Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Optimize librustc_driver.so with BOLT #116352

Merged
merged 5 commits into from
Oct 14, 2023
Merged

Optimize librustc_driver.so with BOLT #116352

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
240a7dd
Build GCC with support for BOLT
Kobzol Jul 31, 2023
589e38a
Enable relocations for BOLT
Kobzol Oct 2, 2023
dd7c5a0
Optimize `librustc_driver.so` with BOLT
Kobzol Oct 2, 2023
9a0e90f
Add `--enable-bolt-settings` bootstrap flag
Kobzol Oct 9, 2023
482a820
Pass BOLT settings at the correct step
Kobzol Oct 11, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 6 additions & 0 deletions src/bootstrap/bin/rustc.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,12 @@ fn main() {
eprintln!("{prefix} libdir: {libdir:?}");
}

if env::var_os("RUSTC_BOLT_LINK_FLAGS").is_some() {
if let Some("rustc_driver") = crate_name {
cmd.arg("-Clink-args=-Wl,-q");
}
}
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This was added after the debug printing, so the extra flags won't show up when the command is printed. Was that deliberate?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Definitely not, good catch, thanks! #123189


let start = Instant::now();
let (child, status) = {
let errmsg = format!("\nFailed to run:\n{cmd:?}\n-------------");
Expand Down
5 changes: 5 additions & 0 deletions src/bootstrap/compile.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -906,6 +906,11 @@ impl Step for Rustc {
cargo.arg("-p").arg(krate);
}

if builder.build.config.enable_bolt_settings && compiler.stage == 1 {
// Relocations are required for BOLT to work.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would've expected this if to gate on the usage of BOLT somehow -- do we have a config flag for that? I think just a generic config flag is fine ("enable-bolt-settings") is ok, we don't need it to actually do optimizations. Maybe even "opt-dist" is the right name for it.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is what I have discussed in the PR description and on Zulip. @onur-ozkan has expressed a desire to avoid a BOLT-specific flag, although it seems like the most straightforward solution to me.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't have problem with doing this with using flags/config.toml. My point was more about its behaviour.

Add something like --bolt-flags, which would set the flag only for the cases where it's needed (and thus tying its behavior to opt-dist)

Like here, "which would set the flag only for the cases where it's needed" this seems very limited experience to me.

Copy link
Contributor Author

@Kobzol Kobzol Oct 9, 2023 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah, the interaction of the flag seems very specific. However, I feel like that's also true in general of several other similar flags. For example, the PGO generate/use flags are also only performed in stage 2, and basically I don't think that they are very useful outside of opt-dist.

The fact that we pass a specific linker flag is tied to BOLT - that won't really change. The fact that we only pass it to librustc_driver is tied to the way the compiler is distributed, and unless that changes, it also don't make sense to do it in any other way. And performing BOLT on earlier stage than 2 also doesn't make sense. So from this point of view, I think that the behavior of the flag is not that limited, because it's pretty much the only way we could do it that currently makes sense.

bootstrap and opt-dist are intrinsically intertwined, for better or worse, so I don't think that this flag will change that or create some unique, "anti-systemic" solution :D

cargo.env("RUSTC_BOLT_LINK_FLAGS", "1");
}

let _guard = builder.msg_sysroot_tool(
Kind::Build,
compiler.stage,
Expand Down
2 changes: 2 additions & 0 deletions src/bootstrap/config.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -234,6 +234,7 @@ pub struct Config {
pub llvm_profile_use: Option<String>,
pub llvm_profile_generate: bool,
pub llvm_libunwind_default: Option<LlvmLibunwind>,
pub enable_bolt_settings: bool,

pub reproducible_artifacts: Vec<String>,

Expand Down Expand Up @@ -1128,6 +1129,7 @@ impl Config {
config.free_args = std::mem::take(&mut flags.free_args);
config.llvm_profile_use = flags.llvm_profile_use;
config.llvm_profile_generate = flags.llvm_profile_generate;
config.enable_bolt_settings = flags.enable_bolt_settings;

// Infer the rest of the configuration.

Expand Down
3 changes: 3 additions & 0 deletions src/bootstrap/flags.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -152,6 +152,9 @@ pub struct Flags {
/// generate PGO profile with llvm built for rustc
#[arg(global(true), long)]
pub llvm_profile_generate: bool,
/// Enable BOLT link flags
#[arg(global(true), long)]
pub enable_bolt_settings: bool,
/// Additional reproducible artifacts that should be added to the reproducible artifacts archive.
#[arg(global(true), long)]
pub reproducible_artifact: Vec<String>,
Expand Down
7 changes: 6 additions & 1 deletion src/ci/docker/host-x86_64/dist-x86_64-linux/build-gcc.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,10 +27,15 @@ sed -i'' 's|ftp://gcc\.gnu\.org/|https://gcc.gnu.org/|g' ./contrib/download_prer
./contrib/download_prerequisites
mkdir ../gcc-build
cd ../gcc-build

