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// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#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
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