[Bug tree-optimization/111221] Floating point handling a*1.0 vs. a+0.0

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111221

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
That is GCC will remove additions of -0.0:
double addneg0 (double a)
{
  return a + -0.0;
}

Gets optimized to just `return a;`.