[Bug rtl-optimization/81194] [8 Regression] ICE during RTL pass: expand

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81194

--- Comment #11 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Peter Bergner from comment #10)
> I'm testing the attached patch which fixes the ICE.

Except this ICEs on the following simple test case.  I'll see if this is due to
a simple oversite or ...

bergner@pike:~/gcc/BUGS/PR81194$ cat swtch.i 
int a;
void
b (void)
{
  switch (a)
    {
      case 6:
      default:
        break;
    }
}
bergner@pike:~/gcc/BUGS/PR81194$
/home/bergner/gcc/build/gcc-fsf-mainline-pr81194-x86_64-debug/gcc/xgcc
-B/home/bergner/gcc/build/gcc-fsf-mainline-pr81194-x86_64-debug/gcc -O2 -S
swtch.i
during GIMPLE pass: cfg
swtch.i: In function ‘b’:
swtch.i:3:1: internal compiler error: Segmentation fault
 b (void)
 ^
0x10e97613 crash_signal
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/toplev.c:338
0x1060bcb8 find_edge(basic_block_def*, basic_block_def*)
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/cfganal.c:498
0x11ce3783 make_edge(basic_block_def*, basic_block_def*, int)
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/cfg.c:315
0x10f0390f make_edges
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/tree-cfg.c:930
0x10f0168b build_gimple_cfg
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/tree-cfg.c:248
0x10f01f27 execute_build_cfg
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/tree-cfg.c:398
0x10f0209b execute
        /home/bergner/gcc/gcc-fsf-mainline-pr80775/gcc/tree-cfg.c:434

It seems cleanup_tree_cfg() has removed the entire function at this point.