[lelanthran]

> I’ve always assumed access past the end of an array can’t always be detected in C, so I don’t see how those instructions could be eliminated.

"Can't always be detected" is jut a different way of saying "Can sometimes be detected".

Upon detection, I'd rather that the compiler still emit the instructions, not elide the code altogether.

[twoodfin]

Now the behavior of your compiler/runtime stack is dependent on the sophistication of your compiler or runtime relative to the particular code at issue + the specific information available statically or dynamically in the instance.

That does not seem like an improvement if your goal is predictable, consistent behavior.

[lelanthran]

> Now the behavior of your compiler/runtime stack is dependent on the sophistication of your compiler or runtime relative to the particular code at issue + the specific information available statically or dynamically in the instance.

> That does not seem like an improvement if your goal is predictable, consistent behavior.

Getting unpredictable outcomes only on some items is better than getting unpredictable outcomes on every item. This is what I meant when I said moving UB to IB might not fix everything, but it is certainly a solid start!