[Bug tree-optimization/114635] OpenMP reductions fail dependency analysis

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114635

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #14)
> I think
> 
>   if (safelen)
>     {
>       poly_uint64 val;
>       safelen = OMP_CLAUSE_SAFELEN_EXPR (safelen);
>       if (!poly_int_tree_p (safelen, &val))
>         safelen_int = 0;
>       else
>         safelen_int = MIN (constant_lower_bound (val), INT_MAX);
> 
> should simply become
> 
>         safelen_int = constant_upper_bound_with_limit (val, INT_MAX);
> 
> ?  Usually targets do have a limit on the actual length but I see
> constant_upper_bound_with_limit doesn't query such.  But it would
> be a more appropriate way to say there might be an actual target limit here?

OMP_CLAUSE_SAFELEN_EXPR is always an INTEGER_CST, the FEs verify that and error
if it is not.  So, I must say I don't really understand parts of the
r8-5649-g9d2f08ab97be
changes.  I can understand the intent to make max_vf a poly_int, but don't
understand why safelen should be, what would it mean and when it would be set
that way?