Release Cosmopolitan v3.6.0

This release is an atomic upgrade to GCC 14.1.0 with C23 and C++23

third_party/libcxx/__bit/bit_cast.h

@@ -19,13 +19,21 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#ifndef _LIBCPP_CXX03_LANG
+
+template <class _ToType, class _FromType>
+_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI constexpr _ToType __bit_cast(const _FromType& __from) noexcept {
+  return __builtin_bit_cast(_ToType, __from);
+}
+
+#endif // _LIBCPP_CXX03_LANG
+
 #if _LIBCPP_STD_VER >= 20
 
 template <class _ToType, class _FromType>
-  requires(sizeof(_ToType) == sizeof(_FromType) &&
-           is_trivially_copyable_v<_ToType> &&
+  requires(sizeof(_ToType) == sizeof(_FromType) && is_trivially_copyable_v<_ToType> &&
            is_trivially_copyable_v<_FromType>)
-_LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr _ToType bit_cast(const _FromType& __from) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _ToType bit_cast(const _FromType& __from) noexcept {
   return __builtin_bit_cast(_ToType, __from);
 }
 

third_party/libcxx/__bit/bit_ceil.h

@@ -21,25 +21,33 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER >= 20
+#if _LIBCPP_STD_VER >= 17
 
-template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_ceil(_Tp __t) noexcept {
+template <class _Tp>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp __bit_ceil(_Tp __t) noexcept {
   if (__t < 2)
     return 1;
-  const unsigned __n = numeric_limits<_Tp>::digits - std::countl_zero((_Tp)(__t - 1u));
-  _LIBCPP_ASSERT(__n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil");
+  const unsigned __n = numeric_limits<_Tp>::digits - std::__countl_zero((_Tp)(__t - 1u));
+  _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(__n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil");
 
   if constexpr (sizeof(_Tp) >= sizeof(unsigned))
     return _Tp{1} << __n;
   else {
-    const unsigned __extra = numeric_limits<unsigned>::digits - numeric_limits<_Tp>::digits;
+    const unsigned __extra   = numeric_limits<unsigned>::digits - numeric_limits<_Tp>::digits;
     const unsigned __ret_val = 1u << (__n + __extra);
     return (_Tp)(__ret_val >> __extra);
   }
 }
 
-#endif // _LIBCPP_STD_VER >= 20
+#  if _LIBCPP_STD_VER >= 20
+
+template <__libcpp_unsigned_integer _Tp>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_ceil(_Tp __t) noexcept {
+  return std::__bit_ceil(__t);
+}
+
+#  endif // _LIBCPP_STD_VER >= 20
+#endif   // _LIBCPP_STD_VER >= 17
 
 _LIBCPP_END_NAMESPACE_STD
 

third_party/libcxx/__bit/bit_floor.h

@@ -23,7 +23,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 #if _LIBCPP_STD_VER >= 20
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_floor(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_floor(_Tp __t) noexcept {
   return __t == 0 ? 0 : _Tp{1} << std::__bit_log2(__t);
 }
 

third_party/libcxx/__bit/bit_width.h

@@ -22,7 +22,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int bit_width(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int bit_width(_Tp __t) noexcept {
   return __t == 0 ? 0 : std::__bit_log2(__t) + 1;
 }
 

third_party/libcxx/__bit/blsr.h

@@ -17,15 +17,15 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unsigned __libcpp_blsr(unsigned __x) _NOEXCEPT {
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR unsigned __libcpp_blsr(unsigned __x) _NOEXCEPT {
   return __x ^ (__x & -__x);
 }
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unsigned long __libcpp_blsr(unsigned long __x) _NOEXCEPT {
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR unsigned long __libcpp_blsr(unsigned long __x) _NOEXCEPT {
   return __x ^ (__x & -__x);
 }
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unsigned long long __libcpp_blsr(unsigned long long __x) _NOEXCEPT {
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR unsigned long long __libcpp_blsr(unsigned long long __x) _NOEXCEPT {
   return __x ^ (__x & -__x);
 }
 

third_party/libcxx/__bit/byteswap.h

@@ -23,8 +23,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 #if _LIBCPP_STD_VER >= 23
 
