Rexgexp benchmark

This compares Pcre with Pcre2 and Re.

The benchmark were done on a Thinkpad from 2024 with an Intel Ultra 7 and 32GB of ram.

I first generated a large file (239M) with reoccuring pattern $$//$$ appearing 50 000 times. Code for that can be found in bin/gen.ml. The file is not included because it exceed github's size limit.

Then I tested splitting and replacing, a 1000 times each.

I got the following results:

Pcre

split: 58.065355 replace: 62.342115

with ~study:true and ~jit_compile:true: split: 18.949022 replace: 20.299579

Pcre2

split: 16.756501 replace: 18.157539

Re

split: 242.511451 replace: 328.344440