https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104480
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Marc Mutz from comment #0) > the movl might not be atomic, even on x86, and then a different core may > observe the writes out of order, which probably shouldn't happen. Nothing in your code imposes an ordering on those stores. Another thread cannot observe it, because you are using non-atomic operations. If you want a specific order, you need to use atomics (or volatile, but that would be the wrong solution).
