richardstartin edited a comment on pull request #7487:
URL: https://github.com/apache/pinot/pull/7487#issuecomment-927795364
Here's a quick comparison to show what's at stake here (I don't think the
benchmark is worth maintaining in this project). Note that I selected lengths
which aren't aligned to make sure slower tail loops execute, which won't happen
on aligned inputs.
```java
@State(Scope.Benchmark)
public class BenchmarkByteArrayCompare {
@Param({"7", "31", "1023"})
int _length;
@Param("1")
int _offset;
private byte[] _left;
private byte[] _right;
@Setup(Level.Trial)
public void setup() {
_left = new byte[_length];
ThreadLocalRandom.current().nextBytes(_left);
_right = Arrays.copyOf(_left, _left.length);
_right[_right.length - _offset] = (byte) ~_left[_left.length - _offset];
}
@Benchmark
public int compare() {
return ByteArray.compare(_left, _right);
}
}
```
```
Benchmark (_length) (_offset) Mode Cnt Score
Error Units
BenchmarkByteArrayCompare.compare 7 1 avgt 5 5.942
± 0.048 ns/op
BenchmarkByteArrayCompare.compare 31 1 avgt 5 15.298
± 1.040 ns/op
BenchmarkByteArrayCompare.compare 1023 1 avgt 5 320.390
± 1.262 ns/op
Benchmark (_length) (_offset) Mode Cnt Score
Error Units
BenchmarkByteArrayCompare.compare 7 1 avgt 5 7.913 ±
0.174 ns/op
BenchmarkByteArrayCompare.compare 31 1 avgt 5 8.351 ±
0.016 ns/op
BenchmarkByteArrayCompare.compare 1023 1 avgt 5 22.765 ±
1.566 ns/op
```
For inputs shorter than 8 bytes, there is a small setup cost of the order of
1ns, but for larger inputs the improvement is huge.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org
For additional commands, e-mail: commits-h...@pinot.apache.org
