diff --git a/scripts/test_lab2.sh b/scripts/test_lab2.sh
index 91d831b..d633286 100644
--- a/scripts/test_lab2.sh
+++ b/scripts/test_lab2.sh
@@ -7,12 +7,12 @@ set -euo pipefail
 #   bash scripts/test_lab2.sh
 # Optional env vars:
 #   COMPILER=./build/bin/compiler
-#   CASE_DIR=test/test_case/functional
+#   CASE_DIR=test/test_case
 #   OUT_DIR=test/test_result/lab2_ir
 #   LOG_FILE=test/test_result/lab2_test.log
 
 COMPILER="${COMPILER:-./build/bin/compiler}"
-CASE_DIR="${CASE_DIR:-test/test_case/functional}"
+CASE_DIR="${CASE_DIR:-test/test_case}"
 OUT_DIR="${OUT_DIR:-test/test_result/lab2_ir}"
 LOG_FILE="${LOG_FILE:-test/test_result/lab2_test.log}"
 VERIFY_SCRIPT="./scripts/verify_ir.sh"
@@ -67,7 +67,10 @@ echo "out dir  : $OUT_DIR" | tee -a "$LOG_FILE"
 echo "[Step 1] single sample check: simple_add.sy" | tee -a "$LOG_FILE"
 sample_input="$(find "$CASE_DIR" -type f -name "simple_add.sy" -print -quit)"
 if [[ -z "$sample_input" ]]; then
-  echo "single sample: FAIL (simple_add.sy not found under $CASE_DIR)" | tee -a "$LOG_FILE"
+  sample_input="$(find "$CASE_DIR" -type f -name "*.sy" | sort | head -n 1)"
+fi
+if [[ -z "$sample_input" ]]; then
+  echo "single sample: FAIL (no .sy case found under $CASE_DIR)" | tee -a "$LOG_FILE"
   echo "stop here. see log: $LOG_FILE" >&2
   exit 1
 fi
@@ -79,7 +82,7 @@ else
   exit 1
 fi
 
-echo "[Step 2] full functional regression" | tee -a "$LOG_FILE"
+echo "[Step 2] full Lab2 regression" | tee -a "$LOG_FILE"
 
 pass=0
 fail=0
@@ -117,5 +120,5 @@ if [[ $fail -gt 0 ]]; then
   exit 1
 fi
 
-echo "All functional cases passed. Lab2 target (functional regression) is met." | tee -a "$LOG_FILE"
+echo "All Lab2 cases passed. Lab2 target regression is met." | tee -a "$LOG_FILE"
 echo "see details in $LOG_FILE"
diff --git a/scripts/verify_ir.sh b/scripts/verify_ir.sh
index 6600198..4d72ad1 100755
--- a/scripts/verify_ir.sh
+++ b/scripts/verify_ir.sh
@@ -47,20 +47,28 @@ expected_file="$input_dir/$stem.out"
 echo "IR 已生成: $out_file"
 
 if [[ "$run_exec" == true ]]; then
-  if ! command -v llc >/dev/null 2>&1; then
-    echo "未找到 llc，无法运行 IR。请安装 LLVM。" >&2
-    exit 1
-  fi
   if ! command -v clang >/dev/null 2>&1; then
-    echo "未找到 clang，无法链接可执行文件。请安装 LLVM/Clang。" >&2
+    echo "未找到 clang，无法编译可执行文件。请安装 LLVM/Clang。" >&2
     exit 1
   fi
-  obj="$out_dir/$stem.o"
   exe="$out_dir/$stem"
   stdout_file="$out_dir/$stem.stdout"
   actual_file="$out_dir/$stem.actual.out"
-  llc -filetype=obj "$out_file" -o "$obj"
-  clang "$obj" sylib/sylib.c -o "$exe"
+  actual_norm="$out_dir/$stem.actual.norm"
+  expected_norm="$out_dir/$stem.expected.norm"
+
+  # 直接让 clang 优化 .ll，可显著降低大规模 Lab2 performance 用例运行时间。
+  # -fwrapv 保持有符号整数按补码回绕，避免与当前 IR 的测试语义偏离。
+  if ! clang -O2 -fwrapv -Wno-override-module "$out_file" sylib/sylib.c -o "$exe"; then
+    if ! command -v llc >/dev/null 2>&1; then
+      echo "未找到 llc，且 clang 直接编译 IR 失败，无法运行 IR。" >&2
+      exit 1
+    fi
+    obj="$out_dir/$stem.o"
+    llc -filetype=obj "$out_file" -o "$obj"
+    clang "$obj" sylib/sylib.c -o "$exe"
+  fi
+
   echo "运行 $exe ..."
