/* * xxHash - Extremely Fast Hash algorithm * Copyright (C) 2012-2023, Yann Collet * * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * You can contact the author at : * - xxHash homepage: http://www.xxhash.com * - xxHash source repository : https://github.com/Cyan4973/xxHash */ // xxhash64 is based on commit d2df04efcbef7d7f6886d345861e5dfda4edacc1. Removed // everything but a simple interface for computing xxh64. // xxh3_64bits is based on commit d5891596637d21366b9b1dcf2c0007a3edb26a9e (July // 2023). // xxh3_128bits is based on commit b0adcc54188c3130b1793e7b19c62eb1e669f7df // (June 2024). #include "llvm/Support/xxhash.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/Endian.h" #include #if !defined(LLVM_XXH_USE_NEON) #if (defined(__aarch64__) || defined(_M_ARM64) || defined(_M_ARM64EC)) && \ !defined(__ARM_BIG_ENDIAN) #define LLVM_XXH_USE_NEON 1 #else #define LLVM_XXH_USE_NEON 0 #endif #endif #if LLVM_XXH_USE_NEON #include #endif using namespace llvm; using namespace support; static uint64_t rotl64(uint64_t X, size_t R) { return (X << R) | (X >> (64 - R)); } constexpr uint32_t PRIME32_1 = 0x9E3779B1; constexpr uint32_t PRIME32_2 = 0x85EBCA77; constexpr uint32_t PRIME32_3 = 0xC2B2AE3D; static const uint64_t PRIME64_1 = 11400714785074694791ULL; static const uint64_t PRIME64_2 = 14029467366897019727ULL; static const uint64_t PRIME64_3 = 1609587929392839161ULL; static const uint64_t PRIME64_4 = 9650029242287828579ULL; static const uint64_t PRIME64_5 = 2870177450012600261ULL; static uint64_t round(uint64_t Acc, uint64_t Input) { Acc += Input * PRIME64_2; Acc = rotl64(Acc, 31); Acc *= PRIME64_1; return Acc; } static uint64_t mergeRound(uint64_t Acc, uint64_t Val) { Val = round(0, Val); Acc ^= Val; Acc = Acc * PRIME64_1 + PRIME64_4; return Acc; } static uint64_t XXH64_avalanche(uint64_t hash) { hash ^= hash >> 33; hash *= PRIME64_2; hash ^= hash >> 29; hash *= PRIME64_3; hash ^= hash >> 32; return hash; } uint64_t llvm::xxHash64(StringRef Data) { size_t Len = Data.size(); uint64_t Seed = 0; const unsigned char *P = Data.bytes_begin(); const unsigned char *const BEnd = Data.bytes_end(); uint64_t H64; if (Len >= 32) { const unsigned char *const Limit = BEnd - 32; uint64_t V1 = Seed + PRIME64_1 + PRIME64_2; uint64_t V2 = Seed + PRIME64_2; uint64_t V3 = Seed + 0; uint64_t V4 = Seed - PRIME64_1; do { V1 = round(V1, endian::read64le(P)); P += 8; V2 = round(V2, endian::read64le(P)); P += 8; V3 = round(V3, endian::read64le(P)); P += 8; V4 = round(V4, endian::read64le(P)); P += 8; } while (P <= Limit); H64 = rotl64(V1, 1) + rotl64(V2, 7) + rotl64(V3, 12) + rotl64(V4, 18); H64 = mergeRound(H64, V1); H64 = mergeRound(H64, V2); H64 = mergeRound(H64, V3); H64 = mergeRound(H64, V4); } else { H64 = Seed + PRIME64_5; } H64 += (uint64_t)Len; while (reinterpret_cast(P) + 8 <= reinterpret_cast(BEnd)) { uint64_t const K1 = round(0, endian::read64le(P)); H64 ^= K1; H64 = rotl64(H64, 27) * PRIME64_1 + PRIME64_4; P += 8; } if (reinterpret_cast(P) + 4 <= reinterpret_cast(BEnd)) { H64 ^= (uint64_t)(endian::read32le(P)) * PRIME64_1; H64 = rotl64(H64, 23) * PRIME64_2 + PRIME64_3; P += 4; } while (P < BEnd) { H64 ^= (*P) * PRIME64_5; H64 = rotl64(H64, 11) * PRIME64_1; P++; } return XXH64_avalanche(H64); } uint64_t llvm::xxHash64(ArrayRef Data) { return xxHash64({(const char *)Data.data(), Data.size()}); } constexpr size_t XXH3_SECRETSIZE_MIN = 136; constexpr size_t XXH_SECRET_DEFAULT_SIZE = 192; /* Pseudorandom data taken directly from FARSH */ // clang-format off constexpr uint8_t kSecret[XXH_SECRET_DEFAULT_SIZE] = { 0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c, 0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f, 0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21, 0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c, 0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3, 0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8, 0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d, 0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64, 0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb, 0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e, 