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71b1354d32
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Phase 10: FREE-TINY-FAST MONO LEGACY DIRECT (GO +1.89%)
Results:
- A/B test: +1.89% on Mixed (10-run, clean env)
- Baseline: 51.96M ops/s
- Optimized: 52.94M ops/s
- Improvement: +984K ops/s (+1.89%)
- C6-heavy verification: +7.86% (nonlegacy_mask works correctly, no misfires)
Strategy:
- Extend Phase 9 (C0-C3 DUALHOT) to C4-C7 LEGACY DIRECT
- Fail-Fast principle: Never misclassify MID/ULTRA/V7 as LEGACY
- nonlegacy_mask: Cached at init, hot path uses single bit operation
Success factors:
1. Performance improvement: +1.89% (1.9x GO threshold)
2. Safety verified: nonlegacy_mask prevents MID v3 misfire in C6-heavy
3. Phase 9 coexistence: C0-C3 (Phase 9) + C4-C7 (Phase 10) = full LEGACY coverage
4. Minimal overhead: Single bit operation in hot path (mask & (1u<<class))
Implementation:
- Patch 1: ENV gate box (free_tiny_fast_mono_legacy_direct_env_box.h)
- ENV: HAKMEM_FREE_TINY_FAST_MONO_LEGACY_DIRECT=0/1 (default 0)
- nonlegacy_mask cached (reuses free_policy_fast_v2_nonlegacy_mask())
- Probe window: 64 (avoid bench_profile putenv race)
- Patch 2: Early-exit in free_tiny_fast() (malloc_tiny_fast.h)
- Conditions: !nonlegacy_mask, route==LEGACY, !LARSON_FIX, done==1
- Direct call: tiny_legacy_fallback_free_base()
- Patch 3: Visibility (free_path_stats_box.h)
- mono_legacy_direct_hit counter (compile-out in release)
- Patch 4: cleanenv extension (run_mixed_10_cleanenv.sh)
- ENV leak protection
Safety verification (C6-heavy):
- OFF: 19.75M ops/s
- ON: 21.30M ops/s (+7.86%)
- nonlegacy_mask correctly excludes C6 (MID v3 active)
- Improvement from C0-C5, C7 direct path acceleration
Files modified:
- core/bench_profile.h: add to MIXED_TINYV3_C7_SAFE preset
- core/front/malloc_tiny_fast.h: early-exit insertion
- core/box/free_path_stats_box.h: counter
- core/box/free_tiny_fast_mono_legacy_direct_env_box.h: NEW (ENV gate + nonlegacy_mask)
- scripts/run_mixed_10_cleanenv.sh: ENV leak protection
Health check: PASSED (all profiles)
Promotion: Added to MIXED_TINYV3_C7_SAFE preset (default ON, opt-out)
Rollback: HAKMEM_FREE_TINY_FAST_MONO_LEGACY_DIRECT=0
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
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2025-12-14 20:09:40 +09:00 |
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871034da1f
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Phase 9: FREE-TINY-FAST MONO DUALHOT (GO +2.72%)
Results:
- A/B test: +2.72% on Mixed (10-run, clean env)
- Baseline: 48.89M ops/s
- Optimized: 50.22M ops/s
- Improvement: +1.33M ops/s (+2.72%)
- Stability: Standard deviation reduced by 60.8% (2.44M → 955K ops/s)
Strategy:
- Transplant C0-C3 "second hot" path to monolithic free_tiny_fast()
- Early-exit within monolithic (no hot/cold split)
- FastLane free now benefits from C0-C3 direct path
Success factors:
1. Performance improvement: +2.72% (2.7x GO threshold)
2. Stability improvement: 2.6x more stable (stdev 60.8% reduction)
3. Learned from Phase 7 failure:
- Phase 7: Function split (hot/cold) → NO-GO
- Phase 9: Early-exit within monolithic → GO
4. FastLane free compatibility: C0-C3 direct path now works with FastLane
5. Policy snapshot overhead reduction: C0-C3 (48% of Mixed) skip route lookup
Implementation:
- Patch 1: ENV gate box (free_tiny_fast_mono_dualhot_env_box.h)
- ENV: HAKMEM_FREE_TINY_FAST_MONO_DUALHOT=0/1 (default 0)
- Probe window: 64 (avoid bench_profile putenv race)
- Patch 2: Early-exit in free_tiny_fast() (malloc_tiny_fast.h)
- Conditions: class_idx <= 3, !LARSON_FIX, route==LEGACY
- Direct call: tiny_legacy_fallback_free_base()
- Patch 3: Visibility (free_path_stats_box.h)
- mono_dualhot_hit counter (compile-out in release)
- Patch 4: cleanenv extension (run_mixed_10_cleanenv.sh)
- ENV leak protection
Files modified:
- core/bench_profile.h: add to MIXED_TINYV3_C7_SAFE preset
- core/front/malloc_tiny_fast.h: early-exit insertion
- core/box/free_path_stats_box.h: counter
- core/box/free_tiny_fast_mono_dualhot_env_box.h: NEW (ENV gate)
- scripts/run_mixed_10_cleanenv.sh: ENV leak protection
Health check: PASSED (all profiles)
Promotion: Added to MIXED_TINYV3_C7_SAFE preset (default ON, opt-out)
Rollback: HAKMEM_FREE_TINY_FAST_MONO_DUALHOT=0
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
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2025-12-14 19:16:49 +09:00 |
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