aicodix___code/cauchy_reed_solomon_erasure_coding.hh
2023-06-05 10:56:41 +02:00

331 lines
15 KiB
C++

/*
Cauchy Reed Solomon Erasure Coding
Copyright 2023 Ahmet Inan <inan@aicodix.de>
*/
#pragma once
#ifdef __ARM_NEON
#include <arm_neon.h>
#endif
#ifdef __AVX2__
#include <immintrin.h>
#else
#ifdef __SSE4_1__
#include <smmintrin.h>
#endif
#endif
namespace CODE {
template <typename GF>
struct CauchyReedSolomonErasureCoding
{
typedef typename GF::value_type value_type;
typedef typename GF::ValueType ValueType;
typedef typename GF::IndexType IndexType;
IndexType row_num, row_den;
// $a_{ij} = \frac{1}{x_i + y_j}$
IndexType cauchy_matrix(int i, int j)
{
ValueType row(i), col(ValueType::N - j);
return rcp(index(row + col));
}
// $b_{ij} = \frac{\prod_{k=1}^{n}{(x_j + y_k)(x_k + y_i)}}{(x_j + y_i)\prod_{k \ne j}^{n}{(x_j - x_k)}\prod_{k \ne i}^{n}{(y_i - y_k)}}$
IndexType inverse_cauchy_matrix(const ValueType *rows, int i, int j, int n)
{
#if 0
ValueType col_i(ValueType::N - i);
IndexType prod_xy(0), prod_x(0), prod_y(0);
for (int k = 0; k < n; k++) {
ValueType col_k(ValueType::N - k);
prod_xy *= index(rows[j] + col_k) * index(rows[k] + col_i);
if (k != j)
prod_x *= index(rows[j] + rows[k]);
if (k != i)
prod_y *= index(col_i + col_k);
}
return prod_xy / (index(rows[j] + col_i) * prod_x * prod_y);
#else
ValueType col_i(ValueType::N - i);
if (j == 0) {
IndexType num(0), den(0);
for (int k = 0; k < n; k++) {
ValueType col_k(ValueType::N - k);
num *= index(rows[k] + col_i);
if (k != i)
den *= index(col_i + col_k);
}
row_num = num;
row_den = den;
}
IndexType num(row_num), den(row_den);
for (int k = 0; k < n; k++) {
ValueType col_k(ValueType::N - k);
num *= index(rows[j] + col_k);
if (k != j)
den *= index(rows[j] + rows[k]);
}
return num / (index(rows[j] + col_i) * den);
#endif
}
#if defined(__ARM_NEON) && !defined(__aarch64__)
static inline uint8x16_t vqtbl1q_u8(uint8x16_t lut, uint8x16_t idx)
{
uint8x8x2_t l82 = {{ vget_low_u8(lut), vget_high_u8(lut) }};
uint8x8_t lo = vtbl2_u8(l82, vget_low_u8(idx));
uint8x8_t hi = vtbl2_u8(l82, vget_high_u8(idx));
return vcombine_u8(lo, hi);
}
#endif
#if defined(__ARM_NEON) || defined(__AVX2__) || defined(__SSE4_1__)
void mac_simd(uint8_t *c, const uint8_t *a, IndexType b, int size, bool init)
{
alignas(16) uint8_t bln[16], bhn[16];
for (int i = 0; i < 16; ++i) {
bln[i] = (b * ValueType(i)).v;
bhn[i] = (b * ValueType(i << 4)).v;
}
#ifdef __ARM_NEON
uint8x16_t l16 = vld1q_u8(bln);
uint8x16_t h16 = vld1q_u8(bhn);
for (int i = 0; i < size; i += 16, a += 16, c += 16) {
uint8x16_t a16 = vld1q_u8(reinterpret_cast<const uint8_t *>(__builtin_assume_aligned(a, 16)));
uint8x16_t aln = vandq_u8(a16, vdupq_n_u8(15));
uint8x16_t ahn = vshrq_n_u8(a16, 4);
uint8x16_t cln = vqtbl1q_u8(l16, aln);
uint8x16_t chn = vqtbl1q_u8(h16, ahn);
uint8x16_t c16 = veorq_u8(cln, chn);
if (!init)
c16 = veorq_u8(c16, vld1q_u8(reinterpret_cast<const uint8_t *>(__builtin_assume_aligned(c, 16))));
vst1q_u8(reinterpret_cast<uint8_t *>(__builtin_assume_aligned(c, 16)), c16);
