RFR: 8259074: regex benchmarks and tests

[Martin Buchholz]

On Mon, 1 Feb 2021 10:22:14 GMT, Claes Redestad <redestad at openjdk.org> wrote:

>> @amalloy - you are invited to comment on regex content
>> @cl4es @shipilev - you are invited to point out my jmh bad practices
>
> The assertion discussion aside, the micros look fine to me. 
> 
> With an eye towards reducing total run time I'd ask you to consider if all parameter combinations are useful or if we can get the same value after some pruning.

@cl4es I agree pruning is a good idea. I settled on 3 data points with 16x separations as good enough to clearly show the difference between O(1) O(N) O(N^2) and O(2^N) (although O(2^N) would "run forever").

(although ... please tell me you're not actually running these benchmarks in an automated fashion ... too expensive, and needs a human to interpret the results)

-------------

PR: https://git.openjdk.java.net/jdk/pull/1940