// Copyright 2015 The Gemmlowp Authors. All Rights Reserved.
//
// 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.
// pack_neon.h: optimized NEON specializations of the templates in pack.h.
#ifndef GEMMLOWP_INTERNAL_PACK_NEON_H_
#define GEMMLOWP_INTERNAL_PACK_NEON_H_
#include "pack.h"
#include <arm_neon.h>
namespace gemmlowp {
typedef SideMap<const std::uint8_t, SideMapOrder::WidthMajor>
WidthMajorUint8SideMap;
template <int Cells>
using DepthMajorSideFormatNCells4x2 = KernelSideFormat<CellFormat<4, 2>, Cells>;
template <int Cells>
class PackingRegisterBlock<
WidthMajorUint8SideMap,
PackedSideBlock<DepthMajorSideFormatNCells4x2<Cells>>>
: public PackingRegisterBlockBase<
WidthMajorUint8SideMap,
PackedSideBlock<DepthMajorSideFormatNCells4x2<Cells>>> {
public:
typedef DepthMajorSideFormatNCells4x2<Cells> KernelSideFormat;
typedef typename KernelSideFormat::Cell CellFormat;
static const int kCells = KernelSideFormat::kCells;
static const int kCellWidth = CellFormat::kWidth;
static const int kKernelWidth = CellFormat::kWidth * kCells;
static const int kCellDepth = CellFormat::kDepth;
static const int kCellSize = CellFormat::kSize;
void Pack(PackedSideBlock<KernelSideFormat>* dst, int start_width) {
std::uint8_t* dst_ptr = dst->current_data();
const std::uint8_t* const src_ptr = this->complete_src_.data();
const int stride = this->complete_src_.stride();
// Load source WidthMajor data
uint8x16_t src_lines[4 * kCells];
for (int i = 0; i < 4 * kCells; i++) {
src_lines[i] = vld1q_u8(src_ptr + i * stride);
}
// Reorder the data within registers to make DepthMajor 4x2 cells
uint8x16x2_t src_lines_intertwined_2x[2 * kCells];
for (int i = 0; i < kCells; i++) {
src_lines_intertwined_2x[2 * i] =
vzipq_u8(src_lines[4 * i], src_lines[4 * i + 2]);
src_lines_intertwined_2x[2 * i + 1] =
vzipq_u8(src_lines[4 * i + 1], src_lines[4 * i + 3]);
}
uint8x16x2_t src_lines_intertwined_4x[2 * kCells];
for (int i = 0; i < kCells; i++) {
src_lines_intertwined_4x[2 * i] =
vzipq_u8(src_lines_intertwined_2x[2 * i].val[0],
src_lines_intertwined_2x[2 * i + 1].val[0]);
src_lines_intertwined_4x[2 * i + 1] =
vzipq_u8(src_lines_intertwined_2x[2 * i].val[1],
src_lines_intertwined_2x[2 * i + 1].val[1]);
}
// Store the resulting DepthMajor 4x2 cells in the destination packed block
for (int outer = 0; outer < 2; outer++) {
for (int inner = 0; inner < 2; inner++) {
for (int cell = 0; cell < kCells; cell++) {
uint8x8_t value = vget_low_u8(
src_lines_intertwined_4x[2 * cell + outer].val[inner]);
vst1_u8(dst_ptr, value);
dst_ptr += 8;
}
for (int cell = 0; cell < kCells; cell++) {
uint8x8_t value = vget_high_u8(
src_lines_intertwined_4x[2 * cell + outer].val[inner]);
vst1_u8(dst_ptr, value);
dst_ptr += 8;
}
}
}
// Compute sums across the depth dimension
uint16x8_t sums_of_2_cells[kCells][4];
for (int outer = 0; outer < 2; outer++) {
for (int inner = 0; inner < 2; inner++) {
int i = 2 * outer + inner;
for (int cell = 0; cell < kCells; cell++) {
sums_of_2_cells[cell][i] = vaddl_u8(
vget_low_u8(
src_lines_intertwined_4x[2 * cell + outer].val[inner]),
vget_high_u8(
src_lines_intertwined_4x[2 * cell + outer].val[inner]));
}
}
}
int32x4_t sums_of_4_cells[kCells][4];
for (int i = 0; i < 4; i++) {
for (int cell = 0; cell < kCells; cell++) {
sums_of_4_cells[cell][i] = vreinterpretq_s32_u32(
vaddl_u16(vget_low_u16(sums_of_2_cells[cell][i]),
vget_high_u16(sums_of_2_cells[cell][i])));
}
}
// Update the sums_of_each_slice vector
for (int cell = 0; cell < kCells; cell++) {
