REAL             function slapy2( x, y )
!
!  -- LAPACK auxiliary routine --
!  -- LAPACK is a software package provided by Univ. of Tennessee,    --
!  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
!
!     .. Scalar Arguments ..
      REAL               x, y
!     ..
!
!  =====================================================================
!
!     .. Parameters ..
      REAL               zero
      parameter( zero = 0.0e0 )
      REAL               one
      parameter( one = 1.0e0 )
!     ..
!     .. Local Scalars ..
      REAL               w, xabs, yabs, z, hugeval
      LOGICAL            x_is_nan, y_is_nan
!     ..
!     .. External Functions ..
      LOGICAL            sisnan
      EXTERNAL           sisnan
!     ..
!     .. External Subroutines ..
      REAL               slamch
!     ..
!     .. Intrinsic Functions ..
      INTRINSIC          abs, max, min, sqrt
!     ..
!     .. Executable Statements ..
!
!     x_is_nan = sisnan( x )
!     y_is_nan = sisnan( y )
!     IF ( x_is_nan ) slapy2 = x
!     IF ( y_is_nan ) slapy2 = y
!     hugeval = slamch( 'Overflow' )

         xabs = abs( x )
         yabs = abs( y )
         w = max( xabs, yabs )
         z = min( xabs, yabs )
         IF( z.EQ.zero ) THEN
            slapy2 = w
         ELSE
            slapy2 = w*sqrt( one+( z / w )**2 )
         END IF

      RETURN
!
!     End of SLAPY2
!
      END