Files
hakmem/core/box
Moe Charm (CI) c687673a99 Phase 2 B4: Wrapper Layer Hot/Cold Split (malloc/free) - ADOPT (+1.47%)
- Implement malloc_cold() helper (noinline,cold) for LD mode, jemalloc, force_libc
- Add malloc() hot/cold dispatch with HAKMEM_WRAP_SHAPE=1 ENV gate
- Implement free_cold() helper (noinline,cold) for classification, ownership checks
- Add free() hot/cold dispatch: hot path returns early, cold path delegates to free_cold()
- Lock_depth symmetry verified on all return paths (malloc: ++/--, free: consistent)

A/B Testing Results (Mixed 10-run):
  WRAP_SHAPE=0 (default): 34,750,578 ops/s
  WRAP_SHAPE=1 (optimized): 35,262,596 ops/s
  Average gain: +1.47% (Median: +1.39%)
  ✓ Decision: GO (exceeds +1.0% threshold)

Implementation Strategy:
- Separate frequently-executed code from rare paths (LD, jemalloc, diagnostics)
- Keep hot path instruction count minimal (returns early on success)
- L1 I-cache pressure reduction via noinline,cold attributes
- Default OFF (HAKMEM_WRAP_SHAPE=0) maintains backward compatibility

Files:
- core/box/hak_wrappers.inc.h: malloc_cold(), free_cold(), hot/cold dispatches
- core/box/wrapper_env_box.h/c: HAKMEM_WRAP_SHAPE ENV variable caching

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-13 17:08:24 +09:00
..