https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104480
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Richard Biener from comment #2) > I don't think [intro.memory]/3 https://eel.is/c++draft/intro.memory The only thing this mentions is: Two or more threads of execution can access separate memory locations without interfering with each other. So that means you can access S2.a1 and S2.a2 on two seperate threads seperately. It also means you cannot depend on the sequence if you write S2.a1 and S2.a2 either and reading it in the same order from the other thread. Unless you have a memory barrier. So I think this is invalid too.