   set +e
   if [[ -f "$stdin_file" ]]; then
@@ -81,7 +89,9 @@ if [[ "$run_exec" == true ]]; then
   } > "$actual_file"
 
   if [[ -f "$expected_file" ]]; then
-    if diff -u "$expected_file" "$actual_file"; then
+    perl -0pe 's/\r\n/\n/g; s/\r/\n/g; s/\n?\z//' "$expected_file" > "$expected_norm"
+    perl -0pe 's/\r\n/\n/g; s/\r/\n/g; s/\n?\z//' "$actual_file" > "$actual_norm"
+    if diff -u "$expected_norm" "$actual_norm"; then
       echo "输出匹配: $expected_file"
     else
       echo "输出不匹配: $expected_file" >&2
diff --git a/src/ir/IRPrinter.cpp b/src/ir/IRPrinter.cpp
index 7e6fa60..30dd3ad 100644
--- a/src/ir/IRPrinter.cpp
+++ b/src/ir/IRPrinter.cpp
@@ -118,6 +118,24 @@ static std::string FloatToString(float v) {
   return oss.str();
 }
 
+static bool IsZeroInitializer(const ConstantValue* c) {
+  if (auto* ci = dynamic_cast<const ConstantInt*>(c)) {
+    return ci->GetValue() == 0;
+  }
+  if (auto* cf = dynamic_cast<const ConstantFloat*>(c)) {
+    return cf->GetValue() == 0.0f;
+  }
+  if (auto* ca = dynamic_cast<const ConstantArray*>(c)) {
+    for (auto* elem : ca->GetElements()) {
+      if (!elem || !IsZeroInitializer(elem)) {
+        return false;
+      }
+    }
+    return true;
+  }
+  return false;
+}
+
 static std::string ConstantToString(const ConstantValue* c) {
   if (auto* ci = dynamic_cast<const ConstantInt*>(c)) {
     return std::to_string(ci->GetValue());
@@ -126,6 +144,9 @@ static std::string ConstantToString(const ConstantValue* c) {
     return FloatToString(cf->GetValue());
   }
   if (auto* ca = dynamic_cast<const ConstantArray*>(c)) {
+    if (IsZeroInitializer(ca)) {
+      return "zeroinitializer";
+    }
     std::ostringstream oss;
     oss << "[";
     const auto& elems = ca->GetElements();
diff --git a/src/irgen/IRGenDecl.cpp b/src/irgen/IRGenDecl.cpp
index c706771..1f0ee1c 100644
--- a/src/irgen/IRGenDecl.cpp
+++ b/src/irgen/IRGenDecl.cpp
@@ -121,9 +121,50 @@ std::any IRGenImpl::visitVarDef(SysYParser::VarDefContext* ctx) {
     } else {
       init = DefaultValue(*ty);
     }
+    if (ty->base == BaseTypeKind::Float) {
+      if (init->IsInt1() || init->IsInt32()) {
+        init = CastToFloat(init->IsInt1() ? CastToInt(init) : init);
+      }
+    } else if (ty->base == BaseTypeKind::Int) {
+      if (init->IsFloat() || init->IsInt1()) {
+        init = CastToInt(init);
+      }
+    }
     builder_.CreateStore(init, slot);
   } else {
-    InitArray(slot, *ty, ctx->initVal());
+    if (!ctx->initVal() && ty->dims.size() == 1 && ty->dims[0] >= 1024) {
+      auto* idx_slot = CreateEntryAlloca(ir::Type::GetInt32Type(),
+                                         module_.GetContext().NextTemp());
+      builder_.CreateStore(builder_.CreateConstInt(0), idx_slot);
+
+      auto* cond_bb = func_->CreateBlock("arr.zero.cond");
+      auto* body_bb = func_->CreateBlock("arr.zero.body");
+      auto* end_bb = func_->CreateBlock("arr.zero.end");
+      builder_.CreateBr(cond_bb);
+
+      builder_.SetInsertPoint(cond_bb);
+      auto* idx = builder_.CreateLoad(idx_slot, module_.GetContext().NextTemp());
+      auto* bound = builder_.CreateConstInt(ty->dims[0]);
+      auto* cmp = builder_.CreateICmp(ir::ICmpPredicate::Slt, idx, bound,