}
#else
#ifdef __AVX2__
__m128i l16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bln));
__m128i h16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhn));
__m256i l162 = _mm256_broadcastsi128_si256(l16);
__m256i h162 = _mm256_broadcastsi128_si256(h16);
for (int i = 0; i < size; i += 32, a += 32, c += 32) {
__m256i a32 = _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(a, 32)));
__m256i aln = _mm256_and_si256(a32, _mm256_set1_epi8(15));
__m256i cln = _mm256_shuffle_epi8(l162, aln);
__m256i ahn = _mm256_and_si256(_mm256_srli_epi16(a32, 4), _mm256_set1_epi8(15));
__m256i chn = _mm256_shuffle_epi8(h162, ahn);
__m256i c32 = _mm256_xor_si256(cln, chn);
if (!init)
c32 = _mm256_xor_si256(c32, _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(c, 32))));
_mm256_store_si256(reinterpret_cast<__m256i *>(__builtin_assume_aligned(c, 32)), c32);
}
#else
__m128i l16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bln));
__m128i h16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhn));
for (int i = 0; i < size; i += 16, a += 16, c += 16) {
__m128i a16 = _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(a, 16)));
__m128i aln = _mm_and_si128(a16, _mm_set1_epi8(15));
__m128i cln = _mm_shuffle_epi8(l16, aln);
__m128i ahn = _mm_and_si128(_mm_srli_epi16(a16, 4), _mm_set1_epi8(15));
__m128i chn = _mm_shuffle_epi8(h16, ahn);
__m128i c16 = _mm_xor_si128(cln, chn);
if (!init)
c16 = _mm_xor_si128(c16, _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(c, 16))));
_mm_store_si128(reinterpret_cast<__m128i *>(__builtin_assume_aligned(c, 16)), c16);
}
#endif
#endif
}
void mac_simd(uint16_t *c, const uint16_t *a, IndexType b, int size, bool init)
{
alignas(16) uint8_t blll[16], bllh[16], blhl[16], blhh[16], bhll[16], bhlh[16], bhhl[16], bhhh[16];
for (int i = 0; i < 16; ++i) {
uint16_t bll = (b * ValueType(i)).v;
uint16_t blh = (b * ValueType(i << 4)).v;
uint16_t bhl = (b * ValueType(i << 8)).v;
uint16_t bhh = (b * ValueType(i << 12)).v;
blll[i] = bll; bhll[i] = bll >> 8;
bllh[i] = blh; bhlh[i] = blh >> 8;
blhl[i] = bhl; bhhl[i] = bhl >> 8;
blhh[i] = bhh; bhhh[i] = bhh >> 8;
}
#ifdef __ARM_NEON
uint8x16_t lll16 = vld1q_u8(blll);
uint8x16_t llh16 = vld1q_u8(bllh);
uint8x16_t lhl16 = vld1q_u8(blhl);
uint8x16_t lhh16 = vld1q_u8(blhh);
uint8x16_t hll16 = vld1q_u8(bhll);
uint8x16_t hlh16 = vld1q_u8(bhlh);
uint8x16_t hhl16 = vld1q_u8(bhhl);
uint8x16_t hhh16 = vld1q_u8(bhhh);
for (int i = 0; i < size; i += 16, a += 16, c += 16) {
uint16x8_t al8 = vld1q_u16(reinterpret_cast<const uint16_t *>(__builtin_assume_aligned(a, 16)));
uint16x8_t ah8 = vld1q_u16(reinterpret_cast<const uint16_t *>(__builtin_assume_aligned(a+8, 16)));
uint8x16_t al16 = (uint8x16_t)vorrq_u16(vshlq_n_u16(ah8, 8), vandq_u16(al8, vdupq_n_u16(255)));
uint8x16_t ah16 = (uint8x16_t)vorrq_u16(vandq_u16(ah8, vdupq_n_u16(0xff00)), vshrq_n_u16(al8, 8));
uint8x16_t alln = vandq_u8(al16, vdupq_n_u8(15));
uint8x16_t clll = vqtbl1q_u8(lll16, alln);
