/* * rapidhash V3 - Very fast, high quality, platform-independent hashing algorithm. * * Based on 'wyhash', by Wang Yi * * Copyright (C) 2025 Nicolas De Carli * * 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. * * You can contact the author at: * - rapidhash source repository: https://github.com/Nicoshev/rapidhash */ #pragma once /* * Includes. */ #include #include #if defined(_MSC_VER) # include # if defined(_M_X64) && !defined(_M_ARM64EC) # pragma intrinsic(_umul128) # endif #endif /* * C/C++ macros. */ #ifdef _MSC_VER # define RAPIDHASH_ALWAYS_INLINE __forceinline #elif defined(__GNUC__) # define RAPIDHASH_ALWAYS_INLINE inline __attribute__((__always_inline__)) #else # define RAPIDHASH_ALWAYS_INLINE inline #endif #ifdef __cplusplus # define RAPIDHASH_NOEXCEPT noexcept # define RAPIDHASH_CONSTEXPR constexpr # ifndef RAPIDHASH_INLINE # define RAPIDHASH_INLINE RAPIDHASH_ALWAYS_INLINE # endif # if __cplusplus >= 201402L && !defined(_MSC_VER) # define RAPIDHASH_INLINE_CONSTEXPR RAPIDHASH_ALWAYS_INLINE constexpr # else # define RAPIDHASH_INLINE_CONSTEXPR RAPIDHASH_ALWAYS_INLINE # endif #else # define RAPIDHASH_NOEXCEPT # define RAPIDHASH_CONSTEXPR static const # ifndef RAPIDHASH_INLINE # define RAPIDHASH_INLINE static RAPIDHASH_ALWAYS_INLINE # endif # define RAPIDHASH_INLINE_CONSTEXPR RAPIDHASH_INLINE #endif /* * Unrolled macro. * Improves large input speed, but increases code size and worsens small input speed. * * RAPIDHASH_COMPACT: Normal behavior. * RAPIDHASH_UNROLLED: * */ #ifndef RAPIDHASH_UNROLLED # define RAPIDHASH_COMPACT #elif defined(RAPIDHASH_COMPACT) # error "cannot define RAPIDHASH_COMPACT and RAPIDHASH_UNROLLED simultaneously." #endif /* * Protection macro, alters behaviour of rapid_mum multiplication function. * * RAPIDHASH_FAST: Normal behavior, max speed. * RAPIDHASH_PROTECTED: Extra protection against entropy loss. */ #ifndef RAPIDHASH_PROTECTED # define RAPIDHASH_FAST #elif defined(RAPIDHASH_FAST) # error "cannot define RAPIDHASH_PROTECTED and RAPIDHASH_FAST simultaneously." #endif /* * Likely and unlikely macros. */ #if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__) # define _likely_(x) __builtin_expect(x,1) # define _unlikely_(x) __builtin_expect(x,0) #else # define _likely_(x) (x) # define _unlikely_(x) (x) #endif /* * Endianness macros. */ #ifndef RAPIDHASH_LITTLE_ENDIAN # if defined(_WIN32) || defined(__LITTLE_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) # define RAPIDHASH_LITTLE_ENDIAN # elif defined(__BIG_ENDIAN__) || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) # define RAPIDHASH_BIG_ENDIAN # else # warning "could not determine endianness! Falling back to little endian." # define RAPIDHASH_LITTLE_ENDIAN # endif #endif /* * Default secret parameters. */ RAPIDHASH_CONSTEXPR uint64_t rapid_secret[8] = { 0x2d358dccaa6c78a5ull, 0x8bb84b93962eacc9ull, 0x4b33a62ed433d4a3ull, 0x4d5a2da51de1aa47ull, 0xa0761d6478bd642full, 0xe7037ed1a0b428dbull, 0x90ed1765281c388cull, 0xaaaaaaaaaaaaaaaaull}; /* * 64*64 -> 128bit multiply function. * * @param A Address of 64-bit number. * @param B Address of 64-bit number. * * Calculates 128-bit C = *A * *B. * * When RAPIDHASH_FAST is defined: * Overwrites A contents with C's low 64 bits. * Overwrites B contents with C's high 64 bits. * * When RAPIDHASH_PROTECTED is defined: * Xors and overwrites A contents with C's low 64 bits. * Xors and overwrites B contents with C's high 64 bits. */ RAPIDHASH_INLINE_CONSTEXPR void rapid_mum(uint64_t *A, uint64_t *B) RAPIDHASH_NOEXCEPT { #if defined(__SIZEOF_INT128__) __uint128_t r=*A; r*=*B; #ifdef RAPIDHASH_PROTECTED *A^=(uint64_t)r; *B^=(uint64_t)(r>>64); #else *A=(uint64_t)r; *B=(uint64_t)(r>>64); #endif #elif defined(_MSC_VER) && (defined(_WIN64) || defined(_M_HYBRID_CHPE_ARM64)) #if defined(_M_X64) #ifdef RAPIDHASH_PROTECTED uint64_t a, b; a=_umul128(*A,*B,&b); *A^=a; *B^=b; #else *A=_umul128(*A,*B,B); #endif #else #ifdef RAPIDHASH_PROTECTED uint64_t a, b; b = __umulh(*A, *B); a = *A * *B; *A^=a; *B^=b; #else uint64_t c = __umulh(*A, *B); *A = *A * *B; *B = c; #endif #endif #else uint64_t ha=*A>>32, hb=*B>>32, la=(uint32_t)*A, lb=(uint32_t)*B; uint64_t rh=ha*hb, rm0=ha*lb, rm1=hb*la, rl=la*lb, t=rl+(rm0<<32), c=t>32)+(rm1>>32)+c; #ifdef RAPIDHASH_PROTECTED *A^=lo; *B^=hi; #else *A=lo; *B=hi; #endif #endif } /* * Multiply and xor mix function. * * @param A 64-bit number. * @param B 64-bit number. * * Calculates 128-bit C = A * B. * Returns 64-bit xor between high and low 64 bits of C. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapid_mix(uint64_t A, uint64_t B) RAPIDHASH_NOEXCEPT { rapid_mum(&A,&B); return A^B; } /* * Read functions. */ #ifdef RAPIDHASH_LITTLE_ENDIAN RAPIDHASH_INLINE uint64_t rapid_read64(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint64_t v; memcpy(&v, p, sizeof(uint64_t)); return v;} RAPIDHASH_INLINE uint64_t rapid_read32(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint32_t v; memcpy(&v, p, sizeof(uint32_t)); return v;} #elif defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__) RAPIDHASH_INLINE uint64_t rapid_read64(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint64_t v; memcpy(&v, p, sizeof(uint64_t)); return __builtin_bswap64(v);} RAPIDHASH_INLINE uint64_t rapid_read32(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint32_t v; memcpy(&v, p, sizeof(uint32_t)); return __builtin_bswap32(v);} #elif defined(_MSC_VER) RAPIDHASH_INLINE uint64_t rapid_read64(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint64_t v; memcpy(&v, p, sizeof(uint64_t)); return _byteswap_uint64(v);} RAPIDHASH_INLINE uint64_t rapid_read32(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint32_t v; memcpy(&v, p, sizeof(uint32_t)); return _byteswap_ulong(v);} #else RAPIDHASH_INLINE uint64_t rapid_read64(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint64_t v; memcpy(&v, p, 8); return (((v >> 56) & 0xff)| ((v >> 40) & 0xff00)| ((v >> 24) & 0xff0000)| ((v >> 8) & 0xff000000)| ((v << 8) & 0xff00000000)| ((v << 24) & 0xff0000000000)| ((v << 40) & 0xff000000000000)| ((v << 56) & 0xff00000000000000)); } RAPIDHASH_INLINE uint64_t rapid_read32(const uint8_t *p) RAPIDHASH_NOEXCEPT { uint32_t v; memcpy(&v, p, 4); return (((v >> 24) & 0xff)| ((v >> 8) & 0xff00)| ((v << 8) & 0xff0000)| ((v << 24) & 0xff000000)); } #endif /* * rapidhash main function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * @param secret Triplet of 64-bit secrets used to alter hash result predictably. