After llvm commit 669ddd1e9b1226432b003dbba05b99f8e992285b
Author: Arthur Eubanks <aeuba...@google.com>
Turn on the new pass manager by default
the following benchmarks grew in size by more than 1%:
- 403.gcc grew in size by 2% from 2586180 to 2648252 bytes
Below reproducer instructions can be used to re-build both "first_bad" and
"last_good" cross-toolchains used in this bisection. Naturally, the scripts
will fail when triggerring benchmarking jobs if you don't have access to Linaro
TCWG CI.
For your convenience, we have uploaded tarballs with pre-processed source and
assembly files at:
- First_bad save-temps:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-669ddd1e9b1226432b003dbba05b99f8e992285b/save-temps/
- Last_good save-temps:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-b15cbaf5a03d0b32dbc32c37766e32ccf66e6c87/save-temps/
- Baseline save-temps:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-baseline/save-temps/
Configuration:
- Benchmark: SPEC CPU2006
- Toolchain: Clang + Glibc + LLVM Linker
- Version: all components were built from their latest release branch
- Target: aarch64-linux-gnu
- Compiler flags: -Os -flto
- Hardware: APM Mustang 8x X-Gene1
This benchmarking CI is work-in-progress, and we welcome feedback and
suggestions at linaro-toolchain@lists.linaro.org . In our improvement plans is
to add support for SPEC CPU2017 benchmarks and provide "perf report/annotate"
data behind these reports.
THIS IS THE END OF INTERESTING STUFF. BELOW ARE LINKS TO BUILDS, REPRODUCTION
INSTRUCTIONS, AND THE RAW COMMIT.
This commit has regressed these CI configurations:
- tcwg_bmk_llvm_apm/llvm-release-aarch64-spec2k6-Os_LTO
First_bad build:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-669ddd1e9b1226432b003dbba05b99f8e992285b/
Last_good build:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-b15cbaf5a03d0b32dbc32c37766e32ccf66e6c87/
Baseline build:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/build-baseline/
Even more details:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/
Reproduce builds:
<cut>
mkdir investigate-llvm-669ddd1e9b1226432b003dbba05b99f8e992285b
cd investigate-llvm-669ddd1e9b1226432b003dbba05b99f8e992285b
# Fetch scripts
git clone https://git.linaro.org/toolchain/jenkins-scripts
# Fetch manifests and test.sh script
mkdir -p artifacts/manifests
curl -o artifacts/manifests/build-baseline.sh
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/manifests/build-baseline.sh
--fail
curl -o artifacts/manifests/build-parameters.sh
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/manifests/build-parameters.sh
--fail
curl -o artifacts/test.sh
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_apm-llvm-release-aarch64-spec2k6-Os_LTO/7/artifact/artifacts/test.sh
--fail
chmod +x artifacts/test.sh
# Reproduce the baseline build (build all pre-requisites)
./jenkins-scripts/tcwg_bmk-build.sh @@ artifacts/manifests/build-baseline.sh
# Save baseline build state (which is then restored in artifacts/test.sh)
mkdir -p ./bisect
rsync -a --del --delete-excluded --exclude /bisect/ --exclude /artifacts/
--exclude /llvm/ ./ ./bisect/baseline/
cd llvm
# Reproduce first_bad build
git checkout --detach 669ddd1e9b1226432b003dbba05b99f8e992285b
../artifacts/test.sh
# Reproduce last_good build
git checkout --detach b15cbaf5a03d0b32dbc32c37766e32ccf66e6c87
../artifacts/test.sh
cd ..
</cut>
Full commit (up to 1000 lines):
<cut>
commit 669ddd1e9b1226432b003dbba05b99f8e992285b
Author: Arthur Eubanks <aeuba...@google.com>
Date: Mon Jan 25 11:00:56 2021 -0800
Turn on the new pass manager by default
This turns on the new pass manager by default for the optimization pipeline
in
Clang and ThinLTO in various LLD backends. This also makes uses of `opt
-instcombine` use the new pass manager (unless specifically opted out).
This does not affect the backend target-dependent codegen pipeline.
If this causes regressions, you can opt out of the new pass manager
either via the -DENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=OFF CMake flag
while building LLVM, or via various compiler flags, e.g.
-flegacy-pass-manager for Clang or -Wl,--lto-legacy-pass-manager for
ELF LLD. Please file bugs for any regressions.
Major differences:
* The inliner works slightly differently
* -O1 does some amount of inlining
* LCSSA and LoopSimplify are run before all loop passes
* Loop unswitching is implemented slightly differently
* A new SpeculateAroundPHIs pass is added to the pipeline
https://lists.llvm.org/pipermail/llvm-dev/2021-January/148098.html
Reviewed By: asbirlea, ychen, MaskRay, echristo
Differential Revision: https://reviews.llvm.org/D95380
---
llvm/CMakeLists.txt | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 1affc289e64b..f5298de9f7ca 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -688,8 +688,8 @@ else()
endif()
option(LLVM_ENABLE_PLUGINS "Enable plugin support"
${LLVM_ENABLE_PLUGINS_default})
-set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER FALSE CACHE BOOL
- "Enable the experimental new pass manager by default.")
+set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER TRUE CACHE BOOL
+ "Enable the new pass manager by default.")
include(HandleLLVMOptions)
</cut>
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