[Bug rtl-optimization/81595] New: [8 Regression] ICE: verify_flow_info failed (error: multiple hot/cold transitions found)

["asolokha at gmx dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81595

            Bug ID: 81595
           Summary: [8 Regression] ICE: verify_flow_info failed (error:
                    multiple hot/cold transitions found)
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: x86_64-pc-linux-gnu

gcc-8.0.0-alpha20170723 snapshot ICEs when compiling the following snippet w/
-O2 (-O3, -Ofast):

void
lo (int *bo, int *og, int *cv, int nk, int ac)
{
  while (nk != 0)
    {
      if (*bo != 0)
        {
          int he = 1;

 a6:
          if (*og != 0)
            {
              while (he < 2)
                {
                  he = 0;
                  bo = (int *)&bo;
 qa:
                  ++he;
                }
              while (*cv != 0)
                {
                }
            }
          he /= 0;
        }
      else
        {
          *cv /= (*cv != 0) ? 2 : 0;
          while (ac < 1)
            {
              *og = 0;
              if (ac != 0)
                goto a6;
              ++ac;
            }
          goto qa;
        }
      }
}

% x86_64-pc-linux-gnu-gcc-8.0.0-alpha20170723 -O2 -w -c cdcoibzd.c
cdcoibzd.c: In function 'lo':
cdcoibzd.c:39:1: error: multiple hot/cold transitions found (bb 11)
 }
 ^
cdcoibzd.c:39:1: error: multiple hot/cold transitions found (bb 12)
during RTL pass: bbro
cdcoibzd.c:39:1: internal compiler error: verify_flow_info failed

This PR can be a duplicate of PR81301 and/or PR81559.