Merge branch 'midend-SCCP' into midend

src/include/midend/IR.h

@@ -514,12 +514,15 @@ public:
   explicit BasicBlock(Function *parent, const std::string &name = "")
       : Value(Type::getLabelType(), name), parent(parent) {}
   ~BasicBlock() override {
-    for (auto pre : predecessors) {
-      pre->removeSuccessor(this);
-    }
-    for (auto suc : successors) {
-      suc->removePredecessor(this);
-    }
+    // for (auto pre : predecessors) {
+    //   pre->removeSuccessor(this);
+    // }
+    // for (auto suc : successors) {
+    //   suc->removePredecessor(this);
+    // }
+    // 这些关系应该在 BasicBlock 被从 Function 中移除时，
+    // 由负责 CFG 优化的 Pass (例如 SCCP 的 RemoveDeadBlock) 显式地清理。
+    // 析构函数只负责清理 BasicBlock 自身拥有的资源（例如，指令列表）。
   }
   
 public:
@@ -599,7 +602,7 @@ public:
     prev->addSuccessor(next);
     next->addPredecessor(prev);
   }
-  void removeInst(iterator pos) { instructions.erase(pos); }
+  iterator removeInst(iterator pos) { return instructions.erase(pos); }
   void removeInst(Instruction *inst) {
     auto pos = std::find_if(instructions.begin(), instructions.end(),
                             [inst](const std::unique_ptr<Instruction> &i) { return i.get() == inst; });
@@ -626,6 +629,21 @@ class User : public Value {
   explicit User(Type *type, const std::string &name = "") : Value(type, name) {}
 
  public:
+  // ~User() override {
+  //   // 当 User 对象被销毁时（例如，LoadInst 或 StoreInst 被删除时），
+  //   // 它必须通知它所使用的所有 Value，将对应的 Use 关系从它们的 uses 列表中移除。
+  //   // 这样可以防止 Value 的 uses 列表中出现悬空的 Use 对象。
+  //   for (const auto &use_ptr : operands) {
+  //     // 确保 use_ptr 非空，并且其内部指向的 Value* 也非空
+  //     // (虽然通常情况下不会为空，但为了健壮性考虑)
+  //     if (use_ptr && use_ptr->getValue()) {
+  //       use_ptr->getValue()->removeUse(use_ptr);
+  //     }
+  //   }
+  //   // operands 向量本身是 std::vector<std::shared_ptr<Use>>，
+  //   // 在此析构函数结束后，operands 向量会被销毁，其内部的 shared_ptr 也会被释放，
+  //   // 如果 shared_ptr 引用计数降为0，Use 对象本身也会被销毁。
+  // }
   unsigned getNumOperands() const { return operands.size(); }  ///< 获取操作数数量
   auto operand_begin() const { return operands.begin(); }              ///< 返回操作数列表的开头迭代器
   auto operand_end() const { return operands.end(); }                  ///< 返回操作数列表的结尾迭代器
@@ -695,15 +713,13 @@ class Instruction : public User {
     kCondBr = 0x1UL << 30,
     kBr = 0x1UL << 31,
     kReturn = 0x1UL << 32,
+    kUnreachable = 0x1UL << 33,
     // mem op
-    kAlloca = 0x1UL << 33,
-    kLoad = 0x1UL << 34,
-    kStore = 0x1UL << 35,
-    kGetElementPtr = 0x1UL << 36,
-    kMemset = 0x1UL << 37,
-    // kGetSubArray = 0x1UL << 38,
-    // Constant Kind removed as Constants are now Values, not Instructions.
-    // kConstant = 0x1UL << 37, // Conflicts with kMemset if kept as is
+    kAlloca = 0x1UL << 34,
+    kLoad = 0x1UL << 35,
+    kStore = 0x1UL << 36,
+    kGetElementPtr = 0x1UL << 37,
+    kMemset = 0x1UL << 38,
     // phi
     kPhi = 0x1UL << 39,
     kBitItoF = 0x1UL << 40,
@@ -832,7 +848,7 @@ public:
     return kind & MemoryOpMask;
   }
   bool isTerminator() const {
-    static constexpr uint64_t TerminatorOpMask = kCondBr | kBr | kReturn;
+    static constexpr uint64_t TerminatorOpMask = kCondBr | kBr | kReturn | kUnreachable;
     return kind & TerminatorOpMask;
   }
   bool isCmp() const {
@@ -852,6 +868,7 @@ public:
   }
   bool isUnconditional() const { return kind == kBr; }
   bool isConditional() const { return kind == kCondBr; }
+  bool isCondBr() const { return kind == kCondBr; }
   bool isPhi() const { return kind == kPhi; }
   bool isAlloca() const { return kind == kAlloca; }
   bool isLoad() const { return kind == kLoad; }
@@ -860,6 +877,7 @@ public:
   bool isMemset() const { return kind == kMemset; }
   bool isCall() const { return kind == kCall; }
   bool isReturn() const { return kind == kReturn; }
+  bool isUnreachable() const { return kind == kUnreachable; }
   bool isDefine() const {
     static constexpr uint64_t DefineOpMask = kAlloca | kStore | kPhi;
     return (kind & DefineOpMask) != 0U;
@@ -894,6 +912,9 @@ class PhiInst : public Instruction {
  public:
   Value* getValue(unsigned k) const {return getOperand(2 * k);}  ///< 获取位置为k的值
   BasicBlock* getBlock(unsigned k) const {return dynamic_cast<BasicBlock*>(getOperand(2 * k + 1));}
+  //增加llvm同名方法实现获取value和block
+  Value* getIncomingValue(unsigned k) const {return getOperand(2 * k);}  ///< 获取位置为k的值
+  BasicBlock* getIncomingBlock(unsigned k) const {return dynamic_cast<BasicBlock*>(getOperand(2 * k + 1));}
 
