[Bug tree-optimization/106064] Wrong code comparing two global zero-sized arrays

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106064

--- Comment #11 from Alex Coplan <acoplan at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #8)
> The IMHO UB case is for a != b when one address is at the start of one
> object and the other address is at the end of another one

Just to dig a little deeper on this, what makes this case UB? Is there
something in the standard to this effect?