On Nov 19, 2010, at 11:46 AM, Dario Teixeira wrote:

> Hi,
> 
>> What would be really nice is to make a JIT for a language that really
>> need one, like PHP! There are lots of companies out there (Yahoo,
>> Facebook, wikimedia) that spend hundreds of millions of dollars on
>> machines that run PHP bytecode interpreters implemented by people who
>> are not Xavier Leroy.
> 
> Actually, Facebook has a compiler that transforms PHP source code into C++ [1],
> and they claim a 50% reduction in CPU usage.

Yes, which is good. But if you think about it is "only" a x2 speedup vs a
really slow bytecode interpreter (the Zend PHP interpreter). PHP is known
for being more than 30 times slower than C. 
It's even slower than Ruby on http://shootout.alioth.debian.org/u32/which-programming-languages-are-fastest.php
There are lots of opportunities to do better IMHO.

>  It's an interesting approach,
> though I suspect that even as we speak a new circle of hell is being warmed
> up

Oh yeah.

> especially for those who are enabling PHP's continued existence thanks
> to gimmicks such as this one...
> 
> Cheers,
> Dario Teixeira
> 
> [1] https://github.com/facebook/hiphop-php/wiki/
> 
> 
> 
>