Github user kiszk commented on the issue: https://github.com/apache/spark/pull/19916 Thank you for checking Java bytecode. I am talking about native code, not about bytecode. Hotspot compiler may eliminate statements. I think that this elapsed time includes interpreter execution, JIT compilation, and native code execution. It would be good to add warm-up. I think that it is not the best to write a long-running loop in `main()` method since it leads to on-stack-replacement. It would be good to put the long-running target loop into a callee. I think that it would be good to store a result into a global variable unlikely to eliminate unused variables and related operations. WDYT? ``` Integer globalVar g; void targetMethod() { Integer b; for(long i = 0; i < 1000000000; ++ i){ b += ((Integer)a) + 1; } g = b; } // warm up for (int i = 0; i < 10000000; i++) { targetMethod();} long start = System.currentTimeMillis(); targetMethod(); long end = System.currentTimeMillis();} ```
--- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org