[Bug tree-optimization/81633] [7/8 Regression] Incorrect floating point result with tree vectoriser

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81633

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
In *.ifcvt dump we have
  _69 = identity[j_31][0];
  _71 = _69 * _69;
  tmp[j_31][0] = _71;
  _77 = identity[j_31][1];
  _78 = _69 * _77;
  tmp[j_31][1] = _78;
  _84 = identity[j_31][2];
  _85 = _69 * _84;
  tmp[j_31][2] = _85;
  _91 = identity[j_31][3];
  _92 = _69 * _91;
  tmp[j_31][3] = _92;
but the fact that the first stmt is _69 * _69 doesn't mean the whole SLP is a
square of another vector.