LiteLoaderBDS-1.16.40/LLPreLoader/third-party/rawpdb/Foundation/PDB_BitUtil.h
2023-03-03 10:18:21 -08:00

56 lines
1.5 KiB
C++

// Copyright 2011-2022, Molecular Matters GmbH <office@molecular-matters.com>
// See LICENSE.txt for licensing details (2-clause BSD License: https://opensource.org/licenses/BSD-2-Clause)
#pragma once
#include "PDB_Assert.h"
#include "PDB_DisableWarningsPush.h"
#include <type_traits>
#include <intrin.h>
#include "PDB_DisableWarningsPop.h"
namespace PDB
{
namespace BitUtil
{
template <typename T>
PDB_NO_DISCARD inline constexpr bool IsPowerOfTwo(T value) PDB_NO_EXCEPT
{
static_assert(std::is_unsigned<T>::value == true, "T must be an unsigned type.");
PDB_ASSERT(value != 0u, "Invalid value.");
return (value & (value - 1u)) == 0u;
}
template <typename T>
PDB_NO_DISCARD inline constexpr T RoundUpToMultiple(T numToRound, T multipleOf) PDB_NO_EXCEPT
{
static_assert(std::is_unsigned<T>::value == true, "T must be an unsigned type.");
PDB_ASSERT(IsPowerOfTwo(multipleOf), "Multiple must be a power-of-two.");
return (numToRound + (multipleOf - 1u)) & ~(multipleOf - 1u);
}
// Finds the position of the first set bit in the given value starting from the LSB, e.g. FindFirstSetBit(0b00000010) == 1.
// This operation is also known as CTZ (Count Trailing Zeros).
template <typename T>
PDB_NO_DISCARD inline uint32_t FindFirstSetBit(T value) PDB_NO_EXCEPT;
template <>
PDB_NO_DISCARD inline uint32_t FindFirstSetBit(uint32_t value) PDB_NO_EXCEPT
{
PDB_ASSERT(value != 0u, "Invalid value.");
unsigned long result = 0u;
_BitScanForward(&result, value);
return result;
}
}
}