gp-reflect-hot — measured, still hint
Status
hint. Wall-clock JSONL: gp-reflect-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug. The matcher is FieldByName, MethodByName, and reflect.New. TypeOf and ValueOf alone are not matched.
Measurement
Before calls FieldByName("A") every iteration. After reads the field. An earlier TypeOf microbench was 1.05×. A fair rerun against a saved kind was 1.31× (200000 ops), so that call was dropped. reflect.New of an int versus a stack zero was about 41× (100000 ops); that after side does not allocate.
| role | case | median_ms | ops | ratio |
|---|---|---|---|---|
| after | direct field | 0.061292 | 200000 | 1 |
| before | FieldByName every iteration | 6.220041 | 200000 | 101.482 |
go1.27.3, 2026-10-23. Warm 3, median of 9.
Name lookup is the shape that showed a cost. Default stays hint.
Unblock
Do not set the default to error from this file alone. Another input or a cold path can erase the difference. Corpus triage is still required before any default change.