[gcc r15-10615] libstdc++: std::atomic should use std::addressof

[Jonathan Wakely]

https://gcc.gnu.org/g:48f85d31b5bc62c0a0173890ff101def00291d58

commit r15-10615-g48f85d31b5bc62c0a0173890ff101def00291d58
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Dec 4 21:07:19 2025 +0000

    libstdc++: std::atomic should use std::addressof
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/atomic_wait.h (__detail::__atomic_compare): Use
            std::addressof instead of &.
            * include/std/atomic (atomic::wait, atomic::notify_one)
            (atomic::notify_all): Likewise.
    
    Reviewed-by: Patrick Palka <ppalka@redhat.com>
    
    (cherry picked from commit 7a2d14187611ac5a7e9af24397455b3f0503fdcb)

Diff:
---
 libstdc++-v3/include/bits/atomic_wait.h | 3 ++-
 libstdc++-v3/include/std/atomic         | 9 ++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/libstdc++-v3/include/bits/atomic_wait.h b/libstdc++-v3/include/bits/atomic_wait.h
index 6d1554f68a56..2cfeed72eeeb 100644
--- a/libstdc++-v3/include/bits/atomic_wait.h
+++ b/libstdc++-v3/include/bits/atomic_wait.h
@@ -188,7 +188,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       bool __atomic_compare(const _Tp& __a, const _Tp& __b)
       {
 	// TODO make this do the correct padding bit ignoring comparison
-	return __builtin_memcmp(&__a, &__b, sizeof(_Tp)) == 0;
+	return __builtin_memcmp(std::addressof(__a), std::addressof(__b),
+				sizeof(_Tp)) == 0;
       }
 
     struct __waiter_pool_base
diff --git a/libstdc++-v3/include/std/atomic b/libstdc++-v3/include/std/atomic
index 9b1aca0fc09a..eac888231588 100644
--- a/libstdc++-v3/include/std/atomic
+++ b/libstdc++-v3/include/std/atomic
@@ -401,21 +401,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void
       wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
       {
-	std::__atomic_wait_address_v(&_M_i, __old,
-			   [__m, this] { return this->load(__m); });
+	std::__atomic_wait_address_v(std::addressof(_M_i), __old,
+				     [__m, this] { return this->load(__m); });
       }
 
       // TODO add const volatile overload
 
       void
       notify_one() noexcept
-      { std::__atomic_notify_address(&_M_i, false); }
+      { std::__atomic_notify_address(std::addressof(_M_i), false); }
 
       void
       notify_all() noexcept
-      { std::__atomic_notify_address(&_M_i, true); }
+      { std::__atomic_notify_address(std::addressof(_M_i), true); }
 #endif // __cpp_lib_atomic_wait
-
     };
 
   /// Partial specialization for pointer types.