java循环i++vs i+=2

Question

我一直在尝试一种高效的算法来寻找素数，作为我尝试的一部分，我一直在使用以下代码。我有一个想法，通过改变I+=2的激励来加速循环，但实际上，这个改变似乎给我的程序的运行时间增加了2秒。有谁能解释为什么会发生这种情况，因为循环似乎需要完成一半的工作才能完成

for(int i = answers.get(answers.size()-1)+2;i<n;i++) {
        int bit = i%64;
        int currentInt = i/64;

        int isPrime = (primes[currentInt] >> bit) & 1;
        if(isPrime == 1) {answers.add(i);}
    }

完整代码如下：

import java.util.ArrayList;
import java.util.List;
import java.util.stream.IntStream;

public class Primes15 {
  static Long start;

  public static IntStream stream() {
    int numbers = 15350808;
    int n = 982451712;
    List<Integer> answers = new ArrayList<>();
    long[] inverseShifts = new long[64];
    long temp = 1;

    for(int i = 0; i < inverseShifts.length; i++) {
      inverseShifts[i] = temp ^ -1;
      temp = temp << 1;
    }

    long[] primes = new long[numbers+1];
    primes[0] = -6148914691370734930L;
    for(int i = 1;i<primes.length; i++) {
      primes[i] = -6148914691370734934L;
    }

    System.out.println("Setup taken " + (System.currentTimeMillis() - start) + "  millis");
    start = System.currentTimeMillis();

    for(int p =3; p*p <=n; p+=2) {
      int bit = p%64;
      int currentInt = p/64;
      long isPrime = (primes[currentInt] >> bit) & 1;
      if(isPrime == 1) {
        answers.add(p);
        int cPrimeSquared = p*p;
        int change = (p==2)? p : p+p;
        for(int i = cPrimeSquared; i <= n; i += change) {
          int innerBit = i % 64;
          int innerInt = i /64;
          isPrime = (primes[innerInt] >> innerBit) & 1;
          if(isPrime == 1) {
            primes[innerInt] = primes[innerInt] & inverseShifts[innerBit];
          }
        }
      }
      System.out.println("finder took " + (System.currentTimeMillis() - start) + "  ms");
      start = System.currentTimeMillis();
      for(int i = answers.get(answers.size()-1)+2; i<n; i++) {
        int bit = i%64;
        int currentInt = i/64;
        long isPrime = (primes[currentInt] >> bit) & 1;
        if(isPrime == 1) {answers.add(i);}
      }
      System.out.println("search took " + (System.currentTimeMillis() - start) + "  ms");
      start = System.currentTimeMillis();

      return answers.stream().mapToInt(i->i);
    }

  public static void main(String[] args) {
    start = System.currentTimeMillis();
    stream();
    Long finish = System.currentTimeMillis();
    System.out.println("Time taken " + (finish - start) + "  millis");
  }
}