[Bug tree-optimization/117529] Missed optimization: (y != 0 && x > (unsigned)(-1) / y) (multiplication overflow check)

[Explorer09 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117529

--- Comment #3 from Kang-Che Sung <Explorer09 at gmail dot com> ---
The func4 example that Andrew Pinski provided makes me realize that this func5
should optimize to the same code:

```c
bool func5(unsigned long long x, unsigned long long y)
{
    if ((x | y) == 0) return 0;
    unsigned long long res;
    return __builtin_umulll_overflow(x, y, &res);
}
```