Ok, well even for dynamic languages threaded code is likely to give you a noticeable speedup. The only negative example I'm aware of was adding threaded code (+superinstructions) to the Tcl interpreter, which resulted in slowdowns sometimes.
Even though the potential is not going to be as big as for Java, Forth, and OCaml interpreters (where people frequently report 2x speedups), for example Python gains between 20 and 45%. But somebody already replied to a similar inquiry and said that ANSI C compatibility is more important than the increase in performance. (Python uses conditional compilation to achieve both.)
Even though the potential is not going to be as big as for Java, Forth, and OCaml interpreters (where people frequently report 2x speedups), for example Python gains between 20 and 45%. But somebody already replied to a similar inquiry and said that ANSI C compatibility is more important than the increase in performance. (Python uses conditional compilation to achieve both.)