[Bug tree-optimization/82032] New: [8 Regression] ICE in try_switch_expansion, at tree-switch-conversion.c:2063

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82032

            Bug ID: 82032
           Summary: [8 Regression] ICE in try_switch_expansion, at
                    tree-switch-conversion.c:2063
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

Mine issue on:

$ cat ice.ii
template <typename a> class b
{
public:
  typename a::aa operator[] (typename a::c) {}
};
class d
{
public:
  typedef long c;
  typedef int aa;
};
struct e
{
  int af[4];
  int ag;
};
b<d> f;
bool
g (e &i)
{
  for (int h; h; ++h)
    switch (f[h])
      {
      case 'x':
      case 'a':
        i.af[h] = 3;
        break;
      default:
        return false;
      }
}

$ g++ ice.ii -O3
during GIMPLE pass: switchlower
ice.ii: In function ‘bool g(e&)’:
ice.ii:19:1: internal compiler error: in try_switch_expansion, at
tree-switch-conversion.c:2063
 g (e &i)
 ^
0x61a3e0 try_switch_expansion
        .././../gcc/tree-switch-conversion.c:2063
0xc90a66 execute
        .././../gcc/tree-switch-conversion.c:2215