LWN: Comments on "First PHP 8 alpha released"

First PHP 8 alpha released

DG — Wed, 01 Jul 2020 12:34:28 +0000

Not JIT based, but for comparison of HHVM with PHP there's
https://kinsta.com/blog/hhvm-wordpress/ - see about 1/3 of the way down which seems to show PHP 7.2 is faster than HHVM (at least for Wordpress)

https://hhvm.com/blog/2018/09/12/end-of-php-support-futur... - HHVM dropping support for PHP - so any comparison is going to be difficult.

First PHP 8 alpha released

Sesse — Wed, 01 Jul 2020 11:41:51 +0000

Random searching found a test that indicates that four years ago, HHVM was 30% faster than PHP 7 on Wordpress. And PHP 8's JIT is (according to the authors) 3.5% faster than PHP 7.3 on Wordpress. YMMV.

https://www.wpoven.com/blog/hhvm-vs-php-7-performance-sho...

First PHP 8 alpha released

epa — Wed, 01 Jul 2020 11:32:18 +0000

It would be interesting to see a comparison between this effort and the JIT compiler for PHP developed by Facebook (which has now evolved into its own PHP dialect called Hack).

First PHP 8 alpha released

flussence — Wed, 01 Jul 2020 07:34:19 +0000

A JIT isn't just for existing code; it changes the performance equation for code that would once have been unthinkable to write. This plus PHP7's FFI makes a transition away from hard-to-maintain PECL plugins more viable.

First PHP 8 alpha released

Sesse — Tue, 30 Jun 2020 20:28:43 +0000

To answer my own question: A bit further down on the page, they have Wordpress numbers. It improves a meager 3.5% (they give no error bars).

First PHP 8 alpha released

Sesse — Tue, 30 Jun 2020 20:24:45 +0000

The JIT looks awful; extremely simplistic bytecode-to-asm with nearly no type inference. Is this really worth it? Is it a good design to iterate on and build a faster JIT from? What are the real-world speedups for e.g. Wordpress, if an ideal case such as Mandelbrot only yields 4x?