Update libcxx to 2 Apr 2024 239236b8c2154aa49e98bc7ed774a7d2712edf50

```
[libc++] Remove pair dependency (#85621)
[libc++] Simplify the implementation of <stddef.h> (#86843)
Update the "Current Status" section of the website to be current. (#84507)
[libc++] Optimize the two range overload of mismatch (#86853)
[libc++] Refactor __tuple_like and __pair_like (#85206)
[libc++][test] Improves src include paths. (#86864)
[libc++] Document guidelines for applying [[nodiscard]] (#84000)
[libc++] Optimize the std::mismatch tail (#83440)
[libc++] Remove <queue> and <stack> includes from <format> (#85520)
[libc++] Switch FreeBSD to C++26 (#86658)
[libc++] Fix one case in saturate_cast.pass.cpp for 64-bit on z/OS (#86724)
[libc++][test] Remove tests that testing std::variant<T&> (#84222)
[libc++] <experimental/simd> Reduce types for template parameter U in tests (#83781)
[libc++] Switch FreeBSD CI job to Clang 17 (#86320)
[libc++][CI] Updates the documentation. (#85264)
[libc++][format] Adds ABI tags to inline constexpr variables. (#86293)
[libc++][test] Fix race condition in condition_variable_any tests (#84788)
[libc++] Vectorize mismatch (#73255)
[libc++] Don't push and pop extensions diagnostics when using clang modules (#85917)
[libc++][ranges] use `static operator()` for C++23 ranges (#86052)
[libc++] Implement LWG3528 (`make_from_tuple` can perform (the equivalent of) a C-style cast) (#85263)
[libc++] Remove macros for keeping std::allocator members and void specialization after C++20 (#85806)
[libc++] Deprecates std::errc constants. (#80542)
[libcxx] [cmake] Fix cmake_path(ABSOLUTE_PATH) for empty CMAKE_INSTALL_PREFIX
[libc++][CI] Reenables the module tests. (#85799)
[libc++][ranges] remove `__workaround_52970` (#85683)
[libc++][ranges] LWG3715: `view_interface::empty` is overconstrained (#85004)
[libcxx] [modules] Fix relative paths with absolute LIBCXX_INSTALL_MODULES_DIR (#85756)
[libc++][format] Fixes nested concept evaluation. (#85548)
[libc++][CMake] Removes LIBCXX_ENABLE_CLANG_TIDY. (#85262)
[libc++] Remove __unconstrained_reverse_iterator (#85582)
[libc++] Simplify the implementation of remove_reference (#85207)
[libcxx][test] Create feature host-can-create-symlinks (#82204)
[libc++] Use __is_scoped_enum for the implementation of is_scoped_enum if it's available (#85580)
[libc++] Add missing hide-from-ABI annotations on virtual functions (#85439)
[libc++] Optimize ranges::fill{,_n} for vector<bool>::iterator (#84642)
[libc++] Add <locale> include in <chrono> (#85521)
[libc++] Remove <locale> includes from <format> (#85478)
[libc++] P2602R2 Poison Pills are Too Toxic (#74534)
[libc++] Fixes run-buildbot-container. (#84644)
[libc++] Add [[nodiscard]] to static numeric limit functions (#83748)
 Rework Modules CMake to be (more) idiomatic. (#84936)
[libc++] Enables TZDB tests. (#82108)
[libc++] Remove a few includes from <__functional/hash.h> (#83254)
[libc++] Implements filebuf unbuffered. (#76629)
[libc++][CI] Updates the version number of the latest release.
[libc++] Remove <tuple> include from <__format/concepts.h> (#80214)
[runtimes] Prefer -fvisibility-global-new-delete=force-hidden (#84917)
[libc++] Fix tests on musl (#85085)
[libc++] Remove _LIBCPP_ENABLE_NARROWING_CONVERSIONS_IN_VARIANT (#83928)
[libcxx] Fix incorrect type in the has-1024-bit-atomics feature test (#84904)
[libc++] Improves UB handling in ios_base destructor. (#76525)
[libc++][CI] Installs tzdata package in Docker. (#84643)
[libc++][TZDB] Fixes parsing interleaved rules. (#84808)
[libc++][hardening] Check bounds on arithmetic in __bounded_iter (#78876)
[libc++][hardening] Add iterator validity checks on unordered containers (#80230)
[libc++][hardening] Reclassify string_view(ptr, len)'s size assertion (#79297)
[libc++] Re-enable the clang_modules_include test for Objective-C++ (#66801)
[libc++] Remove XFAIL for SIMD in optimized build (#84767)
[libcxx] Update 128-bit-atomics feature test (#83841)
[libc++] Only forward-declare ABI-functions in exception_ptr.h if they are meant to be used (#84707)
[libc++][test] Don't include `test_format_context.h` in `parse.pass.cpp` (#83734)
[libc++] Add missing include in test (#84579)
[libc++] Remove <tuple> from <variant> (#83183)
[RFC][libc++] Reworks clang-tidy selection. (#81362)
[libc++] Remove <array> include from <span> (#83742)
[libc++][format] Updates LWG3462 status. (#80550)
[libc++][format] Update LWG3701 status. (#80545)
[libc++][test] Fix MSVC warning C4127 in `array.cons/initialization.pass.cpp` (#79793)
[libc++] Simplify the std::pair constructor overload set (#81448)
[libc++] Allow the use of extensions in the implementation (#79532)
[libc++] Don't build against libcxxrt by default on FreeBSD (#84484)
Actually disable the module generation tests.
