[Bug fortran/55978] [4.8 Regression] class_optional_2.f90 -Os fails

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55978

--- Comment #1 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2013-01-14 21:29:25 UTC ---
For -O0, valgrind complains about

==15263== Conditional jump or move depends on uninitialised value(s)
==15263==    at 0x4F26355: _gfortran_internal_pack (in_pack_generic.c:54)
==15263==    by 0x403762: a3a1.2119 (in /home/ig25/Krempel/Os/a.out)
==15263==    by 0x400B26: MAIN__ (in /home/ig25/Krempel/Os/a.out)
==15263==    by 0x408F0E: main (in /home/ig25/Krempel/Os/a.out)

and

==15263== 
==15263== Conditional jump or move depends on uninitialised value(s)
==15263==    at 0x4F26447: _gfortran_internal_pack (in_pack_generic.c:159)
==15263==    by 0x403762: a3a1.2119 (in /home/ig25/Krempel/Os/a.out)
==15263==    by 0x400B26: MAIN__ (in /home/ig25/Krempel/Os/a.out)
==15263==    by 0x408F0E: main (in /home/ig25/Krempel/Os/a.out)

which is

  size = GFC_DESCRIPTOR_SIZE (source);
  switch (type_size)

and


  dim = GFC_DESCRIPTOR_RANK (source);

respectively.

Reduced test case (run with -fcoarray=single):

! { dg-do run }
! { dg-options "-fcoarray=single" }
!
! PR fortran/50981
! PR fortran/54618
!

  implicit none
  type t
   integer, allocatable :: i
  end type t
  type, extends (t):: t2
   integer, allocatable :: j
  end type t2

  call a3a()

contains

 subroutine a3a(z, z2, z3)
   type(t2), optional :: z(4)
   type(t2), optional, pointer :: z2(:)
   type(t2), optional, allocatable :: z3(:)
   type(t2), allocatable :: x(:)
   type(t2), pointer :: y(:)
   y => null()
   call a4t2(y)
 end subroutine a3a

 subroutine a4t2(x)
   type(t2), intent(in), optional :: x(4)
   if (present (x)) call abort ()
   !print *, present(x)
 end subroutine a4t2

end