   auto& getincomings() const {return blk2val;}  ///< 获取所有的基本块和对应的值
 
@@ -1059,12 +1080,10 @@ class UncondBrInst : public Instruction {
   friend class Function;
 
 protected:
-  UncondBrInst(BasicBlock *block, std::vector<Value *> args,
+  UncondBrInst(BasicBlock *block,
                BasicBlock *parent = nullptr)
       : Instruction(kBr, Type::getVoidType(), parent, "") {
-    // assert(block->getNumArguments() == args.size());
     addOperand(block);
-    addOperands(args);
   }
 
 public:
@@ -1072,6 +1091,16 @@ public:
   auto getArguments() const {
     return make_range(std::next(operand_begin()), operand_end());
   }
+  std::vector<BasicBlock *> getSuccessors() const {
+    std::vector<BasicBlock *> succs;
+    // 假设无条件分支的目标块是它的第一个操作数
+    if (getNumOperands() > 0) {
+      if (auto target_bb = dynamic_cast<BasicBlock *>(getOperand(0))) {
+        succs.push_back(target_bb);
+      }
+    }
+    return succs;
+  }
 
 }; // class UncondBrInst
 
@@ -1083,17 +1112,12 @@ class CondBrInst : public Instruction {
   friend class Function;
   
 protected:
-  CondBrInst(Value *condition, BasicBlock *thenBlock, BasicBlock *elseBlock,
-             const std::vector<Value *> &thenArgs,
-             const std::vector<Value *> &elseArgs, BasicBlock *parent = nullptr)
+  CondBrInst(Value *condition, BasicBlock *thenBlock, BasicBlock *elseBlock, 
+              BasicBlock *parent = nullptr)
       : Instruction(kCondBr, Type::getVoidType(), parent, "") {
-    // assert(thenBlock->getNumArguments() == thenArgs.size() and
-    //        elseBlock->getNumArguments() == elseArgs.size());
     addOperand(condition);
     addOperand(thenBlock);
     addOperand(elseBlock);
-    addOperands(thenArgs);
-    addOperands(elseArgs);
   }
 public:
   Value* getCondition() const { return getOperand(0); }
@@ -1103,29 +1127,39 @@ public:
   BasicBlock* getElseBlock() const {
     return dynamic_cast<BasicBlock *>(getOperand(2));
   }
-  // auto getThenArguments() const {
-  //   auto begin = std::next(operand_begin(), 3);
-  //   // auto end = std::next(begin, getThenBlock()->getNumArguments());
-  //   return make_range(begin, end);
-  // }
-  // auto getElseArguments() const {
-  //   auto begin =
-  //       std::next(operand_begin(), 3 + getThenBlock()->getNumArguments());
-  //   auto end = operand_end();
-  //   return make_range(begin, end);
-  // }
+  std::vector<BasicBlock *> getSuccessors() const {
+    std::vector<BasicBlock *> succs;
+    // 假设条件分支的真实块是第二个操作数，假块是第三个操作数
+    // 操作数通常是：[0] 条件值, [1] TrueTargetBlock, [2] FalseTargetBlock
+    if (getNumOperands() > 2) {
+      if (auto true_bb = getThenBlock()) {
+        succs.push_back(true_bb);
+      }
+      if (auto false_bb = getElseBlock()) {
+        succs.push_back(false_bb);
+      }
+    }
+    return succs;
+  }
 
