140's 8, box layout, written in aup with no new opcode (aup's examples/layout.aup: a subset of CSS Flexbox 1 written down first, one line, row or column, padding, gap, six justify-content, four align-items, grow and shrink with 9.7's loop, cross sizes stretched, nothing sized by content): 2,000 random trees (29,388 nodes; 7,659 items frozen at their padding by the loop) are Taffy 0.15's within 0.01 (layout_taffy, built by cargo; the worst 8.3e-5) and layout.py's bit for bit on the three paths, the paths the same; the single-pass subset first tried refused 66% of trees, so the loop came in; Taffy given min sizes equal to the padding (given 0 it floors at 0 while resolving lengths, where 9.7 floors the content box), the reference adding from the left (sum compensates since Python 3.12); module_specs in make check: 100 trees (tests/specs/layout); bars: 116 lines against Python's 54, 4,754 ns a node, Taffy's 644 (7.4x), pure Python 5,396 (Pure 1.14x faster), 1,494 instructions a node (9.7's loop 44%); four frictions; aup's rows read by position no longer copy (99,067 ns a node before); the suite table's row 8; CHECKPOINT's direction row

1 files changed, 8 insertions, 0 deletions

diff --git a/research/experiments/044-specs/2026-10-19-layout.jsonl b/research/experiments/044-specs/2026-10-19-layout.jsonl
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--- /dev/null
+++ b/research/experiments/044-specs/2026-10-19-layout.jsonl
@@ -0,0 +1,8 @@
+{"what": "check", "tool": "layout_check.py 2000", "trees": 2000, "nodes": 29388, "refused": {}, "floored": {"items": 7659, "trees": 1399}, "taffy_right": 2000, "taffy_worst": 8.33333334639974e-05, "right": {"batches": 2000, "rounds": 2000, "all": 2000}, "paths_same": true, "aup_lines": 116, "aup_brace_lines": 17, "python_lines": 54}
+{"what": "time", "tool": "layout_time.c (ROUNDS 1)", "trees": 2000, "nodes": 29388, "right": 2000, "jit": "0", "batch": "", "pure_ns_per_node": 4754.0, "instructions": 43902659, "instructions_per_node": 1493.9}
+{"what": "time", "tool": "layout_time.c (ROUNDS 1)", "trees": 2000, "nodes": 29388, "right": 2000, "jit": "0", "batch": "0", "pure_ns_per_node": 4916.5, "instructions": 43902659, "instructions_per_node": 1493.9}
+{"what": "time", "tool": "layout_time.c (ROUNDS 1)", "trees": 2000, "nodes": 29388, "right": 2000, "jit": "all", "batch": "", "pure_ns_per_node": 4751.1, "instructions": 43902659, "instructions_per_node": 1493.9}
+{"what": "time", "tool": "layout_taffy --time 3 (each tree built and laid out)", "trees": 2000, "nodes": 29388, "taffy_ns_per_node": 644.1}
+{"what": "time", "tool": "layout.py (median of seven passes)", "trees": 2000, "nodes": 29388, "python_ns_per_node": 5396.1}
+{"what": "time before", "note": "aup before e5a6209: input.rows[k] read a copy of the rows (LIST_VALUE)", "tool": "layout_time.c (ROUNDS 1)", "trees": 2000, "nodes": 29388, "paths": {"batches": 99066.7, "all": 98324.0}, "instructions_per_node": 1539.2}
+{"what": "instructions by stage", "note": "the app cut after each stage, cumulative, a node (batches)", "kids_found_and_boxes_made": 159.2, "items_lists": 488.3, "before_9_7_loop": 508.6, "after_9_7_loop": 1166.3, "whole": 1493.9}