectionalIntraPredictorZone3)
dsp->directional_intra_predictor_zone3 =
DirectionalIntraPredictorZone3_SSE4_1;
#endif
}
} // namespace
} // namespace low_bitdepth
//------------------------------------------------------------------------------
#if LIBGAV1_MAX_BITDEPTH >= 10
namespace high_bitdepth {
namespace {
//------------------------------------------------------------------------------
// 7.11.2.4. Directional intra prediction process
// Special case: An |xstep| of 64 corresponds to an angle delta of 45, meaning
// upsampling is ruled out. In addition, the bits masked by 0x3F for
// |shift_val| are 0 for all multiples of 64, so the formula
// val = top[top_base_x]*shift + top[top_base_x+1]*(32-shift), reduces to
// val = top[top_base_x+1] << 5, meaning only the second set of pixels is
// involved in the output. Hence |top| is offset by 1.
inline void DirectionalZone1_Step64(uint16_t* dst, ptrdiff_t stride,
const uint16_t* const top, const int width,
const int height) {
ptrdiff_t offset = 1;
if (height == 4) {
memcpy(dst, top + offset, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 1, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 2, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 3, width * sizeof(dst[0]));
return;
}
int y = height;
do {
memcpy(dst, top + offset, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 1, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 2, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 3, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 4, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 5, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 6, width * sizeof(dst[0]));
dst += stride;
memcpy(dst, top + offset + 7, width * sizeof(dst[0]));
dst += stride;
offset += 8;
y -= 8;
} while (y != 0);
}
// Produce a weighted average whose weights sum to 32.
inline __m128i CombineTopVals4(const __m128i& top_vals, const __m128i& sampler,
const __m128i& shifts,
const __m128i& top_indices,
const __m128i& final_top_val,
const __m128i& border_index) {
const __m128i sampled_values = _mm_shuffle_epi8(top_vals, sampler);
__m128i prod = _mm_mullo_epi16(sampled_values, shifts);
prod = _mm_hadd_epi16(prod, prod);
const __m128i result = RightShiftWithRounding_U16(prod, 5 /*log2(32)*/);
const __m128i past_max = _mm_cmpgt_epi16(top_indices, border_index);
// Replace pixels from invalid range with top-right corner.
return _mm_blendv_epi8(result, final_top_val, past_max);
}
// When width is 4, only one load operation is needed per iteration. We also
// avoid extra loop precomputations that cause too much overhead.
inline void DirectionalZone1_4xH(uint16_t* dst, ptrdiff_t stride,
const uint16_t* const top, const int height,
const int xstep, const bool upsampled,
const __m128i& sampler) {
const int upsample_shift = static_cast<int>(upsampled);
const int index_scale_bits = 6 - upsample_shift;
const int max_base_x = (height + 3 /* width - 1 */) << upsample_shift;
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
const __m128i final_top_val = _mm_set1_epi16(top[max_base_x]);
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to the top_base_x, it is used to mask values
// that pass the end of |top|. Starting from 1 to simulate "cmpge" because
// only cmpgt is available.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
// All rows from |min_corner_only_y| down will simply use memcpy.
// |max_base_x| is always greater than |height|, so clipping the denominator
// to 1 is enough to make the logic work.
const int xstep_units = std::max(xstep >> index_scale_bits, 1);
const int min_corner_only_y = std::min(max_base_x / xstep_units, height);
int y = 0;
int top_x = xstep;
const __m128i max_shift = _mm_set1_epi16(32);
for (; y < min_corner_only_y; ++y, dst += stride, top_x += xstep) {
const int top_base_x = top_x >> index_scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi16(shift_val);
const __m128i opposite_shift = _mm_sub_epi16(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi16(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
// Load 8 values because we will select the sampled values based on
// |upsampled|.
const __m128i values = LoadUnaligned16(top + top_base_x);
const __m128i pred =
CombineTopVals4(values, sampler, shifts, top_index_vect, final_top_val,
max_base_x_vect);
StoreLo8(dst, pred);
}
// Fill in corner-only rows.
for (; y < height; ++y) {
Memset(dst, top[max_base_x], /* width */ 4);
dst += stride;
}
}
// General purpose combine function.
// |check_border| means the final source value has to be duplicated into the
// result. This simplifies the loop structures that use precomputed boundaries
// to identify sections where it is safe to compute without checking for the
// right border.
template <bool check_border>
inline __m128i CombineTopVals(
const __m128i& top_vals_0, const __m128i& top_vals_1,
const __m128i& sampler, const __m128i& shifts,
const __m128i& top_indices = _mm_setzero_si128(),
const __m128i& final_top_val = _mm_setzero_si128(),
const __m128i& border_index = _mm_setzero_si128()) {
constexpr int scale_int_bits = 5;
const __m128i sampled_values_0 = _mm_shuffle_epi8(top_vals_0, sampler);
const __m128i sampled_values_1 = _mm_shuffle_epi8(top_vals_1, sampler);
const __m128i prod_0 = _mm_mullo_epi16(sampled_values_0, shifts);
const __m128i prod_1 = _mm_mullo_epi16(sampled_values_1, shifts);
const __m128i combined = _mm_hadd_epi16(prod_0, prod_1);
const __m128i result = RightShiftWithRounding_U16(combined, scale_int_bits);
if (check_border) {
const __m128i past_max = _mm_cmpgt_epi16(top_indices, border_index);
// Replace pixels from invalid range with top-right corner.
