From a82dad1cb2c20153325966ce4423c1659cbb876f Mon Sep 17 00:00:00 2001 From: "Moe Charm (CI)" Date: Mon, 15 Dec 2025 21:36:46 +0900 Subject: [PATCH] Update CURRENT_TASK: Phase 19-6C Complete (+1.98% GO) --- CURRENT_TASK.md | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/CURRENT_TASK.md b/CURRENT_TASK.md index f91fbd0e..082d5caf 100644 --- a/CURRENT_TASK.md +++ b/CURRENT_TASK.md @@ -80,6 +80,40 @@ **Ref**: - `docs/analysis/PHASE19_FASTLANE_INSTRUCTION_REDUCTION_6B_FREE_STATIC_ROUTE_FOR_FREE_AB_TEST_RESULTS.md` +### Phase 19-6C Duplicate tiny_route_for_class() Consolidation — ✅ GO (+1.98%) + +**Goal**: Eliminate 2-3x redundant route computations in free path +- `free_tiny_fast_hot()` line 654-661: Computed route_kind_free (SmallRouteKind) +- `free_tiny_fast_cold()` line 389-402: **RECOMPUTED** route (tiny_route_kind_t) — REDUNDANT +- `free_tiny_fast()` legacy_fallback line 894-905: **RECOMPUTED** same as cold — REDUNDANT + +**Solution**: Pass-down pattern (no function split) +- Create helper: `free_tiny_fast_compute_route_and_heap()` +- Compute route once in caller context, pass as 2 parameters +- Remove redundant computation from cold path body +- Update call sites to use helper instead of recomputing + +**A/B Test Results** (Mixed 10-run): +- Baseline (Phase 19-6B state): mean **53.49M** ops/s +- Optimized (Phase 19-6C): mean **54.55M** ops/s +- Delta: **+1.98% mean** → ✅ GO (exceeds +0.5-1.0% target) + +**Changes**: +- File: `core/front/malloc_tiny_fast.h` + - Add helper function `free_tiny_fast_compute_route_and_heap()` (lines 382-403) + - Modify `free_tiny_fast_cold()` signature to accept pre-computed route + use_tiny_heap (lines 411-412) + - Remove route computation from cold path body (was lines 416-429) + - Update call site in `free_tiny_fast_hot()` cold_path label (lines 720-722) + - Replace duplicate computation in `legacy_fallback` with helper call (line 901) + +**Key insight**: +- Instruction delta: -15-25 instructions per cold-path free (~20% of cold path overhead) +- Route computation eliminated: 1x (was computed 2-3x before) +- Parameter passing overhead: negligible (2 ints on stack) + +**Ref**: +- `docs/analysis/PHASE19_FASTLANE_INSTRUCTION_REDUCTION_6C_DUPLICATE_ROUTE_DEDUP_DESIGN.md` + --- ## 更新メモ（2025-12-15 Phase 19-3b ENV-SNAPSHOT-PASSDOWN）