https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112598
--- Comment #15 from Robin Dapp <rdapp at gcc dot gnu.org> --- Does the =m fix your issue? Or is the code gen different then and we're just lucky? For my problem it doesn't help because we still don't recognize an alias between load and store and the load is moved. Richi's RFC patch from a while ago helps, though. I cc'd you.
