PHP 8 to Add a JIT

Since PHP 7.0 some performance improvements have been made, optimizations for the HashTable (a core data structure for PHP), specializations in the Zend VM for certain opcodes, specializations in the compiler for certain sequences, and a constant stream of improvements to the Optimizer component of OPCache … and many others besides, too boring to list. Maybe not the answer you were expecting: In the general case, applications written in PHP are I/O bound, and JIT works best on CPU bound code. There is clearly a difference, but the fact is that machine code has a calling convention, and Zend VM has a calling convention, machine code has a prologue and Zend VM has a prologue: Whether you call some_c_level_function() in Zend Opcodes or machine code doesn’t make a significant difference to the performance of the application making the call – although it may seem to make a significant difference to that call.

Source: blog.krakjoe.ninja