[boomanaiden154]

PGO can be used in such situations, but the profile needs to be checked in. Same code + same profile -> same binary (assuming the compiler is deterministic, which is tested quite extensively).

There are several big projects that use PGO (like Chrome), and you can get a deterministic build at whatever revision using PGO as the profiles are checked in to the repository.

[vlovich123]

It’s called autofdo although I’ve struggled to get it working well in Rust.

[boomanaiden154]

It's not called AutoFDO. AutoFDO refers to a specific sampling-based profile technique out of Google (https://dl.acm.org/doi/abs/10.1145/2854038.2854044). Sometimes people will refer to that as PGO though (with PGO and FDO being somewhat synonymous, but PGO seeming to be the preferred term in the open source LLVM world). Chrome specifically uses instrumented PGO which is very much not AutoFDO.

PGO works just fine in Rust and has support built into the compiler (https://doc.rust-lang.org/rustc/profile-guided-optimization....).