Files
hakorune/docs/development/current/main/investigations
tomoaki a2c5fd90fe feat(joinir): Phase 188.3 - Pattern6 (NestedLoopMinimal) 選択ロジック実装
## Phase 188.3 進捗: Phase 2 完了 (6/13 tasks)

### 実装完了 

**Phase 1: Fixture作成**
- apps/tests/phase1883_nested_minimal.hako 追加
  - Add/Compare のみ(乗算なし)
  - 期待 exit code: 9 (3×3 nested loops)
- 既存 lowering で fallback 動作確認

**Phase 2: 選択ロジック (SSOT)**
- LoopPatternContext に step_tree_max_loop_depth フィールド追加
- choose_pattern_kind() に Pattern6 選択ロジック実装:
  1. Cheap check (has_inner_loop)
  2. StepTree 構築 (max_loop_depth 取得)
  3. AST validation (is_pattern6_lowerable)
- pattern6_nested_minimal.rs モジュール作成 (stub)
- LOOP_PATTERNS に Pattern6 entry 追加
- **検証**: Pattern6 が正しく選択される 

### 設計原則 (確認済み)

1. **Fail-Fast**: Pattern6 選択後は Ok(None) で逃げない
2. **outer 変数 write-back 検出 → validation false** (Phase 188.4+)
3. **最小実装**: inner local だけ、Pattern1 モデル二重化
4. **cfg! 依存なし**: production で動作

### 検証結果

```
[choose_pattern_kind] has_inner_loop=true
[choose_pattern_kind] max_loop_depth=2
[choose_pattern_kind] is_pattern6_lowerable=true
 Pattern6 SELECTED!
```

Stub からの期待エラー:
```
[ERROR]  [Pattern6] Nested loop lowering not yet implemented
```

### 次: Phase 3 (Lowering 実装 - 推定4時間)

残りタスク:
- Phase 3-1: AST 抽出ヘルパー
- Phase 3-2: Validation ヘルパー
- Phase 3-3: Continuation 生成 (outer_step, inner_step, k_inner_exit)
- Phase 3-4: fixture が exit=9 を返すことを検証

### 変更ファイル

**新規**:
- apps/tests/phase1883_nested_minimal.hako
- src/mir/builder/control_flow/joinir/patterns/pattern6_nested_minimal.rs
- docs/development/current/main/phases/phase-188.{1,2,3}/README.md

**変更**:
- src/mir/builder/control_flow/joinir/routing.rs (Pattern6 選択)
- src/mir/builder/control_flow/joinir/patterns/router.rs (Context 拡張)
- src/mir/builder/control_flow/joinir/patterns/mod.rs (module 宣言)

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-27 05:45:12 +09:00
..

Investigations Folder

This folder contains investigation notes and analysis for debugging sessions.

Active Investigations

Phase 131-12: LLVM Wrong Result (Case C)

Status: Root cause identified Problem: LLVM backend returns wrong results for loop exit values Root Cause: vmap object identity mismatch between Pass A and Pass C

Key Documents:

  1. phase131-12-case-c-llvm-wrong-result.md - Initial investigation scope
  2. phase131-12-p1-vmap-identity-analysis.md - Detailed trace analysis
  3. phase131-12-p1-trace-summary.md - Executive summary with fix recommendations

Quick Summary:

  • Bug: Pass A deletes _current_vmap before Pass C runs
  • Impact: Terminators use wrong vmap object, missing all Pass A writes
  • Fix: Store vmap_cur in deferred_terminators tuple (Option 3)

Next Steps:

  1. Implement Option 3 fix in block_lower.py
  2. Add Fail-Fast check in instruction_lower.py
  3. Verify with NYASH_LLVM_VMAP_TRACE=1
  4. Run full test suite

Trace Environment Variables

Phase 131-12-P1 Traces

NYASH_LLVM_VMAP_TRACE=1    # Object identity and vmap keys tracing
NYASH_LLVM_USE_HARNESS=1   # Enable llvmlite harness
NYASH_LLVM_DUMP_IR=<path>  # Save LLVM IR to file

Investigation Workflow

  1. Scope - Define problem and test case (phase131-12-case-c-*.md)
  2. Trace - Add instrumentation and collect data (phase131-12-p1-vmap-identity-*.md)
  3. Analysis - Identify root cause with evidence (phase131-12-p1-trace-summary.md)
  4. Fix - Implement solution with validation
  5. Document - Update investigation notes with results

Archive

Completed investigations are kept for reference and pattern recognition.

JoinIR Generalization Study (Historical)

  • joinir-generalization-study.mdPhase 131138 の状況と一般化案の相談用コンテキスト。SSOT は design/ を参照)