RFR: JDK-8266431: Dual-Pivot Quicksort improvements (Radix sort) [v10]

[Laurent Bourgès]

On Mon, 29 Nov 2021 21:16:32 GMT, iaroslavski <duke at openjdk.java.net> wrote:

>> Sorting:
>> 
>> - adopt radix sort for sequential and parallel sorts on int/long/float/double arrays (almost random and length > 6K)
>> - fix tryMergeRuns() to better handle case when the last run is a single element
>> - minor javadoc and comment changes
>> 
>> Testing:
>> - add new data inputs in tests for sorting
>> - add min/max/infinity values to float/double testing
>> - add tests for radix sort
>
> iaroslavski has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JDK-8266431: Dual-Pivot Quicksort improvements (Radix sort)
>   
>   * Updated javadoc
>   * Optimized insertion sort threshold
>   * Refactored parallel sorting section
>   * Improved step for pivot candidates
>   * Changed condition for Radix sort

Vladimir,
I updated the benchmarking code and here are the complete test results: system vs dpqs 21.5 vs 21.11:
https://github.com/bourgesl/nearly-optimal-mergesort-code/blob/master/sort-bench/results/2021/2021-12-final/DPQS-sort-1k-1M-stats.out

Full results:
https://github.com/bourgesl/nearly-optimal-mergesort-code/blob/master/sort-bench/results/2021/2021-12-final/sort-1k-1M-stats.out

All good, on 1k, 10k, 100k, 1m integer arrays.
Congratulations
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PR: https://git.openjdk.java.net/jdk/pull/3938