∟"long" Add and Assignment: 34 Nanoseconds per Step
This section provides a tutorial example on how to perform benchmark tests to find out how long an add and assignment loop will take to run. The answer is 34 nanoseconds per step.
The next test is to measure the add operation performance.
Here is the test method:
/**
* BenchmarkTestLong.java
* Copyright (c) 2010 by Dr. Herong Yang, herongyang.com
*/
class BenchmarkTestLong {
...
// Test method for an add operation in a loop
public static long add(int steps, BenchmarkRunner runner) {
long x = 0;
long i = 0;
long last = steps;
runner.startTimer();
for (i=0; i<last; i++) {
x = i+i;
}
runner.stopTimer();
return x;
}
}
The loop runs 34 nanoseconds per step with an add operation in the assignment statement.
clearly, the execution time of an add operation, i+i, is about 10 nanoseconds in interpreted-only mode.
This conclusion can be arrived from test results of 10000, 100000 and 1000000 steps and minus
the assignment loop execution time: 34 - 24 = 10 nanoseconds.
