https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92720
--- Comment #5 from Dennis Clarke <dclarke at blastwave dot org> --- Glad someone looked at this. I was going to try again with LLVM/Clang and then a few other places on a few other architectures. Why bother? However if this is "implementation defined" then we should see a paragraph somewhere in a standards doc regarding this. Somewhere.