[Bug middle-end/68314] [6 Regression] Invalid read in build_pbb_minimal_scattering_polyhedrons (graphite-sese-to-poly.c:148)

[spop at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68314

--- Comment #2 from Sebastian Pop <spop at gcc dot gnu.org> ---
This patch exposes the problem without valgrind:

diff --git a/gcc/graphite-sese-to-poly.c b/gcc/graphite-sese-to-poly.c
index 2054fad..b932dae 100644
--- a/gcc/graphite-sese-to-poly.c
+++ b/gcc/graphite-sese-to-poly.c
@@ -143,6 +143,9 @@ build_pbb_minimal_scattering_polyhedrons (isl_aff
*static_sched, poly_bb_p pbb,
          /* False for loop dimension.  */
          sequence_and_loop_dims[i + j] = false;
        }
+
+      gcc_assert (nb_sequence_dim > j);
+
       /* Fake loops make things shifted by one.  */
       if (sequence_dims && sequence_dims[j] == i)
        sequence_and_loop_dims[i + j] = true;