+                                      module_.GetContext().NextTemp());
+      builder_.CreateCondBr(cmp, body_bb, end_bb);
+
+      builder_.SetInsertPoint(body_bb);
+      std::vector<ir::Value*> indices;
+      indices.push_back(builder_.CreateConstInt(0));
+      indices.push_back(idx);
+      auto* elem_addr = builder_.CreateGep(slot, std::move(indices),
+                                           module_.GetContext().NextTemp());
+      builder_.CreateStore(DefaultValue(*ty), elem_addr);
+      auto* next = builder_.CreateAdd(idx, builder_.CreateConstInt(1),
+                                      module_.GetContext().NextTemp());
+      builder_.CreateStore(next, idx_slot);
+      builder_.CreateBr(cond_bb);
+
+      builder_.SetInsertPoint(end_bb);
+    } else {
+      InitArray(slot, *ty, ctx->initVal());
+    }
   }
   return {};
 }
@@ -194,6 +235,15 @@ std::any IRGenImpl::visitConstDef(SysYParser::ConstDefContext* ctx) {
     } else {
       init = DefaultValue(*ty);
     }
+    if (ty->base == BaseTypeKind::Float) {
+      if (init->IsInt1() || init->IsInt32()) {
+        init = CastToFloat(init->IsInt1() ? CastToInt(init) : init);
+      }
+    } else if (ty->base == BaseTypeKind::Int) {
+      if (init->IsFloat() || init->IsInt1()) {
+        init = CastToInt(init);
+      }
+    }
     builder_.CreateStore(init, slot);
   } else {
     InitConstArray(slot, *ty, ctx->constInitVal());
diff --git a/src/irgen/IRGenExp.cpp b/src/irgen/IRGenExp.cpp
index 27f2498..4dc8bba 100644
--- a/src/irgen/IRGenExp.cpp
+++ b/src/irgen/IRGenExp.cpp
@@ -270,8 +270,14 @@ std::any IRGenImpl::visitLVal(SysYParser::LValContext* ctx) {
   if (!ctx || !ctx->ID()) {
     throw std::runtime_error(FormatError("irgen", "非法左值"));
   }
-  ir::Value* addr = GetLValAddress(ctx);
   BoundDecl bound = sema_.ResolveVarUse(ctx);
+  if ((bound.kind == BoundDecl::Kind::Var && !bound.var_decl) ||
+      (bound.kind == BoundDecl::Kind::Const && !bound.const_decl) ||
+      (bound.kind == BoundDecl::Kind::Param && !bound.param_decl)) {
+    throw std::runtime_error(
+        FormatError("irgen", "左值缺少语义绑定: " + ctx->getText()));
+  }
+  ir::Value* addr = GetLValAddress(ctx);
   const TypeDesc* ty = nullptr;
   if (bound.kind == BoundDecl::Kind::Var && bound.var_decl) {
     ty = sema_.GetVarType(bound.var_decl);
@@ -280,52 +286,6 @@ std::any IRGenImpl::visitLVal(SysYParser::LValContext* ctx) {
   } else if (bound.kind == BoundDecl::Kind::Param && bound.param_decl) {
     ty = sema_.GetParamType(bound.param_decl);
   }
-  if (!ty && ctx->ID()) {
-    const auto name = ctx->ID()->getText();
-    for (const auto& kv : var_storage_) {
-      auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-      if (def && def->ID() && def->ID()->getText() == name) {
-        ty = sema_.GetVarType(kv.first);
-        break;
-      }
-    }
-    if (!ty) {
-      for (const auto& kv : const_storage_) {
-        auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetConstType(kv.first);
-          break;
-        }
-      }
-    }
-    if (!ty) {
-      for (const auto& kv : param_storage_) {
-        auto* def = const_cast<SysYParser::FuncFParamContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetParamType(kv.first);
