diff --git a/lang/src/llvm_ir/boxes/builder.hako b/lang/src/llvm_ir/boxes/builder.hako
index 2d7c13a1..68b894c7 100644
--- a/lang/src/llvm_ir/boxes/builder.hako
+++ b/lang/src/llvm_ir/boxes/builder.hako
@@ -1,3 +1,13 @@
+using "../instructions/const.hako" as ConstInst
+using "../instructions/binop.hako" as BinOpInst
+using "../instructions/compare.hako" as CompareInst
+using "../instructions/ret.hako" as RetInst
+using "../instructions/branch.hako" as BranchInst
+using "../instructions/jump.hako" as JumpInst
+using "../instructions/copy.hako" as CopyInst
+using "../instructions/phi.hako" as PhiInst
+using "../instructions/loopform.hako" as LoopFormInst
+
 // LLVMBuilderBox — 命令構築（v0: const/binop/ret の骨格）
 static box LLVMBuilderBox {
   program_ret0(){
@@ -125,4 +135,258 @@ static box LLVMBuilderBox {
            "{\\\"op\\\":\\\"const\\\",\\\"dst\\\":3,\\\"value\\\":{\\\"type\\\":\\\"i64\\\",\\\"value\\\":0}}," +
            "{\\\"op\\\":\\\"ret\\\",\\\"value\\\":3}] } ] } ] }"
   }
+
+  // 新しい統合定数命令のテスト - ConstInstを使用
+  test_const_instructions(){
+    local result = {}
+    
+    // i64定数テスト
+    result.i64_const = ConstInst.lower_const(1, {"type": "i64", "value": 42})
+    
+    // f64定数テスト
+    result.f64_const = ConstInst.lower_const(2, {"type": "f64", "value": 3.14})
+    
+    // void定数テスト
+    result.void_const = ConstInst.lower_const(3, {"type": "void"})
+    
+    // 文字列定数テスト
+    result.string_const = ConstInst.lower_const(4, {"type": "string", "value": "Hello, Hakorune!"})
+    
+    // StringBoxハンドルテスト
+    result.handle_const = ConstInst.lower_const(5, {"type": {"kind": "handle", "box_type": "StringBox"}, "value": "Boxed String"})
+    
+    return result
+  }
+
+  // 単純な定数命令を使ったプログラム生成
+  program_with_new_const(value, const_type){
+    local const_inst = ConstInst.lower_const(1, {"type": const_type, "value": value})
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [ { \"id\": 0, \"instructions\": [" +
+           const_inst + "," +
+           "{\"op\":\"ret\",\"value\":1}] } ] } ] }"
+  }
+
+  // 新しい統合二項演算命令のテスト - BinOpInstを使用
+  test_binop_instructions(){
+    local result = {}
+    
+    // 算術演算テスト
+    result.add = BinOpInst.lower_binop("+", 1, 2, 3)
+    result.sub = BinOpInst.lower_binop("-", 1, 2, 3)
+    result.mul = BinOpInst.lower_binop("*", 1, 2, 3)
+    result.div = BinOpInst.lower_binop("/", 1, 2, 3)
+    result.mod = BinOpInst.lower_binop("%", 1, 2, 3)
+    
+    // ビット演算テスト
+    result.and = BinOpInst.lower_binop("&", 1, 2, 3)
+    result.or = BinOpInst.lower_binop("|", 1, 2, 3)
+    result.xor = BinOpInst.lower_binop("^", 1, 2, 3)
+    result.shl = BinOpInst.lower_binop("<<", 1, 2, 3)
+    result.shr = BinOpInst.lower_binop(">>", 1, 2, 3)
+    
+    // 比較演算テスト（compareに委譲）
+    result.eq = BinOpInst.lower_binop("==", 1, 2, 3)
+    result.ne = BinOpInst.lower_binop("!=", 1, 2, 3)
+    result.lt = BinOpInst.lower_binop("<", 1, 2, 3)
+    result.gt = BinOpInst.lower_binop(">", 1, 2, 3)
+    result.le = BinOpInst.lower_binop("<=", 1, 2, 3)
+    result.ge = BinOpInst.lower_binop(">=", 1, 2, 3)
+    
+    return result
+  }
+
+  // 二項演算命令を使ったプログラム生成
+  program_with_new_binop(lhs, rhs, op){
+    local lhs_const = ConstInst.lower_const(1, {"type": "i64", "value": lhs})
+    local rhs_const = ConstInst.lower_const(2, {"type": "i64", "value": rhs})
+    local binop_inst = BinOpInst.lower_binop(op, 1, 2, 3)
+    local ret_inst = RetInst.lower_return(3)
+    
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [ { \"id\": 0, \"instructions\": [" +
+           lhs_const + "," +
+           rhs_const + "," +
+           binop_inst + "," +
+           ret_inst + "] } ] } ] }"
+  }
+
+  // 全命令の統合テスト
+  test_all_instructions() {
+    local result = {}
+    
+    // 定数命令テスト
+    result.const = ConstInst.lower_const(1, {"type": "i64", "value": 42})
+    
+    // 二項演算命令テスト
+    result.binop = BinOpInst.lower_binop("+", 1, 2, 3)
+    
+    // 比較命令テスト
+    result.compare = CompareInst.lower_compare(">", 1, 2, 3)
+    
+    // リターン命令テスト
+    result.ret = RetInst.lower_return(3)
+    
+    return result
+  }
+
+  // 完全なプログラム生成例
+  generate_example_program() {
+    // プログラム: 42 + 100 > 50 ? 1 : 0
+    local const1 = ConstInst.lower_const(1, {"type": "i64", "value": 42})
+    local const2 = ConstInst.lower_const(2, {"type": "i64", "value": 100})
+    local const3 = ConstInst.lower_const(3, {"type": "i64", "value": 50})
+    local add = BinOpInst.lower_binop("+", 1, 2, 4)
+    local cmp = CompareInst.lower_compare(">", 4, 3, 5)
+    local const4 = ConstInst.lower_const(6, {"type": "i64", "value": 1})
+    local const5 = ConstInst.lower_const(7, {"type": "i64", "value": 0})
+    
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [ { \"id\": 0, \"instructions\": [" +
+           const1 + "," +
+           const2 + "," +
+           const3 + "," +
+           add + "," +
+           cmp + "," +
+           const4 + "," +
+           const5 + "," +
+           "{\"op\":\"ret\",\"value\":6}] } ] } ] }"
+  }
+
+  // Phase v1制御フロー命令の統合テスト
+  test_control_flow_instructions() {
+    local result = {}
+    
+    // 分岐命令テスト
+    result.branch = BranchInst.lower_branch(3, 1, 2)
+    
+    // ジャンプ命令テスト
+    result.jump = JumpInst.lower_jump(5)
+    
+    // コピー命令テスト
+    result.copy = CopyInst.lower_copy(4, 2)
+    
+    return result
+  }
+
+  // 制御フロー命令を使ったプログラム生成
+  program_with_control_flow() {
+    // if (x > 0) { return 1 } else { return 0 }
+    local const_x = ConstInst.lower_const(1, {"type": "i64", "value": 10})
+    local const_0 = ConstInst.lower_const(2, {"type": "i64", "value": 0})
+    local const_1 = ConstInst.lower_const(3, {"type": "i64", "value": 1})
+    local const_2 = ConstInst.lower_const(4, {"type": "i64", "value": 2})
+    
+    local cmp = CompareInst.lower_compare(">", 1, 2, 5)
+    local branch = BranchInst.lower_branch(5, 1, 2)
+    local ret1 = RetInst.lower_return(3)
+    local ret2 = RetInst.lower_return(4)
+    
+    // ブロック1 (then)
+    local block1 = "{\"id\":1,\"instructions\":[" + ret1 + "]}"
+    
+    // ブロック2 (else)  
+    local block2 = "{\"id\":2,\"instructions\":[" + ret2 + "]}"
+    
+    // ブロック0 (entry)
+    local block0 = "{\"id\":0,\"instructions\":[" + const_x + "," + const_0 + "," + const_1 + "," + const_2 + "," + cmp + "," + branch + "]}"
+    
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [" + block0 + "," + block1 + "," + block2 + "] } ] }"
+  }
+
+  // 全命令の統合テスト（v0 + v1）
+  test_all_instructions_v1() {
+    local result = me.test_all_instructions()
+
+    // Phase v1命令を追加
+    result.branch = BranchInst.lower_branch(3, 1, 2)
+    result.jump = JumpInst.lower_jump(5)
+    result.copy = CopyInst.lower_copy(4, 2)
+
+    return result
+  }
+
+  // ====== Phase v2-A: PHI Instructions ======
+
+  // PHI命令の生成（ヘルパー）
+  // incoming_list: [{"value":1,"block":1}, {"value":2,"block":2}, ...]
