Change the default optimisation level to -O3 [14.0.x]

[fwyzard]

Backport of #9183 .

[fwyzard]

backport #9183

[cmsbuild]

A new Pull Request was created by @fwyzard for branch IB/CMSSW_14_0_X/master.

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

• Backported from Change the default optimisation level to -O3 #9183

[cmsbuild]

cms-bot internal usage

[fwyzard]

cms-sw/cmssw#44931 shows a 2.4% speed up to the HLT, running with the x86-64-v3 microarch.

[fwyzard]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-b79d82/39334/summary.html
COMMIT: 8213bc7
CMSSW: CMSSW_14_0_X_2024-05-10-1100/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/9184/39334/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 102 lines to the logs
• Reco comparison results: 60 differences found in the comparisons
• DQMHistoTests: Total files compared: 48
• DQMHistoTests: Total histograms compared: 3327413
• DQMHistoTests: Total failures: 1200
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3326193
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 47 files compared)
• Checked 202 log files, 165 edm output root files, 48 DQM output files
• TriggerResults: no differences found

[fwyzard]

test parameters:

• full_cmssw = true