iteration commit status primary_metric_name primary_metric_value description 0 e7c0ed95a333 baseline weighted_median_neigh_seconds 0.36158 baseline 1 2d1eda35b944 rejected weighted_median_neigh_seconds 0.47712 Split the orthogonal half-bin/newton self-bin traversal in `npair_bin.cpp` and cache per-atom cutoff/special-bond lookups to reduce repeated hot-path branches and memory accesses [Correctness held, but the `src/npair_bin.cpp` refactor regressed `weighted_median_neigh_seconds` from 0.36158 to 0.47712 (+31.95%), so the incumbent stays.] 2 32b495fdb66b accepted weighted_median_neigh_seconds 0.33535 Specialize the orthogonal half/bin/newton neighbor build in `src/npair_bin.cpp` to remove generic branches and hoist per-atom special-bond/cutoff setup out of the innermost loop [Correctness held with zero failures, and the targeted `src/npair_bin.cpp` hot-path specialization improved `weighted_median_neigh_seconds` from 0.36158 to 0.33535 (-7.25%), so the candidate becomes the new incumbent.] 3 380bf2b0146b accepted weighted_median_neigh_seconds 0.32842 Add a benchmark-specific fast path in `NPairBin<1,1,0,0,0>::build()` for standard molecular systems without neighbor exclusions, removing repeated `special_i` setup and `exclude` checks from the hot orthogonal half/bin/newton loops. [Candidate improves weighted_median_neigh_seconds from 0.33535 to 0.32842 with correctness intact, so it becomes the new incumbent.] 4 3bd7cbc7ee03 rejected weighted_median_neigh_seconds 0.32287 Skip `find_special()` and `minimum_image_check()` for different-molecule pairs inside the incumbent `NPairBin<1,1,0,0,0>::build()` molecular/no-exclusion fast path, keeping same-molecule pairs on the original special-neighbor handling. [Correctness held and weighted_median_neigh_seconds improved to 0.32287, but the -1.69% gain versus incumbent missed the benchmark contract’s 2.0% minimum improvement threshold, so 380bf2b0146b remains incumbent.] 5 1a1935b59c00 rejected weighted_median_neigh_seconds 0.32384 Add a `maxspecial <= 2` molecular/no-exclusion fast path in `NPairBin<1,1,0,0,0>::build()` that bypasses generic `find_special()` scans for different-molecule pairs and uses direct same-molecule special-tag matching. [Correctness held and weighted_median_neigh_seconds improved to 0.32384, but the 1.39% gain versus incumbent 380bf2b0146b missed the benchmark contract’s 2.0% minimum improvement threshold.] 6 c4128d3970b2 accepted weighted_median_neigh_seconds 0.31969 Refine the incumbent `NPairBin<1,1,0,0,0>::build()` fast path by early-accepting different-molecule pairs and skipping `minimum_image_check()` for owned same-molecule specials when `special_flag[1..3] == 2`. [Correctness held and weighted_median_neigh_seconds improved from 0.32842 to 0.31969 (-2.66% vs incumbent), clearing the benchmark contract’s 2.0% promotion gate.] 7 d89e6f820474 rejected weighted_median_neigh_seconds 0.32426 Replace the remaining same-molecule `find_special()` scan in the incumbent `NPairBin<1,1,0,0,0>::build()` fast path with direct two-entry encoded-special tag checks when `nspecial[i][2] <= 2`, preserving the incumbent different-molecule early accept and ghost minimum-image fallback. [Correctness held, but the candidate regressed weighted_median_neigh_seconds from 0.31969 to 0.32426 (+1.43% vs incumbent), so c4128d3970b2 remains incumbent.] 8 d381c38751ec rejected weighted_median_neigh_seconds 0.33329 Split the benchmark-hot molecular/no-exclusion neighbor build into encoded-special and generic variants in `src/npair_bin.cpp`, using an encoded-only special lookup and special-hit-first branch order to cut residual same-molecule hot-loop branching. [Correctness held, but splitting the same-molecule fast path into encoded-special and generic variants regressed weighted_median_neigh_seconds from 0.31969 to 0.33329 (+4.25%), so c4128d3970b2 remains incumbent.] 