+  emit_phi(dst, incoming_list) {
+    local phi_box = new PhiInst.LLVMPhiInstructionBox()
+    return phi_box.lower_phi(dst, incoming_list)
+  }
+
+  // PHI統合テストプログラム: if-then-else with PHI merge
+  // val_then と val_else の値を PHI で統合
+  program_phi_merge(val_then, val_else) {
+    // Block 0: Entry (分岐判定)
+    local const1 = ConstInst.inst_const_i64(1, 1)
+    local cmp = CompareInst.inst_compare_eq(2, 1, 1)
+    local branch = BranchInst.inst_if_then_else(2, 1, 2)
+    local b0 = "{\"id\":0,\"instructions\":[" + const1 + "," + cmp + "," + branch + "]}"
+
+    // Block 1: Then分岐
+    local const_then = ConstInst.inst_const_i64(3, val_then)
+    local jump1 = JumpInst.lower_jump(3)
+    local b1 = "{\"id\":1,\"instructions\":[" + const_then + "," + jump1 + "]}"
+
+    // Block 2: Else分岐
+    local const_else = ConstInst.inst_const_i64(4, val_else)
+    local jump2 = JumpInst.lower_jump(3)
+    local b2 = "{\"id\":2,\"instructions\":[" + const_else + "," + jump2 + "]}"
+
+    // Block 3: PHI merge + return
+    local incoming = new ArrayBox()
+    local item1 = new MapBox()
+    item1.set("value", 3)
+    item1.set("block", 1)
+    incoming.push(item1)
+
+    local item2 = new MapBox()
+    item2.set("value", 4)
+    item2.set("block", 2)
+    incoming.push(item2)
+
+    local phi = me.emit_phi(5, incoming)
+    local const_zero = ConstInst.inst_const_i64(6, 0)
+    local ret = RetInst.inst_ret_value(6)
+    local b3 = "{\"id\":3,\"instructions\":[" + phi + "," + const_zero + "," + ret + "]}"
+
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [" + b0 + "," + b1 + "," + b2 + "," + b3 + "] } ] }"
+  }
+
+  // 全命令の統合テスト（v0 + v1 + v2-A）
+  test_all_instructions_v2a() {
+    local result = me.test_all_instructions_v1()
+
+    // Phase v2-A命令を追加
+    local phi_incoming = new ArrayBox()
+    local phi_item1 = new MapBox()
+    phi_item1.set("value", 1)
+    phi_item1.set("block", 1)
+    phi_incoming.push(phi_item1)
+
+    local phi_item2 = new MapBox()
+    phi_item2.set("value", 2)
+    phi_item2.set("block", 2)
+    phi_incoming.push(phi_item2)
+
+    result.phi = me.emit_phi(5, phi_incoming)
+
+    return result
+  }
+
+  // Phase v2 LoopForm 命令
+  // Args:
+  //   self: static box receiver (implicit)
+  //   loop_id: ループID
+  //   blocks: ブロックIDマップ {"preheader": 10, "header": 11, ...}
+  //   condition_vid: 条件式の値ID
+  //   options: オプション設定（省略可）
+  // Returns:
+  //   LoopForm JSON 文字列
+  lower_loopform(self, loop_id, blocks, condition_vid, options) {
+    return LoopFormInst.lower_loopform(self, loop_id, blocks, condition_vid, options)
+  }
+
+  // LoopForm 命令を emit（builder メソッド）
+  emit_loopform(self, loop_id, blocks, condition_vid, options) {
+    return me.lower_loopform(self, loop_id, blocks, condition_vid, options)
+  }
 }
diff --git a/lang/src/llvm_ir/instructions/binop.hako b/lang/src/llvm_ir/instructions/binop.hako
new file mode 100644
index 00000000..6e791c88
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/binop.hako
@@ -0,0 +1,119 @@
+// LLVM BinOp Instruction Box — Python binop.py のHakorune実装
+// MIR二項演算命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMBinOpInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_binop()に相当
+  lower_binop(op, lhs, rhs, dst) {
+    // 比較演算子はcompare命令に委譲
+    if op == "==" || op == "!=" || op == "<" || op == ">" || op == "<=" || op == ">=" {
+      return me._delegate_to_compare(op, lhs, rhs, dst)
+    }
+    
+    // 算術演算子
+    if op == "+" {
+      return me.inst_binop_add(lhs, rhs, dst)
+    }
+    
+    if op == "-" {
+      return me.inst_binop_sub(lhs, rhs, dst)
+    }
+    
+    if op == "*" {
+      return me.inst_binop_mul(lhs, rhs, dst)
+    }
+    
+    if op == "/" {
+      return me.inst_binop_div(lhs, rhs, dst)
+    }
+    
+    if op == "%" {
+      return me.inst_binop_mod(lhs, rhs, dst)
+    }
+    
+    // ビット演算子
+    if op == "&" {
+      return me.inst_binop_and(lhs, rhs, dst)
+    }
+    
+    if op == "|" {
+      return me.inst_binop_or(lhs, rhs, dst)
+    }
+    
+    if op == "^" {
+      return me.inst_binop_xor(lhs, rhs, dst)
+    }
+    
+    if op == "<<" {
+      return me.inst_binop_shl(lhs, rhs, dst)
+    }
+    
+    if op == ">>" {
+      return me.inst_binop_shr(lhs, rhs, dst)
+    }
+    
+    // 未知の演算子はaddにフォールバック
+    return me.inst_binop_add(lhs, rhs, dst)
+  }
+
+  // 比較演算子の委譲
+  _delegate_to_compare(op, lhs, rhs, dst) {
+    // JSON: {"op":"compare","dst":3,"operation":">","lhs":1,"rhs":2}
+    return "{\"op\":\"compare\",\"dst\":" + dst + ",\"operation\":\"" + op + "\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  // 算術演算子
+  inst_binop_add(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"+\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_sub(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"-\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_mul(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"*\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_div(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"/\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_mod(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"%\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  // ビット演算子
+  inst_binop_and(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"&\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_or(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"|\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_xor(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"^\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_shl(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\"<<\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  inst_binop_shr(lhs, rhs, dst) {
+    return "{\"op\":\"binop\",\"dst\":" + dst + ",\"operation\":\">>\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_binop(op, lhs, rhs, dst) {
+    local json = me.lower_binop(op, lhs, rhs, dst)
+    print("Generated binop instruction: " + json)
+    return json
+  }
+
+  // 文字列連結の特殊処理（簡易版）
+  // Python: concat_hh → Hakorune: binop "+" に委譲
