feat(llvm): Phase 131-11-H/12 - ループキャリアPHI型修正 & vmap snapshot SSOT
## Phase 131-11-H: ループキャリアPHI型修正 - PHI生成時に初期値（entry block）の型のみ使用 - backedge の値を型推論に使わない（循環依存回避） - NYASH_CARRIER_PHI_DEBUG=1 でトレース ## Phase 131-12-P0: def_blocks 登録 & STRICT エラー化 - safe_vmap_write() で PHI 上書き保護 - resolver miss を STRICT でエラー化（フォールバック 0 禁止） - def_blocks 自動登録 ## Phase 131-12-P1: vmap_cur スナップショット実装 - DeferredTerminator 構造体（block, term_ops, vmap_snapshot） - Pass A で vmap_cur をスナップショット - Pass C でスナップショット復元（try-finally） - STRICT モード assert ## 結果 - ✅ MIR PHI型: Integer（正しい） - ✅ VM: Result: 3 - ✅ vmap snapshot 機構: 動作確認 - ⚠️ LLVM: Result: 0（別のバグ、次Phase で調査） 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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# Phase 131-12-P1: vmap Object Identity Trace - Summary
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## Status: ✅ Root Cause Identified
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**Date**: 2025-12-14
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**Investigation**: vmap_cur object identity issue causing wrong values in LLVM backend
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**Result**: **Hypothesis C confirmed** - Object identity problem in Pass A→C temporal coupling
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## Critical Discovery
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### The Smoking Gun
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```python
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# Pass A (block_lower.py line 168)
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builder._current_vmap = vmap_cur # ← Create per-block vmap
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# Pass A (block_lower.py line 240)
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builder._deferred_terminators[bid] = (bb, term_ops) # ← Defer terminators
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# Pass A (block_lower.py line 265)
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delattr(builder, '_current_vmap') # ← DELETE vmap_cur ❌
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# Pass C (lower_terminators, line 282)
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# When lowering deferred terminators:
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vmap_ctx = getattr(owner, '_current_vmap', owner.vmap) # ← Falls back to global vmap! ❌
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```
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**Problem**: Pass A deletes `_current_vmap` before Pass C runs, causing terminators to use the wrong vmap object.
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### Trace Evidence
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```
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bb1 block creation: vmap_ctx id=140506427346368 ← Creation
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bb1 const instruction: vmap_ctx id=140506427346368 ← Same (good)
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bb1 ret terminator: vmap_ctx id=140506427248448 ← DIFFERENT (bad!)
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^^^^^^^^^^^^^^
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This is owner.vmap, not vmap_cur!
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```
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**Impact**: Values written to `vmap_cur` in Pass A are invisible to terminators in Pass C.
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## The Bug Flow
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1. **Pass A**: Create `vmap_cur` for block
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2. **Pass A**: Lower body instructions → writes go to `vmap_cur`
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3. **Pass A**: Store terminators for later
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4. **Pass A**: **Delete `_current_vmap`** ← THE BUG
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5. **Pass C**: Lower terminators → fallback to `owner.vmap` (different object!)
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6. **Result**: Terminators read from wrong vmap, missing all Pass A writes
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## Proof: Per-Block vs Global vmap
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### Expected (Per-Block Context)
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```python
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vmap_cur = {...} # Block-local SSA values
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builder._current_vmap = vmap_cur
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# All instructions in this block use the SAME object
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```
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### Actual (Broken State)
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```python
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vmap_cur = {...} # Block-local SSA values
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builder._current_vmap = vmap_cur # Pass A body instructions use this
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# Pass A ends
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delattr(builder, '_current_vmap') # DELETED!
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# Pass C starts
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vmap_ctx = owner.vmap # Falls back to GLOBAL vmap (different object!)
