mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-29 19:10:26 +00:00
18a40587ea
Problem: - Hash functions can be `constexpr`, but are not. Solution: - Change `inline` keyword to `constexpr`. - Add `static_assert` tests to ensure the hash functions work in a `constexpr` context.
75 lines
2.3 KiB
C++
75 lines
2.3 KiB
C++
/*
|
|
* 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));
|
|
}
|