+  inst_string_concat(lhs, rhs, dst) {
+    return me.inst_binop_add(lhs, rhs, dst)
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/branch.hako b/lang/src/llvm_ir/instructions/branch.hako
new file mode 100644
index 00000000..bcb6f3e4
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/branch.hako
@@ -0,0 +1,47 @@
+// LLVM Branch Instruction Box — Python branch.py のHakorune実装
+// MIR分岐命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMBranchInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_branch()に相当
+  lower_branch(cond_vid, then_bid, else_bid) {
+    return me.inst_branch(cond_vid, then_bid, else_bid)
+  }
+
+  // 分岐命令の生成
+  inst_branch(cond_vid, then_bid, else_bid) {
+    // JSON: {"op":"branch","cond":3,"then":1,"else":2}
+    return "{\"op\":\"branch\",\"cond\":" + cond_vid + ",\"then\":" + then_bid + ",\"else\":" + else_bid + "}"
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_branch(cond_vid, then_bid, else_bid) {
+    local json = me.lower_branch(cond_vid, then_bid, else_bid)
+    print("Generated branch instruction: " + json)
+    return json
+  }
+
+  // 条件付きジャンプのヘルパー
+  if_then_else(condition, then_block, else_block) {
+    return me.inst_branch(condition, then_block, else_block)
+  }
+
+  // 単純な条件分岐（true/false）
+  simple_branch(cond_val, true_block, false_block) {
+    // cond_val: 0=false, 1=true
+    return me.inst_branch(cond_val, true_block, false_block)
+  }
+
+  // 複数の分岐をまとめて生成
+  batch_branch(branch_list) {
+    local results = []
+    local i = 0
+    while i < branch_list.size() {
+      local branch = branch_list[i]
+      local json = me.lower_branch(branch.cond, branch.then_block, branch.else_block)
+      results.push(json)
+      i = i + 1
+    }
+    return results
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/compare.hako b/lang/src/llvm_ir/instructions/compare.hako
new file mode 100644
index 00000000..5d73cf7c
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/compare.hako
@@ -0,0 +1,71 @@
+// LLVM Compare Instruction Box — Python compare.py のHakorune実装
+// MIR比較命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMCompareInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_compare()に相当
+  lower_compare(op, lhs, rhs, dst) {
+    // 比較演算子の検証
+    if !me._is_valid_operator(op) {
+      print("Warning: Invalid compare operator: " + op + ", defaulting to ==")
+      op = "=="
+    }
+    
+    return me.inst_compare(op, lhs, rhs, dst)
+  }
+
+  // 有効な比較演算子の検証
+  _is_valid_operator(op) {
+    return op == "==" || op == "!=" || op == "<" || op == ">" || op == "<=" || op == ">="
+  }
+
+  // 比較命令の生成
+  inst_compare(op, lhs, rhs, dst) {
+    return "{\"op\":\"compare\",\"dst\":" + dst + ",\"operation\":\"" + op + "\",\"lhs\":" + lhs + ",\"rhs\":" + rhs + "}"
+  }
+
+  // 各比較演算子の個別メソッド
+  inst_eq(lhs, rhs, dst) {
+    return me.inst_compare("==", lhs, rhs, dst)
+  }
+
+  inst_ne(lhs, rhs, dst) {
+    return me.inst_compare("!=", lhs, rhs, dst)
+  }
+
+  inst_lt(lhs, rhs, dst) {
+    return me.inst_compare("<", lhs, rhs, dst)
+  }
+
+  inst_gt(lhs, rhs, dst) {
+    return me.inst_compare(">", lhs, rhs, dst)
+  }
+
+  inst_le(lhs, rhs, dst) {
+    return me.inst_compare("<=", lhs, rhs, dst)
+  }
+
+  inst_ge(lhs, rhs, dst) {
+    return me.inst_compare(">=", lhs, rhs, dst)
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_compare(op, lhs, rhs, dst) {
+    local json = me.lower_compare(op, lhs, rhs, dst)
+    print("Generated compare instruction: " + json)
+    return json
+  }
+
+  // 複数の比較をまとめて生成（効率化）
+  batch_compare(compare_list) {
+    local results = []
+    local i = 0
+    while i < compare_list.size() {
+      local cmp = compare_list[i]
+      local json = me.lower_compare(cmp.op, cmp.lhs, cmp.rhs, cmp.dst)
+      results.push(json)
+      i = i + 1
+    }
+    return results
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/const.hako b/lang/src/llvm_ir/instructions/const.hako
new file mode 100644
index 00000000..c6d2f74d
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/const.hako
@@ -0,0 +1,80 @@
+// LLVM Const Instruction Box — Python const.py のHakorune実装
+// MIR定数命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMConstInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_const()に相当
+  lower_const(dst, value_dict) {
+    local const_type = value_dict.type
+    local const_val = value_dict.value
+
+    if const_type == "i64" {
+      return me.inst_const_i64(dst, const_val)
+    }
+    
+    if const_type == "f64" {
+      return me.inst_const_f64(dst, const_val)
+    }
+    
+    if const_type == "void" {
+      return me.inst_const_void(dst)
+    }
+    
+    if const_type == "string" {
+      return me.inst_const_string(dst, const_val)
+    }
+
+    // 未知の型の場合はi64の0として扱う（Pythonのフォールバックと同じ）
+    return me.inst_const_i64(dst, 0)
+  }
+
+  // i64整数定数
+  inst_const_i64(dst, value) {
+    // JSON形式の定数命令を生成
+    // {"op":"const","dst":1,"value":{"type":"i64","value":42}}
+    return "{\"op\":\"const\",\"dst\":" + dst + ",\"value\":{\"type\":\"i64\",\"value\":" + value + "}}"
+  }
+
+  // f64浮動小数点定数
+  inst_const_f64(dst, value) {
+    // JSON形式の定数命令を生成
+    // {"op":"const","dst":1,"value":{"type":"f64","value":3.14}}
+    return "{\"op\":\"const\",\"dst\":" + dst + ",\"value\":{\"type\":\"f64\",\"value\":" + value + "}}"
+  }
+
+  // void/null定数 - i64の0として表現
+  inst_const_void(dst) {
+    // Pythonの実装ではi64の0を使用
+    return "{\"op\":\"const\",\"dst\":" + dst + ",\"value\":{\"type\":\"void\",\"value\":0}}"
+  }
+
+  // 文字列定数
+  inst_const_string(dst, str_value) {
+    // JSON文字列エスケープ処理
+    local escaped = me._escape_json_string(str_value)
+    return "{\"op\":\"const\",\"dst\":" + dst + ",\"value\":{\"type\":\"string\",\"value\":\"" + escaped + "\"}}"
+  }
+
+  // JSON文字列エスケープヘルパー
+  _escape_json_string(s) {
+    if s == null {
+      return ""
+    }
+
+    local result = s.toString()
+    result = result.replace("\\", "\\\\")
+    result = result.replace("\"", "\\\"")
+    result = result.replace("\n", "\\n")
+    result = result.replace("\t", "\\t")
+    result = result.replace("\r", "\\r")
+    
