The compiler team had our weekly triage meeting on 2019-10-31. You can find the minutes on the compiler-team repository. Each week, we have general announcements from the team followed by check-ins from two of the compiler team working groups.

Rust 1.39 ships on Thursday!

PGO is available in the stable compiler. Docs are in the rustc-dev-guide and the rustc-book

Unfortunately we don't observe significant performance gains from applying it (except for tiny synthetic test cases).

@michaelwoerister asked for people to try PGO on irlo but haven't gotten a lot of feedback.

There is one interesting theory that Rust doesn't profit as much as C++ because it defaults to having fewer compilation units and thus can make better inlining decisions in the non-PGO case.