[Bug tree-optimization/98236] x plus/minus y cmp 0 produces unoptimal code

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98236

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is likely because we expand from

int bar (int x, int y)
{
  int _6;

  <bb 2> [local count: 1073741824]:
  if (x_2(D) != y_3(D))
    goto <bb 3>; [48.88%]
  else
    goto <bb 4>; [51.12%]

  <bb 3> [local count: 524845000]:
  foo ();

  <bb 4> [local count: 1073741824]:
  _6 = x_2(D) - y_3(D);
  return _6;

which means we simplified the condition to x != y.  So related to PR91384