+    return result
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_const(dst, value_dict) {
+    local json = me.lower_const(dst, value_dict)
+    print("Generated const instruction: " + json)
+    return json
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/copy.hako b/lang/src/llvm_ir/instructions/copy.hako
new file mode 100644
index 00000000..e2bd5f20
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/copy.hako
@@ -0,0 +1,51 @@
+// LLVM Copy Instruction Box — Python copy.py のHakorune実装
+// MIRコピー命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMCopyInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_copy()に相当
+  lower_copy(dst, src) {
+    return me.inst_copy(dst, src)
+  }
+
+  // コピー命令の生成
+  inst_copy(dst, src) {
+    // JSON: {"op":"copy","dst":4,"src":2}
+    return "{\"op\":\"copy\",\"dst\":" + dst + ",\"src\":" + src + "}"
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_copy(dst, src) {
+    local json = me.lower_copy(dst, src)
+    print("Generated copy instruction: " + json)
+    return json
+  }
+
+  // 値の移動（エイリアス）
+  move_value(src_reg, dst_reg) {
+    return me.inst_copy(dst_reg, src_reg)
+  }
+
+  // レジスタのコピー
+  copy_register(src, dst) {
+    return me.inst_copy(dst, src)
+  }
+
+  // パラメータのコピー
+  copy_param(param_num, dst_reg) {
+    return me.inst_copy(dst_reg, param_num)
+  }
+
+  // 複数のコピーをまとめて生成
+  batch_copy(copy_list) {
+    local results = []
+    local i = 0
+    while i < copy_list.size() {
+      local copy = copy_list[i]
+      local json = me.lower_copy(copy.dst, copy.src)
+      results.push(json)
+      i = i + 1
+    }
+    return results
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/jump.hako b/lang/src/llvm_ir/instructions/jump.hako
new file mode 100644
index 00000000..e741d939
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/jump.hako
@@ -0,0 +1,56 @@
+// LLVM Jump Instruction Box — Python jump.py のHakorune実装
+// MIRジャンプ命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMJumpInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_jump()に相当
+  lower_jump(target_bid) {
+    return me.inst_jump(target_bid)
+  }
+
+  // ジャンプ命令の生成
+  inst_jump(target_bid) {
+    // JSON: {"op":"jump","target":5}
+    return "{\"op\":\"jump\",\"target\":" + target_bid + "}"
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_jump(target_bid) {
+    local json = me.lower_jump(target_bid)
+    print("Generated jump instruction: " + json)
+    return json
+  }
+
+  // ラベルへのジャンプ
+  jump_to_label(label_id) {
+    return me.inst_jump(label_id)
+  }
+
+  // ループヘッドへのジャンプ
+  jump_loop_head(loop_block) {
+    return me.inst_jump(loop_block)
+  }
+
+  // ループ終了へのジャンプ
+  jump_loop_end(exit_block) {
+    return me.inst_jump(exit_block)
+  }
+
+  // 関数終了へのジャンプ
+  jump_to_epilogue(epilogue_block) {
+    return me.inst_jump(epilogue_block)
+  }
+
+  // 複数のジャンプをまとめて生成
+  batch_jump(jump_list) {
+    local results = []
+    local i = 0
+    while i < jump_list.size() {
+      local jump = jump_list[i]
+      local json = me.lower_jump(jump.target)
+      results.push(json)
+      i = i + 1
+    }
+    return results
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/loopform.hako b/lang/src/llvm_ir/instructions/loopform.hako
new file mode 100644
index 00000000..80426979
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/loopform.hako
@@ -0,0 +1,271 @@
+// LLVM LoopForm Instruction Box — Python loopform.py のHakorune実装
+// 実験的ループ正規化（paper-e-loop-signal-ir）をJSON形式に変換し、C++バックエンドに渡す
+//
+// LoopForm は 6-block 構造でループを表現:
+//   preheader → header → body → dispatch → latch → exit
+//                ↑__________________|
+//
+// 特徴:
+// - break/continue を tag/payload PHI で明示的に処理
+// - Safepoint 自動挿入（GC 安全点）
+// - Iteration counter (structural PHI)
+
+static box LLVMLoopFormInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_while_loopform()に相当
+  // Stage 1: 基本 LoopForm 構造の JSON 生成
+  // Stage 2: PHI incoming 配列化、computed フラグ追加
+  //
+  // Args:
+  //   loop_id: ループID（整数）
+  //   blocks: ブロックIDマップ
+  //     形式: {"preheader": 10, "header": 11, "body": 12,
+  //            "dispatch": 13, "latch": 14, "exit": 15}
+  //   condition_vid: 条件式の値ID（MIR condition）
+  //   options: オプション設定（MapBox）
+  //     - mode: "mir" | "payload" (default: "mir")
+  //     - payload_max: Payload モード時の上限 (default: 1000000)
+  //     - use_guard: Structural guard 使用 (default: false)
+  //     - enable_safepoint: Safepoint 有効化 (default: true)
+  //
+  // Returns:
+  //   JSON文字列: {"op":"loopform","loop_id":1,"blocks":{...},...}
+  //   Stage 2: Header PHI/Dispatch PHI は incoming 配列 + computed フラグ
+  //
+  lower_loopform(self, loop_id, blocks, condition_vid, options) {
+    // Null チェック
+    if blocks == null {
+      return me._loopform_error_fallback(self, "blocks is null")
+    }
+
+    local json = "{"
+    json = json + "\"op\":\"loopform\""
+    json = json + ",\"loop_id\":" + loop_id.toString()
+
+    // Blocks 構造を JSON 化
+    json = json + ",\"blocks\":" + me._build_blocks_json(self, blocks)
+
+    // Header PHI 情報を JSON 化
+    json = json + ",\"header_phi\":" + me._build_header_phi_json(self, blocks)
+
+    // Condition 情報を JSON 化
+    json = json + ",\"condition\":" + me._build_condition_json(self, condition_vid, options)
+
+    // Dispatch PHI 情報を JSON 化
+    json = json + ",\"dispatch_phis\":" + me._build_dispatch_phis_json(self, blocks)
+
+    // Safepoint 情報を JSON 化
+    json = json + ",\"safepoint\":" + me._build_safepoint_json(self, options)
+
+    json = json + "}"
+    return json
+  }
+
+  // Blocks マップを JSON 化
+  // Args:
+  //   blocks: {"preheader": 10, "header": 11, ...}
+  // Returns:
+  //   JSON: {"preheader":10,"header":11,...}
+  _build_blocks_json(self, blocks) {
+    local json = "{"
+
+    // 6つのブロックIDを取得
+    local preheader = blocks.get("preheader")
+    local header = blocks.get("header")
+    local body = blocks.get("body")
+    local dispatch = blocks.get("dispatch")
+    local latch = blocks.get("latch")
+    local exit = blocks.get("exit")
+
+    json = json + "\"preheader\":" + preheader.toString()