uint8x16_t chll = vqtbl1q_u8(hll16, alln);
uint8x16_t alhn = vshrq_n_u8(al16, 4);
uint8x16_t cllh = vqtbl1q_u8(llh16, alhn);
uint8x16_t chlh = vqtbl1q_u8(hlh16, alhn);
uint8x16_t ahln = vandq_u8(ah16, vdupq_n_u8(15));
uint8x16_t clhl = vqtbl1q_u8(lhl16, ahln);
uint8x16_t chhl = vqtbl1q_u8(hhl16, ahln);
uint8x16_t ahhn = vshrq_n_u8(ah16, 4);
uint8x16_t clhh = vqtbl1q_u8(lhh16, ahhn);
uint8x16_t chhh = vqtbl1q_u8(hhh16, ahhn);
uint16x8_t cl16 = (uint16x8_t)veorq_u8(veorq_u8(clll, cllh), veorq_u8(clhl, clhh));
uint16x8_t ch16 = (uint16x8_t)veorq_u8(veorq_u8(chll, chlh), veorq_u8(chhl, chhh));
uint16x8_t cl8 = vorrq_u16(vshlq_n_u16(ch16, 8), vandq_u16(cl16, vdupq_n_u16(255)));
uint16x8_t ch8 = vorrq_u16(vandq_u16(ch16, vdupq_n_u16(0xff00)), vshrq_n_u16(cl16, 8));
if (!init) {
cl8 = veorq_u16(cl8, vld1q_u16(reinterpret_cast<const uint16_t *>(__builtin_assume_aligned(c, 16))));
ch8 = veorq_u16(ch8, vld1q_u16(reinterpret_cast<const uint16_t *>(__builtin_assume_aligned(c+8, 16))));
}
vst1q_u16(reinterpret_cast<uint16_t *>(__builtin_assume_aligned(c, 16)), cl8);
vst1q_u16(reinterpret_cast<uint16_t *>(__builtin_assume_aligned(c+8, 16)), ch8);
}
#else
#ifdef __AVX2__
__m128i lll16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blll));
__m128i llh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bllh));
__m128i lhl16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blhl));
__m128i lhh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blhh));
__m128i hll16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhll));
__m128i hlh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhlh));
__m128i hhl16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhhl));
__m128i hhh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhhh));
__m256i lll162 = _mm256_broadcastsi128_si256(lll16);
__m256i llh162 = _mm256_broadcastsi128_si256(llh16);
__m256i lhl162 = _mm256_broadcastsi128_si256(lhl16);
__m256i lhh162 = _mm256_broadcastsi128_si256(lhh16);
__m256i hll162 = _mm256_broadcastsi128_si256(hll16);
__m256i hlh162 = _mm256_broadcastsi128_si256(hlh16);
__m256i hhl162 = _mm256_broadcastsi128_si256(hhl16);
__m256i hhh162 = _mm256_broadcastsi128_si256(hhh16);
for (int i = 0; i < size; i += 32, a += 32, c += 32) {
__m256i al16 = _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(a, 32)));
__m256i ah16 = _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(a+16, 32)));
__m256i al32 = _mm256_or_si256(_mm256_slli_epi16(ah16, 8), _mm256_and_si256(al16, _mm256_set1_epi16(255)));
__m256i ah32 = _mm256_or_si256(_mm256_and_si256(ah16, _mm256_set1_epi16(0xff00)), _mm256_srli_epi16(al16, 8));
__m256i alln = _mm256_and_si256(al32, _mm256_set1_epi8(15));
__m256i clll = _mm256_shuffle_epi8(lll162, alln);
__m256i chll = _mm256_shuffle_epi8(hll162, alln);
__m256i alhn = _mm256_and_si256(_mm256_srli_epi16(al32, 4), _mm256_set1_epi8(15));
__m256i cllh = _mm256_shuffle_epi8(llh162, alhn);
__m256i chlh = _mm256_shuffle_epi8(hlh162, alhn);
__m256i ahln = _mm256_and_si256(ah32, _mm256_set1_epi8(15));
