https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85164
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to rsand...@gcc.gnu.org from comment #6)
Thanks for handling this.
> > template<unsigned int N, typename Ca>
> > inline POLY_BINARY_COEFF (Ca, Ca)
> > known_alignment (const poly_int_pod<N, Ca> &a)
> > {
> > typedef POLY_BINARY_COEFF (Ca, Ca) C;
> > C r = a.coeffs[0];
> > for (unsigned int i = 1; i < N; ++i)
> > r |= a.coeffs[i];
> > return r & -r;
> > }
> >
> > The poly_int* stuff makes this much harder to fix, it is unclear if there is
> > some way to get the unsigned type for the C type and use that as r & -(Cuns)
> > r;
> > to avoid the UB, and there is no poly_uint_rtx_p or something to request
> > poly_uint64 from the rtx. Richard?
>
> Changing:
>
> (unsigned HOST_WIDE_INT) known_alignment (const_op0)
>
> to:
>
> known_alignment (poly_uint64 (const_op0))
>
> should work.
That will handle this specific case, I was just hoping that for known_alignment
we could fix all the cases that could be called on poly_int64. For
HOST_WIDE_INT_MIN, do we want known_alignment to return HOST_WIDE_INT_MIN or
something different? It is maximum alignment admittedly only if we are
treating the result as unsigned. Or shall we in known_alignment assert or
compile time assert that it is unsigned and fix all the users?