+    json = json + ",\"header\":" + header.toString()
+    json = json + ",\"body\":" + body.toString()
+    json = json + ",\"dispatch\":" + dispatch.toString()
+    json = json + ",\"latch\":" + latch.toString()
+    json = json + ",\"exit\":" + exit.toString()
+
+    json = json + "}"
+    return json
+  }
+
+  // Header PHI 情報を JSON 化
+  // Iteration PHI: φ(0 from preheader, i_next from latch)
+  // Stage 2: incoming 配列形式 - 完全な PHI 構造
+  // Args:
+  //   blocks: ブロックIDマップ
+  // Returns:
+  //   JSON: {"dst":0,"incoming":[{"value":0,"block":10},{"value":0,"block":14,"computed":true}]}
+  _build_header_phi_json(self, blocks) {
+    local preheader = blocks.get("preheader")
+    local latch = blocks.get("latch")
+
+    local json = "{"
+    json = json + "\"dst\":0"  // Placeholder, C++ が決定
+    json = json + ",\"incoming\":["
+
+    // Incoming 1: Preheader からの初期値（定数0）
+    json = json + "{\"value\":0,\"block\":" + preheader.toString() + "}"
+
+    // Incoming 2: Latch からの継続値（i_next_latch = hdr_phi + 1）
+    json = json + ",{\"value\":0,\"block\":" + latch.toString() + ",\"computed\":true}"
+
+    json = json + "]"
+    json = json + "}"
+    return json
+  }
+
+  // Condition 情報を JSON 化
+  // Args:
+  //   vid: MIR condition の値ID
+  //   options: オプション設定
+  // Returns:
+  //   JSON: {"mode":"mir","vid":5}
+  _build_condition_json(self, vid, options) {
+    local mode = "mir"  // Default mode
+    local payload_max = 1000000
+    local use_guard = 0
+
+    // Options から設定を取得
+    if options != null {
+      local has_mode = options.has("mode")
+      if has_mode {
+        mode = options.get("mode")
+      }
+
+      local has_max = options.has("payload_max")
+      if has_max {
+        payload_max = options.get("payload_max")
+      }
+
+      local has_guard = options.has("use_guard")
+      if has_guard {
+        use_guard = options.get("use_guard")
+      }
+    }
+
+    local json = "{"
+    json = json + "\"mode\":\"" + mode + "\""
+    json = json + ",\"vid\":" + vid.toString()
+
+    // Payload モード時は max 値を含める
+    if mode == "payload" {
+      json = json + ",\"payload_max\":" + payload_max.toString()
+    }
+
+    // Guard 使用時
+    if use_guard != 0 {
+      json = json + ",\"use_guard\":true"
+    }
+
+    json = json + "}"
+    return json
+  }
+
+  // Dispatch PHI 情報を JSON 化
+  // Tag PHI: φ(1 from header, 0 from body) — break=1, continue=0
+  // Payload PHI: φ(0 from header, i_next_body from body) — iteration counter
+  // Stage 2: computed フラグでBody計算を明示
+  // Args:
+  //   blocks: ブロックIDマップ
+  // Returns:
+  //   JSON: {"tag":{...},"payload":{...}}
+  _build_dispatch_phis_json(self, blocks) {
+    local header = blocks.get("header")
+    local body = blocks.get("body")
+
+    local json = "{"
+
+    // Tag PHI: break(1) / continue(0) signal
+    json = json + "\"tag\":{"
+    json = json + "\"dst\":0"  // Placeholder, C++ が決定
+    json = json + ",\"incoming\":["
+    json = json + "{\"value\":1,\"block\":" + header.toString() + "}"  // Break from header
+    json = json + ",{\"value\":0,\"block\":" + body.toString() + "}"   // Continue from body
+    json = json + "]}"
+
+    // Payload PHI: iteration counter
+    json = json + ",\"payload\":{"
+    json = json + "\"dst\":0"  // Placeholder, C++ が決定
+    json = json + ",\"incoming\":["
+    json = json + "{\"value\":0,\"block\":" + header.toString() + "}"  // Break時は0（初期値）
+    json = json + ",{\"value\":0,\"block\":" + body.toString() + ",\"computed\":true}"  // Continue時はi_next_body（hdr_phi + 1）
+    json = json + "]}"
+
+    json = json + "}"
+    return json
+  }
+
+  // Safepoint 情報を JSON 化
+  // Args:
+  //   options: オプション設定
+  // Returns:
+  //   JSON: {"enabled":true,"location":"loop_header"}
+  _build_safepoint_json(self, options) {
+    local enabled = 1  // Default: enabled
+
+    // Options から設定を取得
+    if options != null {
+      local has_safepoint = options.has("enable_safepoint")
+      if has_safepoint {
+        enabled = options.get("enable_safepoint")
+      }
+    }
+
+    local json = "{"
+    json = json + "\"enabled\":"
+    if enabled != 0 {
+      json = json + "true"
+    }
+    if enabled == 0 {
+      json = json + "false"
+    }
+    json = json + ",\"location\":\"loop_header\""
+    json = json + "}"
+    return json
+  }
+
+  // エラーフォールバック
+  _loopform_error_fallback(self, message) {
+    // エラー時は空の JSON を返す（C++ backend がエラー処理）
+    return "{\"op\":\"loopform\",\"error\":\"" + message + "\"}"
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_loopform(self, loop_id, blocks, condition_vid, options) {
+    local json = me.lower_loopform(self, loop_id, blocks, condition_vid, options)
+    print("Generated LoopForm instruction: " + json)
+    return json
+  }
+
+  // ヘルパー: blocks 検証（デバッグ用）
+  _validate_blocks(self, blocks) {
+    if blocks == null {
+      return 0
+    }
+
+    // 6つの必須ブロックが存在するか確認
+    local keys = new ArrayBox()
+    keys.push("preheader")
+    keys.push("header")
+    keys.push("body")
+    keys.push("dispatch")
+    keys.push("latch")
+    keys.push("exit")
+
+    local i = 0
+    local len = keys.length()
+    loop(i < len) {
+      local key = keys.get(i)
+      local has_key = blocks.has(key)
+
+      if has_key == 0 {
+        print("WARNING: Missing block key: " + key)
+        return 0
+      }
+
+      i = i + 1
+    }
+
+    return 1
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/phi.hako b/lang/src/llvm_ir/instructions/phi.hako
new file mode 100644
index 00000000..d809b0f7
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/phi.hako
@@ -0,0 +1,157 @@
+// LLVM PHI Instruction Box — Python phi.py のHakorune実装
+// MIR PHI命令（SSA値マージング）をJSON形式に変換し、C++バックエンドに渡す
+//
+// PHI命令はSSA形式で制御フローの合流点における値のマージを表現する
+// 例: if (cond) { x = 1 } else { x = 2 } → x = PHI(1 from bb1, 2 from bb2)
+
+static box LLVMPhiInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_phi()に相当
+  // Stage 1: 基本PHI生成（JSON生成のみ）
+  //
+  // Args:
+  //   dst: 出力先レジスタID（整数）
+  //   incoming_list: incoming値のリスト
+  //     形式: [{"value":1,"block":1}, {"value":2,"block":2}, ...]
