Someone has committed a patch that is causing both gfortran.dg/do_3.F90 and gfortran.dg/c_char_tests.f03 to fail at -O3 on amd64-*-freebsd. A quick inspection of fortran/ChangeLog doesn't yield a pointer to any particular commit. This may be caused by some middle-end change, but I won't have time to narrow down the revision until later tonight.
-- Steve