Jordan DeLong
e3bdb5123f
If DCE eliminates a block that ends with a Jmp_, two things can currently go wrong. One is that linearscan will still inspect the incoming edge to try to precolor jump destinations and fail an assert; the other is that the type of the DefLabel destination may be too relaxed. This diff adds a new checkCfg invariant that all incoming edges to a DefLabel are in the block list for the trace, and weakens the assert in linearscan so things still work if DCE is turned off but a block becomes unreachable. Also changes dce's removeUnreachable to reflowTypes if it removes an incoming edge.
HipHop VM for PHP 
HipHop VM (HHVM) is a new open-source virtual machine designed for executing programs written in PHP. HHVM uses a just-in-time compilation approach to achieve superior performance while maintaining the flexibility that PHP developers are accustomed to. HipHop VM (and before it HPHPc) has realized > 5x increase in throughput for Facebook compared with Zend PHP 5.2.
HipHop is most commonly run as a standalone server, replacing both Apache and modphp.
Installing
You can install a prebuilt package or compile from source.
Running
You can run standalone programs just by passing them to hhvm: hhvm my_script.php.
HipHop bundles in a webserver. So if you want to run on port 80 with document root /var/www:
sudo hhvm -m server /var/www
For anything more complicated, you'll want to make a config.hdf and run sudo hhvm -m server -c config.hdf.
Contributing
We'd love to have your help in making HipHop better. If you run into problems, please open an issue, or better yet, fork us and send a pull request. Join us on #hhvm on freenode.
If you want to help but don't know where to start, try fixing some of the Zend tests that don't pass. You can run them with hphp/test/run. When they work, move them to zend/good and send a pull request.
Before changes can be accepted a Contributors Licensing Agreement (pdf - print, sign, scan, link) must be signed.
Licence
HipHop VM is licensed under the PHP and Zend licenses except as otherwise noted.