[Bug fortran/88364] [9 Regression] Wrong-code due to CLOBBER

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88364

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-valid-code           |wrong-code
                 CC|                            |tkoenig at gcc dot gnu.org
   Target Milestone|---                         |9.0

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Testcase (FAILs with -O2):

module pr88364
  implicit none
  type t
    integer :: b = -1
    integer :: c = 2
  end type t
contains
  subroutine f1 (x)
    integer, intent(out) :: x
    x = 5
  end subroutine f1
  subroutine f2 ()
    type(t) :: x
    call f1 (x%b)
    if (x%b .ne. 5 .or. x%c .ne. 2) stop 1
  end subroutine f2
end module pr88364
  use pr88364
  call f2
end

If t doesn't have c field, it would be ok to clobber whole x, even when we want
to clobber just x%b, because x%b occupies all bits of x.

Likely started with r264506 aka PR41453 fix.