> Languages like Swift and Objective-C hide the reference counting for you, so 'instruction pollution' is not really something I care about. The overhead at th

> Languages like Swift and Objective-C hide the reference counting for you, so 'instruction pollution' is not really something I care about. The overhead at the instruction & memory level is fairly minimal for these language too, by means of using tagged pointers. I'm pretty sure the compiler is smart enough to factor out reference counting for complete sections where it can determine objects can impossibly go out of scope (e.g. sections where aliasing can be ruled out, and all assignments are to locals, such as in many loops). New Swift Ownership API can help, but compiler is not that good to figure out exclusive ownership all by themselves without any annotation. It is common to have more than 10% of you time in RC environment spent on refcount calculations and locks acquisition (some stats: http://iacoma.cs.uiuc.edu/iacoma-papers/pact18.pdf http://iacoma.cs.uiuc.edu/iacoma-papers/pact18.pdf).