__m256i clhl = _mm256_shuffle_epi8(lhl162, ahln);
__m256i chhl = _mm256_shuffle_epi8(hhl162, ahln);
__m256i ahhn = _mm256_and_si256(_mm256_srli_epi16(ah32, 4), _mm256_set1_epi8(15));
__m256i clhh = _mm256_shuffle_epi8(lhh162, ahhn);
__m256i chhh = _mm256_shuffle_epi8(hhh162, ahhn);
__m256i cl32 = _mm256_xor_si256(_mm256_xor_si256(clll, cllh), _mm256_xor_si256(clhl, clhh));
__m256i ch32 = _mm256_xor_si256(_mm256_xor_si256(chll, chlh), _mm256_xor_si256(chhl, chhh));
__m256i cl16 = _mm256_or_si256(_mm256_slli_epi16(ch32, 8), _mm256_and_si256(cl32, _mm256_set1_epi16(255)));
__m256i ch16 = _mm256_or_si256(_mm256_and_si256(ch32, _mm256_set1_epi16(0xff00)), _mm256_srli_epi16(cl32, 8));
if (!init) {
cl16 = _mm256_xor_si256(cl16, _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(c, 32))));
ch16 = _mm256_xor_si256(ch16, _mm256_load_si256(reinterpret_cast<const __m256i *>(__builtin_assume_aligned(c+16, 32))));
}
_mm256_store_si256(reinterpret_cast<__m256i *>(__builtin_assume_aligned(c, 32)), cl16);
_mm256_store_si256(reinterpret_cast<__m256i *>(__builtin_assume_aligned(c+16, 32)), ch16);
}
#else
__m128i lll16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blll));
__m128i llh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bllh));
__m128i lhl16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blhl));
__m128i lhh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(blhh));
__m128i hll16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhll));
__m128i hlh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhlh));
__m128i hhl16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhhl));
__m128i hhh16 = _mm_load_si128(reinterpret_cast<const __m128i *>(bhhh));
for (int i = 0; i < size; i += 16, a += 16, c += 16) {
__m128i al8 = _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(a, 16)));
__m128i ah8 = _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(a+8, 16)));
__m128i al16 = _mm_or_si128(_mm_slli_epi16(ah8, 8), _mm_and_si128(al8, _mm_set1_epi16(255)));
__m128i ah16 = _mm_or_si128(_mm_and_si128(ah8, _mm_set1_epi16(0xff00)), _mm_srli_epi16(al8, 8));
__m128i alln = _mm_and_si128(al16, _mm_set1_epi8(15));
__m128i clll = _mm_shuffle_epi8(lll16, alln);
__m128i chll = _mm_shuffle_epi8(hll16, alln);
__m128i alhn = _mm_and_si128(_mm_srli_epi16(al16, 4), _mm_set1_epi8(15));
__m128i cllh = _mm_shuffle_epi8(llh16, alhn);
__m128i chlh = _mm_shuffle_epi8(hlh16, alhn);
__m128i ahln = _mm_and_si128(ah16, _mm_set1_epi8(15));
__m128i clhl = _mm_shuffle_epi8(lhl16, ahln);
__m128i chhl = _mm_shuffle_epi8(hhl16, ahln);
__m128i ahhn = _mm_and_si128(_mm_srli_epi16(ah16, 4), _mm_set1_epi8(15));
__m128i clhh = _mm_shuffle_epi8(lhh16, ahhn);
__m128i chhh = _mm_shuffle_epi8(hhh16, ahhn);
__m128i cl16 = _mm_xor_si128(_mm_xor_si128(clll, cllh), _mm_xor_si128(clhl, clhh));
__m128i ch16 = _mm_xor_si128(_mm_xor_si128(chll, chlh), _mm_xor_si128(chhl, chhh));
__m128i cl8 = _mm_or_si128(_mm_slli_epi16(ch16, 8), _mm_and_si128(cl16, _mm_set1_epi16(255)));
__m128i ch8 = _mm_or_si128(_mm_and_si128(ch16, _mm_set1_epi16(0xff00)), _mm_srli_epi16(cl16, 8));
if (!init) {
