Exact speed-ups of the per-pass geometry post-refinement; outputs are byte-identical.
Joint fit: the distance-held solve starts from nominal and reads nothing the free solve
produces, so it now runs on its own thread (std::async) beside the free solve and its
covariance, and is used only where the free fit converged, as before. Each solve has its own
copy of the tilt block and one shared, non-owned CauchyLoss instead of one per residual. The
covariance's Jacobian evaluation is threaded (Covariance::Options::num_threads): each residual
block writes its own rows, so the values do not depend on the thread count.
Rotation scale: the all-data fit and the five leave-a-fifth-out folds differ only in which of
the five per-fifth sums they add, so their golden-section searches are stepped together, one
event sweep per step for all of them, and fits whose brackets still coincide share the point.
Each fit takes the same steps on the same sums as before: cost_grid's per-(k, fifth) sums are
bit-identical whatever k it is handed alongside. About 23 event sweeps instead of ~140.
Measured per pass (rc173 baseline -> this, GPU build, box shared with other jobs; post-refine
log timestamps, joint fit / rotation-scale fit):
lyso 0.36 / 0.28 s -> 0.28 / 0.19 s
cytc 0.42 / 0.35 s -> 0.36 / 0.22 s
myob 0.29 / 0.04 s -> 0.23 / 0.04 s
sparse 0.20 / 0.06 s -> 0.14 / 0.07 s
p.hkl, p.mtz, p_P1.mtz, p_unmerged.mtz byte-identical to the rc173 outputs on GPU myob, cytc,
lyso, sparse and CPU-only cytc, and the logged post-refinement lines (geometry, residuals, k)
identical.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C
leonarski_fandClaude Opus 5.5
7e83da0722