https://gcc.gnu.org/g:599d2902b0afd56485b56752a75b0f7a3b090c76
commit r16-4418-g599d2902b0afd56485b56752a75b0f7a3b090c76 Author: Tomasz Kamiński <[email protected]> Date: Tue Oct 14 11:06:35 2025 +0200 libstdc++: Fix required alignment computation for floating points [PR122267] Before the r16-4349-g90dde804626f13 the required alignment of floating point, and pointer specialization used __alignof__(_Vt) as required_alignment, and mentioned commit changed them to alignof(_Vt). This values differs on i686 for double, as alignof(double) is 4, and __alignof__(double) is 8. This patch restores the previous behavior. PR libstdc++/122267 libstdc++-v3/ChangeLog: * include/bits/atomic_base.h (__atomic_ref_base<const _Tp>::_S_required_alignment): Use __alignof__ instead of alignof. Reviewed-by: Jonathan Wakely <[email protected]> Diff: --- libstdc++-v3/include/bits/atomic_base.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h index 0f3f6b1925d3..7e4ad2b12723 100644 --- a/libstdc++-v3/include/bits/atomic_base.h +++ b/libstdc++-v3/include/bits/atomic_base.h @@ -1538,7 +1538,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _S_required_aligment() { if constexpr (is_floating_point_v<_Vt> || is_pointer_v<_Vt>) - return alignof(_Vt); + return __alignof__(_Vt); else if constexpr ((sizeof(_Vt) & (sizeof(_Vt) - 1)) || sizeof(_Vt) > 16) return alignof(_Vt); else
