[Bug middle-end/108459] New: [OpenMP] ICE during GIMPLE pass: ompexp (segfault) in expand_omp_for_init_counts

[burnus at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108459

            Bug ID: 108459
           Summary: [OpenMP] ICE during GIMPLE pass: ompexp (segfault) in
                    expand_omp_for_init_counts
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code, openmp
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

The following innocent looking code gives an ICE. As probably visible from the
look of the code, it was found via Fortran code, related to patch work for
PR fortran/107424.

This affects all versions down to GCC 11, which is the first one to support
non-rectangular loop nests.


Compiling the C test below with '-fopenmp' gives:

during GIMPLE pass: ompexp
ff.c: In function ‘s1’:
ff.c:12:13: internal compiler error: Segmentation fault
   12 |     #pragma omp for collapse(2)
      |             ^~~
0xef701f crash_signal
        ../../repos/gcc-trunk-commit/gcc/toplev.cc:314
0x7f9f608ce51f ???
        ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0xbc5560 is_gimple_val(tree_node*)
        ../../repos/gcc-trunk-commit/gcc/gimple-expr.cc:837
0xc368f3 force_gimple_operand_1(tree_node*, gimple**, bool (*)(tree_node*),
tree_node*)
        ../../repos/gcc-trunk-commit/gcc/gimplify-me.cc:55
0xc36b0f force_gimple_operand_gsi_1(gimple_stmt_iterator*, tree_node*, bool
(*)(tree_node*), tree_node*, bool, gsi_iterator_update)
        ../../repos/gcc-trunk-commit/gcc/gimplify-me.cc:115
0xc36b0f force_gimple_operand_gsi(gimple_stmt_iterator*, tree_node*, bool,
tree_node*, bool, gsi_iterator_update)
        ../../repos/gcc-trunk-commit/gcc/gimplify-me.cc:141
0x1de8b5e expand_omp_for_init_counts
        ../../repos/gcc-trunk-commit/gcc/omp-expand.cc:2011



void s1 (int *a1, int *a2)
{
  int i;
  int j;

  {
    int D4266;
    int D4267;

    D4266 = -*a1;
    D4267 = *a2;
    #pragma omp for collapse(2)
    for (i = 1; i <= 16; i = i + 1)
      for (j = i * D4266 + D4267; j <= 16; j = j + 1)
        {
        }
  }
}