forked from ShuriZma/suyu
87 lines
2.2 KiB
C++
87 lines
2.2 KiB
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
|