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhash_internal(const void *key, size_t len, uint64_t seed, const uint64_t* secret) RAPIDHASH_NOEXCEPT { const uint8_t *p=(const uint8_t *)key; seed ^= rapid_mix(seed ^ secret[2], secret[1]); uint64_t a=0, b=0; size_t i = len; if (_likely_(len <= 16)) { if (len >= 4) { seed ^= len; if (len >= 8) { const uint8_t* plast = p + len - 8; a = rapid_read64(p); b = rapid_read64(plast); } else { const uint8_t* plast = p + len - 4; a = rapid_read32(p); b = rapid_read32(plast); } } else if (len > 0) { a = (((uint64_t)p[0])<<45)|p[len-1]; b = p[len>>1]; } else a = b = 0; } else { if (len > 112) { uint64_t see1 = seed, see2 = seed; uint64_t see3 = seed, see4 = seed; uint64_t see5 = seed, see6 = seed; #ifdef RAPIDHASH_COMPACT do { seed = rapid_mix(rapid_read64(p) ^ secret[0], rapid_read64(p + 8) ^ seed); see1 = rapid_mix(rapid_read64(p + 16) ^ secret[1], rapid_read64(p + 24) ^ see1); see2 = rapid_mix(rapid_read64(p + 32) ^ secret[2], rapid_read64(p + 40) ^ see2); see3 = rapid_mix(rapid_read64(p + 48) ^ secret[3], rapid_read64(p + 56) ^ see3); see4 = rapid_mix(rapid_read64(p + 64) ^ secret[4], rapid_read64(p + 72) ^ see4); see5 = rapid_mix(rapid_read64(p + 80) ^ secret[5], rapid_read64(p + 88) ^ see5); see6 = rapid_mix(rapid_read64(p + 96) ^ secret[6], rapid_read64(p + 104) ^ see6); p += 112; i -= 112; } while(i > 112); #else while (i > 224) { seed = rapid_mix(rapid_read64(p) ^ secret[0], rapid_read64(p + 8) ^ seed); see1 = rapid_mix(rapid_read64(p + 16) ^ secret[1], rapid_read64(p + 24) ^ see1); see2 = rapid_mix(rapid_read64(p + 32) ^ secret[2], rapid_read64(p + 40) ^ see2); see3 = rapid_mix(rapid_read64(p + 48) ^ secret[3], rapid_read64(p + 56) ^ see3); see4 = rapid_mix(rapid_read64(p + 64) ^ secret[4], rapid_read64(p + 72) ^ see4); see5 = rapid_mix(rapid_read64(p + 80) ^ secret[5], rapid_read64(p + 88) ^ see5); see6 = rapid_mix(rapid_read64(p + 96) ^ secret[6], rapid_read64(p + 104) ^ see6); seed = rapid_mix(rapid_read64(p + 112) ^ secret[0], rapid_read64(p + 120) ^ seed); see1 = rapid_mix(rapid_read64(p + 128) ^ secret[1], rapid_read64(p + 136) ^ see1); see2 = rapid_mix(rapid_read64(p + 144) ^ secret[2], rapid_read64(p + 152) ^ see2); see3 = rapid_mix(rapid_read64(p + 160) ^ secret[3], rapid_read64(p + 168) ^ see3); see4 = rapid_mix(rapid_read64(p + 176) ^ secret[4], rapid_read64(p + 184) ^ see4); see5 = rapid_mix(rapid_read64(p + 192) ^ secret[5], rapid_read64(p + 200) ^ see5); see6 = rapid_mix(rapid_read64(p + 208) ^ secret[6], rapid_read64(p + 216) ^ see6); p += 224; i -= 224; } if (i > 112) { seed = rapid_mix(rapid_read64(p) ^ secret[0], rapid_read64(p + 8) ^ seed); see1 = rapid_mix(rapid_read64(p + 16) ^ secret[1], rapid_read64(p + 24) ^ see1); see2 = rapid_mix(rapid_read64(p + 32) ^ secret[2], rapid_read64(p + 40) ^ see2); see3 = rapid_mix(rapid_read64(p + 48) ^ secret[3], rapid_read64(p + 56) ^ see3); see4 = rapid_mix(rapid_read64(p + 64) ^ secret[4], rapid_read64(p + 72) ^ see4); see5 = rapid_mix(rapid_read64(p + 80) ^ secret[5], rapid_read64(p + 88) ^ see5); see6 = rapid_mix(rapid_read64(p + 96) ^ secret[6], rapid_read64(p + 104) ^ see6); p += 112; i -= 112; } #endif seed ^= see1; see2 ^= see3; see4 ^= see5; seed ^= see6; see2 ^= see4; seed ^= see2; } if (i > 16) { seed = rapid_mix(rapid_read64(p) ^ secret[2], rapid_read64(p + 8) ^ seed); if (i > 32) { seed = rapid_mix(rapid_read64(p + 16) ^ secret[2], rapid_read64(p + 24) ^ seed); if (i > 48) { seed = rapid_mix(rapid_read64(p + 