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suyu/src/common/bit_set.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

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C++

// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <array>
#include <bit>
#include "common/alignment.h"
#include "common/bit_util.h"
#include "common/common_types.h"
namespace Common {
namespace impl {
template <typename Storage, size_t N>
class BitSet {
public:
constexpr BitSet() = default;
constexpr void SetBit(size_t i) {
this->words[i / FlagsPerWord] |= GetBitMask(i % FlagsPerWord);
}
constexpr void ClearBit(size_t i) {
this->words[i / FlagsPerWord] &= ~GetBitMask(i % FlagsPerWord);
}
constexpr size_t CountLeadingZero() const {
for (size_t i = 0; i < NumWords; i++) {
if (this->words[i]) {
return FlagsPerWord * i + CountLeadingZeroImpl(this->words[i]);
}
}
return FlagsPerWord * NumWords;
}
constexpr size_t GetNextSet(size_t n) const {
for (size_t i = (n + 1) / FlagsPerWord; i < NumWords; i++) {
Storage word = this->words[i];
if (!IsAligned(n + 1, FlagsPerWord)) {
word &= GetBitMask(n % FlagsPerWord) - 1;
}
if (word) {
return FlagsPerWord * i + CountLeadingZeroImpl(word);
}
}
return FlagsPerWord * NumWords;
}
private:
static_assert(std::is_unsigned_v<Storage>);
static_assert(sizeof(Storage) <= sizeof(u64));
static constexpr size_t FlagsPerWord = BitSize<Storage>();
static constexpr size_t NumWords = AlignUp(N, FlagsPerWord) / FlagsPerWord;
static constexpr auto CountLeadingZeroImpl(Storage word) {
return std::countl_zero(static_cast<unsigned long long>(word)) -
(BitSize<unsigned long long>() - FlagsPerWord);
}
static constexpr Storage GetBitMask(size_t bit) {
return Storage(1) << (FlagsPerWord - 1 - bit);
}
std::array<Storage, NumWords> words{};
};
} // namespace impl
template <size_t N>
using BitSet8 = impl::BitSet<u8, N>;
template <size_t N>
using BitSet16 = impl::BitSet<u16, N>;
template <size_t N>
using BitSet32 = impl::BitSet<u32, N>;
template <size_t N>
using BitSet64 = impl::BitSet<u64, N>;
} // namespace Common