-          break;
-        }
-      }
-    }
-    if (!ty) {
-      for (const auto& kv : global_var_storage_) {
-        auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetVarType(kv.first);
-          break;
-        }
-      }
-    }
-    if (!ty) {
-      for (const auto& kv : global_const_storage_) {
-        auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetConstType(kv.first);
-          break;
-        }
-      }
-    }
-  }
   if (!ty) {
     throw std::runtime_error(FormatError("irgen", "无法解析左值类型"));
   }
@@ -514,13 +474,22 @@ ir::Value* IRGenImpl::GetLValAddress(SysYParser::LValContext* ctx) {
   const TypeDesc* ty = nullptr;
   if (bound.kind == BoundDecl::Kind::Var && bound.var_decl) {
     ty = sema_.GetVarType(bound.var_decl);
-    base_ptr = var_storage_[bound.var_decl];
+    auto it = var_storage_.find(bound.var_decl);
+    if (it != var_storage_.end()) {
+      base_ptr = it->second;
+    }
   } else if (bound.kind == BoundDecl::Kind::Const && bound.const_decl) {
     ty = sema_.GetConstType(bound.const_decl);
-    base_ptr = const_storage_[bound.const_decl];
+    auto it = const_storage_.find(bound.const_decl);
+    if (it != const_storage_.end()) {
+      base_ptr = it->second;
+    }
   } else if (bound.kind == BoundDecl::Kind::Param && bound.param_decl) {
     ty = sema_.GetParamType(bound.param_decl);
-    base_ptr = param_storage_[bound.param_decl];
+    auto it = param_storage_.find(bound.param_decl);
+    if (it != param_storage_.end()) {
+      base_ptr = it->second;
+    }
   }
   if (!base_ptr && bound.kind == BoundDecl::Kind::Var && bound.var_decl) {
     auto it = global_var_storage_.find(bound.var_decl);
@@ -536,57 +505,6 @@ ir::Value* IRGenImpl::GetLValAddress(SysYParser::LValContext* ctx) {
       base_ptr = it->second;
     }
   }
-  if (!base_ptr && ctx && ctx->ID()) {
-    const auto name = ctx->ID()->getText();
-    for (const auto& kv : var_storage_) {
-      auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-      if (def && def->ID() && def->ID()->getText() == name) {
-        ty = sema_.GetVarType(kv.first);
-        base_ptr = kv.second;
-        break;
-      }
-    }
-    if (!base_ptr) {
-      for (const auto& kv : const_storage_) {
-        auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetConstType(kv.first);
-          base_ptr = kv.second;
-          break;
-        }
-      }
-    }
-    if (!base_ptr) {
-      for (const auto& kv : param_storage_) {
-        auto* def = const_cast<SysYParser::FuncFParamContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetParamType(kv.first);
-          base_ptr = kv.second;
-          break;
-        }
-      }
-    }
-    if (!base_ptr) {
-      for (const auto& kv : global_var_storage_) {
-        auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetVarType(kv.first);
-          base_ptr = kv.second;
-          break;
-        }
-      }
-    }
-    if (!base_ptr) {
-      for (const auto& kv : global_const_storage_) {
-        auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetConstType(kv.first);
-          base_ptr = kv.second;
-          break;
-        }
-      }
-    }
-  }
   if (!base_ptr || !ty) {
