[Bug libfortran/122957] -fdefault-integer-8 is results in wrong v_list in user defined IO

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122957

--- Comment #7 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Mon, Dec 22, 2025 at 10:23:32PM +0000, jvdelisle at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122957
> 
> --- Comment #6 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
> It occurs to me that I should update the documentation for -fdefault-integer-8
> to inform. I will keep this PR open until I have done so.
> 

See the -freal-4-real-8, etc options.  It has

     These options should be used
     with care and may not be suitable for your codes.  Areas of
     possible concern include calls to external procedures, alignment in
     ‘EQUIVALENCE’ and/or ‘COMMON’, generic interfaces, BOZ literal
     constant conversion, and I/O and calls to intrinsic procedures when
     passing a value to the ‘kind=’ dummy argument.  Inspection of the
     intermediate representation of the translated Fortran code,
     produced by ‘-fdump-fortran-original’ or ‘-fdump-tree-original’, is
     suggested.

Note, anything that is implemented in Fortran and included in
libgfortran may suffer from a change in ABI.