diff --git a/libstdc++-v3/config/cpu/generic/atomicity_mutex/atomicity.h b/libstdc++-v3/config/cpu/generic/atomicity_mutex/atomicity.h index 7d5772d54840..d088f69fe9a4 100644 --- a/libstdc++-v3/config/cpu/generic/atomicity_mutex/atomicity.h +++ b/libstdc++-v3/config/cpu/generic/atomicity_mutex/atomicity.h @@ -44,7 +44,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw () { __gnu_cxx::__scoped_lock sentry(get_atomic_mutex()); - return __gnu_cxx::__exchange_and_add_single(__mem, __val); + // The volatile qualification is meaningless. All changes to the memory + // location happen while this mutex is locked so it's not volatile at all. + auto __mem2 = const_cast<_Atomic_word*>(__mem); + return __gnu_cxx::__exchange_and_add_single(__mem2, __val); } void