[Bug middle-end/118879] Missed optimisation: std::in_range simpler size check

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118879

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> ```
> int f0(long long v)
> {
>     unsigned long long t = v;
>     t += 0x80'00'00'00ull;
>     if (t <= 0xff'ff'ff'ff)
>     return v;
>     return 0;
> }
> ```


So something like:
```
(simplify
 (le (plus @0 INTEGER_CST@2) INTEGER_CST@3))
 (if (exact_log2 (@2) != -1 && @3 == mask(exact_log2 (@2)+1))
  (with {
   tree otype = TREE_TYPE (@0);
   tree inner_type = signed_int_type (exact_log2 (@2)+1);
   }
  (eq (convert:otype (convert:itype @0)) @0))
```

ISo mine.