https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99334
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- GCC 6.2 is not supported anymore (nor 7.x). I can't reproduce the code you posted with any of 5.5, 6.4.1, 7.4.1 nor current trunk. If you can't reproduce with a supported compiler, there is nothing to do, if you can, you'll need to specify version and how exactly it has been configured e.g. if you have some non-standard default --with-tune=, --with-arch= etc.