9 2894990122f9 rejected weighted_median_neigh_seconds 0.3187 Cache per-neighbor ownership/tag/molecule values and use an encoded-only special lookup inside the incumbent molecular/no-exclusion half/bin/newton fast path in `src/npair_bin.cpp` [Correctness held, but 0.31870 improves on incumbent 0.31969 by only 0.31%, below the 2.0% promotion threshold.] 10 b21ee6319e89 rejected weighted_median_neigh_seconds 0.3221 Split the incumbent molecular/no-exclusion self-bin walk in `NPairBin<1,1,0,0,0>::build()` into owned and ghost tails so owned self-bin neighbors avoid repeated ghost-order checks while the accepted stencil path stays unchanged. [Correctness held, but weighted_median_neigh_seconds regressed from 0.31969 to 0.32210 (+0.75% vs incumbent), so the candidate cannot replace the incumbent or clear the 2.0% promotion gate.] 11 8c29b124a2c6 accepted weighted_median_neigh_seconds 0.3115 Use contiguous `_noalias` aliases for hot coordinate/type/tag/molecule arrays in the incumbent `NPairBin<1,1,0,0,0>::build()` path [Correctness held and the candidate cut weighted_median_neigh_seconds from 0.31969 to 0.31150 (-2.56% vs incumbent), clearing the 2.0% promotion gate.] 12 e5d6d4548fe4 rejected weighted_median_neigh_seconds 0.31003 Extend the incumbent `NPairBin<1,1,0,0,0>::build()` hot path with additional neighbor-array aliasing, one-time neighbor coordinate/tag/molecule caching, and cached half-box minimum-image checks [Correctness held and weighted_median_neigh_seconds improved to 0.31003, but the -0.47% gain versus incumbent missed the benchmark contract’s 2.0% promotion threshold.] 13 7adf3bfc72a8 rejected weighted_median_neigh_seconds 0.31711 Replace the incumbent molecular/no-exclusion `NPairBin<1,1,0,0,0>::build()` special handling with a direct encoded-two-special tag lookup path when `nspecial[i][2] <= 2`, bypassing the hot `molecule[j]`/`find_special()` path for non-matching neighbors while preserving the incumbent fallback and ghost minimum-image behavior. [Correctness held, but the candidate regressed weighted_median_neigh_seconds from 0.31150 to 0.31711 (+1.80% vs incumbent), so 8c29b124a2c68bbc7efea2fbd01f26b5ad40288a remains incumbent.] 14 e536920bfbe5 rejected weighted_median_neigh_seconds 0.30666 Add explicit `jnext` traversal and light next-neighbor coordinate prefetching to the incumbent `NPairBin<1,1,0,0,0>::build()` hot path, alongside local `_noalias` aliases for bin traversal arrays, while preserving the accepted single-path molecular/no-exclusion logic. [Correct and faster at 0.30666 neigh seconds, but the 1.55% gain versus incumbent 8c29b124a2c68bbc7efea2fbd01f26b5ad40288a misses the 2.0% promotion gate.] 15 e5eef089d2d0 rejected weighted_median_neigh_seconds 0.30618 Combine explicit jnext traversal and next-neighbor coordinate prefetching with cached periodic half-box checks, bin-array noalias aliases, and per-neighbor coordinate/tag/molecule caching in the incumbent NPairBin<1,1,0,0,0> hot path [Correctness held and weighted_median_neigh_seconds improved to 0.30618, but the 1.71% gain versus incumbent missed the benchmark contract’s 2.0% promotion threshold.] 16 d5b0238dc967 rejected weighted_median_neigh_seconds 0.30551 Refine the single-path molecular half/bin/newton builder in src/npair_bin.cpp with explicit jnext traversal, x-only next-neighbor prefetch, cached half-box minimum-image checks, bin/list _noalias aliases, and delayed generic-only setup after the fast-path return [Correctness held and weighted_median_neigh_seconds improved to 0.30551, but the 1.92% gain versus incumbent missed the 2.0% promotion threshold.] 17 4a9dda87cf45 rejected weighted_median_neigh_seconds 0.30695 Combine iteration-16 style `NPairBin<1,1,0,0,0>` jnext/prefetch/half-box fast-path refinements with contiguous `Neighbor` `xhold` copy and `check_distance()` alias cleanup [Correctness passed and weighted_median_neigh_seconds improved to 0.30695, but the 1.46% gain versus incumbent missed the benchmark contract’s 2.0% promotion threshold.] 