[Bug tree-optimization/91069] [10 Regression] Miscompare of 453.povray since r272843

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91069

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
It "mismatches" in

            if (sel.series_p (1, 1, nelts + 1, 1))
              {
                /* After canonicalizing the first elt to come from the
                   first vector we only can insert the first elt from
                   the first vector.  */
                at = 0;
                if ((ins = fold_read_from_vector (cop0, 0)))
                  op0 = op1;
              }

it should read from element sel[0], not 0.  Testing patch.