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rpcs3/Utilities/hash.h
2018-08-18 16:14:30 +03:00

51 lines
976 B
C++

#pragma once
#include <stdint.h>
namespace rpcs3
{
template<typename T>
static size_t hash_base(T value)
{
return static_cast<size_t>(value);
}
template<typename T, typename U>
static size_t hash_struct_base(const T& value)
{
// FNV 64-bit
size_t result = 14695981039346656037ull;
const U *bits = reinterpret_cast<const U*>(&value);
for (size_t n = 0; n < (sizeof(T) / sizeof(U)); ++n)
{
result ^= bits[n];
result *= 1099511628211ull;
}
return result;
}
template<typename T>
static size_t hash_struct(const T& value)
{
// TODO: use c++17 if constexpr
static constexpr auto block_sz = sizeof(T);
if ((block_sz & 0x7) == 0)
{
return hash_struct_base<T, u64>(value);
}
if ((block_sz & 0x3) == 0)
{
return hash_struct_base<T, u32>(value);
}
if ((block_sz & 0x1) == 0)
{
return hash_struct_base<T, u16>(value);
}
return hash_struct_base<T, u8>(value);
}
}