[Bug middle-end/58742] pointer arithmetic simplification

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58742

--- Comment #19 from Richard Biener <rguenth at gcc dot gnu.org> ---
The original identity will remain.  That is,

;; Function fx (fx, funcdef_no=0, decl_uid=1743, symbol_order=0)

fx (int * b, int * e)
{
  long int e.0_2;
  long int b.1_4;
  long int _5;
  long unsigned int _6;
  int * _7;

  <bb 2>:
  e.0_2 = (long int) e_1(D);
  b.1_4 = (long int) b_3(D);
  _5 = e.0_2 - b.1_4;
  _6 = (long unsigned int) _5;
  _7 = b_3(D) + _6;
  return _7;

}

that is to be pattern-matched separately, in associate_pointerplus.  Of course
that's only a piece of associating as b+5+(e-b) will then still not be
optimized.