Guilherme Ottoni
d078c2b895
This diff adds an initial framework for profile-guided optimizations
in the JIT. Two new translation modes are added, effectively creating
a multi-gear JIT:
1. Profile: this collects profiling data, which includes execution
counters and type information.
2. Optimize: this uses data collected by Profiling translations to
produce optimized translations.
Right now, the Optimize gear is solely used to produce larger
compilation regions (traces), which increase the scope of
optimizations exposed to the JIT (compared to tracelets). This is
still work in progress, and it's disabled by default.
This diff also fixes a number of bugs exposed by trace regions, gets
tools/reduce working again, and makes a number of improvements to
tc-print related to the new translation modes.
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 in the current directory:
sudo hhvm -m server
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.