As far as I can tell, the source code of the benchmark didn't change at all. The only difference between them is that former uses PHP 7.1 and the latter uses PHP 7.2.
So... I would start at the differences between PHP 7.1 and PHP 7.2. I would also first attempt to reproduce the result locally, to rule out changes in environment in the benchmark game (speculatively speaking).
Today, it is faster: https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
As far as I can tell, the source code of the benchmark didn't change at all. The only difference between them is that former uses PHP 7.1 and the latter uses PHP 7.2.
So... I would start at the differences between PHP 7.1 and PHP 7.2. I would also first attempt to reproduce the result locally, to rule out changes in environment in the benchmark game (speculatively speaking).