"Usually" often does not apply to java compilers. Most java compilers won't actually do tail recursion transformations. You can check this yourself by running the snippet below. Tail recursion transformation would rewrite the recursion into "while (true) {}". If the program crashes with a StackOverflow the compiler does not do the optimization; if it continues infinitely without any problem the compiler does the optimization.

Results: sun-1.3.x, sun-1.4.x, sun01.5.0beta1 don't do tail recursion optimization (both for client and server vm). Only ibm-1.3.1 and ibm-1.4.1 do it.

public class TailRecursionTest {

private static int loop(int i) { return loop(i); }

public static void main(String[] args) { loop(0); } }

Francois Beausoleil wrote: