gcc/testsuite/gfortran.dg/g77/cabs.f

c { dg-do run }
      program cabs_1
      complex      z0
      real         r0
      complex(kind=8)   z1
      real(kind=8)       r1

      z0 = cmplx(3.,4.)
      r0 = cabs(z0)
      if (r0 .ne. 5.) STOP 1

      z1 = dcmplx(3.d0,4.d0)
      r1 = zabs(z1)
      if (r1 .ne. 5.d0) STOP 2
      end