[Bug tree-optimization/85284] New: [7/8 Regression] Loop miscompilation starting with r238367

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85284

            Bug ID: 85284
           Summary: [7/8 Regression] Loop miscompilation starting with
                    r238367
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

static int p[48], v;

int
main ()
{
  p[32] = 1;
  for (int i = 48; i--;)
    if (p[i])
      {
        if (i > 39 || (i > 7 && (i & 7) > 2))
          break;
        if (i < 8)
          v = 1;
        else if (!(i & 1))
          v = 2;
        else
          v = 3;
      }
  if (v != 2)
    __builtin_abort ();
  return 0;
}

is miscompiled at -O2 (-O and above) starting with r238367.