int32x4_t s01 =
vaddq_s32(sums_of_4_cells[cell][0], sums_of_4_cells[cell][1]);
int32x4_t s23 =
vaddq_s32(sums_of_4_cells[cell][2], sums_of_4_cells[cell][3]);
int32x4_t s = vaddq_s32(s01, s23);
std::int32_t* sums_of_each_slice_ptr =
dst->sums_of_each_slice() + start_width + 4 * cell;
vst1q_s32(sums_of_each_slice_ptr,
vaddq_s32(s, vld1q_s32(sums_of_each_slice_ptr)));
}
dst->seek_forward_n_cells(kCells * kRegisterSize / kCellDepth);
}
};
template <int Cells>
using WidthMajorSideFormatNCells4x2 =
KernelSideFormat<CellFormat<4, 2, CellOrder::WidthMajor>, Cells>;
template <int Cells>
class PackingRegisterBlock<
WidthMajorUint8SideMap,
PackedSideBlock<WidthMajorSideFormatNCells4x2<Cells>>>
: public PackingRegisterBlockBase<
WidthMajorUint8SideMap,
PackedSideBlock<WidthMajorSideFormatNCells4x2<Cells>>> {
public:
typedef WidthMajorSideFormatNCells4x2<Cells> KernelSideFormat;
typedef typename KernelSideFormat::Cell CellFormat;
static const int kCells = KernelSideFormat::kCells;
static const int kCellWidth = CellFormat::kWidth;
static const int kKernelWidth = CellFormat::kWidth * kCells;
static const int kCellDepth = CellFormat::kDepth;
static const int kCellSize = CellFormat::kSize;
void Pack(PackedSideBlock<KernelSideFormat>* dst, int start_width) {
std::uint8_t* dst_ptr = dst->current_data();
const std::uint8_t* src_ptr = this->complete_src_.data();
const int stride = this->complete_src_.stride();
// Load source WidthMajor data
uint16x8_t src_lines[kCells * 4];
for (int i = 0; i < kCells; i++) {
// This packing path is used with our current
// less-than-8-bit kernel, and the partial unrolling of this loop
// results in substantially faster code (thanks to better
// register allocation) on Nexus 5.
#define GEMMLOWP_UNROLLED_LOOP_ITER(k) \
src_lines[4 * i + k] = vreinterpretq_u16_u8(vld1q_u8(src_ptr)); \
src_ptr += stride;
GEMMLOWP_UNROLLED_LOOP_ITER(0)
GEMMLOWP_UNROLLED_LOOP_ITER(1)
GEMMLOWP_UNROLLED_LOOP_ITER(2)
GEMMLOWP_UNROLLED_LOOP_ITER(3)
#undef GEMMLOWP_UNROLLED_LOOP_ITER
}
// Reorder the data within registers to make WidthMajor 4x2 cells
uint16x8x2_t src_lines_intertwined_2x[2 * kCells];
for (int i = 0; i < kCells; i++) {
src_lines_intertwined_2x[2 * i] =
vzipq_u16(src_lines[4 * i], src_lines[4 * i + 2]);
src_lines_intertwined_2x[2 * i + 1] =
vzipq_u16(src_lines[4 * i + 1], src_lines[4 * i + 3]);
}
uint16x8x2_t src_lines_intertwined_4x[2 * kCells];
for (int i = 0; i < kCells; i++) {
src_lines_intertwined_4x[2 * i] =
vzipq_u16(src_lines_intertwined_2x[2 * i].val[0],
src_lines_intertwined_2x[2 * i + 1].val[0]);
src_lines_intertwined_4x[2 * i + 1] =
vzipq_u16(src_lines_intertwined_2x[2 * i].val[1],
src_lines_intertwined_2x[2 * i + 1].val[1]);
}
// Store the resulting WidthMajor 4x2 cells in the destination packed block
for (int outer = 0; outer < 2; outer++) {
for (int inner = 0; inner < 2; inner++) {
for (int cell = 0; cell < kCells; cell++) {
uint8x8_t value = vreinterpret_u8_u16(vget_low_u16(
src_lines_intertwined_4x[2 * cell + outer].val[inner]));
vst1_u8(dst_ptr, value);
dst_ptr += 8;
}
for (int cell = 0; cell < kCells; cell++) {
uint8x8_t value = vreinterpret_u8_u16(vget_high_u16(
src_lines_intertwined_4x[2 * cell + outer].val[inner]));
vst1_u8(dst_ptr, value);
dst_ptr += 8;
}
}
}
// Compute sums across the depth dimension
uint16x8_t sums_of_2[kCells][4];
for (int outer = 0; outer < 2; outer++) {
for (int inner = 0; inner < 2; inner++) {
int i = 2 * outer + inner;
for (int cell = 0; cell < kCells; cell++) {
