[Bug tree-optimization/86955] strlen of a known string in member array plus offset not folded

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86955

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
   Last reconfirmed|2019-06-07 00:00:00         |2021-11-23

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Martin Sebor from comment #1)
> The reason is that the strlen pass sees the following:
Note we get now (after r12-5465-g911b633803):
  _1 = &p_4(D)->a;
  __builtin_memcpy (_1, "123", 4);
  _2 = p_4(D) + 2;
  _3 = __builtin_strlen (_2);


But strlen pass still does not understand p_4(D)+4 is the same as &p_4(D)->a[1]