Do not use -Ofast in libxz

[fwyzard]

-Ofast implies -funsafe-math-optimizations, which affects the global FP state for all programs: when used at link time, it may include libraries or startup files that change the default FPU control word or other similar optimisations.

[fwyzard]

please test

[cmsbuild]

A new Pull Request was created by @fwyzard for branch IB/CMSSW_16_1_X/master.

@akritkbehera, @iarspider, @raoatifshad, @smuzaffar can you please review it and eventually sign? Thanks.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.
cms-bot commands are listed here

[cmsbuild]

cms-bot internal usage

[cmsbuild]

-1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50534/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-12-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50534/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed External Build

I found compilation warning when building: See details on the summary page.

[fwyzard]

please test

what ?

[cmsbuild]

-1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50540/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-12-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50540/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed External Build

I found compilation warning when building: See details on the summary page.

[fwyzard]

please test

[cmsbuild]

-1

Failed Tests: RelVals
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7a57f6/50591/summary.html
COMMIT: cce7e6a
CMSSW: CMSSW_16_1_X_2026-01-13-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/10273/50591/install.sh to create a dev area with all the needed externals and cmssw changes.

Failed RelVals

• 34634.999

----- Begin Fatal Exception 14-Jan-2026 03:48:58 CET-----------------------
An exception of category 'OutOfBound' occurred while
   [0] Processing  Event run: 1 lumi: 1 event: 4 stream: 0
   [1] Running path 'HLTriggerFinalPath'
   [2] Prefetching for module TriggerSummaryProducerAOD/'hltTriggerSummaryAOD'
   [3] Prefetching for module L1HPSPFTauProducer/'l1tHPSPFTauProducer'
   [4] Prefetching for module L1TPFCandMultiMerger/'l1tLayer1'
   [5] Prefetching for module L1TCorrelatorLayer1Producer/'l1tLayer1HGCal'
   [6] Calling method for module HGCalBackendLayer2Producer/'l1tHGCalBackEndLayer2Producer'
Exception Message:
TC X1 = 0.0713466 out of the seeding histogram bounds 0.076 - 0.58
----- End Fatal Exception -------------------------------------------------