FreeBSD on powerpc 32 bit is moving to LLVM (actually, it's now using LLVM since Dec 26. I enabled atomic.c on this platform and found it was emiting calls to make decisions about lock/lock free at runtime.
We know in advance 8 byte (64 bits) operations need lock and there's no plans to create something like a "libatomic", so this patch.
As FreeBSD13-CURRENT ships this patch, I would like your inputs. Thanks!
 PowerPC clang announcement - https://lists.freebsd.org/pipermail/freebsd-ppc/2019-December/011042.html