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Diffstat (limited to 'contrib/fastutf8/avx2.c')
| -rw-r--r-- | contrib/fastutf8/avx2.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/contrib/fastutf8/avx2.c b/contrib/fastutf8/avx2.c new file mode 100644 index 0000000..765c62f --- /dev/null +++ b/contrib/fastutf8/avx2.c @@ -0,0 +1,314 @@ +/* + * MIT License + * + * Copyright (c) 2019 Yibo Cai + * Copyright (c) 2019 Vsevolod Stakhov + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "config.h" +#include "fastutf8.h" +#include "platform_config.h" + + +#ifndef __clang__ +#pragma GCC push_options +#pragma GCC target("avx2") +#endif + +#ifndef __SSE2__ +#define __SSE2__ +#endif +#ifndef __SSE__ +#define __SSE__ +#endif +#ifndef __SSE4_2__ +#define __SSE4_2__ +#endif +#ifndef __SSE4_1__ +#define __SSE4_1__ +#endif +#ifndef __SSEE3__ +#define __SSEE3__ +#endif +#ifndef __AVX__ +#define __AVX__ +#endif +#ifndef __AVX2__ +#define __AVX2__ +#endif + +#include <immintrin.h> + +/* + * Map high nibble of "First Byte" to legal character length minus 1 + * 0x00 ~ 0xBF --> 0 + * 0xC0 ~ 0xDF --> 1 + * 0xE0 ~ 0xEF --> 2 + * 0xF0 ~ 0xFF --> 3 + */ +static const int8_t _first_len_tbl[] = { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, +}; + +/* Map "First Byte" to 8-th item of range table (0xC2 ~ 0xF4) */ +static const int8_t _first_range_tbl[] = { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 8, 8, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 8, 8, +}; + +/* + * Range table, map range index to min and max values + * Index 0 : 00 ~ 7F (First Byte, ascii) + * Index 1,2,3: 80 ~ BF (Second, Third, Fourth Byte) + * Index 4 : A0 ~ BF (Second Byte after E0) + * Index 5 : 80 ~ 9F (Second Byte after ED) + * Index 6 : 90 ~ BF (Second Byte after F0) + * Index 7 : 80 ~ 8F (Second Byte after F4) + * Index 8 : C2 ~ F4 (First Byte, non ascii) + * Index 9~15 : illegal: i >= 127 && i <= -128 + */ +static const int8_t _range_min_tbl[] = { + 0x00, 0x80, 0x80, 0x80, 0xA0, 0x80, 0x90, 0x80, + 0xC2, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, + 0x00, 0x80, 0x80, 0x80, 0xA0, 0x80, 0x90, 0x80, + 0xC2, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, 0x7F, +}; +static const int8_t _range_max_tbl[] = { + 0x7F, 0xBF, 0xBF, 0xBF, 0xBF, 0x9F, 0xBF, 0x8F, + 0xF4, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, + 0x7F, 0xBF, 0xBF, 0xBF, 0xBF, 0x9F, 0xBF, 0x8F, + 0xF4, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, +}; + +/* + * Tables for fast handling of four special First Bytes(E0,ED,F0,F4), after + * which the Second Byte are not 80~BF. It contains "range index adjustment". + * +------------+---------------+------------------+----------------+ + * | First Byte | original range| range adjustment | adjusted range | + * +------------+---------------+------------------+----------------+ + * | E0 | 2 | 2 | 4 | + * +------------+---------------+------------------+----------------+ + * | ED | 2 | 3 | 5 | + * +------------+---------------+------------------+----------------+ + * | F0 | 3 | 3 | 6 | + * +------------+---------------+------------------+----------------+ + * | F4 | 4 | 4 | 8 | + * +------------+---------------+------------------+----------------+ + */ +/* index1 -> E0, index14 -> ED */ +static const int8_t _df_ee_tbl[] = { + 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, + 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, +}; +/* index1 -> F0, index5 -> F4 */ +static const int8_t _ef_fe_tbl[] = { + 0, 3, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 3, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, +}; + +static inline __m256i push_last_byte_of_a_to_b(__m256i a, __m256i b) + __attribute__((__target__("avx2"))); +static inline __m256i push_last_byte_of_a_to_b(__m256i a, __m256i b) +{ + return _mm256_alignr_epi8(b, _mm256_permute2x128_si256(a, b, 0x21), 15); +} + +static inline __m256i push_last_2bytes_of_a_to_b(__m256i a, __m256i b) + __attribute__((__target__("avx2"))); +static inline __m256i push_last_2bytes_of_a_to_b(__m256i a, __m256i b) +{ + return _mm256_alignr_epi8(b, _mm256_permute2x128_si256(a, b, 0x21), 14); +} + +static inline __m256i push_last_3bytes_of_a_to_b(__m256i a, __m256i b) + __attribute__((__target__("avx2"))); +static inline __m256i push_last_3bytes_of_a_to_b(__m256i a, __m256i b) +{ + return _mm256_alignr_epi8(b, _mm256_permute2x128_si256(a, b, 0x21), 13); +} + +off_t rspamd_fast_utf8_validate_avx2 (const unsigned char *data, size_t len) + __attribute__((__target__("avx2"))); + +/* 5x faster than naive method */ +/* Return 0 - success, -1 - error, >0 - first error char(if RET_ERR_IDX = 1) */ +off_t rspamd_fast_utf8_validate_avx2 (const unsigned char *data, size_t len) +{ + off_t err_pos = 1; + + if (len >= 32) { + __m256i prev_input = _mm256_set1_epi8 (0); + __m256i prev_first_len = _mm256_set1_epi8 (0); + + /* Cached tables */ + const __m256i first_len_tbl = + _mm256_lddqu_si256 ((const __m256i *) _first_len_tbl); + const __m256i first_range_tbl = + _mm256_lddqu_si256 ((const __m256i *) _first_range_tbl); + const __m256i range_min_tbl = + _mm256_lddqu_si256 ((const __m256i *) _range_min_tbl); + const __m256i range_max_tbl = + _mm256_lddqu_si256 ((const __m256i *) _range_max_tbl); + const __m256i df_ee_tbl = + _mm256_lddqu_si256 ((const __m256i *) _df_ee_tbl); + const __m256i ef_fe_tbl = + _mm256_lddqu_si256 ((const __m256i *) _ef_fe_tbl); + + __m256i error = _mm256_set1_epi8 (0); + + while (len >= 32) { + const __m256i input = _mm256_lddqu_si256 ((const __m256i *) data); + + /* high_nibbles = input >> 4 */ + const __m256i high_nibbles = + _mm256_and_si256 (_mm256_srli_epi16 (input, 4), _mm256_set1_epi8 (0x0F)); + + /* first_len = legal character length minus 1 */ + /* 0 for 00~7F, 1 for C0~DF, 2 for E0~EF, 3 for F0~FF */ + /* first_len = first_len_tbl[high_nibbles] */ + __m256i first_len = _mm256_shuffle_epi8 (first_len_tbl, high_nibbles); + + /* First Byte: set range index to 8 for bytes within 0xC0 ~ 0xFF */ + /* range = first_range_tbl[high_nibbles] */ + __m256i range = _mm256_shuffle_epi8 (first_range_tbl, high_nibbles); + + /* Second Byte: set range index to first_len */ + /* 0 for 00~7F, 1 for C0~DF, 2 for E0~EF, 3 for F0~FF */ + /* range |= (first_len, prev_first_len) << 1 byte */ + range = _mm256_or_si256 ( + range, push_last_byte_of_a_to_b (prev_first_len, first_len)); + + /* Third Byte: set range index to saturate_sub(first_len, 1) */ + /* 0 for 00~7F, 0 for C0~DF, 1 for E0~EF, 2 for F0~FF */ + __m256i tmp1, tmp2; + + /* tmp1 = saturate_sub(first_len, 1) */ + tmp1 = _mm256_subs_epu8 (first_len, _mm256_set1_epi8 (1)); + /* tmp2 = saturate_sub(prev_first_len, 1) */ + tmp2 = _mm256_subs_epu8 (prev_first_len, _mm256_set1_epi8 (1)); + + /* range |= (tmp1, tmp2) << 2 bytes */ + range = _mm256_or_si256 (range, push_last_2bytes_of_a_to_b (tmp2, tmp1)); + + /* Fourth Byte: set range index to saturate_sub(first_len, 2) */ + /* 0 for 00~7F, 0 for C0~DF, 0 for E0~EF, 1 for F0~FF */ + /* tmp1 = saturate_sub(first_len, 2) */ + tmp1 = _mm256_subs_epu8 (first_len, _mm256_set1_epi8 (2)); + /* tmp2 = saturate_sub(prev_first_len, 2) */ + tmp2 = _mm256_subs_epu8 (prev_first_len, _mm256_set1_epi8 (2)); + /* range |= (tmp1, tmp2) << 3 bytes */ + range = _mm256_or_si256 (range, push_last_3bytes_of_a_to_b (tmp2, tmp1)); + + /* + * Now we have below range indices caluclated + * Correct cases: + * - 8 for C0~FF + * - 3 for 1st byte after F0~FF + * - 2 for 1st byte after E0~EF or 2nd byte after F0~FF + * - 1 for 1st byte after C0~DF or 2nd byte after E0~EF or + * 3rd byte after F0~FF + * - 0 for others + * Error cases: + * 9,10,11 if non ascii First Byte overlaps + * E.g., F1 80 C2 90 --> 8 3 10 2, where 10 indicates error + */ + + /* Adjust Second Byte range for special First Bytes(E0,ED,F0,F4) */ + /* Overlaps lead to index 9~15, which are illegal in range table */ + __m256i shift1, pos, range2; + /* shift1 = (input, prev_input) << 1 byte */ + shift1 = push_last_byte_of_a_to_b (prev_input, input); + pos = _mm256_sub_epi8 (shift1, _mm256_set1_epi8 (0xEF)); + /* + * shift1: | EF F0 ... FE | FF 00 ... ... DE | DF E0 ... EE | + * pos: | 0 1 15 | 16 17 239| 240 241 255| + * pos-240: | 0 0 0 | 0 0 0 | 0 1 15 | + * pos+112: | 112 113 127| >= 128 | >= 128 | + */ + tmp1 = _mm256_subs_epu8 (pos, _mm256_set1_epi8 ((char)240)); + range2 = _mm256_shuffle_epi8 (df_ee_tbl, tmp1); + tmp2 = _mm256_adds_epu8 (pos, _mm256_set1_epi8 (112)); + range2 = _mm256_add_epi8 (range2, _mm256_shuffle_epi8 (ef_fe_tbl, tmp2)); + + range = _mm256_add_epi8 (range, range2); + + /* Load min and max values per calculated range index */ + __m256i minv = _mm256_shuffle_epi8 (range_min_tbl, range); + __m256i maxv = _mm256_shuffle_epi8 (range_max_tbl, range); + + /* Check value range */ + error = _mm256_cmpgt_epi8(minv, input); + error = _mm256_or_si256(error, _mm256_cmpgt_epi8(input, maxv)); + /* 5% performance drop from this conditional branch */ + if (!_mm256_testz_si256(error, error)) { + break; + } + + prev_input = input; + prev_first_len = first_len; + + data += 32; + len -= 32; + err_pos += 32; + } + + /* Error in first 16 bytes */ + if (err_pos == 1) { + goto do_naive; + } + + /* Find previous token (not 80~BF) */ + int32_t token4 = _mm256_extract_epi32 (prev_input, 7); + const int8_t *token = (const int8_t *) &token4; + int lookahead = 0; + + if (token[3] > (int8_t) 0xBF) { + lookahead = 1; + } + else if (token[2] > (int8_t) 0xBF) { + lookahead = 2; + } + else if (token[1] > (int8_t) 0xBF) { + lookahead = 3; + } + + data -= lookahead; + len += lookahead; + err_pos -= lookahead; + } + + /* Check remaining bytes with naive method */ +do_naive: + if (len > 0) { + off_t err_pos2 = rspamd_fast_utf8_validate_ref (data, len); + + if (err_pos2) { + return err_pos + err_pos2 - 1; + } + } + + return 0; +} + +#ifndef __clang__ +#pragma GCC pop_options +#endif + |