https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121103
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #2) > Confirmed. > > When `memmove(p->d, a.s, a.n);` is folded into: > > ;; basic block 3, loop depth 0 > ;; pred: 2 > _7 = MEM <unsigned long> [(char * {ref-all})&c]; > MEM <unsigned long> [(char * {ref-all})&b] = _7; > ;; succ: > > The noreturn function call is gone. I am not sure what is the correct fix. Not doing s/a.n/8/ also causes the problem but in forwprop1 rather than fre.