solidjs / solid / 34893262890

71%

main: 89%

push

github

bench(signals): amortize projection-root-write over 20 commits per body (#3435)

Three benchmarks share one process and one set of 20k-key fixtures, and
each body performed a single commit. V8 emits a one-off ~100k-instruction
tier-up chunk that attaches to whichever frame is running when it fires and
lands in exactly one of the three windows — at ~540k Ir per root write that
is 16-20% of a window, and it moves between windows on unrelated changes.
CodSpeed's bisection of #3431 (2026-09-14) made this exact: a change costing
~300 instructions on its own path read as -8.9% on the root write and x2.4
on the untouched nested write; a provably no-op extra call added to `next`
read as -5.5% on the root write and +22% on the untouched store setter
(537,655 → 508,044 and 513,411 → 627,428 Ir; every reactive-graph symbol
bit-identical).

Each body now runs COMMITS = 20 commits. The chunk amortizes to <1% of a
window — below the 5% gate — and the three stay per-commit comparable,
which is the parity this file guards (#3352 derive vs #3044 setter floor).
Absolute numbers re-baseline ×20.

Co-authored-by: Claude via Cursor <noreply@cursor.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

519 of 790 branches covered (65.7%)

Branch coverage included in aggregate %.

772 of 1007 relevant lines covered (76.66%)

15.08 hits per line