1 /* 2 * xxHash - Fast Hash algorithm 3 * Copyright (C) 2012-2016, Yann Collet 4 * 5 * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are 9 * met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above 14 * copyright notice, this list of conditions and the following disclaimer 15 * in the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * You can contact the author at : 31 * - xxHash homepage: http://www.xxhash.com 32 * - xxHash source repository : https://github.com/Cyan4973/xxHash 33 */ 34 35 /* based on revision d2df04efcbef7d7f6886d345861e5dfda4edacc1 Removed 36 * everything but a simple interface for computing XXh64. */ 37 38 #include "llvm/Support/xxhash.h" 39 #include "llvm/Support/Endian.h" 40 41 #include <stdlib.h> 42 #include <string.h> 43 44 using namespace llvm; 45 using namespace support; 46 47 static uint64_t rotl64(uint64_t X, size_t R) { 48 return (X << R) | (X >> (64 - R)); 49 } 50 51 static const uint64_t PRIME64_1 = 11400714785074694791ULL; 52 static const uint64_t PRIME64_2 = 14029467366897019727ULL; 53 static const uint64_t PRIME64_3 = 1609587929392839161ULL; 54 static const uint64_t PRIME64_4 = 9650029242287828579ULL; 55 static const uint64_t PRIME64_5 = 2870177450012600261ULL; 56 57 static uint64_t round(uint64_t Acc, uint64_t Input) { 58 Acc += Input * PRIME64_2; 59 Acc = rotl64(Acc, 31); 60 Acc *= PRIME64_1; 61 return Acc; 62 } 63 64 static uint64_t mergeRound(uint64_t Acc, uint64_t Val) { 65 Val = round(0, Val); 66 Acc ^= Val; 67 Acc = Acc * PRIME64_1 + PRIME64_4; 68 return Acc; 69 } 70 71 uint64_t llvm::xxHash64(StringRef Data) { 72 size_t Len = Data.size(); 73 uint64_t Seed = 0; 74 const unsigned char *P = Data.bytes_begin(); 75 const unsigned char *const BEnd = Data.bytes_end(); 76 uint64_t H64; 77 78 if (Len >= 32) { 79 const unsigned char *const Limit = BEnd - 32; 80 uint64_t V1 = Seed + PRIME64_1 + PRIME64_2; 81 uint64_t V2 = Seed + PRIME64_2; 82 uint64_t V3 = Seed + 0; 83 uint64_t V4 = Seed - PRIME64_1; 84 85 do { 86 V1 = round(V1, endian::read64le(P)); 87 P += 8; 88 V2 = round(V2, endian::read64le(P)); 89 P += 8; 90 V3 = round(V3, endian::read64le(P)); 91 P += 8; 92 V4 = round(V4, endian::read64le(P)); 93 P += 8; 94 } while (P <= Limit); 95 96 H64 = rotl64(V1, 1) + rotl64(V2, 7) + rotl64(V3, 12) + rotl64(V4, 18); 97 H64 = mergeRound(H64, V1); 98 H64 = mergeRound(H64, V2); 99 H64 = mergeRound(H64, V3); 100 H64 = mergeRound(H64, V4); 101 102 } else { 103 H64 = Seed + PRIME64_5; 104 } 105 106 H64 += (uint64_t)Len; 107 108 while (P + 8 <= BEnd) { 109 uint64_t const K1 = round(0, endian::read64le(P)); 110 H64 ^= K1; 111 H64 = rotl64(H64, 27) * PRIME64_1 + PRIME64_4; 112 P += 8; 113 } 114 115 if (P + 4 <= BEnd) { 116 H64 ^= (uint64_t)(endian::read32le(P)) * PRIME64_1; 117 H64 = rotl64(H64, 23) * PRIME64_2 + PRIME64_3; 118 P += 4; 119 } 120 121 while (P < BEnd) { 122 H64 ^= (*P) * PRIME64_5; 123 H64 = rotl64(H64, 11) * PRIME64_1; 124 P++; 125 } 126 127 H64 ^= H64 >> 33; 128 H64 *= PRIME64_2; 129 H64 ^= H64 >> 29; 130 H64 *= PRIME64_3; 131 H64 ^= H64 >> 32; 132 133 return H64; 134 } 135 136 uint64_t llvm::xxHash64(ArrayRef<uint8_t> Data) { 137 return xxHash64({(const char *)Data.data(), Data.size()}); 138 } 139