[Bug tree-optimization/123645] [12-16 Regression] Miscompile at -O1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123645

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is actually undefined.
```
uint64_t backsmith_pure_7(BS_VEC(int32_t, 8) BS_ARG_3)
{
    BS_VEC(uint16_t, 32) BS_VAR_2[6];
    if (BS_ARG_3[7]) return 4083;
    return BS_VAR_2[0][7];
}
```

BS_VAR_2 is uninitialized. so it could return anything.