https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71942
--- Comment #5 from Albi <albrecht.guendel at web dot de> --- OK ok, i see. Its a missed optimization due to volatile-problems.. I got a workaround however: #define IO_READ(x) ( static_cast<decltype(x)>( *const_cast< typename std::remove_volatile<decltype(x)>::type* >(&(x)) )) The volatile is taken away and then added again: no redundant instructions anymore. However i am not sure if that breaks anything (volatile related).. but at least for me it worked fine so far.