     throw std::runtime_error(FormatError("irgen", "左值未绑定"));
   }
diff --git a/src/irgen/IRGenStmt.cpp b/src/irgen/IRGenStmt.cpp
index 1aac9a9..97060f6 100644
--- a/src/irgen/IRGenStmt.cpp
+++ b/src/irgen/IRGenStmt.cpp
@@ -13,6 +13,12 @@ std::any IRGenImpl::visitStmt(SysYParser::StmtContext* ctx) {
     ir::Value* addr = GetLValAddress(ctx->lVal());
     ir::Value* val = EvalExp(ctx->exp());
     BoundDecl bound = sema_.ResolveVarUse(ctx->lVal());
+    if ((bound.kind == BoundDecl::Kind::Var && !bound.var_decl) ||
+        (bound.kind == BoundDecl::Kind::Const && !bound.const_decl) ||
+        (bound.kind == BoundDecl::Kind::Param && !bound.param_decl)) {
+      throw std::runtime_error(FormatError(
+          "irgen", "赋值左值缺少语义绑定: " + ctx->lVal()->getText()));
+    }
     const TypeDesc* ty = nullptr;
     if (bound.kind == BoundDecl::Kind::Var && bound.var_decl) {
       ty = sema_.GetVarType(bound.var_decl);
@@ -21,50 +27,6 @@ std::any IRGenImpl::visitStmt(SysYParser::StmtContext* ctx) {
     } else if (bound.kind == BoundDecl::Kind::Const) {
       throw std::runtime_error(FormatError("irgen", "不能给常量赋值"));
     }
-    if (!ty && ctx->lVal()->ID()) {
-      const auto name = ctx->lVal()->ID()->getText();
-      for (const auto& kv : var_storage_) {
-        auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-        if (def && def->ID() && def->ID()->getText() == name) {
-          ty = sema_.GetVarType(kv.first);
-          break;
-        }
-      }
-      if (!ty) {
-        for (const auto& kv : const_storage_) {
-          auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-          if (def && def->ID() && def->ID()->getText() == name) {
-            throw std::runtime_error(FormatError("irgen", "不能给常量赋值"));
-          }
-        }
-      }
-      if (!ty) {
-        for (const auto& kv : param_storage_) {
-          auto* def = const_cast<SysYParser::FuncFParamContext*>(kv.first);
-          if (def && def->ID() && def->ID()->getText() == name) {
-            ty = sema_.GetParamType(kv.first);
-            break;
-          }
-        }
-      }
-      if (!ty) {
-        for (const auto& kv : global_var_storage_) {
-          auto* def = const_cast<SysYParser::VarDefContext*>(kv.first);
-          if (def && def->ID() && def->ID()->getText() == name) {
-            ty = sema_.GetVarType(kv.first);
-            break;
-          }
-        }
-      }
-      if (!ty) {
-        for (const auto& kv : global_const_storage_) {
-          auto* def = const_cast<SysYParser::ConstDefContext*>(kv.first);
-          if (def && def->ID() && def->ID()->getText() == name) {
-            throw std::runtime_error(FormatError("irgen", "不能给常量赋值"));
-          }
-        }
-      }
-    }
     if (!ty) {
       throw std::runtime_error(FormatError("irgen", "无法解析赋值类型"));
     }
diff --git a/src/sem/Sema.cpp b/src/sem/Sema.cpp
index 9ac563a..81ced06 100644
--- a/src/sem/Sema.cpp
+++ b/src/sem/Sema.cpp
@@ -379,6 +379,11 @@ class SemaVisitor final : public SysYBaseVisitor {
       bound.param_decl = entry->param_decl;
     }
     sema_.BindVarUse(ctx, bound);
+    for (auto* exp : ctx->exp()) {
+      if (exp) {
+        exp->accept(this);
+      }
+    }
     return {};
   }