3 ms·

Sure but in practice Rust is as performant as C/C++ in benchmarks, so IMHO 'integer overflow is UB' should be scrapped..

• MaxBarraclough 6y ago
  The same argument applies to various other instances of undefined behaviour. Integer division in Java never results in undefined behaviour. Divide-by-zero results in an exception, as does (Integer.MIN_VALUE / -1). In C/C++, both of those operations result in undefined behaviour. Modern JVMs have to generate some additional instructions to implement this [0], but I wonder if the real-world performance penalty is that substantial. Another example is reading an uninitialized variable, which is undefined behaviour in C/C++. Does this footgun really improve performance, with modern compilers? I don't have a solid answer here but I suspect not. > IMHO 'integer overflow is UB' should be scrapped The C committee is opposed to radical change, they never want to step on the toes of exotic compilers and exotic hardware architectures, so I doubt they'll ever change it. I think it would be more realistic to ask the major compiler vendors to commit to never doing anything unsafe on signed integer overflow. I believe GCC has an 'opt-in' flag for this. I wonder what the performance cost is, if any. Perhaps it breaks some optimisations, but as you say, other fast languages like Rust seem to get by fine. [0] https://www.javaer101.com/en/article/3166570.html https://www.javaer101.com/en/article/3166570.html