6 files changed, 83 insertions, 14 deletions
diff --git a/libcxx/docs/ReleaseNotes/21.rst b/libcxx/docs/ReleaseNotes/21.rst
index 642bf7d..2b1aa28 100644
--- a/libcxx/docs/ReleaseNotes/21.rst
+++ b/libcxx/docs/ReleaseNotes/21.rst
@@ -53,8 +53,7 @@ Implemented Papers
 - P2711R1: Making multi-param constructors of ``views`` ``explicit`` (`Github <https://github.com/llvm/llvm-project/issues/105252>`__)
 - P2770R0: Stashing stashing ``iterators`` for proper flattening (`Github <https://github.com/llvm/llvm-project/issues/105250>`__)
 - P2655R3: ``common_reference_t`` of ``reference_wrapper`` Should Be a Reference Type (`Github <https://github.com/llvm/llvm-project/issues/105260>`__)
-- P2944R3: Comparisons for ``reference_wrapper`` (`Github <https://github.com/llvm/llvm-project/issues/105424>`__)
-- P3379R0: Constrain ``std::expected equality`` operators (`Github <https://github.com/llvm/llvm-project/issues/118135>`__)
+- P3379R0: Constrain ``std::expected`` equality operators (`Github <https://github.com/llvm/llvm-project/issues/118135>`__)
 
 Improvements and New Features
 -----------------------------
diff --git a/libcxx/docs/ReleaseNotes/22.rst b/libcxx/docs/ReleaseNotes/22.rst
index 0fd7e53..1a7a2c7 100644
--- a/libcxx/docs/ReleaseNotes/22.rst
+++ b/libcxx/docs/ReleaseNotes/22.rst
@@ -44,6 +44,7 @@ Implemented Papers
 - P3223R2: Making ``std::istream::ignore`` less surprising (`Github <https://llvm.org/PR148178>`__)
 - P3060R3: Add ``std::views::indices(n)`` (`Github <https://llvm.org/PR148175>`__)
 - P2835R7: Expose ``std::atomic_ref``'s object address (`Github <https://llvm.org/PR118377>`__)
+- P2944R3: Comparisons for ``reference_wrapper`` (`Github <https://llvm.org/PR105424>`__)
 - P3168R2: Give ``std::optional`` Range Support (`Github <https://llvm.org/PR105430>`__)
 
