[Bug c/106860] New: [12/13 Regression] ICE in single_pred_edge, at basic-block.h:347

["gscfq@t-online.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106860

            Bug ID: 106860
           Summary: [12/13 Regression] ICE in single_pred_edge, at
                    basic-block.h:347
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Started with r12 between 20211219 and 20220109, at -O3 or -Ofast,
and with file gcc.dg/graphite/isl-ast-gen-user-1.c :
(gcc/g++ configured with --enable-checking=yes)


$ cat isl-ast-gen-user-1.c
static const int N = 12;
int nSlip;

int main ()
{
  int i, j, k, fdot = 0;
  int a[N][N];

  for ( i = 1; i < nSlip; i++)
    {
      for ( j = i+1; j < nSlip; j++)
        {
          for ( k = 0; k < i; k++)
            fdot += a[i][k] * a[k][j];
          a[i][j] = a[i][j] - fdot;
        }
   }

  return 0;
}


$ g++-13-20220904 -c isl-ast-gen-user-1.c -Ofast -ftrapv -fnon-call-exceptions
-fno-tree-fre
during GIMPLE pass: lsplit
isl-ast-gen-user-1.c: In function 'int main()':
isl-ast-gen-user-1.c:4:5: internal compiler error: in single_pred_edge, at
basic-block.h:347
    4 | int main ()
      |     ^~~~
0x1390add single_pred_edge
        ../../gcc/basic-block.h:347
0x1390add split_loop
        ../../gcc/tree-ssa-loop-split.cc:647
0x1390add tree_ssa_split_loops
        ../../gcc/tree-ssa-loop-split.cc:1678