From dda53383d9d932d5d55543c9f0bda7abc6b3241a Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Sun, 24 Jul 2022 08:52:08 -0700
Subject: [PATCH] Revert "Revert "Use ICF (identical code folding) for building
rustc""
This reverts commit rust-lang/rust@45575d23f316af7476ccd0a895234ac59c47a6be,
thereby enabling identical code folding again.
---
src/bootstrap/compile.rs | 6 ++++++
src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile | 3 ++-
src/ci/pgo.sh | 4 ++++
3 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 3d678b2290d..aa7cda46bda 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -651,6 +651,12 @@ impl Step for Rustc {
panic!("Cannot use and generate PGO profiles at the same time");
}
+ // With LLD, we can use ICF (identical code folding) to reduce the executable size
+ // of librustc_driver/rustc and to improve i-cache utilization.
+ if builder.config.use_lld {
+ cargo.rustflag("-Clink-args=-Wl,--icf=all");
+ }
+
let is_collecting = if let Some(path) = &builder.config.rust_profile_generate {
if compiler.stage == 1 {
cargo.rustflag(&format!("-Cprofile-generate={}", path));
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 ab6c888030e..f262bc3c7d8 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
@@ -122,7 +122,8 @@ ENV RUST_CONFIGURE_ARGS \
--set target.x86_64-unknown-linux-gnu.ranlib=/rustroot/bin/llvm-ranlib \
--set llvm.thin-lto=true \
--set llvm.ninja=false \
- --set rust.jemalloc
+ --set rust.jemalloc \
+ --set rust.use-lld=true
ENV SCRIPT ../src/ci/pgo.sh python3 ../x.py dist \
--host $HOSTS --target $HOSTS \
--include-default-paths \
diff --git a/src/ci/pgo.sh b/src/ci/pgo.sh
index 28bed1fa035..4773dc09960 100755
--- a/src/ci/pgo.sh
+++ b/src/ci/pgo.sh
@@ -195,3 +195,7 @@ rm -r $BUILD_ARTIFACTS/llvm $BUILD_ARTIFACTS/lld
$@ \
--rust-profile-use=${RUSTC_PROFILE_MERGED_FILE} \
--llvm-profile-use=${LLVM_PROFILE_MERGED_FILE}
+
+echo "Rustc binary size"
+ls -la ./build/$PGO_HOST/stage2/bin
+ls -la ./build/$PGO_HOST/stage2/lib