addmsf
static void addmsf(u_int *, u_int *, u_int *, u_int, u_int, u_int);
addmsf(&m1, &s1, &f1, tm, ts, tf);
addmsf(&m2, &s2, &f2, m1, s1, f1);
addmsf(&m2, &s2, &f2, tm, ts, tf);