18 08f5ab4a4e02 accepted weighted_median_neigh_seconds 0.29094 Use explicit `jnext` linked-list traversal with bin/list `_noalias` aliases and delayed generic-only setup in the incumbent `NPairBin<1,1,0,0,0>` fast path [Correctness passed and weighted_median_neigh_seconds dropped from 0.31150 to 0.29094 (-6.60% vs incumbent), comfortably clearing the 2.0% promotion gate.] 19 11db74893452 accepted weighted_median_neigh_seconds 0.28487 Optimize Neighbor movement tracking by scanning contiguous x/xhold arrays in check_distance() and bulk-copying xhold in build() while keeping the incumbent npair_bin fast path unchanged [Correctness held and weighted_median_neigh_seconds improved from 0.29094 to 0.28487 (-2.09% vs incumbent), clearing the 2.0% promotion gate.] 20 11db74893452 worker_incomplete weighted_median_neigh_seconds nan optimize iteration 20 [worker loop did not finish cleanly: incomplete_max_iterations] 21 e35c58b86e07 rejected weighted_median_neigh_seconds 0.28995 Widen Neighbor::check_distance() to 8-atom unrolled blocks and compare one blockwise max displacement squared against deltasq, keeping the incumbent semantics while reducing hot-loop branch frequency [Correctness held, but weighted_median_neigh_seconds regressed from 0.28487 to 0.28995 (+1.78% vs incumbent), so 11db74893452 remains incumbent.] 22 708f9b2d16b1 rejected weighted_median_neigh_seconds 0.28503 Specialize the incumbent `NPairBin<1,1,0,0,0>::build()` fast path for all-zero special-bond weights so same-molecule pairs use a cheaper boolean special-neighbor membership test while preserving the existing different-molecule accept path and periodic-image ghost handling. [Correctness held, but the all-zero special-neighbor fast path slightly regressed `weighted_median_neigh_seconds` from 0.28487 to 0.28503, so incumbent `11db748934527306a5e9d2d8c0c51eb47b03158a` stays.] 23 a3f1052997d8 rejected weighted_median_neigh_seconds 0.28469 Add a runtime uniform-cutoff fast path to the specialized `NPairBin<1,1,0,0,0>` molecular/no-exclusion builder so equal-cutoff systems skip per-pair `type[j]` and cutoff-matrix loads, while retaining the local Neighbor cadence cleanups that compiled and smoked correctly. [Correctness held, but the candidate’s 0.06% improvement to 0.28469 `weighted_median_neigh_seconds` is far below the 2.0% promotion threshold, so incumbent `11db74893452` stays.] 24 84babbbb36e3 rejected weighted_median_neigh_seconds 0.49372 Add an axis-aligned early reject in the specialized `NPairBin<1,1,0,0,0>` fast path so pairs exceeding `neighbor->cuttype[itype]` on any single coordinate skip the `type[j]` load and full squared-distance check. [Correctness held, but the axis-aligned early-reject path regressed weighted_median_neigh_seconds from 0.28487 to 0.49372 (+73.31% vs incumbent), so the incumbent stays.] 25 b78acabc90a5 rejected weighted_median_neigh_seconds 0.28592 Isolate the iteration-23 Neighbor cadence fast-check by caching the benchmark-common every=1/delay=0/dist_check=yes no-box path in Neighbor::decide()/check_distance() without any accompanying npair_bin specialization [Correctness held, but the isolated Neighbor cadence-cache path regressed weighted_median_neigh_seconds versus incumbent and missed the 2.0% promotion gate.] 26 ba18979d7807 rejected weighted_median_neigh_seconds 0.28444 Add a benchmark-common `NPairBin<1,1,0,0,0>` fast path for the uniform-cutoff plus all-special-encoded case, using encoded-special lookup and pointer-style neighbor writes to remove generic cutoff and special-flag work from the hot loop. [Correctness passed, but the candidate’s weighted_median_neigh_seconds improved only 0.15% versus incumbent, far below the 2.0% promotion threshold.] 27 321fb756a836 rejected weighted_median_neigh_seconds 0.28559 Cache j-side neighbor coords/tag/molecule once and inline orthogonal half-box minimum-image checks in the specialized NPairBin<1,1,0,0,0> molecular/no-exclusion fast path [Correctness held, but weighted_median_neigh_seconds regressed 0.25% versus incumbent and missed the 2.0% promotion gate.]