Oh, I thought the GP was accusing GCC devs of reckless optimizations. But UBSan is a clang project, so maybe you're interpretation makes more sense. Very confusing thread. :)

Sorry, I should've been more explicit when I responded to the original clang vs gcc comment.

Note that UBSan is (mostly? totally? originally?) a Google project and it's been ported to both clang and gcc.

I mean, if you use GCC does recklessly optimize away (some) security/safety code. This is one of the reasons why we don't use it for code we ship. I work in a safety-conscious industry, where an overeager compiler can literally kill people.