LoopAndRecursionPerf.java 
loop-recursion-perf.c


不加编译优化选项
gcc loop-recursion-perf.c 

Java版本比c 快10倍 ( jvm 做了编译优化 ？)

加编译器优化
gcc -O1 loop-recursion-perf.c 
c版本秒杀Java 

优化之后 ， 感觉像是把结果缓存起来了

完整代码

https://gitee.com/dyyx/hellocode/blob/master/src/LoopAndRecursionPerf.java   
https://gitee.com/dyyx/hellocode/blob/master/web/tech/c/demo/loop-recursion-perf.c




java版本运行结果

5050
5050
num=100,loopCount=10000000,outLoopCount=10


sum_test

331000,5050
318000,5050
297000,5050
301000,5050
296000,5050
298000,5050
296000,5050
296000,5050
297000,5050
297000,5050



sum_recursion_test

1320000,5050
1404000,5050
1428000,5050
1458000,5050
1393000,5050
1382000,5050
1388000,5050
1368000,5050
1401000,5050
1425000,5050


c 未加编译优化选项 版本 
gcc loop-recursion-perf.c 

5050
5050
num=100,loopCount=10000000,outLoopCount=10 


sum_test
2826022,5050
2672223,5050
2651320,5050
2676550,5050
2644865,5050
2622577,5050
2605713,5050
2617831,5050
2650958,5050
2637007,5050


sum_recursion_test
4501735,5050
4597598,5050
4629046,5050
4474304,5050
4551706,5050
4906823,5050
6602356,5050
4553710,5050
4766816,5050
4526677,5050


c 编译优化版本
gcc -O1 loop-recursion-perf.c 

5050
5050
num=100,loopCount=10000000,outLoopCount=10 


sum_test
0,5050
0,5050
0,5050
0,5050
0,5050
0,5050
0,5050
0,5050
0,5050
1,5050


sum_recursion_test
1,5050
0,5050
1,5050
1,5050
1,5050
0,5050
0,5050
1,5050
1,5050
1,5050