Most performance wins from UB come from removing code that someone wrote intentionally. If that code wasn't meant to be run, it shouldn't be written. If it was

Most performance wins from UB come from removing code that someone wrote intentionally. If that code wasn't meant to be run, it shouldn't be written. If it was written, it should be run. Now obviously there are lots of counter-examples for that. You can probably list ten in a minute. But it should be the guiding philosophy of compiler optimizations. If the programmer wrote some code, it shouldn't just be removed. If the program would be faster without that code, the programmer should be the one responsible for deciding whether the code gets removed or not.