This is a fluke. The bisection is searching for an 8% regression in 464.h264ref and it tripped just above 2% threshold on this patch due to benchmarking noise.

-- Maxim Kuvyrkov https://www.linaro.org

On 27 Sep 2021, at 14:42, ci_notify@linaro.org wrote:

After llvm commit e8e2edd8ca88f8b0a7dba141349b2aa83284f3af Author: Erich Keane erich.keane@intel.com

Fix test from 8dd42f, capitalization in test

the following benchmarks slowed down by more than 2%:

• 464.h264ref slowed down by 3% from 10973 to 11249 perf samples
• 464.h264ref:[.] FastFullPelBlockMotionSearch slowed down by 12% from 1446 to 1619 perf samples

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_tx1-llvm-master-a...
• Last_good save-temps: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...
• Baseline save-temps: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...

Configuration:

• Benchmark: SPEC CPU2006
• Toolchain: Clang + Glibc + LLVM Linker
• Version: all components were built from their tip of trunk
• Target: aarch64-linux-gnu
• Compiler flags: -O3
• Hardware: NVidia TX1 4x Cortex-A57

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_tx1/llvm-master-aarch64-spec2k6-O3

First_bad build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Last_good build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Baseline build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Even more details: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...

Reproduce builds:

<cut> mkdir investigate-llvm-e8e2edd8ca88f8b0a7dba141349b2aa83284f3af cd investigate-llvm-e8e2edd8ca88f8b0a7dba141349b2aa83284f3af

# 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_tx1-llvm-master-a... --fail curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... --fail curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... --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 e8e2edd8ca88f8b0a7dba141349b2aa83284f3af ../artifacts/test.sh

# Reproduce last_good build git checkout --detach 77d200a546136c2855063613ff4bca1f682fb23a ../artifacts/test.sh

cd ..

</cut>

Full commit (up to 1000 lines):

<cut> commit e8e2edd8ca88f8b0a7dba141349b2aa83284f3af Author: Erich Keane <erich.keane@intel.com> Date: Fri Sep 24 10:24:17 2021 -0700

Fix test from 8dd42f, capitalization in test

clang/test/CXX/drs/dr17xx.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/test/CXX/drs/dr17xx.cpp b/clang/test/CXX/drs/dr17xx.cpp index 42303c83ae3c..c8648908ebda 100644 --- a/clang/test/CXX/drs/dr17xx.cpp +++ b/clang/test/CXX/drs/dr17xx.cpp @@ -129,7 +129,7 @@ namespace dr1778 { // dr1778: 9 namespace dr1762 { // dr1762: 14 #if __cplusplus >= 201103L float operator ""_E(const char *);

• // expected-error@+2 {{invalid suffix on literal; c++11 requires a space between literal and identifier}}

• // expected-error@+2 {{invalid suffix on literal; C++11 requires a space between literal and identifier}} // expected-warning@+1 {{user-defined literal suffixes not starting with '_' are reserved; no literal will invoke this operator}} float operator ""E(const char *);

#endif

</cut>