https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92462
--- Comment #10 from Alexander Monakov <amonakov at gcc dot gnu.org> --- > atomic_cmpxchg_func tries to cast 'dest' from uint8_t* to int* I made a typo here, I meant uint32_t rather than uint8_t, and there's no aliasing violation here as signedness difference is explicitly OK. It doesn't matter if the function in user code is named cmpxchg or dsjfhg, whether gcc can emit a more efficient bytewise CAS is irrelevant when the user complains that PRE is miscompiling their code. uint8_t is obviously a character type in this particular testcase (as well as, fwiw, on all Glibc targets) OTOH that cmpxchg_using_helper does not return a value is a serious problem, that is undefined behavior in C++. You'll need to submit a valid testcase without that issue.
