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| /*
* xxHash - Fast Hash algorithm
* Copyright (C) 2012-2016, 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
*/
/* based on revision d2df04efcbef7d7f6886d345861e5dfda4edacc1 Removed
* everything but a simple interface for computing XXh64. */
#include "llvm/Support/xxhash.h"
#include "llvm/Support/Endian.h"
#include <stdlib.h>
#include <string.h>
using namespace llvm;
using namespace support;
static uint64_t rotl64(uint64_t X, size_t R) {
return (X << R) | (X >> (64 - R));
}
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;
}
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 (P + 8 <= BEnd) {
uint64_t const K1 = round(0, endian::read64le(P));
H64 ^= K1;
H64 = rotl64(H64, 27) * PRIME64_1 + PRIME64_4;
P += 8;
}
if (P + 4 <= 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++;
}
H64 ^= H64 >> 33;
H64 *= PRIME64_2;
H64 ^= H64 >> 29;
H64 *= PRIME64_3;
H64 ^= H64 >> 32;
return H64;
}
uint64_t llvm::xxHash64(ArrayRef<uint8_t> Data) {
return xxHash64({(const char *)Data.data(), Data.size()});
}
|