cl8 = _mm_xor_si128(cl8, _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(c, 16))));
ch8 = _mm_xor_si128(ch8, _mm_load_si128(reinterpret_cast<const __m128i *>(__builtin_assume_aligned(c+8, 16))));
}
_mm_store_si128(reinterpret_cast<__m128i *>(__builtin_assume_aligned(c, 16)), cl8);
_mm_store_si128(reinterpret_cast<__m128i *>(__builtin_assume_aligned(c+8, 16)), ch8);
}
#endif
#endif
}
#endif
void multiply_accumulate(ValueType *c, const ValueType *a, IndexType b, int len, bool init)
{
#if defined(__ARM_NEON) || defined(__AVX2__) || defined(__SSE4_1__)
#ifdef __AVX2__
int SIMD = 32;
#else
int SIMD = 16;
#endif
if (((GF::M == 8 && sizeof(value_type) == 1) || (GF::M == 16 && sizeof(value_type) == 2)) && reinterpret_cast<uintptr_t>(c) % SIMD == 0 && reinterpret_cast<uintptr_t>(a) % SIMD == 0 && len % SIMD == 0) {
mac_simd(reinterpret_cast<value_type *>(c), reinterpret_cast<const value_type *>(a), b, len, init);
} else
#endif
if (init) {
for (int i = 0; i < len; i++)
c[i] = b * a[i];
} else {
for (int i = 0; i < len; i++)
c[i] = fma(b, a[i], c[i]);
}
}
void encode(const ValueType *data, ValueType *block, int block_num, int block_len, int block_cnt)
{
assert(block_num <= ValueType::N - block_cnt);
for (int k = 0; k < block_cnt; k++) {
IndexType a_ik = cauchy_matrix(block_num, k);
multiply_accumulate(block, data + block_len * k, a_ik, block_len, !k);
}
}
void decode(ValueType *data, const ValueType *blocks, const ValueType *block_nums, int block_num, int block_len, int block_cnt)
{
for (int k = 0; k < block_cnt; k++) {
IndexType b_ik = inverse_cauchy_matrix(block_nums, block_num, k, block_cnt);
multiply_accumulate(data, blocks + block_len * k, b_ik, block_len, !k);
}
}
void encode(const value_type *data, value_type *block, int block_num, int block_len, int block_cnt)
{
encode(reinterpret_cast<const ValueType *>(data), reinterpret_cast<ValueType *>(block), block_num, block_len, block_cnt);
}
void decode(value_type *data, const value_type *blocks, const value_type *block_nums, int block_num, int block_len, int block_cnt)
{
decode(reinterpret_cast<ValueType *>(data), reinterpret_cast<const ValueType *>(blocks), reinterpret_cast<const ValueType *>(block_nums), block_num, block_len, block_cnt);
}
void encode(const void *data, void *block, int block_number, int block_bytes, int block_count)
{
assert(block_bytes % sizeof(value_type) == 0);
encode(reinterpret_cast<const value_type *>(data), reinterpret_cast<value_type *>(block), block_number, block_bytes / sizeof(value_type), block_count);
}
void decode(void *data, const void *blocks, const value_type *block_numbers, int block_number, int block_bytes, int block_count)
{
assert(block_bytes % sizeof(value_type) == 0);
decode(reinterpret_cast<value_type *>(data), reinterpret_cast<const value_type *>(blocks), block_numbers, block_number, block_bytes / sizeof(value_type), block_count);
}
};
}