相同的 for 循环 为什么 Java 比 c 的速度快？

Java

public class DuffDevice {

private static int duff2(int count) {
int i = 0;
do {
++i;
} while (--count >0);
return i;
}

public static void main(String[] args) {
int duff;
long start, end;
DuffDevice duffDevice = new DuffDevice();

start = System.currentTimeMillis();
duff = duff2(Integer.MAX_VALUE - 7);
end = System.currentTimeMillis();
System.out.println(duff + " " + (end - start) + " ms");
}
}

C
#include <sys/time.h>
#include <stdio.h>

int duff(int count) {
}

int main(int argc, char* argv[]) {
struct timeval start_time, end_time;

gettimeofday(&start_time, NULL);

long count = 2147483640;
long i = 0;

do {
++i;
} while (--count);

gettimeofday(&end_time, NULL);

int total_time = 1000000 * (end_time.tv_sec - start_time.tv_sec) + (end_time.tv_usec - start_time.tv_usec);
printf("%d us", total_time);
printf("\n");
printf("%.3f ms", (double) total_time / 1000);
printf("\n");

printf("%l", i);
return 0;
}

Java 耗时情况
2 ms

C 耗时情况
4638.628 ms

性能怎么会相差这么大？