Possible regression in Intel 17?

Code below compiles and functions as expected with Intel 2013, 15, and 16.  Intel 17 gives ICE.  Other compilers seem to handle it as well.  We have a workaround in the "big" code, but would be curious to know if this is valid code or not.

ifort (IFORT) 17.0.1 20161005
Copyright (C) 1985-2016 Intel Corporation.  All rights reserved.

Thanks!

Eric

module prob

   type ddt1
     real              :: f ! function
     real              :: d ! the derivatives of f
   end type ddt1

   interface assignment(=)
     module procedure ddt1_assign_rd
   end interface

contains

   function fun_rd(v1)  result(f1)
     real, intent(in) :: v1
     type(ddt1) :: f1

     f1%f = v1
     f1%d = 0.0

   end function fun_rd


   subroutine ddt1_assign_rd(r, d)
     real,    intent(out)  :: r
     type(ddt1),  intent(in)   :: d

      r = d%f

   end subroutine ddt1_assign_rd

end module


program problem

   use prob

   implicit none
   real       ::  var1

   var1 = 1.0
   var1 = fun_rd(var1)

   print *,  var1

end program problem