# '-fno-reorder-blocks-and-partition' is required to
# enable BOLT optimization of the C++ standard library,
# which is included in librustc_driver.so
hide_output ../gcc-$GCC/configure \
--prefix=/rustroot \
--enable-languages=c,c++ \
--disable-gnu-unique-object
--disable-gnu-unique-object \
--enable-cxx-flags='-fno-reorder-blocks-and-partition'
hide_output make -j$(nproc)
hide_output make install
ln -s gcc /rustroot/bin/cc
Expand Down
15 changes: 15 additions & 0 deletions src/etc/completions/x.py.fish
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ complete -c x.py -n "__fish_use_subcommand" -l include-default-paths -d 'include
complete -c x.py -n "__fish_use_subcommand" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_use_subcommand" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_use_subcommand" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_use_subcommand" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_use_subcommand" -s h -l help -d 'Print help'
complete -c x.py -n "__fish_use_subcommand" -f -a "build" -d 'Compile either the compiler or libraries'
complete -c x.py -n "__fish_use_subcommand" -f -a "check" -d 'Compile either the compiler or libraries, using cargo check'
Expand Down Expand Up @@ -71,6 +72,7 @@ complete -c x.py -n "__fish_seen_subcommand_from build" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from build" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from build" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from build" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from build" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from build" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from check" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from check" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -102,6 +104,7 @@ complete -c x.py -n "__fish_seen_subcommand_from check" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from check" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from check" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from check" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from check" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from check" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from clippy" -s A -d 'clippy lints to allow' -r
complete -c x.py -n "__fish_seen_subcommand_from clippy" -s D -d 'clippy lints to deny' -r
Expand Down Expand Up @@ -137,6 +140,7 @@ complete -c x.py -n "__fish_seen_subcommand_from clippy" -l include-default-path
complete -c x.py -n "__fish_seen_subcommand_from clippy" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from clippy" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from clippy" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from clippy" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from clippy" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from fix" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from fix" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -167,6 +171,7 @@ complete -c x.py -n "__fish_seen_subcommand_from fix" -l include-default-paths -
complete -c x.py -n "__fish_seen_subcommand_from fix" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from fix" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from fix" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from fix" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from fix" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -198,6 +203,7 @@ complete -c x.py -n "__fish_seen_subcommand_from fmt" -l include-default-paths -
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from fmt" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from fmt" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from doc" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from doc" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -230,6 +236,7 @@ complete -c x.py -n "__fish_seen_subcommand_from doc" -l include-default-paths -
complete -c x.py -n "__fish_seen_subcommand_from doc" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from doc" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from doc" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from doc" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from doc" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from test" -l skip -d 'skips tests matching SUBSTRING, if supported by test tool. May be passed multiple times' -r -F
complete -c x.py -n "__fish_seen_subcommand_from test" -l test-args -d 'extra arguments to be passed for the test tool being used (e.g. libtest, compiletest or rustdoc)' -r
Expand Down Expand Up @@ -273,6 +280,7 @@ complete -c x.py -n "__fish_seen_subcommand_from test" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from test" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from test" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from test" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from test" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from test" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from bench" -l test-args -r
complete -c x.py -n "__fish_seen_subcommand_from bench" -l config -d 'TOML configuration file for build' -r -F
Expand Down Expand Up @@ -304,6 +312,7 @@ complete -c x.py -n "__fish_seen_subcommand_from bench" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from bench" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from bench" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from bench" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from bench" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from bench" -s h -l help -d 'Print help'
complete -c x.py -n "__fish_seen_subcommand_from clean" -l stage -d 'Clean a specific stage without touching other artifacts. By default, every stage is cleaned if this option is not used' -r
complete -c x.py -n "__fish_seen_subcommand_from clean" -l config -d 'TOML configuration file for build' -r -F
Expand Down Expand Up @@ -335,6 +344,7 @@ complete -c x.py -n "__fish_seen_subcommand_from clean" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from clean" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from clean" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from clean" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from clean" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from clean" -s h -l help -d 'Print help'
complete -c x.py -n "__fish_seen_subcommand_from dist" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from dist" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -365,6 +375,7 @@ complete -c x.py -n "__fish_seen_subcommand_from dist" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from dist" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from dist" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from dist" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from dist" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from dist" -s h -l help -d 'Print help'
complete -c x.py -n "__fish_seen_subcommand_from install" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from install" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -395,6 +406,7 @@ complete -c x.py -n "__fish_seen_subcommand_from install" -l include-default-pat
complete -c x.py -n "__fish_seen_subcommand_from install" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from install" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from install" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from install" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from install" -s h -l help -d 'Print help'
complete -c x.py -n "__fish_seen_subcommand_from run" -l args -d 'arguments for the tool' -r
complete -c x.py -n "__fish_seen_subcommand_from run" -l config -d 'TOML configuration file for build' -r -F
Expand Down Expand Up @@ -426,6 +438,7 @@ complete -c x.py -n "__fish_seen_subcommand_from run" -l include-default-paths -
complete -c x.py -n "__fish_seen_subcommand_from run" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from run" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from run" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from run" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from run" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from setup" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from setup" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -456,6 +469,7 @@ complete -c x.py -n "__fish_seen_subcommand_from setup" -l include-default-paths
complete -c x.py -n "__fish_seen_subcommand_from setup" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from setup" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from setup" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from setup" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from setup" -s h -l help -d 'Print help (see more with \'--help\')'
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l config -d 'TOML configuration file for build' -r -F
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
Expand Down Expand Up @@ -487,4 +501,5 @@ complete -c x.py -n "__fish_seen_subcommand_from suggest" -l include-default-pat
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l dry-run -d 'dry run; don\'t build anything'
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l json-output -d 'use message-format=json'
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l llvm-profile-generate -d 'generate PGO profile with llvm built for rustc'
complete -c x.py -n "__fish_seen_subcommand_from suggest" -l enable-bolt-settings -d 'Enable BOLT link flags'
complete -c x.py -n "__fish_seen_subcommand_from suggest" -s h -l help -d 'Print help (see more with \'--help\')'
Loading
Loading