Thanks, Mike!
Yes, I need a sponsor and would really appreciate your help.
Sincerely yours,
Ivan
On 30.07.2013 20:32, Mike Duigou wrote:
Hi Ivan;
This looks like a good improvement. My only disappointment is that I didn't
notice it when adding the roundUpToPowerOf2 method!
Do you need a sponsor to push the fix?
Mike
On Jul 30 2013, at 08:35 , Ivan Gerasimov wrote:
Hello everybody!
HashTable needs to calculate the power of two that is not less that the given
number.
This calculation used to be implemented as a relatively inefficient loop
(that's why the issue 7192942 was created).
The implementation was improved with
http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/2e3cc7f599ca
However it can be improved even more. I reused 7192942 number for this propose.
Would you please help with reviewing?
Here's the webrev: http://cr.openjdk.java.net/~igerasim/7192942/0/webrev/
<http://cr.openjdk.java.net/%7Eigerasim/7192942/0/webrev/>
I also created a benchmark test to make sure the improvement is observable.
Here's the jmh benchmark I used:
http://cr.openjdk.java.net/~igerasim/bench/powoftwo/src/main/java/org/benches/PowerOfTwoBench.java
<http://cr.openjdk.java.net/%7Eigerasim/bench/powoftwo/src/main/java/org/benches/PowerOfTwoBench.java>
Benchmark Mode Thr Cnt Sec Mean
Mean error Units
o.b.PowerOfTwoBench.benchPowerOfTwoA avgt 1 20 5 60.697
0.850 msec/op
o.b.PowerOfTwoBench.benchPowerOfTwoB avgt 1 20 5 53.013
0.940 msec/op
The first line is for the current implementation and the second one is for the
proposed change.
Thus, the time gets reduced by 12%.
Sincerely yours,
Ivan
