[Bug fortran/55072] [4.6/4.7/4.8 Regression] Missing internal_pack leads to wrong code with derived type

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55072



--- Comment #15 from janus at gcc dot gnu.org 2012-12-15 20:47:00 UTC ---

(In reply to comment #11)

> FAIL: gfortran.dg/assumed_type_2.f90  -O0   scan-tree-dump-times original

> "sub_array_assumed \\(D" 2

> FAIL: gfortran.dg/assumed_type_2.f90  -O0   scan-tree-dump-times original

> "sub_array_assumed \\(\\(struct t3.0:. .\\) array_t3_ptr.data\\);" 1





Here is a reduced test case for these two failure (which are apparently due to

a single underlying problem):





! { dg-do compile }

! { dg-options "-fdump-tree-original" }



implicit none

type :: t3

  integer :: c

end type t3



type(t3), pointer     :: array_t3_ptr(:,:)



call sub_array_assumed (array_t3_ptr)



contains



  subroutine sub_array_assumed (arg3)

     type(*), target :: arg3(*)

  end subroutine



end



! { dg-final { scan-tree-dump-times "sub_array_assumed \\(D" 0 "original" } }

! { dg-final { scan-tree-dump-times "sub_array_assumed \\(\\(struct t3.0:. .\\)

array_t3_ptr.data\\);" 1 "original" } }

! { dg-final { cleanup-tree-dump "original" } }





The point is this: Without the patch, the subroutine call is translated to:



  sub_array_assumed ((struct t3[0:] *) array_t3_ptr.data);



while, with the patch, it becomes:



    D.1892 = _gfortran_internal_pack (&array_t3_ptr);

    sub_array_assumed (D.1892);



i.e., the argument is packed.





Question is: Is the packing needed here? I would guess that it isn't. And if

not, how do we best avoid it?