sums_of_2[cell][i] = vpaddlq_u8(vreinterpretq_u8_u16(
src_lines_intertwined_4x[2 * cell + outer].val[inner]));
}
}
}
uint16x8_t sums_of_4[kCells][2];
for (int i = 0; i < 2; i++) {
for (int cell = 0; cell < kCells; cell++) {
sums_of_4[cell][i] =
vaddq_u16(sums_of_2[cell][2 * i], sums_of_2[cell][2 * i + 1]);
}
}
uint16x8_t sums_of_8[kCells];
for (int cell = 0; cell < kCells; cell++) {
sums_of_8[cell] = vaddq_u16(sums_of_4[cell][0], sums_of_4[cell][1]);
}
uint16x4_t sums_of_16[kCells];
for (int cell = 0; cell < kCells; cell++) {
sums_of_16[cell] = vadd_u16(vget_low_u16(sums_of_8[cell]),
vget_high_u16(sums_of_8[cell]));
}
// Update the sums_of_each_slice vector
for (int cell = 0; cell < kCells; cell++) {
int32x4_t s = vreinterpretq_s32_u32(vmovl_u16(sums_of_16[cell]));
std::int32_t* sums_of_each_slice_ptr =
dst->sums_of_each_slice() + start_width + 4 * cell;
vst1q_s32(sums_of_each_slice_ptr,
vaddq_s32(s, vld1q_s32(sums_of_each_slice_ptr)));
}
dst->seek_forward_n_cells(kCells * kRegisterSize / kCellDepth);
}
};
#ifdef GEMMLOWP_NEON_32
inline int16x8_t vpaddq_s16(int16x8_t a, int16x8_t b) {
const int16x4_t c = vpadd_s16(vget_low_s16(a), vget_high_s16(a));
const int16x4_t d = vpadd_s16(vget_low_s16(b), vget_high_s16(b));
return vcombine_s16(c, d);
}
#endif
template <int Width>
using Int8FastKernelFormat =
KernelSideFormatInt8<CellFormat<Width, 16, CellOrder::WidthMajor>, 1>;
template <int Width>
class PackingRegisterBlock<WidthMajorUint8SideMap,
PackedSideBlock<Int8FastKernelFormat<Width>>>
: public PackingRegisterBlockBase<
WidthMajorUint8SideMap,
PackedSideBlock<Int8FastKernelFormat<Width>>> {
public:
static_assert(Width == 2 || Width == 4, "");
typedef Int8FastKernelFormat<Width> KernelSideFormat;
typedef typename KernelSideFormat::Cell CellFormat;
static const int kCells = KernelSideFormat::kCells;
static const int kCellWidth = CellFormat::kWidth;
static const int kKernelWidth = CellFormat::kWidth * kCells;
static const int kCellDepth = CellFormat::kDepth;
static const int kCellSize = CellFormat::kSize;
void Pack(PackedSideBlock<KernelSideFormat>* dst, int start_width) {
std::int32_t* sums_ptr = dst->sums_of_each_slice() + start_width;
std::uint8_t* dst_ptr = dst->current_data();
const std::uint8_t* const src_ptr = this->complete_src_.data();
const int stride = this->complete_src_.stride();
// Load source WidthMajor data
uint8x16_t src_lines[Width];
for (int i = 0; i < Width; i++) {
src_lines[i] = vld1q_u8(src_ptr + i * stride);
}
const uint8x16_t sign_bit_dup = vdupq_n_u8(0x80);
for (int i = 0; i < Width; i++) {
src_lines[i] = veorq_u8(src_lines[i], sign_bit_dup);
}
for (int i = 0; i < Width; i++) {
vst1q_u8(dst_ptr + 16 * i, src_lines[i]);
}
int16x8_t sums2[Width];
for (int i = 0; i < Width; i++) {
const int8x8_t lo = vreinterpret_s8_u8(vget_low_u8(src_lines[i]));
const int8x8_t hi = vreinterpret_s8_u8(vget_high_u8(src_lines[i]));
sums2[i] = vaddl_s8(lo, hi);
}
int16x8_t sums4[Width / 2];
for (int i = 0; i < Width / 2; i++) {
sums4[i] = vpaddq_s16(sums2[2 * i], sums2[2 * i + 1]);
}
if (Width == 4) {
int32x4_t sum = vld1q_s32(sums_ptr);
int16x8_t sums8 = vpaddq_s16(sums4[0], sums4[1]);
sum = vpadalq_s16(sum, sums8);
vst1q_s32(sums_ptr, sum);
} else {
assert(Width == 2);
int32x2_t sum = vld1_s32(sums_ptr);
int16x4_t sums8 =
vpadd_s16(vget_low_s16(sums4[0]), vget_high_s16(sums4[0]));
sum = vpadal_s16(sum, sums8);
vst1_s32(sums_ptr, sum);
}
dst->seek_forward_n_cells(1);
}
};
} // namespace gemmlowp
#endif // GEMMLOWP_INTERNAL_PACK_NEON_H_