[Bug tree-optimization/114092] New: ADD_OVERFLOW with resulting type of `_Complex unsigned:1` should be reduced to just `(unsigned)(a) <= 1`

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114092

            Bug ID: 114092
           Summary: ADD_OVERFLOW<a, 0> with resulting type of `_Complex
                    unsigned:1` should be reduced to just `(unsigned)(a)
                    <= 1`
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
struct d
{
  unsigned i:1;
};
_Bool f(int a, struct d b)
{
        return __builtin_add_overflow_p(a, 0, b.i);
}


_Bool f1(int a, struct d b)
{
        return a != 1 && a != 0;
}
```

These 2 functions should produce the same. Here `a+0` overflows an `unsigned:1`
if the value of a is not 0 or 1.

We could extend this to any smaller types too if we want.