+  //     - value: 入力値のレジスタID
+  //     - block: その値が来る基本ブロックID
+  //
+  // Returns:
+  //   JSON文字列: {"op":"phi","dst":5,"incoming":[...]}
+  //
+  lower_phi(dst, incoming_list) {
+    // 空チェック: incoming が空の場合は 0 定数を返す
+    // Python: phi.py 34-37行の動作と同じ
+    if incoming_list == null {
+      return me._phi_empty_fallback(dst)
+    }
+
+    local list_len = incoming_list.length()
+    if list_len == 0 {
+      return me._phi_empty_fallback(dst)
+    }
+
+    // incoming配列をJSON化
+    local incoming_json = me._build_incoming_array(incoming_list)
+
+    // PHI命令のJSON形式を生成
+    // {"op":"phi","dst":5,"incoming":[{"value":1,"block":1},{"value":2,"block":2}]}
+    return "{\"op\":\"phi\",\"dst\":" + dst + ",\"incoming\":" + incoming_json + "}"
+  }
+
+  // 空のPHI: 0定数にフォールバック
+  // Python: phi.py 34-37行
+  _phi_empty_fallback(dst) {
+    // No incoming edges - use zero constant
+    return "{\"op\":\"const\",\"dst\":" + dst + ",\"value\":{\"type\":\"i64\",\"value\":0}}"
+  }
+
+  // incoming配列のJSON化
+  //
+  // Args:
+  //   incoming_list: [{"value":1,"block":1}, {"value":2,"block":2}, ...]
+  //
+  // Returns:
+  //   JSON配列文字列: [{"value":1,"block":1},{"value":2,"block":2}]
+  //
+  _build_incoming_array(incoming_list) {
+    local result = "["
+    local first = 1
+
+    // 各incoming要素をJSON化
+    local i = 0
+    local len = incoming_list.length()
+
+    loop(i < len) {
+      local item = incoming_list.get(i)
+
+      // item は {"value":X, "block":Y} の形式のMapBox
+      local value_id = item.get("value")
+      local block_id = item.get("block")
+
+      // カンマ区切り（最初の要素以外）
+      if first == 0 {
+        result = result + ","
+      }
+      first = 0
+
+      // {"value":X,"block":Y} 形式で追加
+      result = result + "{\"value\":" + value_id + ",\"block\":" + block_id + "}"
+
+      i = i + 1
+    }
+
+    result = result + "]"
+    return result
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_phi(dst, incoming_list) {
+    local json = me.lower_phi(dst, incoming_list)
+    print("Generated PHI instruction: " + json)
+    return json
+  }
+
+  // Stage 2 プレースホルダー: Block End Values管理（将来実装）
+  // Python: phi.py 69-79行の block_end_values スナップショット処理
+  // 注: Hakorune版では不要（C++バックエンドが処理）
+  lower_phi_with_snapshot(dst, incoming_list, block_end_values) {
+    // 現時点では基本版と同じ動作
+    return me.lower_phi(dst, incoming_list)
+  }
+
+  // Stage 3 プレースホルダー: 型変換処理（将来実装）
+  // Python: phi.py 84-103行の型変換処理
+  // 注: Hakorune版では不要（C++バックエンドが処理）
+  lower_phi_with_type_info(dst, incoming_list, type_info) {
+    // 現時点では基本版と同じ動作
+    return me.lower_phi(dst, incoming_list)
+  }
+
+  // Stage 4 プレースホルダー: Strict Mode（将来実装）
+  // Python: phi.py 118-121行の NYASH_LLVM_PHI_STRICT チェック
+  // 注: C++バックエンドで実装予定
+  lower_phi_strict(dst, incoming_list, strict_mode) {
+    // 現時点では基本版と同じ動作
+    return me.lower_phi(dst, incoming_list)
+  }
+
+  // Stage 5 プレースホルダー: 文字列性伝播（将来実装）
+  // Python: phi.py 131-142行の resolver.is_stringish() 処理
+  // 注: C++バックエンドで実装予定
+  lower_phi_with_string_propagation(dst, incoming_list, resolver) {
+    // 現時点では基本版と同じ動作
+    return me.lower_phi(dst, incoming_list)
+  }
+
+  // ヘルパー: incoming要素の検証（デバッグ用）
+  _validate_incoming(incoming_list) {
+    if incoming_list == null {
+      return 0
+    }
+
+    local len = incoming_list.length()
+    if len == 0 {
+      return 0
+    }
+
+    // 各要素が {"value":X, "block":Y} 形式か確認
+    local i = 0
+    loop(i < len) {
+      local item = incoming_list.get(i)
+
+      // value と block フィールドが存在するか
+      local has_value = item.has("value")
+      local has_block = item.has("block")
+
+      if has_value == 0 || has_block == 0 {
+        print("WARNING: Invalid incoming item at index " + i)
+        return 0
+      }
+
+      i = i + 1
+    }
+
+    return 1
+  }
+}
diff --git a/lang/src/llvm_ir/instructions/ret.hako b/lang/src/llvm_ir/instructions/ret.hako
new file mode 100644
index 00000000..69c0649a
--- /dev/null
+++ b/lang/src/llvm_ir/instructions/ret.hako
@@ -0,0 +1,48 @@
+// LLVM Ret Instruction Box — Python ret.py のHakorune実装
+// MIRリターン命令をJSON形式に変換し、C++バックエンドに渡す
+
+static box LLVMRetInstructionBox {
+
+  // メインエントリーポイント - Pythonのlower_return()に相当
+  lower_return(value_id) {
+    if value_id == null || value_id == 0 {
+      // Void return
+      return me.inst_ret_void()
+    } else {
+      // Value return
+      return me.inst_ret_value(value_id)
+    }
+  }
+
+  // Void return命令
+  inst_ret_void() {
+    return "{\"op\":\"ret\",\"value\":null}"
+  }
+
+  // Value return命令
+  inst_ret_value(value_id) {
+    return "{\"op\":\"ret\",\"value\":" + value_id + "}"
+  }
+
+  // 定数値を返す（ショートカット）
+  ret_const_i64(value) {
+    return "{\"op\":\"ret\",\"value\":null}"  // 実際には定数命令 + ret命令が必要
+  }
+
+  // デバッグ用 - 生成された命令の確認
+  debug_ret(value_id) {
+    local json = me.lower_return(value_id)
+    print("Generated ret instruction: " + json)
+    return json
+  }
+
+  // プログラム全体のreturn生成（定数+returnの組み合わせ）
+  program_with_const_ret(const_value) {
+    local const_inst = "{\"op\":\"const\",\"dst\":1,\"value\":{\"type\":\"i64\",\"value\":" + const_value + "}}"
+    local ret_inst = me.inst_ret_value(1)
+    
+    return "{ \"version\": 0, \"functions\": [ { \"name\": \"main\", \"params\": [], \"blocks\": [ { \"id\": 0, \"instructions\": [" +
+           const_inst + "," +
+           ret_inst + "] } ] } ] }"
+  }
+}
diff --git a/tests/phase33/smoke/loopform/for_counter.hako b/tests/phase33/smoke/loopform/for_counter.hako
new file mode 100644
index 00000000..3868f86d
--- /dev/null
+++ b/tests/phase33/smoke/loopform/for_counter.hako
@@ -0,0 +1,57 @@
+// LoopForm Smoke Test 2: Counter-based for loop
+// Tests for loop with explicit counter using loopform
+//
+// Expected behavior (when C++ backend implements loopform):
+//   - Loop from 0 to 9 (10 iterations)
+//   - Use payload mode for structural counter
+//   - Return total iterations
