Successfully identified regression in *llvm* in CI configuration
tcwg_bmk_llvm_tk1/llvm-release-arm-spec2k6-O3. So far, this commit has
regressed CI configurations:
- tcwg_bmk_llvm_tk1/llvm-release-arm-spec2k6-O3
Culprit:
<cut>
commit e771614bae0a05585f720812d5936a0b81dcddf0
Author: David Green <david.gr...@arm.com>
Date: Thu Feb 11 11:58:55 2021 +0000
[ARM] Change getScalarizationOverhead overload used in gather costs. NFC
This changes which of the getScalarizationOverhead overloads is used in
the gather/scatter cost to use the base variant directly, not relying on
the version using heuristics on the number of args with no args
provided. It should still produce the same costs for scalarized
gathers/scatters.
</cut>
Results regressed to (for first_bad == e771614bae0a05585f720812d5936a0b81dcddf0)
# reset_artifacts:
-10
# build_abe binutils:
-9
# build_abe stage1 -- --set gcc_override_configure=--with-mode=arm --set
gcc_override_configure=--disable-libsanitizer:
-8
# build_abe linux:
-7
# build_abe glibc:
-6
# build_abe stage2 -- --set gcc_override_configure=--with-mode=arm --set
gcc_override_configure=--disable-libsanitizer:
-5
# build_llvm true:
-3
# true:
0
# benchmark -- -O3_marm
artifacts/build-e771614bae0a05585f720812d5936a0b81dcddf0/results_id:
1
# 445.gobmk,[.] fastlib regressed by 115
from (for last_good == a31eae840525e9292a3a42c1fdac3fc594f42949)
# reset_artifacts:
-10
# build_abe binutils:
-9
# build_abe stage1 -- --set gcc_override_configure=--with-mode=arm --set
gcc_override_configure=--disable-libsanitizer:
-8
# build_abe linux:
-7
# build_abe glibc:
-6
# build_abe stage2 -- --set gcc_override_configure=--with-mode=arm --set
gcc_override_configure=--disable-libsanitizer:
-5
# build_llvm true:
-3
# true:
0
# benchmark -- -O3_marm
artifacts/build-a31eae840525e9292a3a42c1fdac3fc594f42949/results_id:
1
Artifacts of last_good build:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/artifact/artifacts/build-a31eae840525e9292a3a42c1fdac3fc594f42949/
Results ID of last_good:
tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-release-arm-spec2k6-O3/3644
Artifacts of first_bad build:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/artifact/artifacts/build-e771614bae0a05585f720812d5936a0b81dcddf0/
Results ID of first_bad:
tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-release-arm-spec2k6-O3/3642
Build top page/logs:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/
Configuration details:
Reproduce builds:
<cut>
mkdir investigate-llvm-e771614bae0a05585f720812d5936a0b81dcddf0
cd investigate-llvm-e771614bae0a05585f720812d5936a0b81dcddf0
git clone https://git.linaro.org/toolchain/jenkins-scripts
mkdir -p artifacts/manifests
curl -o artifacts/manifests/build-baseline.sh
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/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_tk1-llvm-release-arm-spec2k6-O3/8/artifact/artifacts/manifests/build-parameters.sh
--fail
curl -o artifacts/test.sh
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/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 e771614bae0a05585f720812d5936a0b81dcddf0
../artifacts/test.sh
# Reproduce last_good build
git checkout --detach a31eae840525e9292a3a42c1fdac3fc594f42949
../artifacts/test.sh
cd ..
</cut>
History of pending regressions and results:
https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/ci/tcwg_bmk_llvm_tk1/llvm-release-arm-spec2k6-O3
Artifacts:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/artifact/artifacts/
Build log:
https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-release-arm-spec2k6-O3/8/consoleText
Full commit (up to 1000 lines):
<cut>
commit e771614bae0a05585f720812d5936a0b81dcddf0
Author: David Green <david.gr...@arm.com>
Date: Thu Feb 11 11:58:55 2021 +0000
[ARM] Change getScalarizationOverhead overload used in gather costs. NFC
This changes which of the getScalarizationOverhead overloads is used in
the gather/scatter cost to use the base variant directly, not relying on
the version using heuristics on the number of args with no args
provided. It should still produce the same costs for scalarized
gathers/scatters.
---
llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
index af67839c2d75..de2c0607d2ed 100644
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -1416,8 +1416,9 @@ unsigned ARMTTIImpl::getGatherScatterOpCost(unsigned
Opcode, Type *DataTy,
unsigned VectorCost = NumElems * LT.first * ST->getMVEVectorCostFactor();
// The scalarization cost should be a lot higher. We use the number of vector
// elements plus the scalarization overhead.
- unsigned ScalarCost =
- NumElems * LT.first + BaseT::getScalarizationOverhead(VTy, {});
+ unsigned ScalarCost = NumElems * LT.first +
+ BaseT::getScalarizationOverhead(VTy, true, false) +
+ BaseT::getScalarizationOverhead(VTy, false, true);
if (EltSize < 8 || Alignment < EltSize / 8)
return ScalarCost;
</cut>
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