Disable aggressive compiler optimizations for VecGeom

[hahnjo]

It seems that gcc10 miscompiles (some of) the VecGeom code at -O3. In my tests, switching back to -O2 fixes the crashes. More details and discussion if that is indeed a compiler problem or an issue in the code in https://sft.its.cern.ch/jira/projects/VECGEOM/issues/VECGEOM-600

[cmsbuild]

A new Pull Request was created by @hahnjo (Jonas Hahnfeld) for branch IB/CMSSW_12_5_X/geant4_vecgeom.

@cmsbuild, @smuzaffar, @aandvalenzuela, @iarspider can you please review it and eventually sign? Thanks.
@perrotta, @dpiparo, @qliphy, @rappoccio you are the release manager for this.
cms-bot commands are listed here

[iarspider]

please test

…

On Sat, Jul 9, 2022, 13:44 cmsbuild ***@***.***> wrote: A new Pull Request was created by @hahnjo <https://github.com/hahnjo> (Jonas Hahnfeld) for branch IB/CMSSW_12_5_X/geant4_vecgeom. @cmsbuild <https://github.com/cmsbuild>, @smuzaffar <https://github.com/smuzaffar>, @aandvalenzuela <https://github.com/aandvalenzuela>, @iarspider <https://github.com/iarspider> can you please review it and eventually sign? Thanks. @perrotta <https://github.com/perrotta>, @dpiparo <https://github.com/dpiparo>, @qliphy <https://github.com/qliphy>, @rappoccio <https://github.com/rappoccio> you are the release manager for this. cms-bot commands are listed here <http://cms-sw.github.io/cms-bot-cmssw-cmds.html> — Reply to this email directly, view it on GitHub <#7987 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAE3NOVLPE7KU7OQWO2I5TLVTFQ2TANCNFSM53DIJAWA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[hahnjo]

A quick update on some further investigations: The crashes are exposed by a change that landed for VecGeom 1.1.19, but the miscompilation can also be reproduced with earlier versions when using gcc10. So this change is probably also a candidate for application to production releases...

[iarspider]

please test for CMSSW_12_5_G4VECGEOM_X/el8_amd64_gcc10

[smuzaffar]

thanks @hahnjo , #7992 include this change for productions releases

[cmsbuild]

-1

Failed Tests: RelVals
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9357ea/26119/summary.html
COMMIT: 08a6186
CMSSW: CMSSW_12_5_G4VECGEOM_X_2022-07-07-2300/el8_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7987/26119/install.sh to create a dev area with all the needed externals and cmssw changes.

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• @fwyzard Update hwloc to version 2.8.0 #7979
• @fwyzard Update alpaka to the devel branch as of 2022.06.21 #7986

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9357ea/26119/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9357ea/26119/git-merge-result

RelVals

• 23234.023234.0_TTbar_14TeV+2026D49+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal/step1_TTbar_14TeV+2026D49+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal.log
• 28234.028234.0_TTbar_14TeV+2026D60+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal/step1_TTbar_14TeV+2026D60+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal.log
• 35034.035034.0_TTbar_14TeV+2026D77+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal/step1_TTbar_14TeV+2026D77+TTbar_14TeV_TuneCP5_GenSimHLBeamSpot14+DigiTrigger+RecoGlobal+HARVESTGlobal.log