+
+using "lang/src/llvm_ir/instructions/loopform.hako" as LoopFormInst
+
+static box Main {
+  main() {
+    print("=== LoopForm Smoke Test 2: for_counter ===")
+
+    // Simulate for loop: for (i = 0; i < 10; i++)
+    local blocks = new MapBox()
+    blocks.set("preheader", 10)
+    blocks.set("header", 11)
+    blocks.set("body", 12)
+    blocks.set("dispatch", 13)
+    blocks.set("latch", 14)
+    blocks.set("exit", 15)
+
+    // Use payload mode with max iterations
+    local options = new MapBox()
+    options.set("mode", "payload")
+    options.set("payload_max", 10)
+    options.set("enable_safepoint", 1)
+
+    // Generate loopform JSON
+    local json = LoopFormInst.lower_loopform(2, blocks, 20, options)
+
+    // Verify JSON structure
+    local has_loopform = json.indexOf("\"op\":\"loopform\"")
+    if has_loopform < 0 {
+      print("ERROR: loopform op not found")
+      return 1
+    }
+
+    local has_payload_mode = json.indexOf("\"mode\":\"payload\"")
+    if has_payload_mode < 0 {
+      print("ERROR: payload mode not found")
+      return 1
+    }
+
+    local has_max = json.indexOf("\"payload_max\":10")
+    if has_max < 0 {
+      print("ERROR: payload_max not found")
+      return 1
+    }
+
+    print("✓ PASS: for_counter loopform generated")
+    print("Note: Actual loop execution requires C++ backend implementation")
+
+    return 0
+  }
+}
diff --git a/tests/phase33/smoke/loopform/if_loop_merge.hako b/tests/phase33/smoke/loopform/if_loop_merge.hako
new file mode 100644
index 00000000..433f559f
--- /dev/null
+++ b/tests/phase33/smoke/loopform/if_loop_merge.hako
@@ -0,0 +1,65 @@
+// LoopForm Smoke Test 3: if-else + loop + merge
+// Tests complex control flow with loopform
+//
+// Expected behavior (when C++ backend implements loopform):
+//   - Conditional branch before loop
+//   - Loop with early exit (break)
+//   - Merge point after loop
+//   - Return merged result
+
+using "lang/src/llvm_ir/instructions/loopform.hako" as LoopFormInst
+
+static box Main {
+  main() {
+    print("=== LoopForm Smoke Test 3: if_loop_merge ===")
+
+    // Simulate: if (cond) { while (i < 3) { if (i == 2) break; i++; } }
+    local blocks = new MapBox()
+    blocks.set("preheader", 20)
+    blocks.set("header", 21)
+    blocks.set("body", 22)
+    blocks.set("dispatch", 23)
+    blocks.set("latch", 24)
+    blocks.set("exit", 25)
+
+    // Use guard to combine condition and structural limit
+    local options = new MapBox()
+    options.set("mode", "mir")
+    options.set("use_guard", 1)
+    options.set("payload_max", 1000000)
+    options.set("enable_safepoint", 1)
+
+    // Generate loopform JSON
+    local json = LoopFormInst.lower_loopform(3, blocks, 30, options)
+
+    // Verify JSON structure
+    local has_loopform = json.indexOf("\"op\":\"loopform\"")
+    if has_loopform < 0 {
+      print("ERROR: loopform op not found")
+      return 1
+    }
+
+    local has_guard = json.indexOf("\"use_guard\":true")
+    if has_guard < 0 {
+      print("ERROR: use_guard not found")
+      return 1
+    }
+
+    local has_dispatch_tag = json.indexOf("\"tag\"")
+    if has_dispatch_tag < 0 {
+      print("ERROR: dispatch tag PHI not found")
+      return 1
+    }
+
+    local has_dispatch_payload = json.indexOf("\"payload\"")
+    if has_dispatch_payload < 0 {
+      print("ERROR: dispatch payload PHI not found")
+      return 1
+    }
+
+    print("✓ PASS: if_loop_merge loopform generated")
+    print("Note: Actual loop execution requires C++ backend implementation")
+
+    return 0
+  }
+}
diff --git a/tests/phase33/smoke/loopform/while_simple.hako b/tests/phase33/smoke/loopform/while_simple.hako
new file mode 100644
index 00000000..9d032f49
--- /dev/null
+++ b/tests/phase33/smoke/loopform/while_simple.hako
@@ -0,0 +1,49 @@
+// LoopForm Smoke Test 1: Basic while loop
+// Tests basic while loop structure with loopform
+//
+// Expected behavior (when C++ backend implements loopform):
+//   - Loop from 0 to 4
+//   - Print each iteration
+//   - Return final counter value (5)
+
+using "lang/src/llvm_ir/instructions/loopform.hako" as LoopFormInst
+
+static box Main {
+  main() {
+    print("=== LoopForm Smoke Test 1: while_simple ===")
+
+    // Simulate while loop: while (i < 5) { i++ }
+    local blocks = new MapBox()
+    blocks.set("preheader", 0)
+    blocks.set("header", 1)
+    blocks.set("body", 2)
+    blocks.set("dispatch", 3)
+    blocks.set("latch", 4)
+    blocks.set("exit", 5)
+
+    local options = new MapBox()
+    options.set("mode", "mir")
+    options.set("enable_safepoint", 1)
+
+    // Generate loopform JSON
+    local json = LoopFormInst.lower_loopform(1, blocks, 10, options)
+
+    // Verify JSON structure
+    local has_loopform = json.indexOf("\"op\":\"loopform\"")
+    if has_loopform < 0 {
+      print("ERROR: loopform op not found")
+      return 1
+    }
+
+    local has_safepoint = json.indexOf("\"enabled\":true")
+    if has_safepoint < 0 {
+      print("ERROR: safepoint not enabled")
+      return 1
+    }
+
+    print("✓ PASS: while_simple loopform generated")
+    print("Note: Actual loop execution requires C++ backend implementation")
+
+    return 0
+  }
+}
diff --git a/tests/phase33/unit/loopform/test_basic.hako b/tests/phase33/unit/loopform/test_basic.hako
new file mode 100644
index 00000000..f4d2e44b
--- /dev/null
+++ b/tests/phase33/unit/loopform/test_basic.hako
@@ -0,0 +1,223 @@
+// LoopForm Instruction Box - Unit Test
+// Stage 1: Basic LoopForm generation
+// Stage 2: PHI incoming arrays + computed flags
+
+using "lang/src/llvm_ir/instructions/loopform.hako" as LoopFormInst
+
+static box Main {
+  main() {
+    print("=== LoopForm Instruction Unit Test (Stage 1 + 2) ===")
+
+    // Test 1: 基本的な LoopForm 命令生成
+    me.test_basic_loopform()
+
+    // Test 2: Blocks 検証
+    me.test_blocks_validation()
+