 Improvements and New Features
diff --git a/libcxx/docs/Status/Cxx2cIssues.csv b/libcxx/docs/Status/Cxx2cIssues.csv
index 7bf7bc9..237217a 100644
--- a/libcxx/docs/Status/Cxx2cIssues.csv
+++ b/libcxx/docs/Status/Cxx2cIssues.csv
@@ -149,5 +149,5 @@
 "`LWG3343 <https://wg21.link/LWG3343>`__","Ordering of calls to ``unlock()`` and ``notify_all()`` in Effects element of ``notify_all_at_thread_exit()`` should be reversed","Not Adopted Yet","|Complete|","16","`#105356 <https://github.com/llvm/llvm-project/issues/105356>`__",""
 "`LWG4139 <https://wg21.link/LWG4139>`__","§[time.zone.leap] recursive constraint in ``<=>``","Not Adopted Yet","|Complete|","20","`#118369 <https://github.com/llvm/llvm-project/issues/118369>`__",""
 "`LWG3456 <https://wg21.link/LWG3456>`__","Pattern used by ``std::from_chars`` is underspecified (option B)","Not Adopted Yet","|Complete|","20","`#118370 <https://github.com/llvm/llvm-project/issues/118370>`__",""
-"`LWG3882 <https://wg21.link/LWG3882>`__","``tuple`` relational operators have confused friendships","Not Adopted Yet","|Complete|","21","The comparsion operators are constrained harder than the proposed resolution. libstdc++ and MSVC STL do the same.",""
+"`LWG3882 <https://wg21.link/LWG3882>`__","``tuple`` relational operators have confused friendships","Not Adopted Yet","|Complete|","22","The comparsion operators are constrained harder than the proposed resolution. libstdc++ and MSVC STL do the same.",""
 "","","","","",""
diff --git a/libcxx/docs/Status/Cxx2cPapers.csv b/libcxx/docs/Status/Cxx2cPapers.csv
index 9b83047..0eedc82 100644
--- a/libcxx/docs/Status/Cxx2cPapers.csv
+++ b/libcxx/docs/Status/Cxx2cPapers.csv
@@ -59,7 +59,7 @@
 "`P2248R8 <https://wg21.link/P2248R8>`__","Enabling list-initialization for algorithms","2024-03 (Tokyo)","","","`#105421 <https://github.com/llvm/llvm-project/issues/105421>`__",""
 "`P2810R4 <https://wg21.link/P2810R4>`__","``is_debugger_present`` ``is_replaceable``","2024-03 (Tokyo)","","","`#105422 <https://github.com/llvm/llvm-project/issues/105422>`__",""
 "`P1068R11 <https://wg21.link/P1068R11>`__","Vector API for random number generation","2024-03 (Tokyo)","","","`#105423 <https://github.com/llvm/llvm-project/issues/105423>`__",""
-"`P2944R3 <https://wg21.link/P2944R3>`__","Comparisons for ``reference_wrapper``","2024-03 (Tokyo)","|Complete|","21","`#105424 <https://github.com/llvm/llvm-project/issues/105424>`__","The changes to ``tuple``'s equality overload from P2165R4 are not yet implemented."
+"`P2944R3 <https://wg21.link/P2944R3>`__","Comparisons for ``reference_wrapper``","2024-03 (Tokyo)","|Complete|","22","`#105424 <https://github.com/llvm/llvm-project/issues/105424>`__","The changes to ``tuple``'s equality overload from P2165R4 are not yet implemented."
 "`P2642R6 <https://wg21.link/P2642R6>`__","Padded ``mdspan`` layouts","2024-03 (Tokyo)","","","`#105425 <https://github.com/llvm/llvm-project/issues/105425>`__",""
 "`P3029R1 <https://wg21.link/P3029R1>`__","Better ``mdspan``'s CTAD","2024-03 (Tokyo)","|Complete|","19","`#105426 <https://github.com/llvm/llvm-project/issues/105426>`__",""
 "","","","","",""
diff --git a/libcxx/test/std/atomics/atomics.types.generic/cas_non_power_of_2.pass.cpp b/libcxx/test/std/atomics/atomics.types.generic/cas_non_power_of_2.pass.cpp
new file mode 100644
index 0000000..13bd761
--- /dev/null
+++ b/libcxx/test/std/atomics/atomics.types.generic/cas_non_power_of_2.pass.cpp
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// https://github.com/llvm/llvm-project/issues/30023
+// compare exchange does not work with types of which the size is not a power of 2
+
+// XFAIL: clang-19, clang-20, clang-21, apple-clang-15, apple-clang-16, apple-clang-17
+// UNSUPPORTED: c++03
+
+// TODO: remove the UNSUPPORTED clang-22 once libc++ CI's clang is updated to include
+// the fix https://github.com/llvm/llvm-project/pull/78707
+// UNSUPPORTED: clang-22
+
+#include <atomic>
+#include <cstring>
+#include <cassert>
+
+template <int Size>
+struct S {
+  char data[Size];
+
+  explicit S(char v = 0) noexcept { memset(&data[0], v, sizeof(data)); }
+
+  // only used in the test to check the results. Not used in atomic operations.
+  friend bool operator==(const S& lhs, const S& rhs) noexcept {
+    return memcmp(&lhs.data[0], &rhs.data[0], sizeof(lhs.data)) == 0;
+  }
+  friend bool operator!=(const S& lhs, const S& rhs) noexcept { return !(lhs == rhs); }
+};
+
+template <int Size>
+struct Expected {
+  Expected(S<Size> ss) : s(ss) {}
+
+  S<Size> s;
+  bool b = true; // used to validate that s's operation won't overwrite the memory next to it
+};
+
+template <int Size>
+void test() {
+  using T = S<Size>;
+  std::atomic<T> a(T(0));
+  Expected<Size> expected{T(17)};
+
+  assert(a.load() != expected.s);
+  assert(expected.b);
+
+  auto r1 = a.compare_exchange_strong(expected.s, T(18), std::memory_order_relaxed);
+
+  assert(!r1);
+  assert(expected.s == T(0)); // expected.s is modified by compare_exchange_strong
+  assert(expected.b);
+  assert(a.load() == T(0));
+
+  auto r2 = a.compare_exchange_strong(expected.s, T(18), std::memory_order_relaxed);
+  assert(r2);
+  assert(a.load() == T(18));
+  assert(expected.s == T(0));
+  assert(expected.b);
+}
+
+int main(int, char**) {
+  test<1>();
+  test<2>();
+  test<3>();
+  test<4>();
+  test<5>();
+  test<6>();
+
+  return 0;
+}
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
index 881a5d2..1c9d72e 100644
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_implicit_lifetime.pass.cpp
@@ -6,10 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+// REQUIRES: std-at-least-c++23
 
 // These compilers don't support __builtin_is_implicit_lifetime yet.
-// UNSUPPORTED: clang-19, gcc-14, gcc-15, apple-clang-16, apple-clang-17
+// UNSUPPORTED: clang-19, gcc-15, apple-clang-17
 
 // <type_traits>
 
@@ -139,13 +139,6 @@ constexpr void test_is_implicit_lifetime() {
   test_is_implicit_lifetime<T[94], true>();
 }
 
-struct ArithmeticTypesTest {
-  template <class T>
-  constexpr void operator()() {
-    test_is_implicit_lifetime<T>();
-  }
-};
-
 constexpr bool test() {
   // Standard fundamental C++ types
 
@@ -155,7 +148,7 @@ constexpr bool test() {
   test_is_implicit_lifetime<const void, false>();
   test_is_implicit_lifetime<volatile void, false>();
 
-  types::for_each(types::arithmetic_types(), ArithmeticTypesTest{});
+  types::for_each(types::arithmetic_types(), []<typename T> { test_is_implicit_lifetime<T>(); });
 
   test_is_implicit_lifetime<Enum>();
   test_is_implicit_lifetime<SignedEnum>();