subroutine tunifd (fdin, fdout)
      double precision fdin, fdout
      double precision din, dout
      integer iuexp, itemp(2), otemp(2)
      equivalence (din, itemp), (dout, otemp)
      din = fdin
      if (itemp(1).eq.0 .and. itemp(2).eq.0) then
         otemp(1) = 0
         otemp(2) = 0
         go to 300
      endif
      iuexp = (iand (ishft (itemp(1),-24),127) - 64) * 4 + 1022
      k = 0
      if (btest (itemp(1),23)) go to 100
      k = k + 1
      if (btest (itemp(1),22)) go to 100
      k = k + 1
      if (btest (itemp(1),21)) go to 100
      k = k + 1
 100  iuexp = iuexp - k
      otemp(1) = ishft (itemp(1),k-3)
      otemp(2) = ishft (itemp(2),k-3)
      if (3-k.ge.1) otemp(2) = ibclr (otemp(2),31)
      if (3-k.ge.2) otemp(2) = ibclr (otemp(2),30)
      if (3-k.ge.3) otemp(2) = ibclr (otemp(2),29)
      otemp(2) = ior(ishft(iand (itemp(1),2**(3-k)-1),32-3+k),otemp(2))
      otemp(1) = ishft (iuexp,20) + iand (otemp(1),1048575)
c     /* 1048575 is 20 1's */
      if (btest (itemp(1),31)) otemp(1) = ibset (otemp(1),31)
 300  fdout = dout
      return
      end