1569709 - add =cross options to --enable-profile* options

Status: RESOLVED FIXED

(Firefox Build System :: General, task)

Comment 1

[Nathan Froyd [:froydnj]]

Attachment: Bug 1569709 - add --enable-profile-{generate,use}=cross option; r=#build

This change gives us the ability to selectively turn on cross-language
PGO, just like we have the ability to selectively turn on cross-language LTO.

There is room for things to go wrong here: it's not guaranteed that
--enable-profile-generate=cross will always be used with
--enable-profile-use=cross. Nothing bad will happen in the sense that
the build will succeed, but it's possible that we miss out on
optimizations on the Rust side. Either we fail to generate profile data
for the Rust code, or the Rust compiler fails to use the profile data.

In the future, we may want to default to cross-language PGO to avoid
these kind of mismatches.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0775acfef6dc
add --enable-profile-{generate,use}=cross option; r=mshal

Comment 3

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/0775acfef6dc