common: BitSet: Various style fixes based on code review feedback.

This commit is contained in:
bunnei 2020-12-04 23:46:37 -08:00
parent b1326d9230
commit d2c0c94f0b

View File

@ -16,6 +16,9 @@
#pragma once #pragma once
#include <array>
#include <bit>
#include "common/alignment.h" #include "common/alignment.h"
#include "common/bit_util.h" #include "common/bit_util.h"
#include "common/common_types.h" #include "common/common_types.h"
@ -24,33 +27,11 @@ namespace Common {
namespace impl { namespace impl {
#define BITSIZEOF(x) (sizeof(x) * CHAR_BIT)
template <typename Storage, size_t N> template <typename Storage, size_t N>
class BitSet { class BitSet {
private:
static_assert(std::is_integral<Storage>::value);
static_assert(std::is_unsigned<Storage>::value);
static_assert(sizeof(Storage) <= sizeof(u64));
static constexpr size_t FlagsPerWord = BITSIZEOF(Storage);
static constexpr size_t NumWords = AlignUp(N, FlagsPerWord) / FlagsPerWord;
static constexpr auto CountLeadingZeroImpl(Storage word) {
return CountLeadingZeroes64(static_cast<unsigned long long>(word)) -
(BITSIZEOF(unsigned long long) - FlagsPerWord);
}
static constexpr Storage GetBitMask(size_t bit) {
return Storage(1) << (FlagsPerWord - 1 - bit);
}
private:
Storage words[NumWords];
public: public:
constexpr BitSet() : words() { /* ... */ constexpr BitSet() = default;
}
constexpr void SetBit(size_t i) { constexpr void SetBit(size_t i) {
this->words[i / FlagsPerWord] |= GetBitMask(i % FlagsPerWord); this->words[i / FlagsPerWord] |= GetBitMask(i % FlagsPerWord);
@ -81,6 +62,24 @@ public:
} }
return FlagsPerWord * NumWords; 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 } // namespace impl