https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91837
--- Comment #3 from Daniel Cooke <dan.cooke89 at gmail dot com> --- I tried replicating the issue on a CentOS machine (AWS EC2) with the exact same CPU and got the correct output. However, I just fired up a fresh AWS EC2 instance running Ubuntu and I can replicate the bug again. Is it possible that the bug is CPU *and* OS specific?