rm -rf /tmp/rustc-pgo
+# We collect LLVM profiling information and rustc profiling information in
+# separate phases. This increases build time -- though not by a huge amount --
+# but prevents any problems from arising due to different profiling runtimes
+# being simultaneously linked in.
+
python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \
--stage 2 library/std \
- --rust-profile-generate=/tmp/rustc-pgo \
--llvm-profile-generate
# Profile libcore compilation in opt-level=0 and opt-level=3
RUSTC_BOOTSTRAP=1 ./build/$PGO_HOST/stage2/bin/rustc --edition=2018 \
--crate-type=lib -Copt-level=3 ../library/core/src/lib.rs
+# Merge the profile data we gathered for LLVM
+# Note that this uses the profdata from the clang we used to build LLVM,
+# which likely has a different version than our in-tree clang.
+/rustroot/bin/llvm-profdata \
+ merge -o /tmp/llvm-pgo.profdata ./build/$PGO_HOST/llvm/build/profiles
+
+# Rustbuild currently doesn't support rebuilding LLVM when PGO options
+# change (or any other llvm-related options); so just clear out the relevant
+# directories ourselves.
+rm -r ./build/$PGO_HOST/llvm ./build/$PGO_HOST/lld
+
+# Okay, LLVM profiling is done, switch to rustc PGO.
+
+python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \
+ --stage 2 library/std \
+ --rust-profile-generate=/tmp/rustc-pgo
+
+# Profile libcore compilation in opt-level=0 and opt-level=3
+RUSTC_BOOTSTRAP=1 ./build/$PGO_HOST/stage2/bin/rustc --edition=2018 \
+ --crate-type=lib ../library/core/src/lib.rs
+RUSTC_BOOTSTRAP=1 ./build/$PGO_HOST/stage2/bin/rustc --edition=2018 \
+ --crate-type=lib -Copt-level=3 ../library/core/src/lib.rs
+
cp -r /tmp/rustc-perf ./
chown -R $(whoami): ./rustc-perf
cd rustc-perf
./build/$PGO_HOST/llvm/bin/llvm-profdata \
merge -o /tmp/rustc-pgo.profdata /tmp/rustc-pgo
-# Merge the profile data we gathered for LLVM
-# Note that this uses the profdata from the clang we used to build LLVM,
-# which likely has a different version than our in-tree clang.
-/rustroot/bin/llvm-profdata \
- merge -o /tmp/llvm-pgo.profdata ./build/$PGO_HOST/llvm/build/profiles
-
# Rustbuild currently doesn't support rebuilding LLVM when PGO options
# change (or any other llvm-related options); so just clear out the relevant
# directories ourselves.
rm -r ./build/$PGO_HOST/llvm ./build/$PGO_HOST/lld
-# This produces the actual final set of artifacts.
+# This produces the actual final set of artifacts, using both the LLVM and rustc
+# collected profiling data.
$@ \
--rust-profile-use=/tmp/rustc-pgo.profdata \
--llvm-profile-use=/tmp/llvm-pgo.profdata