[Bug tree-optimization/123152] [16 regression] ICE when building Valgrind (dominator of 15 should be 42, not 44) since r16-6133-gca8d97f8cb8

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123152

--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
Reduced code seems to be:

struct {
  int segments[]
} seek_to_sample_coarse_f;
int seek_to_sample_coarse_i, seek_to_sample_coarse_f_1;
void seek_to_sample_coarse() {
  int end_pos = seek_to_sample_coarse_f_1;
  for (;;) {
    seek_to_sample_coarse_i = end_pos;
    for (; end_pos > 0; --end_pos)
      if (seek_to_sample_coarse_f.segments[end_pos - 1])
        break;
    if (end_pos)
      break;
  }
}