[libc++] Disable module_std and module_std_compat tests
[libc++] Enable availability based on the compiler instead of __has_extension (#84065)
[libc++] Fixes time formatter test output for Linux on PowerPC (#75526)
[libc++] Remove unused includes from __type_traits/is_convertible.h (#83747)
```
commit_hash:171258d93ab92f516dfb1789300677a164e63219

1 files changed, 130 insertions, 0 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/__algorithm/simd_utils.h b/contrib/libs/cxxsupp/libcxx/include/__algorithm/simd_utils.h
new file mode 100644
index 0000000000..3548c00aa3
--- /dev/null
+++ b/contrib/libs/cxxsupp/libcxx/include/__algorithm/simd_utils.h
@@ -0,0 +1,130 @@
+//===----------------------------------------------------------------------===//
+//
+// 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___ALGORITHM_SIMD_UTILS_H
+#define _LIBCPP___ALGORITHM_SIMD_UTILS_H
+
+#include <__algorithm/min.h>
+#include <__bit/bit_cast.h>
+#include <__bit/countr.h>
+#include <__config>
+#include <__type_traits/is_arithmetic.h>
+#include <__type_traits/is_same.h>
+#include <__utility/integer_sequence.h>
+#include <cstddef>
+#include <cstdint>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+// TODO: Find out how altivec changes things and allow vectorizations there too.
+#if _LIBCPP_STD_VER >= 14 && defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1700 && !defined(__ALTIVEC__) && !defined(__CUDACC__) && !(defined(_MSC_VER) && _LIBCPP_CLANG_VER <= 1801)
+#  define _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS 1
+#else
+#  define _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS 0
+#endif
+
+#if _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS && !defined(__OPTIMIZE_SIZE__)
+#  define _LIBCPP_VECTORIZE_ALGORITHMS 1
+#else
+#  define _LIBCPP_VECTORIZE_ALGORITHMS 0
+#endif
+
+#if _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// This isn't specialized for 64 byte vectors on purpose. They have the potential to significantly reduce performance
+// in mixed simd/non-simd workloads and don't provide any performance improvement for currently vectorized algorithms
+// as far as benchmarks are concerned.
+#  if defined(__AVX__)
+template <class _Tp>
+inline constexpr size_t __native_vector_size = 32 / sizeof(_Tp);
+#  elif defined(__SSE__) || defined(__ARM_NEON__)
+template <class _Tp>
+inline constexpr size_t __native_vector_size = 16 / sizeof(_Tp);
+#  elif defined(__MMX__)
+template <class _Tp>
+inline constexpr size_t __native_vector_size = 8 / sizeof(_Tp);
+#  else
+template <class _Tp>
+inline constexpr size_t __native_vector_size = 1;
+#  endif
+
+template <class _ArithmeticT, size_t _Np>
+using __simd_vector __attribute__((__ext_vector_type__(_Np))) = _ArithmeticT;
+
+template <class _VecT>
+inline constexpr size_t __simd_vector_size_v = []<bool _False = false>() -> size_t {
+  static_assert(_False, "Not a vector!");
+}();
+
+template <class _Tp, size_t _Np>
+inline constexpr size_t __simd_vector_size_v<__simd_vector<_Tp, _Np>> = _Np;
+
+template <class _Tp, size_t _Np>
+_LIBCPP_HIDE_FROM_ABI _Tp __simd_vector_underlying_type_impl(__simd_vector<_Tp, _Np>) {
+  return _Tp{};
+}
+
+template <class _VecT>
+using __simd_vector_underlying_type_t = decltype(std::__simd_vector_underlying_type_impl(_VecT{}));
+
+// This isn't inlined without always_inline when loading chars.
+template <class _VecT, class _Tp>
+_LIBCPP_NODISCARD _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _VecT __load_vector(const _Tp* __ptr) noexcept {
+  return [=]<size_t... _Indices>(index_sequence<_Indices...>) _LIBCPP_ALWAYS_INLINE noexcept {
+    return _VecT{__ptr[_Indices]...};
+  }(make_index_sequence<__simd_vector_size_v<_VecT>>{});
+}
+
+template <class _Tp, size_t _Np>
+_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI bool __all_of(__simd_vector<_Tp, _Np> __vec) noexcept {
+  return __builtin_reduce_and(__builtin_convertvector(__vec, __simd_vector<bool, _Np>));
+}
+
+template <class _Tp, size_t _Np>
+_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI size_t __find_first_set(__simd_vector<_Tp, _Np> __vec) noexcept {
+  using __mask_vec = __simd_vector<bool, _Np>;
+
+  // This has MSan disabled du to https://github.com/llvm/llvm-project/issues/85876
+  auto __impl = [&]<class _MaskT>(_MaskT) _LIBCPP_NO_SANITIZE("memory") noexcept {
+    return std::min<size_t>(
+        _Np, std::__countr_zero(__builtin_bit_cast(_MaskT, __builtin_convertvector(__vec, __mask_vec))));
+  };
+
+  if constexpr (sizeof(__mask_vec) == sizeof(uint8_t)) {
+    return __impl(uint8_t{});
+  } else if constexpr (sizeof(__mask_vec) == sizeof(uint16_t)) {
+    return __impl(uint16_t{});
+  } else if constexpr (sizeof(__mask_vec) == sizeof(uint32_t)) {
+    return __impl(uint32_t{});
+  } else if constexpr (sizeof(__mask_vec) == sizeof(uint64_t)) {
+    return __impl(uint64_t{});
+  } else {
+    static_assert(sizeof(__mask_vec) == 0, "unexpected required size for mask integer type");
+    return 0;
+  }
+}
+
+template <class _Tp, size_t _Np>
+_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI size_t __find_first_not_set(__simd_vector<_Tp, _Np> __vec) noexcept {
+  return std::__find_first_set(~__vec);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_HAS_ALGORITHM_VECTOR_UTILS
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_SIMD_UTILS_H