On 24 April 2014 17:44, Matt Godbolt wrote: > This only happens with std=c++1y, Wextra and -O (which macro-izes > htonl instead of making it an external function). It does not happen > with std=c++11. I don't have an answer, but this reminds me of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57573