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

[Alan Bateman]

On Thu, 13 May 2021 11:31:49 GMT, iaroslavski <github.com+43264149+iaroslavski at openjdk.org> wrote:

>> Perhaps we can resolve this issue in private - my email address is on my profile (or in the commits in `radix-sort-benchmark`)?
>
> @richardstartin And one more addon: my first version of Radix sort, see my github https://github.com/iaroslavski/sorting/tree/master/radixsort uses another name, like skipBytes, then renamed to passLevel.
> So, the common part is "skip". And this method has different number of parameters. I don't see any collision with your code.

> Hi @iaroslavski I'm unconvinced that this work was from 14/06/2020 - I believe this work derives from an unsigned radix sort I implemented on 10/04/2021 [richardstartin/radix-sort-benchmark at ab4da23#diff-6c13d3fb74f38906677dbfa1a70a123c8e5baf4a39219c81ef121e078d0013bcR226](https://github.com/richardstartin/radix-sort-benchmark/commit/ab4da230e1d0ac68e5ee2cee38d71c7e7d50f49b#diff-6c13d3fb74f38906677dbfa1a70a123c8e5baf4a39219c81ef121e078d0013bcR226) which has numerous structural similarities to this work:
> Moreover, @bourgesl forked my repository on 11/04/2021 and communicated with me about doing so. On 25/04/2021 there was a new implementation of `DualPivotQuicksort` with a signed radix sort but the same structural similarities, and with the same method and variable names in places [bourgesl/radix-sort-benchmark at 90ff7e4#diff-397ce8fd791e2ce508cf9127201bc9ab46264cd2a79fd0487a63569f2e4b59b2R607-R609](https://github.com/bourgesl/radix-sort-benchmark/commit/90ff7e427da0fa49f374bff0241fb2487bd87bde#diff-397ce8fd791e2ce508cf9127201bc9ab46264cd2a79fd0487a63569f2e4b59b2R607-R609)

@iaroslavski The attribution is not clear here. Can you provide a summary as to who is contributing to this patch? I can't tell if all involved have signed the OCA or not. I'm sure there will be questions about space/time trade-offs with radix sort but I think it's important to first establish the origins of this patch first.

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PR: https://git.openjdk.java.net/jdk/pull/3938