0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce, 0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e, }; // clang-format on constexpr uint64_t PRIME_MX1 = 0x165667919E3779F9; constexpr uint64_t PRIME_MX2 = 0x9FB21C651E98DF25; // Calculates a 64-bit to 128-bit multiply, then XOR folds it. static uint64_t XXH3_mul128_fold64(uint64_t lhs, uint64_t rhs) { #if defined(__SIZEOF_INT128__) || \ (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128) __uint128_t product = (__uint128_t)lhs * (__uint128_t)rhs; return uint64_t(product) ^ uint64_t(product >> 64); #else /* First calculate all of the cross products. */ const uint64_t lo_lo = (lhs & 0xFFFFFFFF) * (rhs & 0xFFFFFFFF); const uint64_t hi_lo = (lhs >> 32) * (rhs & 0xFFFFFFFF); const uint64_t lo_hi = (lhs & 0xFFFFFFFF) * (rhs >> 32); const uint64_t hi_hi = (lhs >> 32) * (rhs >> 32); /* Now add the products together. These will never overflow. */ const uint64_t cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi; const uint64_t upper = (hi_lo >> 32) + (cross >> 32) + hi_hi; const uint64_t lower = (cross << 32) | (lo_lo & 0xFFFFFFFF); return upper ^ lower; #endif } constexpr size_t XXH_STRIPE_LEN = 64; constexpr size_t XXH_SECRET_CONSUME_RATE = 8; constexpr size_t XXH_ACC_NB = XXH_STRIPE_LEN / sizeof(uint64_t); static uint64_t XXH3_avalanche(uint64_t hash) { hash ^= hash >> 37; hash *= PRIME_MX1; hash ^= hash >> 32; return hash; } static uint64_t XXH3_len_1to3_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { const uint8_t c1 = input[0]; const uint8_t c2 = input[len >> 1]; const uint8_t c3 = input[len - 1]; uint32_t combined = ((uint32_t)c1 << 16) | ((uint32_t)c2 << 24) | ((uint32_t)c3 << 0) | ((uint32_t)len << 8); uint64_t bitflip = (uint64_t)(endian::read32le(secret) ^ endian::read32le(secret + 4)) + seed; return XXH64_avalanche(uint64_t(combined) ^ bitflip); } static uint64_t XXH3_len_4to8_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { seed ^= (uint64_t)byteswap(uint32_t(seed)) << 32; const uint32_t input1 = endian::read32le(input); const uint32_t input2 = endian::read32le(input + len - 4); uint64_t acc = (endian::read64le(secret + 8) ^ endian::read64le(secret + 16)) - seed; const uint64_t input64 = (uint64_t)input2 | ((uint64_t)input1 << 32); acc ^= input64; // XXH3_rrmxmx(acc, len) acc ^= rotl64(acc, 49) ^ rotl64(acc, 24); acc *= PRIME_MX2; acc ^= (acc >> 35) + (uint64_t)len; acc *= PRIME_MX2; return acc ^ (acc >> 28); } static uint64_t XXH3_len_9to16_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t const seed) { uint64_t input_lo = (endian::read64le(secret + 24) ^ endian::read64le(secret + 32)) + seed; uint64_t input_hi = (endian::read64le(secret + 40) ^ endian::read64le(secret + 48)) - seed; input_lo ^= endian::read64le(input); input_hi ^= endian::read64le(input + len - 8); uint64_t acc = uint64_t(len) + byteswap(input_lo) + input_hi + XXH3_mul128_fold64(input_lo, input_hi); return XXH3_avalanche(acc); } LLVM_ATTRIBUTE_ALWAYS_INLINE static uint64_t XXH3_len_0to16_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t const seed) { if (LLVM_LIKELY(len > 8)) return XXH3_len_9to16_64b(input, len, secret, seed); if (LLVM_LIKELY(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed); if (len != 0) return XXH3_len_1to3_64b(input, len, secret, seed); return XXH64_avalanche(seed ^ endian::read64le(secret + 56) ^ endian::read64le(secret + 64)); } static uint64_t XXH3_mix16B(const uint8_t *input, uint8_t const *secret, uint64_t seed) { uint64_t lhs = seed; uint64_t rhs = 0U - seed; lhs += endian::read64le(secret); rhs += endian::read64le(secret + 8); lhs ^= endian::read64le(input); rhs ^= endian::read64le(input + 8); return XXH3_mul128_fold64(lhs, rhs); } /* For mid range keys, XXH3 uses a Mum-hash variant. */ LLVM_ATTRIBUTE_ALWAYS_INLINE static uint64_t XXH3_len_17to128_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t const seed) { uint64_t acc = len * PRIME64_1, acc_end; acc += XXH3_mix16B(input + 0, secret + 0, seed); acc_end = XXH3_mix16B(input + len - 16, secret + 16, seed); if (len > 32) { acc += XXH3_mix16B(input + 16, secret + 32, seed); acc_end += XXH3_mix16B(input + len - 32, secret + 48, seed); if (len > 64) { acc += XXH3_mix16B(input + 32, secret + 64, seed); acc_end += XXH3_mix16B(input + len - 48, secret + 80, seed); if (len > 96) { acc += XXH3_mix16B(input + 48, secret + 96, seed); acc_end += XXH3_mix16B(input + len - 64, secret + 112, seed); } } } return XXH3_avalanche(acc + acc_end); } constexpr size_t XXH3_MIDSIZE_MAX = 240; constexpr size_t XXH3_MIDSIZE_STARTOFFSET = 3; constexpr size_t XXH3_MIDSIZE_LASTOFFSET = 17; LLVM_ATTRIBUTE_NOINLINE static uint64_t XXH3_len_129to240_64b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { uint64_t acc = (uint64_t)len * PRIME64_1; const unsigned nbRounds = len / 16; for (unsigned i = 0; i < 8; ++i) acc += XXH3_mix16B(input + 16 * i, secret + 16 * i, seed); acc = XXH3_avalanche(acc); for (unsigned i = 8; i < nbRounds; ++i) { acc += XXH3_mix16B(input + 16 * i, secret + 16 * (i - 8) + XXH3_MIDSIZE_STARTOFFSET, seed); } /* last bytes */ acc += XXH3_mix16B(input + len - 16, secret + XXH3_SECRETSIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed); return XXH3_avalanche(acc); } #if LLVM_XXH_USE_NEON #define XXH3_accumulate_512 XXH3_accumulate_512_neon #define XXH3_scrambleAcc XXH3_scrambleAcc_neon // NEON implementation based on commit a57f6cce2698049863af8c25787084ae0489d849 // (July 2024), with the following removed: // - workaround for suboptimal codegen on older GCC // - compiler barriers against instruction reordering // - WebAssembly SIMD support // - configurable split between NEON and scalar lanes (benchmarking shows no // penalty when fully doing SIMD on the Apple M1) #if defined(__GNUC__) || defined(__clang__) #define XXH_ALIASING __attribute__((__may_alias__)) #else #define XXH_ALIASING /* nothing */ #endif typedef uint64x2_t xxh_aliasing_uint64x2_t XXH_ALIASING; LLVM_ATTRIBUTE_ALWAYS_INLINE static uint64x2_t XXH_vld1q_u64(void const *ptr) { return vreinterpretq_u64_u8(vld1q_u8((uint8_t const *)ptr)); } LLVM_ATTRIBUTE_ALWAYS_INLINE static void XXH3_accumulate_512_neon(uint64_t *acc, const uint8_t *input, const uint8_t *secret) { xxh_aliasing_uint64x2_t *const xacc = (xxh_aliasing_uint64x2_t *)acc; #ifdef __clang__ #pragma clang loop unroll(full) #endif for (size_t i = 0; i < XXH_ACC_NB / 2; i += 2) { /* data_vec = input[i]; */ uint64x2_t data_vec_1 = XXH_vld1q_u64(input + (i * 16)); uint64x2_t data_vec_2 = XXH_vld1q_u64(input + ((i + 1) * 16)); /* key_vec = secret[i]; */ uint64x2_t key_vec_1 = XXH_vld1q_u64(secret + (i * 16)); uint64x2_t key_vec_2 = XXH_vld1q_u64(secret + ((i + 1) * 16)); /* data_swap = swap(data_vec) */ uint64x2_t data_swap_1 = vextq_u64(data_vec_1, data_vec_1, 1); uint64x2_t data_swap_2 = vextq_u64(data_vec_2, data_vec_2, 1); /* data_key = data_vec ^ key_vec; */ uint64x2_t data_key_1 = veorq_u64(data_vec_1, key_vec_1); uint64x2_t data_key_2 = veorq_u64(data_vec_2, key_vec_2); /* * If we reinterpret the 64x2 vectors as 32x4 vectors, we can use a * de-interleave operation for 4 lanes in 1 step with `vuzpq_u32` to * get one vector with the low 32 bits of each lane, and one vector * with the high 32 bits of each lane. * * The intrinsic returns a double vector because the original ARMv7-a * instruction modified both arguments in place. AArch64 and SIMD128 emit * two instructions from this intrinsic. * * [ dk11L | dk11H | dk12L | dk12H ] -> [ dk11L | dk12L | dk21L | dk22L ] * [ dk21L | dk21H | dk22L | dk22H ] -> [ dk11H | dk12H | dk21H | dk22H ] */ uint32x4x2_t unzipped = vuzpq_u32(vreinterpretq_u32_u64(data_key_1), vreinterpretq_u32_u64(data_key_2)); /* data_key_lo = data_key & 0xFFFFFFFF */ uint32x4_t data_key_lo = unzipped.val[0]; /* data_key_hi = data_key >> 32 */ uint32x4_t data_key_hi = unzipped.val[1]; /* * Then, we can split the vectors horizontally and multiply which, as for * most widening intrinsics, have a variant that works on both high half * vectors for free on AArch64. A similar instruction is available on * SIMD128. * * sum = data_swap + (u64x2) data_key_lo * (u64x2) data_key_hi */ uint64x2_t sum_1 = vmlal_u32(data_swap_1, vget_low_u32(data_key_lo), vget_low_u32(data_key_hi)); uint64x2_t sum_2 = vmlal_u32(data_swap_2, vget_high_u32(data_key_lo), vget_high_u32(data_key_hi)); /* xacc[i] = acc_vec + sum; */ xacc[i] = vaddq_u64(xacc[i], sum_1); xacc[i + 1] = vaddq_u64(xacc[i + 1], sum_2); } } LLVM_ATTRIBUTE_ALWAYS_INLINE static void XXH3_scrambleAcc_neon(uint64_t *acc, const uint8_t *secret) { xxh_aliasing_uint64x2_t *const xacc = (xxh_aliasing_uint64x2_t *)acc; /* { prime32_1, prime32_1 } */ uint32x2_t const kPrimeLo = vdup_n_u32(PRIME32_1); /* { 0, prime32_1, 0, prime32_1 } */ uint32x4_t const kPrimeHi = vreinterpretq_u32_u64(vdupq_n_u64((uint64_t)PRIME32_1 << 32)); for (size_t i = 0; i < XXH_ACC_NB / 2; ++i) { /* xacc[i] ^= (xacc[i] >> 47); */ uint64x2_t acc_vec = XXH_vld1q_u64(acc + (2 * i)); uint64x2_t shifted = vshrq_n_u64(acc_vec, 47); uint64x2_t data_vec = veorq_u64(acc_vec, shifted); /* xacc[i] ^= secret[i]; */ uint64x2_t key_vec = XXH_vld1q_u64(secret + (i * 16)); uint64x2_t data_key = veorq_u64(data_vec, key_vec); /* * xacc[i] *= XXH_PRIME32_1 * * Expanded version with portable NEON intrinsics * * lo(x) * lo(y) + (hi(x) * lo(y) << 32) * * prod_hi = hi(data_key) * lo(prime) << 32 * * Since we only need 32 bits of this multiply a trick can be used, * reinterpreting the vector as a uint32x4_t and multiplying by * { 0, prime, 0, prime } to cancel out the unwanted bits and avoid the * shift. */ uint32x4_t prod_hi = vmulq_u32(vreinterpretq_u32_u64(data_key), kPrimeHi); /* Extract low bits for vmlal_u32 */ uint32x2_t data_key_lo = vmovn_u64(data_key); /* xacc[i] = prod_hi + lo(data_key) * XXH_PRIME32_1; */ xacc[i] = vmlal_u32(vreinterpretq_u64_u32(prod_hi), data_key_lo, kPrimeLo); } } #else #define XXH3_accumulate_512 XXH3_accumulate_512_scalar #define XXH3_scrambleAcc XXH3_scrambleAcc_scalar LLVM_ATTRIBUTE_ALWAYS_INLINE static void XXH3_accumulate_512_scalar(uint64_t *acc, const uint8_t *input, const uint8_t *secret) { for (size_t i = 0; i < XXH_ACC_NB; ++i) { uint64_t data_val = endian::read64le(input + 8 * i); uint64_t data_key = data_val ^ endian::read64le(secret + 8 * i); acc[i ^ 1] += data_val; acc[i] += uint32_t(data_key) * (data_key >> 32); } } LLVM_ATTRIBUTE_ALWAYS_INLINE static void XXH3_scrambleAcc_scalar(uint64_t *acc, const uint8_t *secret) { for (size_t i = 0; i < XXH_ACC_NB; ++i) { acc[i] ^= acc[i] >> 47; acc[i] ^= endian::read64le(secret + 8 * i); acc[i] *= PRIME32_1; } } #endif LLVM_ATTRIBUTE_ALWAYS_INLINE static void XXH3_accumulate(uint64_t *acc, const uint8_t *input, const uint8_t *secret, size_t nbStripes) { for (size_t n = 0; n < nbStripes; ++n) { XXH3_accumulate_512(acc, input + n * XXH_STRIPE_LEN, secret + n * XXH_SECRET_CONSUME_RATE); } } static uint64_t XXH3_mix2Accs(const uint64_t *acc, const uint8_t *secret) { return XXH3_mul128_fold64(acc[0] ^ endian::read64le(secret), acc[1] ^ endian::read64le(secret + 8)); } static uint64_t XXH3_mergeAccs(const uint64_t *acc, const uint8_t *key, uint64_t start) { uint64_t result64 = start; for (size_t i = 0; i < 4; ++i) result64 += XXH3_mix2Accs(acc + 2 * i, key + 16 * i); return XXH3_avalanche(result64); } LLVM_ATTRIBUTE_NOINLINE static uint64_t XXH3_hashLong_64b(const uint8_t *input, size_t len, const uint8_t *secret, size_t secretSize) { const size_t nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE; const size_t block_len = XXH_STRIPE_LEN * nbStripesPerBlock; const size_t nb_blocks = (len - 1) / block_len; alignas(16) uint64_t acc[XXH_ACC_NB] = { PRIME32_3, PRIME64_1, PRIME64_2, PRIME64_3, PRIME64_4, PRIME32_2, PRIME64_5, PRIME32_1, }; for (size_t n = 0; n < nb_blocks; ++n) { XXH3_accumulate(acc, input + n * block_len, secret, nbStripesPerBlock); XXH3_scrambleAcc(acc, secret + secretSize - XXH_STRIPE_LEN); } /* last partial block */ const size_t nbStripes = (len - 1 - (block_len * nb_blocks)) / XXH_STRIPE_LEN; assert(nbStripes <= secretSize / XXH_SECRET_CONSUME_RATE); XXH3_accumulate(acc, input + nb_blocks * block_len, secret, nbStripes); /* last stripe */ constexpr size_t XXH_SECRET_LASTACC_START = 7; XXH3_accumulate_512(acc, input + len - XXH_STRIPE_LEN, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START); /* converge into final hash */ constexpr size_t XXH_SECRET_MERGEACCS_START = 