return _mm_blendv_epi8(result, final_top_val, past_max);
}
return result;
}
// 7.11.2.4 (7) angle < 90
inline void DirectionalZone1_Large(uint16_t* dest, ptrdiff_t stride,
const uint16_t* const top_row,
const int width, const int height,
const int xstep, const bool upsampled,
const __m128i& sampler) {
const int upsample_shift = static_cast<int>(upsampled);
const int index_scale_bits = 6 - upsample_shift;
const int max_base_x = ((width + height) - 1) << upsample_shift;
const __m128i max_shift = _mm_set1_epi16(32);
const int base_step = 1 << upsample_shift;
const int base_step8 = base_step << 3;
// All rows from |min_corner_only_y| down will simply use memcpy.
// |max_base_x| is always greater than |height|, so clipping to 1 is enough
// to make the logic work.
const int xstep_units = std::max(xstep >> index_scale_bits, 1);
const int min_corner_only_y = std::min(max_base_x / xstep_units, height);
// Rows up to this y-value can be computed without checking for bounds.
const int max_no_corner_y = std::min(
LeftShift((max_base_x - (base_step * width)), index_scale_bits) / xstep,
height);
// No need to check for exceeding |max_base_x| in the first loop.
int y = 0;
int top_x = xstep;
for (; y < max_no_corner_y; ++y, dest += stride, top_x += xstep) {
int top_base_x = top_x >> index_scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi16(shift_val);
const __m128i opposite_shift = _mm_sub_epi16(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi16(opposite_shift, shift);
int x = 0;
do {
const __m128i top_vals_0 = LoadUnaligned16(top_row + top_base_x);
const __m128i top_vals_1 =
LoadUnaligned16(top_row + top_base_x + (4 << upsample_shift));
const __m128i pred =
CombineTopVals<false>(top_vals_0, top_vals_1, sampler, shifts);
StoreUnaligned16(dest + x, pred);
top_base_x += base_step8;
x += 8;
} while (x < width);
}
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to |top_base_x|, it is used to mask values
// that pass the end of the |top| buffer. Starting from 1 to simulate "cmpge"
// which is not supported for packed integers.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
const __m128i final_top_val = _mm_set1_epi16(top_row[max_base_x]);
const __m128i base_step8_vect = _mm_set1_epi16(base_step8);
for (; y < min_corner_only_y; ++y, dest += stride, top_x += xstep) {
int top_base_x = top_x >> index_scale_bits;
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi16(shift_val);
const __m128i opposite_shift = _mm_sub_epi16(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi16(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
int x = 0;
const int min_corner_only_x =
std::min(width, ((max_base_x - top_base_x) >> upsample_shift) + 7) & ~7;
for (; x < min_corner_only_x;
x += 8, top_base_x += base_step8,
top_index_vect = _mm_add_epi16(top_index_vect, base_step8_vect)) {
const __m128i top_vals_0 = LoadUnaligned16(top_row + top_base_x);
const __m128i top_vals_1 =
LoadUnaligned16(top_row + top_base_x + (4 << upsample_shift));
const __m128i pred =
CombineTopVals<true>(top_vals_0, top_vals_1, sampler, shifts,
top_index_vect, final_top_val, max_base_x_vect);
StoreUnaligned16(dest + x, pred);
}
// Corner-only section of the row.
Memset(dest + x, top_row[max_base_x], width - x);
}
// Fill in corner-only rows.
for (; y < height; ++y) {
Memset(dest, top_row[max_base_x], width);
dest += stride;
}
}
// 7.11.2.4 (7) angle < 90
inline void DirectionalIntraPredictorZone1_SSE4_1(
void* dest_ptr, ptrdiff_t stride, const void* const top_ptr,
const int width, const int height, const int xstep, const bool upsampled) {
const auto* const top_row = static_cast<const uint16_t*>(top_ptr);
auto* dest = static_cast<uint16_t*>(dest_ptr);
stride /= sizeof(uint16_t);
const int upsample_shift = static_cast<int>(upsampled);
if (xstep == 64) {
DirectionalZone1_Step64(dest, stride, top_row, width, height);
return;
}
// Each base pixel paired with its following pixel, for hadd purposes.
const __m128i adjacency_shuffler = _mm_set_epi16(
0x0908, 0x0706, 0x0706, 0x0504, 0x0504, 0x0302, 0x0302, 0x0100);
// This is equivalent to not shuffling at all.
const __m128i identity_shuffler = _mm_set_epi16(
0x0F0E, 0x0D0C, 0x0B0A, 0x0908, 0x0706, 0x0504, 0x0302, 0x0100);
// This represents a trade-off between code size and speed. When upsampled
// is true, no shuffle is necessary. But to avoid in-loop branching, we
// would need 2 copies of the main function body.