 template <integral _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp byteswap(_Tp __val) noexcept {
-
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp byteswap(_Tp __val) noexcept {
   if constexpr (sizeof(_Tp) == 1) {
     return __val;
   } else if constexpr (sizeof(_Tp) == 2) {
@@ -33,15 +32,15 @@ _LIBCPP_HIDE_FROM_ABI constexpr _Tp byteswap(_Tp __val) noexcept {
     return __builtin_bswap32(__val);
   } else if constexpr (sizeof(_Tp) == 8) {
     return __builtin_bswap64(__val);
-#ifndef _LIBCPP_HAS_NO_INT128
+#  ifndef _LIBCPP_HAS_NO_INT128
   } else if constexpr (sizeof(_Tp) == 16) {
-#if __has_builtin(__builtin_bswap128)
+#    if __has_builtin(__builtin_bswap128)
     return __builtin_bswap128(__val);
-#else
+#    else
     return static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val))) << 64 |
            static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val >> 64)));
-#endif // __has_builtin(__builtin_bswap128)
-#endif // _LIBCPP_HAS_NO_INT128
+#    endif // __has_builtin(__builtin_bswap128)
+#  endif   // _LIBCPP_HAS_NO_INT128
   } else {
     static_assert(sizeof(_Tp) == 0, "byteswap is unimplemented for integral types of this size");
   }

third_party/libcxx/__bit/countl.h

@@ -6,6 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO: __builtin_clzg is available since Clang 19 and GCC 14. When support for older versions is dropped, we can
+//  refactor this code to exclusively use __builtin_clzg.
+
 #ifndef _LIBCPP___BIT_COUNTL_H
 #define _LIBCPP___BIT_COUNTL_H
 
@@ -24,18 +27,23 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_clz(unsigned __x)           _NOEXCEPT { return __builtin_clz(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned __x) _NOEXCEPT {
+  return __builtin_clz(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_clz(unsigned long __x)      _NOEXCEPT { return __builtin_clzl(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long __x) _NOEXCEPT {
+  return __builtin_clzl(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_clz(unsigned long long __x) _NOEXCEPT { return __builtin_clzll(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long long __x) _NOEXCEPT {
+  return __builtin_clzll(__x);
+}
 
-#  ifndef _LIBCPP_HAS_NO_INT128
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_clz(__uint128_t __x) _NOEXCEPT {
+#ifndef _LIBCPP_HAS_NO_INT128
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(__uint128_t __x) _NOEXCEPT {
+#  if __has_builtin(__builtin_clzg)
+  return __builtin_clzg(__x);
+#  else
   // The function is written in this form due to C++ constexpr limitations.
   // The algorithm:
   // - Test whether any bit in the high 64-bits is set
@@ -45,53 +53,54 @@ int __libcpp_clz(__uint128_t __x) _NOEXCEPT {
   // - Any bits set:
   //   - The number of leading zeros of the input is the number of leading
   //     zeros in the high 64-bits.
-  return ((__x >> 64) == 0)
-           ? (64 + __builtin_clzll(static_cast<unsigned long long>(__x)))
-           : __builtin_clzll(static_cast<unsigned long long>(__x >> 64));
+  return ((__x >> 64) == 0) ? (64 + __builtin_clzll(static_cast<unsigned long long>(__x)))
+                            : __builtin_clzll(static_cast<unsigned long long>(__x >> 64));
+#  endif
 }
-#  endif // _LIBCPP_HAS_NO_INT128
+#endif // _LIBCPP_HAS_NO_INT128
 
-template<class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
-int __countl_zero(_Tp __t) _NOEXCEPT
-{
-    static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__countl_zero requires an unsigned integer type");
-    if (__t == 0)
-        return numeric_limits<_Tp>::digits;
+template <class _Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countl_zero(_Tp __t) _NOEXCEPT {
+  static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__countl_zero requires an unsigned integer type");
+#if __has_builtin(__builtin_clzg)
+  return __builtin_clzg(__t, numeric_limits<_Tp>::digits);
+#else  // __has_builtin(__builtin_clzg)
+  if (__t == 0)
+    return numeric_limits<_Tp>::digits;
 
