Agreed that this is why a lot of people support the current UB situation, but the history of UB makes this feel wrong:
> As far as I can tell, C89 did not use performance as a justification for any of its undefined behaviors. They were non-portabilities, like signed overflow and null pointer dereferences, or they were outright bugs, like use-after-free. But now experts like Chris Lattner and Hans Boehm point to optimization potential, not portability, as justification for undefined behaviors. I conclude that the rationales really have shifted from the mid-1980s to today: an idea that meant to capture non-portability has been preserved for performance, trumping concerns like correctness and debuggability.
Oh undoubtedly; I didn't mean to imply that performance was the reason behind the origin of UB, though I can see how my comment would read that way. Thank you for adding the note!
The forgery path is downloading the leaked database of 153 million driver's license images, picking one with the right gender, rough age, weight and height, and printing a card with that text+barcode and your photo.
Related, Matt Levine has recently been writing about how the AI labs are paying huge amounts of money to tech/math/AI people but these people don't actually know how to spend it. https://www.bloomberg.com/opinion/newsletters/2026-09-10/dal... As opposed to the typical finance worker who knows very well how to spend.
Yes, you need to manually verify the statement of the theorem of interest of formalized correctly. But you don't need to anything more than this: you can rely on the proof being correct. And the proof is overwhelmingly the most amount of code.
Yeah I think the verb "removed" is not the right verb here, because the paper in question is OpenAI's hypothetical paper which Alpöge is not on in the first place.
We do tend to impose them on individual drivers who make egregious and consequential failures, that’s the point. If every car running the same software is functionally the same ‘driver’ this class of failure absolutely should trigger a moratorium.
>We do tend to impose them on individual drivers who make egregious and consequential failures, that’s the point.
Do we? It's a common saying that if you want to kill someone with no penalties, have them run over with a car.
Then there are examples like these all over the place. Not to mention distracted driving and DUIs don't even get your license suspended in many or most jurisdictions.
>The Audi, which Jones had bought one month before the crash, was the third car he had totaled in a crash within 11 months. Speed was a factor in all three collisions, but police did not cite Jones in the first two crashes, prosecutors said.
Also see the 80-year-old woman in SF who killed an entire family at a bus stop, while speeding, while going the wrong way on a one way street, and was sentenced to probation and community service and banned from driving for three years.
Very nice. As a follow up would be interesting to also reverse engineer the structure of the vtable itself. I guess it’s a list of pointers to the method implementations?
My first question was, if the vtable only has a single function in it (as in these examples), can the compiler optimize it to a function pointer to save an indirection?
> As far as I can tell, C89 did not use performance as a justification for any of its undefined behaviors. They were non-portabilities, like signed overflow and null pointer dereferences, or they were outright bugs, like use-after-free. But now experts like Chris Lattner and Hans Boehm point to optimization potential, not portability, as justification for undefined behaviors. I conclude that the rationales really have shifted from the mid-1980s to today: an idea that meant to capture non-portability has been preserved for performance, trumping concerns like correctness and debuggability.
https://research.swtch.com/ub
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