daverandom/jitfu

Creating native instructions in PHP since 2014

JIT-Fu

A lesson in the art of JoeJITFu!

JIT-Fu is a PHP extension that exposes an OO API for the creation of native instructions to PHP userland, using libjit.

Disclaimer: the elephpant above is an artists rendition, the actual animal may or may not exist ...

Fibonacci

Because apparently, that's super important ...

<?php
use JITFU\Context;
use JITFU\Type;
use JITFU\Signature;
use JITFU\Func;
use JITFU\Value;

$context = new Context();

$integer   = Type::of(Type::int);

$function = new Func($context, new Signature($integer, [$integer]), function($args) use($integer) {
	$zero     = new Value($this, 0, $integer);
	$one      = new Value($this, 1, $integer);
	$two      = new Value($this, 2, $integer);

	/* if ($arg == 0) return 0; */
	$this->doIf(
		$this->doEq($args[0], $zero),
		function() use ($zero) {
			$this->doReturn($zero);
		}
	);

	/* if ($arg == 1) return 1; */
	$this->doIf(
		$this->doEq($args[0], $one),
		function() use($one) {
			$this->doReturn($one);
		}
	);

	/* return $function($arg-1) + $function($arg-2); */
	$this->doReturn(
		$this->doAdd(
			$this->doCall($this, [$this->doSub($args[0], $one)]),
			$this->doCall($this, [$this->doSub($args[0], $two)])));	
});

$function->dump("Fibonacci");

var_dump($function(40)); /* __invoke with magicalness */
?>

The code above will yield something like the following output:

[joe@localhost jit]$ time php -dextension=jitfu.so objects.php 
function Fibonacci(i1 : int) : int
        incoming_reg(i1, rdi)
.L:
        i6 = i1 == 0
        if i1 != 0 then goto .L0
.L:
        return_int(0)
        ends_in_dead
.L0:
        i7 = i1 == 1
        if i1 != 1 then goto .L1
.L:
        return_int(1)
        ends_in_dead
.L1:
        i8 = i1 - 1
        outgoing_reg(i8, rdi)
        call 0x08215dfd0
.L:
        return_reg(i10, rax)
        i12 = i1 - 2
        outgoing_reg(i12, rdi)
        call 0x08215dfd0
.L:
        return_reg(i14, rax)
        i15 = i10 + i14
        return_int(i15)
        ends_in_dead
.L:
.L:
end

int(102334155)


real    0m1.001s
user    0m0.997s
sys     0m0.003s

On my machine, this is ~60 times faster than PHP.

This library is not useful for compiling Zend opcodes

Installation Instructions

This extension is being developed against the latest libjit sources, it is advisable to install a fresh copy of libjit even if the system has one present:

git clone git://git.sv.gnu.org/libjit.git
cd libjit
./auto_gen.sh
./configure --prefix=/opt
make
sudo make install

Now you can build the PHP extension:

git clone https://github.com/krakjoe/jitfu
cd jitfu
phpize
./configure --with-jitfu=/opt
make
sudo make install

The example sessions above will result in a build of libjit and JIT-Fu

TODO

• integration tests for as much as possible
• bother with windows ... anyone ?
• other cool things, probably
• pecl & phpdoc