We don’t write relaxed atomic kind of code directly (who does this, really?) We use MPI, pthreads primitives, c++ synchronization primitives, openmp, etc. Thes

We don’t write relaxed atomic kind of code directly (who does this, really?) We use MPI, pthreads primitives, c++ synchronization primitives, openmp, etc. These are portable and “just work”. Anecdotally, we haven’t run into any incorrect use of these in our apps yet that cause problems on ARM but not on x86 (although that would be a bug on both), but we aren’t doing anything super fancy.