Rotation prediction enumerated the whole (2h+1)(2k+1)(2l+1) box every frame and kept the ~1% whose
rotation solution lands near the frame. A solution within phi_limit of the frame needs
|f| = ||p0|^2 + 2 S0.p0| <= 2 |S0_perp| |p0| phi_limit, and along an (h, k) column f is a quadratic
in l, so the l that can pass are at most two intervals. Those are walked - widened by 1% in f and by
a whole index at each end - in the same order and with the same arithmetic; the rest the phi test
rejected anyway. Without a phi limit (min_zeta 0) the whole column is walked as before. The GPU
kernel is unchanged.
A new test predicts 1000 random lattices, geometries, axes and rocking widths both ways and
requires the same reflections in the same order, every value bit for bit (30000 cases passed once
locally). CPU build, two interleaved warm runs: 8a1a output loop 241.5 -> 216.3 s, pre-pass loop
90.7 -> 73.8 s, whole run 427.0 -> 384.2 s; 8qaw (with the gzip change before this) loops
116.6 / 251.3 -> 94.4 / 206.8 s, user CPU 14700 -> 12718 s. GPU build within noise.
p.mtz byte-identical on myob, cytc, thau, kdp, 8a1a and 8qaw, GPU and CPU builds.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SVmAWnzCmRKAXVUCdc4iNi
leonarski_fandClaude Opus 5.5
35f42e7334