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[libc++] Refactor bitset::{any, all} #128445

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Merged
merged 3 commits into from
May 28, 2025
Merged

[libc++] Refactor bitset::{any, all} #128445

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3929727
Simplify bitset::{any, all}
winner245 Feb 24, 2025
dc5611d
Refactor any and all
winner245 May 17, 2025
f26d014
remove _Early_return parameter
winner245 May 21, 2025
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78 changes: 30 additions & 48 deletions libcxx/include/bitset
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Original file line number Diff line number Diff line change
Expand Up @@ -144,6 +144,7 @@ template <size_t N> struct hash<std::bitset<N>>;
# include <__cstddef/ptrdiff_t.h>
# include <__cstddef/size_t.h>
# include <__functional/hash.h>
# include <__functional/identity.h>
# include <__functional/unary_function.h>
# include <__type_traits/is_char_like_type.h>
# include <climits>
Expand Down Expand Up @@ -226,8 +227,10 @@ protected:
return to_ullong(integral_constant < bool, _Size< sizeof(unsigned long long) * CHAR_BIT>());
}

_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool all() const _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool all() const _NOEXCEPT { return !__scan_bits(__bit_not()); }
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT {
return __scan_bits(std::__identity());
}
_LIBCPP_HIDE_FROM_ABI size_t __hash_code() const _NOEXCEPT;

template <bool _Sparse, class _CharT, class _Traits, class _Allocator>
Expand All @@ -246,6 +249,12 @@ protected:
}

private:
struct __bit_not {
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@ldionne ldionne May 21, 2025

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I wouldn't block this patch on it, however it might be nice to consider a follow-up refactoring.

We have a __bit_not in valarray here: https://github.com/llvm/llvm-project/blob/main/libcxx/include/valarray#L491

We could provide a single __bit_not in https://github.com/llvm/llvm-project/blob/main/libcxx/include/__functional/operations.h#L220 and use it from both valarray and bitset.

template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp operator()(const _Tp& __x) const _NOEXCEPT {
return ~__x;
}
};
# ifdef _LIBCPP_CXX03_LANG
void __init(unsigned long long __v, false_type) _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI void __init(unsigned long long __v, true_type) _NOEXCEPT;
Expand All @@ -256,6 +265,23 @@ private:
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong(true_type) const;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong(true_type, false_type) const;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long to_ullong(true_type, true_type) const;

template <typename _Proj>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool __scan_bits(_Proj __proj) const _NOEXCEPT {
size_t __n = _Size;
__const_storage_pointer __p = __first_;
// do middle whole words
for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
if (__proj(*__p))
return true;
// do last partial word
if (__n > 0) {
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
if (__proj(*__p) & __m)
return true;
}
return false;
}
};

template <size_t _N_words, size_t _Size>
Expand Down Expand Up @@ -405,40 +431,6 @@ __bitset<_N_words, _Size>::to_ullong(true_type, true_type) const {
return __r;
}

template <size_t _N_words, size_t _Size>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __bitset<_N_words, _Size>::all() const _NOEXCEPT {
// do middle whole words
size_t __n = _Size;
__const_storage_pointer __p = __first_;
for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
if (~*__p)
return false;
// do last partial word
if (__n > 0) {
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
if (~*__p & __m)
return false;
}
return true;
}

template <size_t _N_words, size_t _Size>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool __bitset<_N_words, _Size>::any() const _NOEXCEPT {
// do middle whole words
size_t __n = _Size;
__const_storage_pointer __p = __first_;
for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
if (*__p)
return true;
// do last partial word
if (__n > 0) {
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
if (*__p & __m)
return true;
}
return false;
}

template <size_t _N_words, size_t _Size>
inline size_t __bitset<_N_words, _Size>::__hash_code() const _NOEXCEPT {
size_t __h = 0;
Expand Down Expand Up @@ -753,8 +745,8 @@ public:
_LIBCPP_HIDE_FROM_ABI bool operator!=(const bitset& __rhs) const _NOEXCEPT;
# endif
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool test(size_t __pos) const;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool all() const _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool all() const _NOEXCEPT { return __base::all(); }
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool any() const _NOEXCEPT { return __base::any(); }
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool none() const _NOEXCEPT { return !any(); }
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset operator<<(size_t __pos) const _NOEXCEPT;
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset operator>>(size_t __pos) const _NOEXCEPT;
Expand Down Expand Up @@ -939,16 +931,6 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool bitset<_Size>::test(siz
return (*this)[__pos];
}

template <size_t _Size>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool bitset<_Size>::all() const _NOEXCEPT {
return __base::all();
}

template <size_t _Size>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bool bitset<_Size>::any() const _NOEXCEPT {
return __base::any();
}

template <size_t _Size>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 bitset<_Size>
bitset<_Size>::operator<<(size_t __pos) const _NOEXCEPT {
Expand Down
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