[Bug tree-optimization/69735] New: [6 Regression] internal compiler error: in harmful_loop_in_region, at graphite-scop-detection.c:1045

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69735

            Bug ID: 69735
           Summary: [6 Regression] internal compiler error: in
                    harmful_loop_in_region, at
                    graphite-scop-detection.c:1045
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
                CC: spop at gcc dot gnu.org
  Target Milestone: ---

The following testcase ICEs on aarch64 with -O3 -floop-interchange:
int a[1], d[1];
int b, c, e, f, g, h;
void
fn1 ()
{
  if (g)
    {
      for (; e; e++)
        a[e] = 6;
      for (; f; f++)
        {
          b = 0;
          for (; b <= 1; b++)
            h = d[b];
        }
      c = 5;
    }
  for (;;)
    ;
}

mycrash.c:4:1: internal compiler error: in harmful_loop_in_region, at
graphite-scop-detection.c:1045
 fn1 ()
 ^~~
0x10670f4 harmful_loop_in_region
        $SRC/gcc/graphite-scop-detection.c:1045
0x10670f4 merge_sese
        $SRC/gcc/graphite-scop-detection.c:849
0x10678b1 build_scop_breadth
        $SRC/gcc/graphite-scop-detection.c:902
0x10678b1 build_scop_depth
        $SRC/gcc/graphite-scop-detection.c:880
0x1067872 build_scop_depth
        $SRC/gcc/graphite-scop-detection.c:873
0x106782a build_scop_depth
        $SRC/gcc/graphite-scop-detection.c:866
0x1067fa0 build_scops(vec<scop*, va_heap, vl_ptr>*)
        $SRC/gcc/graphite-scop-detection.c:2000
0x105590d graphite_transform_loops()
        $SRC/gcc/graphite.c:307
0x1055988 graphite_transforms
        $SRC/gcc/graphite.c:356
0x1055988 execute
        $SRC/gcc/graphite.c:433
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

I'm using ISL 0.15.