Depending on the ABI it’s saving a lot of registers, and it is very easy to end up calling it a lot if you cannot guarantee the code that may be called by funct

Depending on the ABI it’s saving a lot of registers, and it is very easy to end up calling it a lot if you cannot guarantee the code that may be called by functions you call and you need to do any cleanup. C++ and other languages tend to make the fast path of no exception extremely fast and store additional data about functions that allow for stack unwinding when an exception is thrown.