https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92077
--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> --- It is quite natural for the compiler to inline functions that are only called once (it won't take more space) (although the compiler doesn't actually know that the function isn't also called in another TU) more aggressively than functions called multiple times. If you specify -O3 -finline-limit=300, we do inline and simplify. Now of course it would be nice if the compiler realized that inlining those functions gives a huge benefit in this case. By the way, at -O2, without -DG, we still emit useless definitions for functions _M_mutate and _M_dispose which are not called by f anymore, probably because we remove those calls too late (FRE3).