32) ^ secret[1], rapid_read64(p + 40) ^ seed); if (i > 64) { seed = rapid_mix(rapid_read64(p + 48) ^ secret[1], rapid_read64(p + 56) ^ seed); if (i > 80) { seed = rapid_mix(rapid_read64(p + 64) ^ secret[2], rapid_read64(p + 72) ^ seed); if (i > 96) { seed = rapid_mix(rapid_read64(p + 80) ^ secret[1], rapid_read64(p + 88) ^ seed); } } } } } } a=rapid_read64(p+i-16) ^ i; b=rapid_read64(p+i-8); } a ^= secret[1]; b ^= seed; rapid_mum(&a, &b); return rapid_mix(a ^ secret[7], b ^ secret[1] ^ i); } /* * rapidhashMicro main function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * @param secret Triplet of 64-bit secrets used to alter hash result predictably. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashMicro_internal(const void *key, size_t len, uint64_t seed, const uint64_t* secret) RAPIDHASH_NOEXCEPT { const uint8_t *p=(const uint8_t *)key; seed ^= rapid_mix(seed ^ secret[2], secret[1]); uint64_t a=0, b=0; size_t i = len; if (_likely_(len <= 16)) { if (len >= 4) { seed ^= len; if (len >= 8) { const uint8_t* plast = p + len - 8; a = rapid_read64(p); b = rapid_read64(plast); } else { const uint8_t* plast = p + len - 4; a = rapid_read32(p); b = rapid_read32(plast); } } else if (len > 0) { a = (((uint64_t)p[0])<<45)|p[len-1]; b = p[len>>1]; } else a = b = 0; } else { if (i > 80) { uint64_t see1 = seed, see2 = seed; uint64_t see3 = seed, see4 = seed; do { seed = rapid_mix(rapid_read64(p) ^ secret[0], rapid_read64(p + 8) ^ seed); see1 = rapid_mix(rapid_read64(p + 16) ^ secret[1], rapid_read64(p + 24) ^ see1); see2 = rapid_mix(rapid_read64(p + 32) ^ secret[2], rapid_read64(p + 40) ^ see2); see3 = rapid_mix(rapid_read64(p + 48) ^ secret[3], rapid_read64(p + 56) ^ see3); see4 = rapid_mix(rapid_read64(p + 64) ^ secret[4], rapid_read64(p + 72) ^ see4); p += 80; i -= 80; } while(i > 80); seed ^= see1; see2 ^= see3; seed ^= see4; seed ^= see2; } if (i > 16) { seed = rapid_mix(rapid_read64(p) ^ secret[2], rapid_read64(p + 8) ^ seed); if (i > 32) { seed = rapid_mix(rapid_read64(p + 16) ^ secret[2], rapid_read64(p + 24) ^ seed); if (i > 48) { seed = rapid_mix(rapid_read64(p + 32) ^ secret[1], rapid_read64(p + 40) ^ seed); if (i > 64) { seed = rapid_mix(rapid_read64(p + 48) ^ secret[1], rapid_read64(p + 56) ^ seed); } } } } a=rapid_read64(p+i-16) ^ i; b=rapid_read64(p+i-8); } a ^= secret[1]; b ^= seed; rapid_mum(&a, &b); return rapid_mix(a ^ secret[7], b ^ secret[1] ^ i); } /* * rapidhashNano main function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * @param secret Triplet of 64-bit secrets used to alter hash result predictably. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashNano_internal(const void *key, size_t len, uint64_t seed, const uint64_t* secret) RAPIDHASH_NOEXCEPT { const uint8_t *p=(const uint8_t *)key; seed ^= rapid_mix(seed ^ secret[2], secret[1]); uint64_t a=0, b=0; size_t i = len; if (_likely_(len <= 16)) { if (len >= 4) { seed ^= len; if (len >= 8) { const uint8_t* plast = p + len - 8; a = rapid_read64(p); b = rapid_read64(plast); } else { const uint8_t* plast = p + len - 4; a = rapid_read32(p); b = rapid_read32(plast); } } else if (len > 0) { a = (((uint64_t)p[0])<<45)|p[len-1]; b = p[len>>1]; } else a = b = 0; } else { if (i > 48) { uint64_t see1 = seed, see2 = seed; do { seed = rapid_mix(rapid_read64(p) ^ secret[0], rapid_read64(p + 8) ^ seed); see1 = rapid_mix(rapid_read64(p + 16) ^ secret[1], rapid_read64(p + 24) ^ see1); see2 = rapid_mix(rapid_read64(p + 32) ^ secret[2], rapid_read64(p + 40) ^ see2); p += 48; i -= 48; } while(i > 48); seed ^= see1; seed ^= see2; } if (i > 16) { seed = rapid_mix(rapid_read64(p) ^ secret[2], rapid_read64(p + 8) ^ seed); if (i > 32) { seed = rapid_mix(rapid_read64(p + 16) ^ secret[2], rapid_read64(p + 24) ^ seed); } } a=rapid_read64(p+i-16) ^ i; b=rapid_read64(p+i-8); } a ^= secret[1]; b ^= seed; rapid_mum(&a, &b); return rapid_mix(a ^ secret[7], b ^ secret[1] ^ i); } /* * rapidhash seeded hash function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * * Calls rapidhash_internal using provided parameters and default secrets. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhash_withSeed(const void *key, size_t len, uint64_t seed) RAPIDHASH_NOEXCEPT { return rapidhash_internal(key, len, seed, rapid_secret); } /* * rapidhash general purpose hash function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * * Calls rapidhash_withSeed using provided parameters and the default seed. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhash(const void *key, size_t len) RAPIDHASH_NOEXCEPT { return rapidhash_withSeed(key, len, 0); } /* * rapidhashMicro seeded hash function. * * Designed for HPC and server applications, where cache misses make a noticeable performance detriment. * Clang-18+ compiles it to ~140 instructions without stack usage, both on x86-64 and aarch64. * Faster for sizes up to 512 bytes, just 15%-20% slower for inputs above 1kb. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * * Calls rapidhash_internal using provided parameters and default secrets. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashMicro_withSeed(const void *key, size_t len, uint64_t seed) RAPIDHASH_NOEXCEPT { return rapidhashMicro_internal(key, len, seed, rapid_secret); } /* * rapidhashMicro hash function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * * Calls rapidhash_withSeed using provided parameters and the default seed. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashMicro(const void *key, size_t len) RAPIDHASH_NOEXCEPT { return rapidhashMicro_withSeed(key, len, 0); } /* * rapidhashNano seeded hash function. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * @param seed 64-bit seed used to alter the hash result predictably. * * Calls rapidhash_internal using provided parameters and default secrets. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashNano_withSeed(const void *key, size_t len, uint64_t seed) RAPIDHASH_NOEXCEPT { return rapidhashNano_internal(key, len, seed, rapid_secret); } /* * rapidhashNano hash function. * * Designed for Mobile and embedded applications, where keeping a small code size is a top priority. * Clang-18+ compiles it to less than 100 instructions without stack usage, both on x86-64 and aarch64. * The fastest for sizes up to 48 bytes, but may be considerably slower for larger inputs. * * @param key Buffer to be hashed. * @param len @key length, in bytes. * * Calls rapidhash_withSeed using provided parameters and the default seed. * * Returns a 64-bit hash. */ RAPIDHASH_INLINE_CONSTEXPR uint64_t rapidhashNano(const void *key, size_t len) RAPIDHASH_NOEXCEPT { return rapidhashNano_withSeed(key, len, 0); }