[Bug tree-optimization/126545] New: [16/17 Regression] Wrong code with ranger and FP comparisons and NaN handling

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126545

            Bug ID: 126545
           Summary: [16/17 Regression] Wrong code with ranger and FP
                    comparisons and NaN handling
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
  Target Milestone: ---

__attribute__((noipa)) int
f (int i, int j, int k)
{
  double z = 0.5 + (double) (k & 7);    /* [0.5, 7.5], never a NaN */
  double a = (double) ((i & 3) - 1);    /* [-1, 2] */
  double y = __builtin_sqrt (a);        /* [-0.0, 1.4142] +-NAN */
  double x = (double) (j & 7);          /* [0, 7], never a NaN */

  if (y < x)
    return 0;
  /* claimed by op1_op2_relation: y >= x */
  if (z < y)
    return 1;
  /* claimed: z >= y, so transitively z >= x */
  if (z >= x)
    return 2;
  return 3;
}

int
main (void)
{
  /* y = sqrt (-1.0) = NaN, so both y < x and z < y are false.
     x = 7.0, z = 0.5, and 0.5 >= 7.0 is false.  */
  if (f (0, 7, 0) != 3)
    __builtin_abort ();
  return 0;
}

aborts on aarch64 at -O2 and passes at -O0