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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Types.h>
constexpr unsigned int_hash(u32 key)
{
key += ~(key << 15);
key ^= (key >> 10);
key += (key << 3);
key ^= (key >> 6);
key += ~(key << 11);
key ^= (key >> 16);
return key;
}
constexpr unsigned double_hash(u32 key)
{
unsigned const magic = 0xBA5EDB01;
if (key == magic)
return 0u;
if (key == 0u)
key = magic;
key ^= key << 13;
key ^= key >> 17;
key ^= key << 5;
return key;
}
constexpr unsigned pair_int_hash(u32 key1, u32 key2)
{
return int_hash((int_hash(key1) * 209) ^ (int_hash(key2 * 413)));
}
constexpr unsigned u64_hash(u64 key)
{
u32 first = key & 0xFFFFFFFF;
u32 last = key >> 32;
return pair_int_hash(first, last);
}
constexpr unsigned ptr_hash(FlatPtr ptr)
{
if constexpr (sizeof(ptr) == 8)
return u64_hash(ptr);
else
return int_hash(ptr);
}
inline unsigned ptr_hash(void const* ptr)
{
return ptr_hash(FlatPtr(ptr));
}
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