[Bug tree-optimization/117760] New: `a != b` implies that a or b is also non-zero

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117760

            Bug ID: 117760
           Summary: `a != b` implies that a or b is also non-zero
           Product: gcc
           Version: 15.0
            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:
```
int f(int a, int b)
{
  if (a != b)
    return a != 0 || b != 0;
  return 0;
}
```

This should just reduce down to `return a != b;` as if a and b are non-equal
implies one of them have to be non-zero as well as both can't be 0.