From c5d65aa58043cc1eac76838319009fce9de1b019 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= Date: Sat, 4 Feb 2023 00:03:12 +0100 Subject: [PATCH] Apply BOLT optimizations without rebuilding LLVM --- src/bootstrap/bolt.rs | 21 ++++++++++----------- src/bootstrap/dist.rs | 23 ++++++++++++++++++++++- src/bootstrap/native.rs | 23 ----------------------- src/ci/stage-build.py | 1 - 4 files changed, 32 insertions(+), 36 deletions(-) diff --git a/src/bootstrap/bolt.rs b/src/bootstrap/bolt.rs index ea37cd47049b..d424852b845d 100644 --- a/src/bootstrap/bolt.rs +++ b/src/bootstrap/bolt.rs @@ -1,12 +1,13 @@ -use std::path::Path; +use std::path::{Path, PathBuf}; use std::process::Command; /// Uses the `llvm-bolt` binary to instrument the binary/library at the given `path` with BOLT. /// When the instrumented artifact is executed, it will generate BOLT profiles into /// `/tmp/prof.fdata..fdata`. -pub fn instrument_with_bolt_inplace(path: &Path) { +/// Returns a path to the instrumented artifact, created in a temporary directory. +pub fn instrument_with_bolt(path: &Path) -> PathBuf { let dir = std::env::temp_dir(); - let instrumented_path = dir.join("instrumented.so"); + let instrumented_path = dir.join(path.file_name().unwrap()); let status = Command::new("llvm-bolt") .arg("-instrument") @@ -21,9 +22,7 @@ pub fn instrument_with_bolt_inplace(path: &Path) { if !status.success() { panic!("Could not instrument {} with BOLT, exit code {:?}", path.display(), status.code()); } - - std::fs::copy(&instrumented_path, path).expect("Cannot copy instrumented artifact"); - std::fs::remove_file(instrumented_path).expect("Cannot delete instrumented artifact"); + instrumented_path } /// Uses the `llvm-bolt` binary to optimize the binary/library at the given `path` with BOLT, @@ -31,9 +30,11 @@ pub fn instrument_with_bolt_inplace(path: &Path) { /// /// The recorded profiles have to be merged using the `merge-fdata` tool from LLVM and the merged /// profile path should be then passed to this function. -pub fn optimize_library_with_bolt_inplace(path: &Path, profile_path: &Path) { +/// +/// Returns a path to the optimized artifact, created in a temporary directory. +pub fn optimize_with_bolt(path: &Path, profile_path: &Path) -> PathBuf { let dir = std::env::temp_dir(); - let optimized_path = dir.join("optimized.so"); + let optimized_path = dir.join(path.file_name().unwrap()); let status = Command::new("llvm-bolt") .arg(&path) @@ -65,7 +66,5 @@ pub fn optimize_library_with_bolt_inplace(path: &Path, profile_path: &Path) { if !status.success() { panic!("Could not optimize {} with BOLT, exit code {:?}", path.display(), status.code()); } - - std::fs::copy(&optimized_path, path).expect("Cannot copy optimized artifact"); - std::fs::remove_file(optimized_path).expect("Cannot delete optimized artifact"); + optimized_path } diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs index 9b2b549612d8..f6f6f4cc8ea9 100644 --- a/src/bootstrap/dist.rs +++ b/src/bootstrap/dist.rs @@ -19,6 +19,7 @@ use std::process::Command; use object::read::archive::ArchiveFile; use object::BinaryFormat; +use crate::bolt::{instrument_with_bolt, optimize_with_bolt}; use crate::builder::{Builder, Kind, RunConfig, ShouldRun, Step}; use crate::cache::{Interned, INTERNER}; use crate::channel; @@ -1904,6 +1905,26 @@ fn add_env(builder: &Builder<'_>, cmd: &mut Command, target: TargetSelection) { } } +fn install_llvm_file(builder: &Builder<'_>, source: &Path, destination: &Path) { + if source.as_os_str().is_empty() { + return; + } + + // After LLVM is built, we modify (instrument or optimize) the libLLVM.so library file. + // This is not done in-place so that the built LLVM files are not "tainted" with BOLT. + // We perform the instrumentation/optimization here, on the fly, just before they are being + // packaged into some destination directory. + let postprocessed = if builder.config.llvm_bolt_profile_generate { + instrument_with_bolt(source) + } else if let Some(path) = &builder.config.llvm_bolt_profile_use { + optimize_with_bolt(source, &Path::new(&path)) + } else { + source.to_path_buf() + }; + + builder.install(&postprocessed, destination, 0o644); +} + /// Maybe add LLVM object files to the given destination lib-dir. Allows either static or dynamic linking. /// /// Returns whether the files were actually copied. @@ -1955,7 +1976,7 @@ fn maybe_install_llvm(builder: &Builder<'_>, target: TargetSelection, dst_libdir } else { PathBuf::from(file) }; - builder.install(&file, dst_libdir, 0o644); + install_llvm_file(builder, &file, dst_libdir); } !builder.config.dry_run() } else { diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs index 5987b641b392..8c2bece1e621 100644 --- a/src/bootstrap/native.rs +++ b/src/bootstrap/native.rs @@ -16,7 +16,6 @@ use std::io; use std::path::{Path, PathBuf}; use std::process::Command; -use crate::bolt::{instrument_with_bolt_inplace, optimize_library_with_bolt_inplace}; use crate::builder::{Builder, RunConfig, ShouldRun, Step}; use crate::channel; use crate::config::{Config, TargetSelection}; @@ -523,34 +522,12 @@ impl Step for Llvm { } } - // After LLVM is built, we modify (instrument or optimize) the libLLVM.so library file - // in place. This is fine, because currently we do not support incrementally rebuilding - // LLVM after a configuration change, so to rebuild it the build files have to be removed, - // which will also remove these modified files. - if builder.config.llvm_bolt_profile_generate { - instrument_with_bolt_inplace(&get_built_llvm_lib_path(&res.llvm_config)); - } - if let Some(path) = &builder.config.llvm_bolt_profile_use { - optimize_library_with_bolt_inplace( - &get_built_llvm_lib_path(&res.llvm_config), - &Path::new(path), - ); - } - t!(stamp.write()); res } } -/// Returns path to a built LLVM library (libLLVM.so). -/// Assumes that we have built LLVM into a single library file. -fn get_built_llvm_lib_path(llvm_config_path: &Path) -> PathBuf { - let mut cmd = Command::new(llvm_config_path); - cmd.arg("--libfiles"); - PathBuf::from(output(&mut cmd).trim()) -} - fn check_llvm_version(builder: &Builder<'_>, llvm_config: &Path) { if !builder.config.llvm_version_check { return; diff --git a/src/ci/stage-build.py b/src/ci/stage-build.py index bd8fd524a262..ebd111e64535 100644 --- a/src/ci/stage-build.py +++ b/src/ci/stage-build.py @@ -805,7 +805,6 @@ def execute_build_pipeline(timer: Timer, pipeline: Pipeline, final_build_args: L gather_llvm_bolt_profiles(pipeline) print_free_disk_space(pipeline) - clear_llvm_files(pipeline) final_build_args += [ "--llvm-bolt-profile-use", pipeline.llvm_bolt_profile_merged_file()