const __m128i sampler = upsampled ? identity_shuffler : adjacency_shuffler;
if (width == 4) {
DirectionalZone1_4xH(dest, stride, top_row, height, xstep, upsampled,
sampler);
return;
}
if (width >= 32) {
DirectionalZone1_Large(dest, stride, top_row, width, height, xstep,
upsampled, sampler);
return;
}
const int index_scale_bits = 6 - upsample_shift;
const int max_base_x = ((width + height) - 1) << upsample_shift;
const __m128i max_shift = _mm_set1_epi16(32);
const int base_step = 1 << upsample_shift;
const int base_step8 = base_step << 3;
// No need to check for exceeding |max_base_x| in the loops.
if (((xstep * height) >> index_scale_bits) + base_step * width < max_base_x) {
int top_x = xstep;
int y = height;
do {
int top_base_x = top_x >> index_scale_bits;
// Permit negative values of |top_x|.
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi16(shift_val);
const __m128i opposite_shift = _mm_sub_epi16(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi16(opposite_shift, shift);
int x = 0;
do {
const __m128i top_vals_0 = LoadUnaligned16(top_row + top_base_x);
const __m128i top_vals_1 =
LoadUnaligned16(top_row + top_base_x + (4 << upsample_shift));
const __m128i pred =
CombineTopVals<false>(top_vals_0, top_vals_1, sampler, shifts);
StoreUnaligned16(dest + x, pred);
top_base_x += base_step8;
x += 8;
} while (x < width);
dest += stride;
top_x += xstep;
} while (--y != 0);
return;
}
// General case. Blocks with width less than 32 do not benefit from x-wise
// loop splitting, but do benefit from using memset on appropriate rows.
// Each 16-bit value here corresponds to a position that may exceed
// |max_base_x|. When added to the top_base_x, it is used to mask values
// that pass the end of |top|. Starting from 1 to simulate "cmpge" which is
// not supported for packed integers.
const __m128i offsets =
_mm_set_epi32(0x00080007, 0x00060005, 0x00040003, 0x00020001);
const __m128i max_base_x_vect = _mm_set1_epi16(max_base_x);
const __m128i final_top_val = _mm_set1_epi16(top_row[max_base_x]);
const __m128i base_step8_vect = _mm_set1_epi16(base_step8);
// All rows from |min_corner_only_y| down will simply use memcpy.
// |max_base_x| is always greater than |height|, so clipping the denominator
// to 1 is enough to make the logic work.
const int xstep_units = std::max(xstep >> index_scale_bits, 1);
const int min_corner_only_y = std::min(max_base_x / xstep_units, height);
int top_x = xstep;
int y = 0;
for (; y < min_corner_only_y; ++y, dest += stride, top_x += xstep) {
int top_base_x = top_x >> index_scale_bits;
const int shift_val = (LeftShift(top_x, upsample_shift) & 0x3F) >> 1;
const __m128i shift = _mm_set1_epi16(shift_val);
const __m128i opposite_shift = _mm_sub_epi16(max_shift, shift);
const __m128i shifts = _mm_unpacklo_epi16(opposite_shift, shift);
__m128i top_index_vect = _mm_set1_epi16(top_base_x);
top_index_vect = _mm_add_epi16(top_index_vect, offsets);
for (int x = 0; x < width; x += 8, top_base_x += base_step8,
top_index_vect = _mm_add_epi16(top_index_vect, base_step8_vect)) {
const __m128i top_vals_0 = LoadUnaligned16(top_row + top_base_x);
const __m128i top_vals_1 =
LoadUnaligned16(top_row + top_base_x + (4 << upsample_shift));
const __m128i pred =
CombineTopVals<true>(top_vals_0, top_vals_1, sampler, shifts,
top_index_vect, final_top_val, max_base_x_vect);
StoreUnaligned16(dest + x, pred);
}
}
// Fill in corner-only rows.
for (; y < height; ++y) {
Memset(dest, top_row[max_base_x], width);
dest += stride;
}
}
void Init10bpp() {
Dsp* const dsp = dsp_internal::GetWritableDspTable(10);
assert(dsp != nullptr);
static_cast<void>(dsp);
#if DSP_ENABLED_10BPP_SSE4_1(DirectionalIntraPredictorZone1)
dsp->directional_intra_predictor_zone1 =
DirectionalIntraPredictorZone1_SSE4_1;
#endif
}
} // namespace
} // namespace high_bitdepth
#endif // LIBGAV1_MAX_BITDEPTH >= 10
void IntraPredDirectionalInit_SSE4_1() {
low_bitdepth::Init8bpp();
#if LIBGAV1_MAX_BITDEPTH >= 10
high_bitdepth::Init10bpp();
#endif
}
} // namespace dsp
} // namespace libgav1
#else // !LIBGAV1_TARGETING_SSE4_1
namespace libgav1 {
namespace dsp {
void IntraPredDirectionalInit_SSE4_1() {}
} // namespace dsp
} // namespace libgav1
#endif // LIBGAV1_TARGETING_SSE4_1