[kibwen]

Neat writeup, and very interesting that they haven't found it to be enough of a performance win to turn it on in production yet.

I was actually most interested to hear about HHIR and their general compiler pipeline. I'm reminded of Rust's recent initiative to rearchitect the compiler with a Rust-specific IR of its own (MIR). Here's an overview of how the compiler devs expect rustc to operate once this work is complete: https://github.com/rust-lang/rfcs/pull/1211#issuecomment-128... and here's a comment expanding on this overview: https://github.com/rust-lang/rfcs/pull/1211#issuecomment-130...

[jwatzman]

> I was actually most interested to hear about HHIR and their general compiler pipeline.

You might also be interested in this post, which goes into some more detail about HHBC and HHIR, and gives some examples of what it looked like about a year ago (which hasn't changed to terribly much): http://hhvm.com/blog/6323/the-journey-of-a-thousand-bytecode...