Edwin Smith
b4c6a50f78
This adds a checkRegisters() function so we can assert if the register allocator botched something. Our IR already must pass SSA rules after register allocation, so its enough to scan the code in dominator preorder, keeping track of what SSATmp is in each register and spill-slot. Then at the point of each use, we can assert that the register/slot assigned to the input tmp actually contains that input tmp. While I was at it, I moved checkCfg() and checkRegisters() to the new check.cpp file, and factored out findDomChildren(). Also, this checker failed on a tracelet that used exactly 16 slots due to the +1 fudge factor added by LinearScan::preAllocSpillLoc. I fixed this by changing the meaning of spill slots; now they are logical slot numbers, and we have a dedicated spillSlotOffset() function to compute the offset from RSP. This can be updated in the future to handle more than just the preallocated spill slots.
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.
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.
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 must be signed and returned.
Licence
HipHop VM is licensed under the PHP and Zend licenses except as otherwise noted.