[Bug middle-end/111324] More optimization about "(X * Y) / Y"

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111324

--- Comment #1 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
In match.pd, there is a pattern:

/* Simplify (t * 2) / 2) -> t.  */
(for div (trunc_div ceil_div floor_div round_div exact_div)
 (simplify
  (div (mult:c @0 @1) @1)
  (if (ANY_INTEGRAL_TYPE_P (type))
   (if (TYPE_OVERFLOW_UNDEFINED (type))
    @0
#if GIMPLE
    (with
     {
       bool overflowed = true;
       value_range vr0, vr1;
       if (INTEGRAL_TYPE_P (type)
           && get_global_range_query ()->range_of_expr (vr0, @0)
           && get_global_range_query ()->range_of_expr (vr1, @1)
           && !vr0.varying_p () && !vr0.undefined_p ()
           && !vr1.varying_p () && !vr1.undefined_p ())
         {

Here, "get_global_range_query" is able to get the value-range info for SSA.
But it does not handle the case t.c. "get_range_query" can handle it.