https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50259 --- Comment #6 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- AFAICT this PR is now fixed on trunk (7.0) and the gcc-5 and 6 branches. Likely r238822. I'll close the PR as FIXED in the coming days unless someone object.