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# Terminators see different data than body instructions! ❌
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```
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## Fix Options (Recommended: Option 3)
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### Option 1: Don't Delete Until Pass C Completes
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- Quick fix but creates temporal coupling
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- Harder to reason about state lifetime
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### Option 2: Read from block_end_values SSOT
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- Good: Uses snapshot as source of truth
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- Issue: Requires restoring to builder state
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### Option 3: Store vmap_cur in Deferred Data (RECOMMENDED)
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```python
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# Pass A (line 240)
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builder._deferred_terminators[bid] = (bb, term_ops, vmap_cur) # ← Add vmap_cur
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# Pass C (line 282)
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for bid, (bb, term_ops, vmap_ctx) in deferred.items():
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builder._current_vmap = vmap_ctx # ← Restore exact context
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# Lower terminators with correct vmap
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```
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**Why Option 3?**
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- Explicit ownership: vmap_cur is passed through deferred tuple
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- No temporal coupling: Pass C gets exact context from Pass A
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- SSOT principle: One source of vmap per block
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- Fail-Fast: Type error if tuple structure changes
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## Architecture Impact
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### Current Problem
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- **Temporal Coupling**: Pass C depends on Pass A's ephemeral state
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- **Silent Fallback**: Wrong vmap used without error
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- **Hidden Sharing**: Global vmap shared across blocks
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### Fixed Architecture (Box-First)
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```
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Pass A: Create vmap_cur (per-block "box")
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↓
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Store in deferred tuple (explicit ownership transfer)
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↓
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Pass C: Restore vmap_cur from tuple (unpack "box")
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↓
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Use exact same object (SSOT)
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```
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**Aligns with CLAUDE.md principles**:
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- ✅ Box-First: vmap_cur is a "box" passed between passes
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- ✅ SSOT: One vmap per block, explicit transfer
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- ✅ Fail-Fast: Type error if deferred tuple changes
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## Test Commands
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### Verify Fix
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```bash
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# Before fix: Shows different IDs for terminator
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NYASH_LLVM_VMAP_TRACE=1 NYASH_LLVM_USE_HARNESS=1 \
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./target/release/hakorune --backend llvm apps/tests/llvm_stage3_loop_only.hako 2>&1 | \
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grep "\[vmap/id\]"
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# After fix: Should show SAME ID throughout block
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```
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### Full Verification
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```bash
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# Check full execution
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NYASH_LLVM_VMAP_TRACE=1 NYASH_LLVM_USE_HARNESS=1 \
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./target/release/hakorune --backend llvm apps/tests/llvm_stage3_loop_only.hako
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# Expected: Result: 3 (matching VM)
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```
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## Files Modified
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### Trace Implementation (Phase 131-12-P1)
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/builders/block_lower.py`
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/builders/instruction_lower.py`
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/instructions/const.py`
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/instructions/copy.py`
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/instructions/binop.py`
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/utils/values.py`
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### Fix Target (Next Phase)
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- `/home/tomoaki/git/hakorune-selfhost/src/llvm_py/builders/block_lower.py` (Option 3)
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## Related Documents
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- Investigation: `/docs/development/current/main/investigations/phase131-12-case-c-llvm-wrong-result.md`
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- Detailed Analysis: `/docs/development/current/main/investigations/phase131-12-p1-vmap-identity-analysis.md`
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- LLVM Inventory: `/docs/development/current/main/phase131-3-llvm-lowering-inventory.md`
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- Environment Variables: `/docs/reference/environment-variables.md`
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## Next Steps
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1. **Implement Option 3 fix** (store vmap_cur in deferred tuple)
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2. **Add Fail-Fast check** in instruction_lower.py (detect missing _current_vmap)
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3. **Verify with trace** (consistent IDs across Pass A→C)
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4. **Run full test suite** (ensure VM/LLVM parity)
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5. **Document pattern** (for future multi-pass architectures)
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## Lessons Learned
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### Box-First Principle Application
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- Mutable builder state (`_current_vmap`) should be **explicitly passed** through phases
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- Don't rely on `getattr` fallbacks - they hide bugs
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- Per-block context is a "box" - treat it as first-class data
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### Fail-Fast Opportunity
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```python
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# BEFORE (silent fallback)
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vmap_ctx = getattr(owner, '_current_vmap', owner.vmap) # Wrong vmap silently used
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# AFTER (fail-fast)
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vmap_ctx = getattr(owner, '_current_vmap', None)
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if vmap_ctx is None:
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raise RuntimeError("Pass A/C timing bug: _current_vmap not set")
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```
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### SSOT Enforcement
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- `block_end_values` is snapshot SSOT
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- `_current_vmap` is working buffer
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- Pass C should **restore** working buffer from SSOT or deferred data
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---
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**Investigation Complete**: Root cause identified with high confidence. Ready for fix implementation.
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