RFR: JDK-8273056 java.util.random does not correctly sample exponential or Gaussian distributions [v2]

[Brian Burkhalter]

On Wed, 1 Dec 2021 17:38:54 GMT, Jim Laskey <jlaskey at openjdk.org> wrote:

>> The modified ziggurat algorithm is not correctly implemented in `java.base/jdk/internal/util/random/RandomSupport.java`. 
>> 
>> Create a histogram of a million samples using 2000 uniform bins with the following range: 
>> Exponential range from 0 to 12. Gaussian range from -8 to 8. 
>> 
>> This does not pass a Chi-square test. If you look at the histogram it is obviously not showing the shape of the PDF for these distributions. Look closely at the range around zero (e.g. +/- 0.5).
>
> Jim Laskey has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:
> 
>  - Merge branch 'master' into 8273056
>  - 8273056 - java.util.random does not correctly sample exponential or Gaussian distributions

Marked as reviewed by bpb (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/6353