11; return XXH3_mergeAccs(acc, secret + XXH_SECRET_MERGEACCS_START, (uint64_t)len * PRIME64_1); } uint64_t llvm::xxh3_64bits(ArrayRef data) { auto *in = data.data(); size_t len = data.size(); if (len <= 16) return XXH3_len_0to16_64b(in, len, kSecret, 0); if (len <= 128) return XXH3_len_17to128_64b(in, len, kSecret, 0); if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_64b(in, len, kSecret, 0); return XXH3_hashLong_64b(in, len, kSecret, sizeof(kSecret)); } /* ========================================== * XXH3 128 bits (a.k.a XXH128) * ========================================== * XXH3's 128-bit variant has better mixing and strength than the 64-bit * variant, even without counting the significantly larger output size. * * For example, extra steps are taken to avoid the seed-dependent collisions * in 17-240 byte inputs (See XXH3_mix16B and XXH128_mix32B). * * This strength naturally comes at the cost of some speed, especially on short * lengths. Note that longer hashes are about as fast as the 64-bit version * due to it using only a slight modification of the 64-bit loop. * * XXH128 is also more oriented towards 64-bit machines. It is still extremely * fast for a _128-bit_ hash on 32-bit (it usually clears XXH64). */ /*! * @internal * @def XXH_rotl32(x,r) * @brief 32-bit rotate left. * * @param x The 32-bit integer to be rotated. * @param r The number of bits to rotate. * @pre * @p r > 0 && @p r < 32 * @note * @p x and @p r may be evaluated multiple times. * @return The rotated result. */ #if __has_builtin(__builtin_rotateleft32) && \ __has_builtin(__builtin_rotateleft64) #define XXH_rotl32 __builtin_rotateleft32 #define XXH_rotl64 __builtin_rotateleft64 /* Note: although _rotl exists for minGW (GCC under windows), performance seems * poor */ #elif defined(_MSC_VER) #define XXH_rotl32(x, r) _rotl(x, r) #define XXH_rotl64(x, r) _rotl64(x, r) #else #define XXH_rotl32(x, r) (((x) << (r)) | ((x) >> (32 - (r)))) #define XXH_rotl64(x, r) (((x) << (r)) | ((x) >> (64 - (r)))) #endif #define XXH_mult32to64(x, y) ((uint64_t)(uint32_t)(x) * (uint64_t)(uint32_t)(y)) /*! * @brief Calculates a 64->128-bit long multiply. * * Uses `__uint128_t` and `_umul128` if available, otherwise uses a scalar * version. * * @param lhs , rhs The 64-bit integers to be multiplied * @return The 128-bit result represented in an @ref XXH128_hash_t. */ static XXH128_hash_t XXH_mult64to128(uint64_t lhs, uint64_t rhs) { /* * GCC/Clang __uint128_t method. * * On most 64-bit targets, GCC and Clang define a __uint128_t type. * This is usually the best way as it usually uses a native long 64-bit * multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64. * * Usually. * * Despite being a 32-bit platform, Clang (and emscripten) define this type * despite not having the arithmetic for it. This results in a laggy * compiler builtin call which calculates a full 128-bit multiply. * In that case it is best to use the portable one. * https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677 */ #if (defined(__GNUC__) || defined(__clang__)) && !defined(__wasm__) && \ defined(__SIZEOF_INT128__) || \ (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128) __uint128_t const product = (__uint128_t)lhs * (__uint128_t)rhs; XXH128_hash_t r128; r128.low64 = (uint64_t)(product); r128.high64 = (uint64_t)(product >> 64); return r128; /* * MSVC for x64's _umul128 method. * * uint64_t _umul128(uint64_t Multiplier, uint64_t Multiplicand, uint64_t * *HighProduct); * * This compiles to single operand MUL on x64. */ #elif (defined(_M_X64) || defined(_M_IA64)) && !defined(_M_ARM64EC) #ifndef _MSC_VER #pragma intrinsic(_umul128) #endif uint64_t product_high; uint64_t const product_low = _umul128(lhs, rhs, &product_high); XXH128_hash_t r128; r128.low64 = product_low; r128.high64 = product_high; return r128; /* * MSVC for ARM64's __umulh method. * * This compiles to the same MUL + UMULH as GCC/Clang's __uint128_t method. */ #elif defined(_M_ARM64) || defined(_M_ARM64EC) #ifndef _MSC_VER #pragma intrinsic(__umulh) #endif XXH128_hash_t r128; r128.low64 = lhs * rhs; r128.high64 = __umulh(lhs, rhs); return r128; #else /* * Portable scalar method. Optimized for 32-bit and 64-bit ALUs. * * This is a fast and simple grade school multiply, which is shown below * with base 10 arithmetic instead of base 0x100000000. * * 9 3 // D2 lhs = 93 * x 7 5 // D2 rhs = 75 * ---------- * 1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15 * 4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45 * 2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21 * + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63 * --------- * 2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27 * + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67 * --------- * 6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975 * * The reasons for adding the products like this are: * 1. It avoids manual carry tracking. Just like how * (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX. * This avoids a lot of complexity. * * 2. It hints for, and on Clang, compiles to, the powerful UMAAL * instruction available in ARM's Digital Signal Processing extension * in 32-bit ARMv6 and later, which is shown below: * * void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm) * { * uint64_t product = (uint64_t)*RdLo * (uint64_t)*RdHi + Rn + Rm; * *RdLo = (xxh_u32)(product & 0xFFFFFFFF); * *RdHi = (xxh_u32)(product >> 32); * } * * This instruction was designed for efficient long multiplication, and * allows this to be calculated in only 4 instructions at speeds * comparable to some 64-bit ALUs. * * 3. It isn't terrible on other platforms. Usually this will be a couple * of 32-bit ADD/ADCs. */ /* First calculate all of the cross products. */ uint64_t const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF); uint64_t const hi_lo = XXH_mult32to64(lhs >> 32, rhs & 0xFFFFFFFF); uint64_t const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32); uint64_t const hi_hi = XXH_mult32to64(lhs >> 32, rhs >> 32); /* Now add the products together. These will never overflow. */ uint64_t const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi; uint64_t const upper = (hi_lo >> 32) + (cross >> 32) + hi_hi; uint64_t const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF); XXH128_hash_t r128; r128.low64 = lower; r128.high64 = upper; return r128; #endif } /*! Seems to produce slightly better code on GCC for some reason. */ LLVM_ATTRIBUTE_ALWAYS_INLINE constexpr uint64_t XXH_xorshift64(uint64_t v64, int shift) { return v64 ^ (v64 >> shift); } LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH3_len_1to3_128b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { /* A doubled version of 1to3_64b with different constants. */ /* * len = 1: combinedl = { input[0], 0x01, input[0], input[0] } * len = 2: combinedl = { input[1], 0x02, input[0], input[1] } * len = 3: combinedl = { input[2], 0x03, input[0], input[1] } */ uint8_t const c1 = input[0]; uint8_t const c2 = input[len >> 1]; uint8_t const c3 = input[len - 1]; uint32_t const combinedl = ((uint32_t)c1 << 16) | ((uint32_t)c2 << 24) | ((uint32_t)c3 << 0) | ((uint32_t)len << 8); uint32_t const combinedh = XXH_rotl32(byteswap(combinedl), 13); uint64_t const bitflipl = (endian::read32le(secret) ^ endian::read32le(secret + 4)) + seed; uint64_t const bitfliph = (endian::read32le(secret + 8) ^ endian::read32le(secret + 12)) - seed; uint64_t const keyed_lo = (uint64_t)combinedl ^ bitflipl; uint64_t const keyed_hi = (uint64_t)combinedh ^ bitfliph; XXH128_hash_t h128; h128.low64 = XXH64_avalanche(keyed_lo); h128.high64 = XXH64_avalanche(keyed_hi); return h128; } LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH3_len_4to8_128b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { seed ^= (uint64_t)byteswap((uint32_t)seed) << 32; uint32_t const input_lo = endian::read32le(input); uint32_t const input_hi = endian::read32le(input + len - 4); uint64_t const input_64 = input_lo + ((uint64_t)input_hi << 32); uint64_t const bitflip = (endian::read64le(secret + 16) ^ endian::read64le(secret + 24)) + seed; uint64_t const keyed = input_64 ^ bitflip; /* Shift len to the left to ensure it is even, this avoids even multiplies. */ XXH128_hash_t m128 = XXH_mult64to128(keyed, PRIME64_1 + (len << 2)); m128.high64 += (m128.low64 << 1); m128.low64 ^= (m128.high64 >> 3); m128.low64 = XXH_xorshift64(m128.low64, 35); m128.low64 *= PRIME_MX2; m128.low64 = XXH_xorshift64(m128.low64, 28); m128.high64 = XXH3_avalanche(m128.high64); return m128; } LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH3_len_9to16_128b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { uint64_t const bitflipl = (endian::read64le(secret + 32) ^ endian::read64le(secret + 40)) - seed; uint64_t const bitfliph = (endian::read64le(secret + 48) ^ endian::read64le(secret + 56)) + seed; uint64_t const input_lo = endian::read64le(input); uint64_t input_hi = endian::read64le(input + len - 8); XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi ^ bitflipl, PRIME64_1); /* * Put len in the middle of m128 to ensure that the length gets mixed to * both the low and high bits in the 128x64 multiply below. */ m128.low64 += (uint64_t)(len - 1) << 54; input_hi ^= bitfliph; /* * Add the high 32 bits of input_hi to the high 32 bits of m128, then * add the long product of the low 32 bits of input_hi and PRIME32_2 to * the high 64 bits of m128. * * The best approach to this operation is different on 32-bit and 64-bit. */ if (sizeof(void *) < sizeof(uint64_t)) { /* 32-bit */ /* * 32-bit optimized version, which is more readable. * * On 32-bit, it removes an ADC and delays a dependency between the two * halves of m128.high64, but it generates an extra mask on 64-bit. */ m128.high64 += (input_hi & 0xFFFFFFFF00000000ULL) + XXH_mult32to64((uint32_t)input_hi, PRIME32_2); } else { /* * 64-bit optimized (albeit more confusing) version. * * Uses some properties of addition and multiplication to remove the mask: * * Let: * a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF) * b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000) * c = PRIME32_2 * * a + (b * c) * Inverse Property: x + y - x == y * a + (b * (1 + c - 1)) * Distributive Property: x * (y + z) == (x * y) + (x * z) * a + (b * 1) + (b * (c - 1)) * Identity Property: x * 1 == x * a + b + (b * (c - 1)) * * Substitute a, b, and c: * input_hi.hi + input_hi.lo + ((uint64_t)input_hi.lo * (PRIME32_2 * - 1)) * * Since input_hi.hi + input_hi.lo == input_hi, we get this: * input_hi + ((uint64_t)input_hi.lo * (PRIME32_2 - 1)) */ m128.high64 += input_hi + XXH_mult32to64((uint32_t)input_hi, PRIME32_2 - 1); } /* m128 ^= XXH_swap64(m128 >> 64); */ m128.low64 ^= byteswap(m128.high64); /* 128x64 multiply: h128 = m128 * PRIME64_2; */ XXH128_hash_t h128 = XXH_mult64to128(m128.low64, PRIME64_2); h128.high64 += m128.high64 * PRIME64_2; h128.low64 = XXH3_avalanche(h128.low64); h128.high64 = XXH3_avalanche(h128.high64); return h128; } /* * Assumption: `secret` size is >= XXH3_SECRET_SIZE_MIN */ LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH3_len_0to16_128b(const uint8_t *input, size_t len, const uint8_t *secret, uint64_t seed) { if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed); if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed); if (len) return XXH3_len_1to3_128b(input, len, secret, seed); XXH128_hash_t h128; uint64_t const bitflipl = endian::read64le(secret + 64) ^ endian::read64le(secret + 72); uint64_t const bitfliph = endian::read64le(secret + 80) ^ endian::read64le(secret + 88); h128.low64 = XXH64_avalanche(seed ^ bitflipl); h128.high64 = XXH64_avalanche(seed ^ bitfliph); return h128; } /* * A bit slower than XXH3_mix16B, but handles multiply by zero better. */ LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH128_mix32B(XXH128_hash_t acc, const uint8_t *input_1, const uint8_t *input_2, const uint8_t *secret, uint64_t seed) { acc.low64 += XXH3_mix16B(input_1, secret + 0, seed); acc.low64 ^= endian::read64le(input_2) + endian::read64le(input_2 + 8); acc.high64 += XXH3_mix16B(input_2, secret + 16, seed); acc.high64 ^= endian::read64le(input_1) + endian::read64le(input_1 + 8); return acc; } LLVM_ATTRIBUTE_ALWAYS_INLINE static XXH128_hash_t XXH3_len_17to128_128b(const uint8_t *input, size_t len, const uint8_t *secret, size_t secretSize, uint64_t seed) { (void)secretSize; XXH128_hash_t acc; acc.low64 = len * PRIME64_1; acc.high64 = 0; if (len > 32) { if (len > 64) { if (len > 96) { acc = XXH128_mix32B(acc, input + 48, input + len - 64, secret + 96, seed); } acc = XXH128_mix32B(acc, input + 32, input + len - 48, secret + 64, seed); } acc = XXH128_mix32B(acc, input + 16, input + len - 32, secret + 32, seed); } acc = XXH128_mix32B(acc, input, input + len - 16, secret, seed); XXH128_hash_t h128; h128.low64 = acc.low64 + acc.high64; h128.high64 = (acc.low64 * PRIME64_1) + (acc.high64 * PRIME64_4) + ((len - seed) * PRIME64_2); h128.low64 = XXH3_avalanche(h128.low64); h128.high64 = (uint64_t)0 - XXH3_avalanche(h128.high64); return h128; } LLVM_ATTRIBUTE_NOINLINE static XXH128_hash_t XXH3_len_129to240_128b(const uint8_t *input, size_t len, const uint8_t *secret, size_t secretSize, uint64_t seed) { (void)secretSize; XXH128_hash_t acc; unsigned i; acc.low64 = len * PRIME64_1; acc.high64 = 0; /* * We set as `i` as offset + 32. We do this so that unchanged * `len` can be used as upper bound. This reaches a sweet spot * where both x86 and aarch64 get simple agen and good codegen * for the loop. */ for (i = 32; i < 160; i += 32) { acc = XXH128_mix32B(acc, input + i - 32, input + i - 16, secret + i - 32, seed); } acc.low64 = XXH3_avalanche(acc.low64); acc.high64 = XXH3_avalanche(acc.high64); /* * NB: `i <= len` will duplicate the last 32-bytes if * len % 32 was zero. This is an unfortunate necessity to keep * the hash result stable. */ for (i = 160; i <= len; i += 32) { acc = XXH128_mix32B(acc, input + i - 32, input + i - 16, secret + XXH3_MIDSIZE_STARTOFFSET + i - 160, seed); } /* last bytes */ acc = XXH128_mix32B(acc, input + len - 16, input + len - 32, secret + XXH3_SECRETSIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16, (uint64_t)0 - seed); XXH128_hash_t h128; h128.low64 = acc.low64 + acc.high64; h128.high64 = (acc.low64 * PRIME64_1) + (acc.high64 * PRIME64_4) + ((len - seed) * PRIME64_2); h128.low64 = XXH3_avalanche(h128.low64); h128.high64 = (uint64_t)0 - XXH3_avalanche(h128.high64); return h128; } LLVM_ATTRIBUTE_ALWAYS_INLINE XXH128_hash_t XXH3_hashLong_128b(const uint8_t *input, size_t len, const uint8_t *secret, size_t secretSize) { const size_t nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE; const size_t block_len = XXH_STRIPE_LEN * nbStripesPerBlock; const size_t nb_blocks = (len - 1) / block_len; alignas(16) uint64_t acc[XXH_ACC_NB] = { PRIME32_3, PRIME64_1, PRIME64_2, PRIME64_3, PRIME64_4, PRIME32_2, PRIME64_5, PRIME32_1, }; for (size_t n = 0; n < nb_blocks; ++n) { XXH3_accumulate(acc, input + n * block_len, secret, nbStripesPerBlock); XXH3_scrambleAcc(acc, secret + secretSize - XXH_STRIPE_LEN); } /* last partial block */ const size_t nbStripes = (len - 1 - (block_len * nb_blocks)) / XXH_STRIPE_LEN; assert(nbStripes <= secretSize / XXH_SECRET_CONSUME_RATE); XXH3_accumulate(acc, input + nb_blocks * block_len, secret, nbStripes); /* last stripe */ constexpr size_t XXH_SECRET_LASTACC_START = 7; XXH3_accumulate_512(acc, input + len - XXH_STRIPE_LEN, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START); /* converge into final hash */ static_assert(sizeof(acc) == 64); XXH128_hash_t h128; constexpr size_t XXH_SECRET_MERGEACCS_START = 11; h128.low64 = XXH3_mergeAccs(acc, secret + XXH_SECRET_MERGEACCS_START, (uint64_t)len * PRIME64_1); h128.high64 = XXH3_mergeAccs( acc, secret + secretSize - sizeof(acc) - XXH_SECRET_MERGEACCS_START, ~((uint64_t)len * PRIME64_2)); return h128; } llvm::XXH128_hash_t llvm::xxh3_128bits(ArrayRef data) { size_t len = data.size(); const uint8_t *input = data.data(); /* * If an action is to be taken if `secret` conditions are not respected, * it should be done here. * For now, it's a contract pre-condition. * Adding a check and a branch here would cost performance at every hash. */ if (len <= 16) return XXH3_len_0to16_128b(input, len, kSecret, /*seed64=*/0); if (len <= 128) return XXH3_len_17to128_128b(input, len, kSecret, sizeof(kSecret), /*seed64=*/0); if (len <= XXH3_MIDSIZE_MAX) return XXH3_len_129to240_128b(input, len, kSecret, sizeof(kSecret), /*seed64=*/0); return XXH3_hashLong_128b(input, len, kSecret, sizeof(kSecret)); }