Function msvc_select_cas_order

Libraries/Threading/Atomic.cpp:87–98

#if _MSC_VER

memory_order msvc_select_cas_order(memory_order success, memory_order failure)
{
    // Promote to acq_rel if release success is combined with acquire/consume failure.
    if (success == memory_order_release && (failure == memory_order_acquire || failure == memory_order_consume))
    {
        return memory_order_acq_rel;
    }
    // Otherwise, the success order is sufficient, because for all other cases
    // the load part of the RMW is at least as strong as the failure load.
    // (e.g. acquire, acq_rel, seq_cst success imply an acquire load).
    return success;
}

#endif