[Bug middle-end/113982] Poor codegen for 64-bit add with carry widening functions

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113982

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |middle-end
   Last reconfirmed|                            |2024-02-18
           Severity|normal                      |enhancement
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
aarch64 looks fine (ok there is an one extra mov):
```
add_wide_1(unsigned long long, unsigned long long):
        adds    x2, x0, x1
        mov     x0, x2
        cset    x1, cs
        ret
add_wide_2(unsigned long long, unsigned long long):
        adds    x0, x0, x1
        cset    x1, cs
        ret

```

So we have:
```
  _1 = (__int128 unsigned) x_6(D);
  _2 = (__int128 unsigned) y_7(D);
  r_8 = _1 + _2;
  _3 = x_6(D) + y_7(D);
  D.2566.sum = _3;
  _4 = r_8 >> 64;
  _5 = (bool) _4;
  D.2566.carry = _5;
```

So if we should convert _5 into:
  _t = .ADD_OVERFLOW (x_3(D), y_4(D));
  _t2 = IMAGPART_EXPR <_t>;
  _5 = (bool) _t2;

And then later on see that r_8 is REALPART_EXPR<_t>;
It would just work ...