perf: std::sqrt over std::hypot in Core

[andiwand]

Replace std::hypot with std::sqrt in a couple of occasions in Core. This is numerically less accurate but much faster which is preferable for seeding and propagation.

blocked by

• refactor: Remove quick math helpers #3701

---

This pull request focuses on optimizing mathematical calculations by replacing std::hypot with more efficient alternatives like std::sqrt and Eigen's norm method. These changes aim to improve performance and maintain code consistency across various files.

Mathematical Optimization:

• Core/include/Acts/EventData/GenericFreeTrackParameters.hpp: Replaced std::hypot with std::sqrt for calculating transverseMagnitude and magnitude.
• Core/include/Acts/Propagator/EigenStepperDenseExtension.hpp: Replaced multiple instances of std::hypot with std::sqrt for various calculations, including tKi, dtp1dl, dtp2dl, dtp3dl, dtp4dl, and energy. [1] [2] [3] [4] [5] [6]
• Core/include/Acts/Propagator/StraightLineStepper.hpp: Replaced std::hypot with std::sqrt for calculating dtds and prop_state.stepping.derivative. [1] [2]
• Core/include/Acts/Seeding/EstimateTrackParamsFromSeed.hpp: Replaced std::hypot with std::sqrt for calculating invTanTheta and qOverPt. [1] [2]
• Core/include/Acts/Utilities/VectorHelpers.hpp: Replaced std::hypot with Eigen's norm method for calculating the perpendicular distance.

Additional changes include similar optimizations in other files to ensure consistency and performance improvements across the codebase.

[github-actions]

📊: Physics performance monitoring for 48367a2

Full contents

physmon summary

• ✅ Particles fatras
• ✅ Particles geant4
• ✅ Particles ttbar
• ✅ Vertices ttbar
• ✅ Truth tracking (KF)
• ✅ Truth tracking (GSF)
• ✅ Truth tracking (GX2F)
• ✅ CKF | trackfinding | single muon | truth smeared seeding
• ✅ Track Summary CKF | trackfinding | single muon | truth smeared seeding
• ✅ Seeding trackfinding | single muon | truth estimated seeding
• ✅ CKF | trackfinding | single muon | truth estimated seeding
• ✅ Track Summary CKF | trackfinding | single muon | truth estimated seeding
• ✅ Seeding trackfinding | single muon | default seeding
• ✅ CKF | trackfinding | single muon | default seeding
• ✅ Track Summary CKF | trackfinding | single muon | default seeding
• ✅ Seeding trackfinding | single muon | orthogonal seeding
• ✅ CKF | trackfinding | single muon | orthogonal seeding
• ✅ Track Summary CKF | trackfinding | single muon | orthogonal seeding
• ✅ Seeding trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Track Summary CKF | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Ambisolver | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ IVF notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF gauss notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF grid time | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Seeding trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Track Summary CKF | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Ambisolver | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF gauss notime | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF grid time | trackfinding | ttbar with 200 pileup | default seeding

[paulgessinger]

Sounds good. Did you measure this by any chance?

[andiwand]

seems to give a 3% speedup on the seeding

[acts-project-service]

🔴 Athena integration test results [0fa82af]

🔴 Some tests have failed!

Please investigate the pipeline!

status	job	report
🟢	report_pull_request
🟢	run_art_test: test_data18_13TeV_1000evt
🟢	run_art_test: test_ttbarPU40_reco
🟢	run_workflow_tests_run4_mc
🟢	run_workflow_tests_run2_mc
🟢	run_workflow_tests_run2_data
🟢	run_workflow_tests_run3_mc
🟢	run_workflow_tests_run3_data
🟢	test_ActsDumpGeometryIdentifiers
🟢	test_ActsCheckObjectCountsCachedWorkflow
🟢	test_ActsCheckObjectCountsWorkflow
🔴	test_ActsEFTrackFit
🟢	test_ActsPersistifySeeds
🟢	test_ActsBenchmarkWithSpot
🟢	test_ActsAnalogueClustering
🔴	test_ActsWorkflowHeavyIons
🟢	test_ActsWorkflowFastTracking
🔴	test_ActsWorkflowCached
🟢	test_ActsWorkflow
🟢	test_ActsValidateAmbiguityResolution
🟢	test_ActsValidateResolvedTracks
🟢	test_ActsValidateTracks
🟢	test_ActsValidateActsCoreSpacePoints
🔴	test_ActsValidateActsSpacePoints
🟢	test_ActsValidateSeeds
🟢	test_ActsValidateOrthogonalSeeds
🟢	test_ActsValidateClusters
🟢	test_ActsPersistifyEDM
🟢	test_ActsGSFRefitting
🟢	test_ActsKfRefitting
🟢	test_ActsExtrapolationAlgTest
🟢	test_ActsITkTest
🟢	run_unit_tests

[asalzburger]

I think that should go in.

[andiwand]

Just kicked off one more Athena CI run but the failure above seems unrelated

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
84.9% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud