rm -rf /tmp/rustc-pgo
+# This path has to be absolute
+LLVM_PROFILE_DIRECTORY_ROOT=/tmp/llvm-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 \
+# LLVM IR PGO does not respect LLVM_PROFILE_FILE, so we have to set the profiling file
+# path through our custom environment variable. We include the PID in the directory path
+# to avoid updates to profile files being lost because of race conditions.
+LLVM_PROFILE_DIR=${LLVM_PROFILE_DIRECTORY_ROOT}/prof-%p python3 ../x.py build \
+ --target=$PGO_HOST \
+ --host=$PGO_HOST \
--stage 2 library/std \
--llvm-profile-generate
gather_profiles "Debug,Opt" "Full" \
"syn-1.0.89,cargo-0.60.0,serde-1.0.136,ripgrep-13.0.0,regex-1.5.5,clap-3.1.6,hyper-0.14.18"
+LLVM_PROFILE_MERGED_FILE=/tmp/llvm-pgo.profdata
+
# Merge the profile data we gathered for LLVM
# Note that this uses the profdata from the clang we used to build LLVM,
# which likely has a different version than our in-tree clang.
-/rustroot/bin/llvm-profdata \
- merge -o /tmp/llvm-pgo.profdata ./build/$PGO_HOST/llvm/build/profiles
+/rustroot/bin/llvm-profdata merge -o ${LLVM_PROFILE_MERGED_FILE} ${LLVM_PROFILE_DIRECTORY_ROOT}
+
+echo "LLVM PGO statistics"
+du -sh ${LLVM_PROFILE_MERGED_FILE}
+du -sh ${LLVM_PROFILE_DIRECTORY_ROOT}
+echo "Profile file count"
+find ${LLVM_PROFILE_DIRECTORY_ROOT} -type f | wc -l
# Rustbuild currently doesn't support rebuilding LLVM when PGO options
# change (or any other llvm-related options); so just clear out the relevant
# Okay, LLVM profiling is done, switch to rustc PGO.
+# The path has to be absolute
+RUSTC_PROFILE_DIRECTORY_ROOT=/tmp/rustc-pgo
+
python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \
--stage 2 library/std \
- --rust-profile-generate=/tmp/rustc-pgo
+ --rust-profile-generate=${RUSTC_PROFILE_DIRECTORY_ROOT}
# Here we're profiling the `rustc` frontend, so we also include `Check`.
# The benchmark set includes various stress tests that put the frontend under pressure.
# rustc invocation ends. Empirically, this can result in some profiling data being lost.
# That's why we override the profile path to include the PID. This will produce many more profiling
# files, but the resulting profile will produce a slightly faster rustc binary.
-LLVM_PROFILE_FILE=/tmp/rustc-pgo/default_%m_%p.profraw gather_profiles "Check,Debug,Opt" "All" \
-"externs,ctfe-stress-5,cargo-0.60.0,token-stream-stress,match-stress,tuple-stress,diesel-1.4.8,bitmaps-3.1.0"
+LLVM_PROFILE_FILE=${RUSTC_PROFILE_DIRECTORY_ROOT}/default_%m_%p.profraw gather_profiles \
+ "Check,Debug,Opt" "All" \
+ "externs,ctfe-stress-5,cargo-0.60.0,token-stream-stress,match-stress,tuple-stress,diesel-1.4.8,bitmaps-3.1.0"
+
+RUSTC_PROFILE_MERGED_FILE=/tmp/rustc-pgo.profdata
# Merge the profile data we gathered
./build/$PGO_HOST/llvm/bin/llvm-profdata \
- merge -o /tmp/rustc-pgo.profdata /tmp/rustc-pgo
+ merge -o ${RUSTC_PROFILE_MERGED_FILE} ${RUSTC_PROFILE_DIRECTORY_ROOT}
+
+echo "Rustc PGO statistics"
+du -sh ${RUSTC_PROFILE_MERGED_FILE}
+du -sh ${RUSTC_PROFILE_DIRECTORY_ROOT}
+echo "Profile file count"
+find ${RUSTC_PROFILE_DIRECTORY_ROOT} -type f | wc -l
# Rustbuild currently doesn't support rebuilding LLVM when PGO options
# change (or any other llvm-related options); so just clear out the relevant
# This produces the actual final set of artifacts, using both the LLVM and rustc
# collected profiling data.
$@ \
- --rust-profile-use=/tmp/rustc-pgo.profdata \
- --llvm-profile-use=/tmp/llvm-pgo.profdata
+ --rust-profile-use=${RUSTC_PROFILE_MERGED_FILE} \
+ --llvm-profile-use=${LLVM_PROFILE_MERGED_FILE}