https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82935
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Well, clang uses a tail call, and we don't. And the reason why we don't is that the call is introduced only during expansion and doesn't therefore have the GF_CALL_TAILCALL flag set (CALL_EXPR_TAILCALL on the CALL_EXPR). The options I see (Richard, any preferences?): 1) turn aggregate assignments during the tailcall pass if at tailcall positions into calls and set the flag 2) introduce a flag like GF_CALL_TAILCALL on structure assignment statements or aggregate clearing, compute it during tailcall pass and check that flag during aggregate copy/clear expansion 3) perform the analysis the tailcall pass does during expansion of aggregate assignment or aggregate clearing