+    // Test 3: Condition モード
+    me.test_condition_modes()
+
+    // Test 4: PHI incoming 配列検証（Stage 2）
+    me.test_phi_incoming_arrays()
+
+    print("=== All Tests Passed! ===")
+    return 0
+  }
+
+  // Test 1: 基本的な LoopForm 命令生成
+  test_basic_loopform() {
+    print("\n[Test 1] Basic LoopForm generation")
+
+    // Blocks マップを作成
+    local blocks = new MapBox()
+    blocks.set("preheader", 10)
+    blocks.set("header", 11)
+    blocks.set("body", 12)
+    blocks.set("dispatch", 13)
+    blocks.set("latch", 14)
+    blocks.set("exit", 15)
+
+    // Options (null でデフォルト使用)
+    local options = null
+
+    local result = LoopFormInst.lower_loopform(1, blocks, 5, options)
+
+    // 期待値: {"op":"loopform","loop_id":1,"blocks":{...},...}
+    print("Generated: " + result)
+
+    // 簡易検証: "loopform" が含まれているか
+    local contains_op = result.indexOf("loopform")
+    if contains_op < 0 {
+      print("ERROR: loopform op not found")
+      return 1
+    }
+
+    // "loop_id":1 が含まれているか
+    local contains_id = result.indexOf("\"loop_id\":1")
+    if contains_id < 0 {
+      print("ERROR: loop_id not found")
+      return 1
+    }
+
+    // "blocks" が含まれているか
+    local contains_blocks = result.indexOf("\"blocks\"")
+    if contains_blocks < 0 {
+      print("ERROR: blocks not found")
+      return 1
+    }
+
+    // "header":11 が含まれているか
+    local contains_header = result.indexOf("\"header\":11")
+    if contains_header < 0 {
+      print("ERROR: header block not found")
+      return 1
+    }
+
+    print("✓ PASS: Basic LoopForm generation")
+    return 0
+  }
+
+  // Test 2: Blocks 検証
+  test_blocks_validation() {
+    print("\n[Test 2] Blocks validation")
+
+    local blocks = new MapBox()
+    blocks.set("preheader", 20)
+    blocks.set("header", 21)
+    blocks.set("body", 22)
+    blocks.set("dispatch", 23)
+    blocks.set("latch", 24)
+    blocks.set("exit", 25)
+
+    local options = null
+    local result = LoopFormInst.lower_loopform(2, blocks, 10, options)
+
+    // 全ブロックIDが含まれているか確認
+    local has_preheader = result.indexOf("\"preheader\":20")
+    local has_header = result.indexOf("\"header\":21")
+    local has_body = result.indexOf("\"body\":22")
+    local has_dispatch = result.indexOf("\"dispatch\":23")
+    local has_latch = result.indexOf("\"latch\":24")
+    local has_exit = result.indexOf("\"exit\":25")
+
+    if has_preheader < 0 || has_header < 0 || has_body < 0 ||
+       has_dispatch < 0 || has_latch < 0 || has_exit < 0 {
+      print("ERROR: Not all blocks found")
+      return 1
+    }
+
+    print("✓ PASS: Blocks validation")
+    return 0
+  }
+
+  // Test 3: Condition モード
+  test_condition_modes() {
+    print("\n[Test 3] Condition modes")
+
+    local blocks = new MapBox()
+    blocks.set("preheader", 30)
+    blocks.set("header", 31)
+    blocks.set("body", 32)
+    blocks.set("dispatch", 33)
+    blocks.set("latch", 34)
+    blocks.set("exit", 35)
+
+    // Test 3a: MIR モード（デフォルト）
+    local options_mir = new MapBox()
+    options_mir.set("mode", "mir")
+
+    local result_mir = LoopFormInst.lower_loopform(3, blocks, 15, options_mir)
+
+    local has_mir_mode = result_mir.indexOf("\"mode\":\"mir\"")
+    if has_mir_mode < 0 {
+      print("ERROR: MIR mode not found")
+      return 1
+    }
+
+    print("✓ PASS: MIR mode")
+
+    // Test 3b: Payload モード（実験的）
+    local options_payload = new MapBox()
+    options_payload.set("mode", "payload")
+    options_payload.set("payload_max", 500000)
+
+    local result_payload = LoopFormInst.lower_loopform(4, blocks, 20, options_payload)
+
+    local has_payload_mode = result_payload.indexOf("\"mode\":\"payload\"")
+    if has_payload_mode < 0 {
+      print("ERROR: Payload mode not found")
+      return 1
+    }
+
+    local has_max = result_payload.indexOf("\"payload_max\":500000")
+    if has_max < 0 {
+      print("ERROR: payload_max not found")
+      return 1
+    }
+
+    print("✓ PASS: Payload mode")
+
+    return 0
+  }
+
+  // Test 4: PHI incoming 配列検証（Stage 2）
+  test_phi_incoming_arrays() {
+    print("\n[Test 4] PHI incoming arrays (Stage 2)")
+
+    local blocks = new MapBox()
+    blocks.set("preheader", 40)
+    blocks.set("header", 41)
+    blocks.set("body", 42)
+    blocks.set("dispatch", 43)
+    blocks.set("latch", 44)
+    blocks.set("exit", 45)
+
+    local options = null
+    local result = LoopFormInst.lower_loopform(5, blocks, 25, options)
+
+    // Test 4a: Header PHI incoming 配列検証
+    // Expected: {"dst":0,"incoming":[{"value":0,"block":40},{"value":0,"block":44,"computed":true}]}
+    local has_header_phi_incoming = result.indexOf("\"header_phi\"")
+    if has_header_phi_incoming < 0 {
+      print("ERROR: header_phi not found")
+      return 1
+    }
+
+    local has_incoming_array = result.indexOf("\"incoming\":[")
+    if has_incoming_array < 0 {
+      print("ERROR: incoming array not found")
+      return 1
+    }
+
+    local has_preheader_incoming = result.indexOf("{\"value\":0,\"block\":40}")
+    if has_preheader_incoming < 0 {
+      print("ERROR: preheader incoming not found")
+      return 1
+    }
+
+    local has_latch_incoming = result.indexOf("{\"value\":0,\"block\":44,\"computed\":true}")
+    if has_latch_incoming < 0 {
+      print("ERROR: latch incoming with computed flag not found")
+      return 1
+    }
+
+    print("✓ PASS: Header PHI incoming array")
+
+    // Test 4b: Dispatch PHI computed フラグ検証
+    local has_dispatch_phis = result.indexOf("\"dispatch_phis\"")
+    if has_dispatch_phis < 0 {
+      print("ERROR: dispatch_phis not found")
+      return 1
+    }
+
+    local has_payload_computed = result.indexOf("{\"value\":0,\"block\":42,\"computed\":true}")
+    if has_payload_computed < 0 {
+      print("ERROR: payload PHI computed flag not found")
+      return 1
+    }
+
+    print("✓ PASS: Dispatch PHI computed flags")
+
+    return 0
+  }
+}