yuzu/src/common/bit_util.h
Morph 99ceb03a1c general: Convert source file copyright comments over to SPDX
This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
2022-04-23 05:55:32 -04:00

66 lines
1.8 KiB
C++

// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <bit>
#include <climits>
#include <cstddef>
#include <type_traits>
#include "common/common_types.h"
namespace Common {
/// Gets the size of a specified type T in bits.
template <typename T>
[[nodiscard]] constexpr std::size_t BitSize() {
return sizeof(T) * CHAR_BIT;
}
[[nodiscard]] constexpr u32 MostSignificantBit32(const u32 value) {
return 31U - static_cast<u32>(std::countl_zero(value));
}
[[nodiscard]] constexpr u32 MostSignificantBit64(const u64 value) {
return 63U - static_cast<u32>(std::countl_zero(value));
}
[[nodiscard]] constexpr u32 Log2Floor32(const u32 value) {
return MostSignificantBit32(value);
}
[[nodiscard]] constexpr u32 Log2Floor64(const u64 value) {
return MostSignificantBit64(value);
}
[[nodiscard]] constexpr u32 Log2Ceil32(const u32 value) {
const u32 log2_f = Log2Floor32(value);
return log2_f + static_cast<u32>((value ^ (1U << log2_f)) != 0U);
}
[[nodiscard]] constexpr u32 Log2Ceil64(const u64 value) {
const u64 log2_f = Log2Floor64(value);
return static_cast<u32>(log2_f + static_cast<u64>((value ^ (1ULL << log2_f)) != 0ULL));
}
template <typename T>
requires std::is_unsigned_v<T>
[[nodiscard]] constexpr bool IsPow2(T value) {
return std::has_single_bit(value);
}
template <typename T>
requires std::is_integral_v<T>
[[nodiscard]] T NextPow2(T value) {
return static_cast<T>(1ULL << ((8U * sizeof(T)) - std::countl_zero(value - 1U)));
}
template <size_t bit_index, typename T>
requires std::is_integral_v<T>
[[nodiscard]] constexpr bool Bit(const T value) {
static_assert(bit_index < BitSize<T>(), "bit_index must be smaller than size of T");
return ((value >> bit_index) & T(1)) == T(1);
}
} // namespace Common