[Bug fortran/21797] New: complex(4) sqrt failures on alpha-linux

["fxcoudert at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

On alpha-linux, I see the following testsuite failures: 

gfortran.dg/f2c_2.f90
gfortran.dg/g77/cabs.f
gfortran.dg/g77/f90-intrinsic-mathematical.f
gfortran.fortran-torture/execute/csqrt_1.f90
gfortran.fortran-torture/execute/intrinsic_abs.f90
gfortran.fortran-torture/execute/math.f90
gfortran.fortran-torture/execute/power.f90

They all have the same cause: SQRT intrinsic doesn't seem to work on
complex(kind=4):

$ cat a.f90 
  complex(4) c, z
  z = (4.0,0.0)
  c = sqrt(z)
  print *, c
  print *, z, c**2 
  end
$ gfc a.f90 && ./a.out
 ( 1.1603759E-02,  0.000000    )
 (  4.000000    ,  0.000000    ) ( 1.3464721E-04,  0.000000    )

Note that the same code works with complex(8), as well as both real kinds.

I'm willing to investigate that issue, but haven't got any idea what to do.

-- 
           Summary: complex(4) sqrt failures on alpha-linux
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fxcoudert at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: alphaev67-unknown-linux-gnu
  GCC host triplet: alphaev67-unknown-linux-gnu
GCC target triplet: alphaev67-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21797