∟"int" Add and Assignment: 17 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 17 nanoseconds per step.
The next test is to measure the add operation performance.
Here is the test method:
/**
* BenchmarkTestInt.java
* Copyright (c) 2010 by Dr. Herong Yang, herongyang.com
*/
class BenchmarkTestInt {
...
// Test method for an add operation in a loop
public static int add(int steps, BenchmarkRunner runner) {
int x = 0;
int i = 0;
int last = steps;
runner.startTimer();
for (i=0; i<last; i++) {
x = i+i;
}
runner.stopTimer();
return x;
}
}
Now the loop runs 17 nanoseconds per step with an add operation and an assignment operation.
Clearly, the execution time of an add operation, i+i, is about 3 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: 17 - 14 = 3 nanoseconds.
