diff options
| author | bors <bors@rust-lang.org> | 2023-10-01 12:49:29 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2023-10-01 12:49:29 +0000 |
| commit | 871407a0341262d2a86703ca43b449d35fa5f236 (patch) | |
| tree | f996eaf179356891e7676935a9e36ac6b84f7b4a | |
| parent | c16823d757b376f90c5f5cbd542ce83235befbc4 (diff) | |
| parent | ca59652866242dd574a5e59cdeeab5c8548eeb49 (diff) | |
| download | rust-871407a0341262d2a86703ca43b449d35fa5f236.tar.gz rust-871407a0341262d2a86703ca43b449d35fa5f236.zip | |
Auto merge of #115554 - Kobzol:single-cgu, r=Mark-Simulacrum
Build `rustc` with a single CGU on x64 Linux This PR adds the `rust.codegen-units=1` setting when compiling the 64-bit Linux `rustc` artifact (the one used for try builds and Linux rustup distribution). This had mixed results in the past, however after the bump to LLVM 17, the results now seem pretty [incredible](https://github.com/rust-lang/rust/pull/115554#issuecomment-1706518199). Instruction counts, cycles, wall time, max RSS and even artifact sizes see large improvements. The last [try build](https://github.com/rust-lang-ci/rust/actions/runs/6077686494/job/16487768049) with this setting took 1h 8m, which is basically the same duration for try builds that we have seen recently. So there shouldn't be any large hit to CI/build time. I hope that this could potentially also reduce codegen noise of `rustc` a little bit, since small changes within a single `rustc` crate should no longer perturb optimizations because of CGU movement. We still do cross-crate LTO, so it won't eliminate it though. r? `@Mark-Simulacrum`
| -rw-r--r-- | src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile index 6f1b2a6a638..c04121a8bee 100644 --- a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile +++ b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile @@ -84,7 +84,8 @@ ENV RUST_CONFIGURE_ARGS \ --set llvm.ninja=false \ --set rust.jemalloc \ --set rust.use-lld=true \ - --set rust.lto=thin + --set rust.lto=thin \ + --set rust.codegen-units=1 ENV SCRIPT python3 ../x.py build --set rust.debug=true opt-dist && \ ./build/$HOSTS/stage0-tools-bin/opt-dist linux-ci -- python3 ../x.py dist \ |