[Bug target/127352] [16/17 Regression] ICE in gen_reg_rtx at -O3 since r16-5975

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127352

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Slightly cleaned up testcase:
_BitInt(65) a, b, c;
__int128 d;
_BitInt(7) e;
long foo (long x) { return x; }
_BitInt(13) bar (unsigned x, _BitInt(3) y) { return y == 0 ? : x; }
_BitInt(65) baz (_BitInt(65) x, _BitInt(5) y) { return y == 0 ? x : y; }
_BitInt(5)
qux ()
{
  _BitInt(47) f;
  unsigned g = d & 15;
  for (unsigned i = 0; i < g; i++)
    {
      switch (a)
        {
        case 0:
          b = 0;
        case 8:
          e = 0;
          break;
        case 10:
          long h = g;
          f = ~foo (~h);
          e = f;
        }
      if (0 >= b)
        continue;
      for (unsigned j = 0; j < 1; j++)
        b = (_BitInt(7)) (0 >= d ? bar (e, a) : 0);
      e = c ? baz (b, i) : 0;
    }
  return b;
}