https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61118
--- Comment #14 from Paul Eggert <eggert at gnu dot org> --- Also please see related reports Bug 21161, Bug 48968, Bug 54561, Bug 65041, and Bug 83162. The last-listed one also is a regression, perhaps induced by the fancier optimization in recent GCC versions. I suspect that the bugs should be merged.