Java 17的計算速度比Java 8慢? - marian

public class Main {
static long fibonacci(long n) {
    if (n <= 1) {
      return n;
    } else {
      return fibonacci(n - 1) + fibonacci(n - 2);
    }
  }
class Fibonacci extends RecursiveTask<Long> {
final long n;
Fibonacci(long n) {
      this.n = n;
    }
protected Long compute() {
      if (n <= 10) {
        return fibonacci(n);
      }
      Fibonacci f1 = new Fibonacci(n - 1);
      f1.fork();
      Fibonacci f2 = new Fibonacci(n - 2);
      return f2.compute() + f1.join();
    }
  }
Map<String, List<Long>> results = new HashMap<>();
void execute(IntFunction<Long> code, int num, String name) {
    long start = System.currentTimeMillis();
    long r = code.apply(num);
    long time = System.currentTimeMillis() - start;
    results.computeIfAbsent(name, k -> new LinkedList<>()).add(time);
    System.out.println(r + " in " + time + " ms");
  }
void run(int num, int repeats) {
    for (int i = 0; i < repeats; i++) {
      execute(n -> fibonacci(n), num, "one");
      execute(n -> new Fibonacci(n).compute(), num, "multi");
    }
 
    results.forEach((k, v) -> 
   System.out.println(k + " " + v.stream().mapToLong(l -> l).average().getAsDouble()));
  }
public static void main(String... args) {
    new Main().run(Integer.valueOf(args[0]),  Integer.valueOf(args[1]));
  }
}