[Bug tree-optimization/69368] [6 Regression] spec2006 test case 416.gamess fails with the g++ 6.0 compiler starting with r232508

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69368

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Dominique d'Humieres from comment #14)
> > But I guess even this doesn't help, while it will help poor man's flexible
> > array members in C/C++, in this Fortran case the problem is that there is
> > COMMON /FMCOM/ X(1)
> > in this TU, while
> > COMMON /FMCOM / X(1000000)
> > in some other TU, and get_ref_base_and_extent caps maxsize at
> > DECL_SIZE - bit_offset (which is generally right, but Fortran COMMON
> > is just weird).
> 
> This invalid Fortran.

Yes, but this is SPEC2k6, so we need some workaround or workaround option or
something for that I'm afraid.

> > So, perhaps we want some flag on the Fortran COMMON decls that would be
> > set on COMMON that ends with an array and would tell get_ref_base_and_extent
> > (and other spots?) that accesses can be beyond end of the decl?
> 
> Related to/ duplicate of pr44882?