The multiplicative spread of the outlier band is the weighted median of
(|ln(I/median)|, weight) pairs, one per usable full, and its sort was the bulk of
that step. SortPairsGPU sorts them on the GPU (by the second key, then stably
by the first) and leaves the sequence std::sort leaves: two pairs that compare
equal are the same two numbers. The values themselves (a logarithm) and the
running sum stay on the host.
p.mtz md5 unchanged on myob, cytc, 8a1a and 8qaw (GPU build); a Catch2 case
checks the device order against std::sort.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SVmAWnzCmRKAXVUCdc4iNi
