/*
american fuzzy lop++ - hashing function
---------------------------------------
The hash32() function is a variant of MurmurHash3, a good
non-cryptosafe hashing function developed by Austin Appleby.
For simplicity, this variant does *NOT* accept buffer lengths
that are not divisible by 8 bytes. The 32-bit version is otherwise
similar to the original; the 64-bit one is a custom hack with
mostly-unproven properties.
Austin's original code is public domain.
Other code written by Michal Zalewski
Copyright 2016 Google Inc. All rights reserved.
Copyright 2019-2022 AFLplusplus Project. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://www.apache.org/licenses/LICENSE-2.0
*/
#ifndef _HAVE_HASH_H
#define _HAVE_HASH_H
#include "types.h"
u32 hash32(u8 *key, u32 len, u32 seed);
u64 hash64(u8 *key, u32 len, u64 seed);
#if 0
The following code is disabled because xxh3 is 30% faster
#ifdef __x86_64__
#define ROL64(_x, _r) ((((u64)(_x)) << (_r)) | (((u64)(_x)) >> (64 - (_r))))
static inline u32 hash32(u8 *key, u32 len, u32 seed) {
const u64 *data = (u64 *)key;
u64 h1 = seed ^ len;
len >>= 3;
while (len--) {
u64 k1 = *data++;
k1 *= 0x87c37b91114253d5ULL;
k1 = ROL64(k1, 31);
k1 *= 0x4cf5ad432745937fULL;
h1 ^= k1;
h1 = ROL64(h1, 27);
h1 = h1 * 5 + 0x52dce729;
}
h1 ^= h1 >> 33;
h1 *= 0xff51afd7ed558ccdULL;
h1 ^= h1 >> 33;
h1 *= 0xc4ceb9fe1a85ec53ULL;
h1 ^= h1 >> 33;
return h1;
}
#else
#define ROL32(_x, _r) ((((u32)(_x)) << (_r)) | (((u32)(_x)) >> (32 - (_r))))
static inline u32 hash32(const void *key, u32 len, u32 seed) {
const u32 *data = (u32 *)key;
u32 h1 = seed ^ len;
len >>= 2;
while (len--) {
u32 k1 = *data++;
k1 *= 0xcc9e2d51;
k1 = ROL32(k1, 15);
k1 *= 0x1b873593;
h1 ^= k1;
h1 = ROL32(h1, 13);
h1 = h1 * 5 + 0xe6546b64;
}
h1 ^= h1 >> 16;
h1 *= 0x85ebca6b;
h1 ^= h1 >> 13;
h1 *= 0xc2b2ae35;
h1 ^= h1 >> 16;
return h1;
}
#endif /* ^__x86_64__ */
#endif
#endif /* !_HAVE_HASH_H */
