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History / Earth Moon Performance Investigation

Revisions

  • Cross-link Earth-Moon investigation page to filed issues #464, #465, #466

    Test User committed May 11, 2026
  • Add Earth–Moon Performance Investigation page First-cut perf report from the #447 toolkit (landed in PR #462). Captures Phase A baselines (perf-runner + criterion + pprof flamegraphs + tier3 wall-clock), Phase B per-phase drilldown, Phase C candidate inventory (C1..C8 with ROI estimates). Target: halve the tier3 earth_moon_clem runtime — 17 min → ≤8.5 min, 83 µs/step → ≤40 µs/step. Top-3 candidates: C5 (per-step Epoch cache), C1+C2 (flat-storage SH coefficients + Gottlieb helpers), C3 (hoist vector3_transform out of the kernel). Cumulative bit-identical estimate is 20-35% step-time reduction; reaching the 2× target needs either C8 (RK4 sub-stage reuse, bit-identity-risky) or an algorithmic change to the Gottlieb recursion.

    Test User committed May 11, 2026