-    if      (sizeof(_Tp) <= sizeof(unsigned int))
-        return std::__libcpp_clz(static_cast<unsigned int>(__t))
-              - (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits);
-    else if (sizeof(_Tp) <= sizeof(unsigned long))
-        return std::__libcpp_clz(static_cast<unsigned long>(__t))
-              - (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits);
-    else if (sizeof(_Tp) <= sizeof(unsigned long long))
-        return std::__libcpp_clz(static_cast<unsigned long long>(__t))
-              - (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits);
-    else
-    {
-        int __ret = 0;
-        int __iter = 0;
-        const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
-        while (true) {
-            __t = std::__rotr(__t, __ulldigits);
-            if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits)
-                break;
-            __ret += __iter;
-            }
-        return __ret + __iter;
+  if (sizeof(_Tp) <= sizeof(unsigned int))
+    return std::__libcpp_clz(static_cast<unsigned int>(__t)) -
+           (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits);
+  else if (sizeof(_Tp) <= sizeof(unsigned long))
+    return std::__libcpp_clz(static_cast<unsigned long>(__t)) -
+           (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits);
+  else if (sizeof(_Tp) <= sizeof(unsigned long long))
+    return std::__libcpp_clz(static_cast<unsigned long long>(__t)) -
+           (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits);
+  else {
+    int __ret                      = 0;
+    int __iter                     = 0;
+    const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
+    while (true) {
+      __t = std::__rotl(__t, __ulldigits);
+      if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits)
+        break;
+      __ret += __iter;
     }
+    return __ret + __iter;
+  }
+#endif // __has_builtin(__builtin_clzg)
 }
 
 #if _LIBCPP_STD_VER >= 20
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int countl_zero(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int countl_zero(_Tp __t) noexcept {
   return std::__countl_zero(__t);
 }
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int countl_one(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int countl_one(_Tp __t) noexcept {
   return __t != numeric_limits<_Tp>::max() ? std::countl_zero(static_cast<_Tp>(~__t)) : numeric_limits<_Tp>::digits;
 }
 

third_party/libcxx/__bit/countr.h

@@ -6,6 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO: __builtin_ctzg is available since Clang 19 and GCC 14. When support for older versions is dropped, we can
+//  refactor this code to exclusively use __builtin_ctzg.
+
 #ifndef _LIBCPP___BIT_COUNTR_H
 #define _LIBCPP___BIT_COUNTR_H
 
@@ -23,22 +26,25 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_ctz(unsigned __x)           _NOEXCEPT { return __builtin_ctz(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned __x) _NOEXCEPT {
+  return __builtin_ctz(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_ctz(unsigned long __x)      _NOEXCEPT { return __builtin_ctzl(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned long __x) _NOEXCEPT {
+  return __builtin_ctzl(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_ctz(unsigned long long __x) _NOEXCEPT { return __builtin_ctzll(__x); }
+_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_ctz(unsigned long long __x) _NOEXCEPT {
+  return __builtin_ctzll(__x);
+}
 
-#if _LIBCPP_STD_VER >= 20
-
-template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int countr_zero(_Tp __t) noexcept {
+template <class _Tp>
+_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countr_zero(_Tp __t) _NOEXCEPT {
+#if __has_builtin(__builtin_ctzg)
+  return __builtin_ctzg(__t, numeric_limits<_Tp>::digits);
+#else  // __has_builtin(__builtin_ctzg)
   if (__t == 0)
     return numeric_limits<_Tp>::digits;
-
   if (sizeof(_Tp) <= sizeof(unsigned int))
     return std::__libcpp_ctz(static_cast<unsigned int>(__t));
   else if (sizeof(_Tp) <= sizeof(unsigned long))
@@ -46,7 +52,7 @@ _LIBCPP_HIDE_FROM_ABI constexpr int countr_zero(_Tp __t) noexcept {
   else if (sizeof(_Tp) <= sizeof(unsigned long long))
     return std::__libcpp_ctz(static_cast<unsigned long long>(__t));
   else {
-    int __ret = 0;
+    int __ret                      = 0;
     const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits;
     while (static_cast<unsigned long long>(__t) == 0uLL) {
       __ret += __ulldigits;
@@ -54,10 +60,18 @@ _LIBCPP_HIDE_FROM_ABI constexpr int countr_zero(_Tp __t) noexcept {
     }
     return __ret + std::__libcpp_ctz(static_cast<unsigned long long>(__t));
   }
+#endif // __has_builtin(__builtin_ctzg)
+}
+
+#if _LIBCPP_STD_VER >= 20
+
+template <__libcpp_unsigned_integer _Tp>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int countr_zero(_Tp __t) noexcept {
+  return std::__countr_zero(__t);
 }
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int countr_one(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int countr_one(_Tp __t) noexcept {
   return __t != numeric_limits<_Tp>::max() ? std::countr_zero(static_cast<_Tp>(~__t)) : numeric_limits<_Tp>::digits;
 }
 

third_party/libcxx/__bit/endian.h

@@ -21,7 +21,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 enum class endian {
   little = 0xDEAD,
-  big = 0xFACE,
+  big    = 0xFACE,
 #  if defined(_LIBCPP_LITTLE_ENDIAN)
   native = little
 #  elif defined(_LIBCPP_BIG_ENDIAN)

third_party/libcxx/__bit/has_single_bit.h

@@ -24,7 +24,7 @@ _LIBCPP_PUSH_MACROS
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr bool has_single_bit(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool has_single_bit(_Tp __t) noexcept {
   return __t != 0 && (((__t & (__t - 1)) == 0));
 }
 

third_party/libcxx/__bit/invert_if.h

@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___BIT_INVERT_IF_H
+#define _LIBCPP___BIT_INVERT_IF_H
+
+#include <__concepts/arithmetic.h>
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <bool _Invert, class _Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp __invert_if(_Tp __v) {
+  if (_Invert)
+    return ~__v;
+  return __v;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___BIT_INVERT_IF_H

third_party/libcxx/__bit/popcount.h

@@ -6,6 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+// TODO: __builtin_popcountg is available since Clang 19 and GCC 14. When support for older versions is dropped, we can
+//  refactor this code to exclusively use __builtin_popcountg.
+
 #ifndef _LIBCPP___BIT_POPCOUNT_H
 #define _LIBCPP___BIT_POPCOUNT_H
 
@@ -23,19 +26,25 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_popcount(unsigned __x)           _NOEXCEPT { return __builtin_popcount(__x); }
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_popcount(unsigned __x) _NOEXCEPT {
+  return __builtin_popcount(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_popcount(unsigned long __x)      _NOEXCEPT { return __builtin_popcountl(__x); }
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_popcount(unsigned long __x) _NOEXCEPT {
+  return __builtin_popcountl(__x);
+}
 
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __libcpp_popcount(unsigned long long __x) _NOEXCEPT { return __builtin_popcountll(__x); }
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_popcount(unsigned long long __x) _NOEXCEPT {
+  return __builtin_popcountll(__x);
+}
 
 #if _LIBCPP_STD_VER >= 20
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr int popcount(_Tp __t) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int popcount(_Tp __t) noexcept {
+#  if __has_builtin(__builtin_popcountg)
+  return __builtin_popcountg(__t);
+#  else  // __has_builtin(__builtin_popcountg)
   if (sizeof(_Tp) <= sizeof(unsigned int))
     return std::__libcpp_popcount(static_cast<unsigned int>(__t));
   else if (sizeof(_Tp) <= sizeof(unsigned long))
@@ -50,6 +59,7 @@ _LIBCPP_HIDE_FROM_ABI constexpr int popcount(_Tp __t) noexcept {
     }
     return __ret;
   }
+#  endif // __has_builtin(__builtin_popcountg)
 }
 
 #endif // _LIBCPP_STD_VER >= 20

third_party/libcxx/__bit/rotate.h

@@ -20,29 +20,35 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-template<class _Tp>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
-_Tp __rotr(_Tp __t, unsigned int __cnt) _NOEXCEPT
-{
-    static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__rotr requires an unsigned integer type");
-    const unsigned int __dig = numeric_limits<_Tp>::digits;
-    if ((__cnt % __dig) == 0)
-        return __t;
-    return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
+template <class _Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp __rotr(_Tp __t, int __cnt) _NOEXCEPT {
+  static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__rotr requires an unsigned integer type");
+  const unsigned int __dig = numeric_limits<_Tp>::digits;
+  if ((__cnt % __dig) == 0)
+    return __t;
+
+  if (__cnt < 0) {
+    __cnt *= -1;
+    return (__t << (__cnt % __dig)) | (__t >> (__dig - (__cnt % __dig))); // rotr with negative __cnt is similar to rotl
+  }
+
+  return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
+}
+
+template <class _Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp __rotl(_Tp __t, int __cnt) _NOEXCEPT {
+  return std::__rotr(__t, -__cnt);
 }
 
 #if _LIBCPP_STD_VER >= 20
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp rotl(_Tp __t, unsigned int __cnt) noexcept {
-  const unsigned int __dig = numeric_limits<_Tp>::digits;
-  if ((__cnt % __dig) == 0)
-    return __t;
-  return (__t << (__cnt % __dig)) | (__t >> (__dig - (__cnt % __dig)));
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp rotl(_Tp __t, int __cnt) noexcept {
+  return std::__rotl(__t, __cnt);
 }
 
 template <__libcpp_unsigned_integer _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp rotr(_Tp __t, unsigned int __cnt) noexcept {
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp rotr(_Tp __t, int __cnt) noexcept {
   return std::__rotr(__t, __cnt);
 }