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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. 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 HOLDER 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.
*/
#pragma once
#include "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)
{
key = ~key + (key >> 23);
key ^= (key << 12);
key ^= (key >> 7);
key ^= (key << 2);
key ^= (key >> 20);
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(const void* ptr)
{
return ptr_hash(FlatPtr(ptr));
}
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