https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120955
--- Comment #23 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Better/more reduced testcase: ``` struct h { int g; constexpr h() : g(0) {} }; struct H { int p[6+8]{0, 1,2,3,4,5,6,7,8,9,10,11,12,13}; h o{}; }; void q(H &r) { r = {}; } ``` But this looks like a trade off of text size vs data size. I still don't see the huge difference which you were originally seeing.