cvc5-cvc5-1.2.0.src.util.hash.h Maven / Gradle / Ivy
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/******************************************************************************
* Top contributors (to current version):
* Andres Noetzli, Morgan Deters, Aina Niemetz
*
* This file is part of the cvc5 project.
*
* Copyright (c) 2009-2024 by the authors listed in the file AUTHORS
* in the top-level source directory and their institutional affiliations.
* All rights reserved. See the file COPYING in the top-level source
* directory for licensing information.
* ****************************************************************************
*
* cvc5 hash utilities.
*/
#include "cvc5_public.h"
#ifndef CVC5__HASH_H
#define CVC5__HASH_H
#include
#include
namespace std {
#ifdef CVC5_NEED_HASH_UINT64_T
// on some versions and architectures of GNU C++, we need a
// specialization of hash for 64-bit values
template <>
struct hash {
size_t operator()(uint64_t v) const {
return v;
}
};/* struct hash */
#endif /* CVC5_NEED_HASH_UINT64_T */
}/* std namespace */
namespace cvc5::internal {
namespace fnv1a {
constexpr uint64_t offsetBasis = 14695981039346656037U;
/**
* FNV-1a hash algorithm for 64-bit numbers.
*
* More details here: http://www.isthe.com/chongo/tech/comp/fnv/index.html
*/
inline uint64_t fnv1a_64(uint64_t v, uint64_t hash = offsetBasis)
{
hash ^= v;
// Compute (hash * 1099511628211)
return hash + (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
(hash << 8) + (hash << 40);
}
} // namespace fnv1a
template , class HashU = std::hash >
struct PairHashFunction {
size_t operator()(const std::pair& pr) const {
uint64_t hash = fnv1a::fnv1a_64(HashT()(pr.first));
return static_cast(fnv1a::fnv1a_64(HashU()(pr.second), hash));
}
};/* struct PairHashFunction */
} // namespace cvc5::internal
#endif /* CVC5__HASH_H */