∟"int" Division and Assignment: 19 Nanoseconds per Step
This section provides a tutorial example on how to perform benchmark tests to find out how long a division and assignment loop will take to run. The answer is 19 nanoseconds per step.
The next test is to measure the division operation performance.
Here is the test method:
/**
* BenchmarkTestInt.java
* Copyright (c) 2010 by Dr. Herong Yang, herongyang.com
*/
class BenchmarkTestInt {
...
// Test method for a division operation in a loop
public static int division(int steps, BenchmarkRunner runner) {
int x = 0;
int i = 0;
int last = steps;
runner.startTimer();
for (i=0; i<last; i++) {
x = i/3;
}
runner.stopTimer();
return x;
}
}
The loop runs 19 nanoseconds per step with a division operation and an assignment operation.
The execution time of a division operation, i/3, is about 5 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: 19 - 14 = 5 nanoseconds.
