[Bug tree-optimization/47004] missed optimization in length comparison

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47004

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.0
           Keywords|                            |missed-optimization
      Known to work|                            |5.1.0
             Status|NEW                         |RESOLVED
      Known to fail|                            |4.9.4

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed for GCC 5 by r5-3799.


We get a VRP range now of:
_4: [0, +INF(OVF)]


For:
  if (f_2(D) <= l_3(D))
    goto <bb 3>;
  else
    goto <bb 4>;

  <bb 3>:
  _4 = l_3(D) - f_2(D);
Which is exactly as we had expected.