 }; // class CondBrInst
 
+class UnreachableInst : public Instruction {
+public:
+  // 构造函数：设置指令类型为 kUnreachable
+  explicit UnreachableInst(const std::string& name, BasicBlock *parent = nullptr)
+      : Instruction(kUnreachable, Type::getVoidType(), parent, "") {}
+
+};
+
 //! Allocate memory for stack variables, used for non-global variable declartion
 class AllocaInst : public Instruction {
   friend class IRBuilder;
   friend class Function;
 protected:
-  AllocaInst(Type *type, const std::vector<Value *> &dims = {},
+  AllocaInst(Type *type,
              BasicBlock *parent = nullptr, const std::string &name = "")
       : Instruction(kAlloca, type, parent, name) {
-    addOperands(dims);
   }
 
 public:
@@ -1133,9 +1167,6 @@ public:
   Type* getAllocatedType() const {
     return getType()->as<PointerType>()->getBaseType();
   }  ///< 获取分配的类型
-  int getNumDims() const { return getNumOperands(); }
-  auto getDims() const { return getOperands(); }
-  Value* getDim(int index) { return getOperand(index); }
 
 }; // class AllocaInst
 
@@ -1182,21 +1213,15 @@ class LoadInst : public Instruction {
   friend class Function;
 
 protected:
-  LoadInst(Value *pointer, const std::vector<Value *> &indices = {},
+  LoadInst(Value *pointer,
            BasicBlock *parent = nullptr, const std::string &name = "")
       : Instruction(kLoad, pointer->getType()->as<PointerType>()->getBaseType(),
                     parent, name) {
     addOperand(pointer);
-    addOperands(indices);
   }
 
 public:
-  int getNumIndices() const { return getNumOperands() - 1; }
   Value* getPointer() const { return getOperand(0); }
-  auto getIndices() const {
-    return make_range(std::next(operand_begin()), operand_end());
-  }
-  Value* getIndex(int index) const { return getOperand(index + 1); }
   
 }; // class LoadInst
 
@@ -1207,22 +1232,15 @@ class StoreInst : public Instruction {
 
 protected:
   StoreInst(Value *value, Value *pointer,
-            const std::vector<Value *> &indices = {},
             BasicBlock *parent = nullptr, const std::string &name = "")
       : Instruction(kStore, Type::getVoidType(), parent, name) {
     addOperand(value);
     addOperand(pointer);
-    addOperands(indices);
   }
 
 public:
-  int getNumIndices() const { return getNumOperands() - 2; }
   Value* getValue() const { return getOperand(0); }
   Value* getPointer() const { return getOperand(1); }
-  auto getIndices() const {
-    return make_range(std::next(operand_begin(), 2), operand_end());
-  }
-  Value* getIndex(int index) const { return getOperand(index + 2); }
 
 }; // class StoreInst
 
@@ -1361,20 +1379,18 @@ protected:
 
 protected:
   GlobalValue(Module *parent, Type *type, const std::string &name,
-              const std::vector<Value *> &dims = {}, 
               ValueCounter init = {})
       : Value(type, name), parent(parent) {
     assert(type->isPointer());
-    // addOperands(dims); 
     // 维度信息已经被记录到Type中，dim只是为了方便初始化
-    numDims = dims.size();
+    numDims = 0;
     if (init.size() == 0) {
       unsigned num = 1;
-      for (unsigned i = 0; i < numDims; i++) {
-        // Assume dims elements are ConstantInteger and cast appropriately
-        auto dim_val = dynamic_cast<ConstantInteger*>(dims[i]);
-        assert(dim_val && "GlobalValue dims must be constant integers");
-        num *= dim_val->getInt();
+      auto arrayType = type->as<ArrayType>();
+      while (arrayType) {
+        numDims++;
+        num *= arrayType->getNumElements();
+        arrayType = arrayType->getElementType()->as<ArrayType>();
       }
       if (dynamic_cast<PointerType *>(type)->getBaseType() == Type::getFloatType()) {
         init.push_back(ConstantFloating::get(0.0F), num); // Use new constant factory
@@ -1386,9 +1402,6 @@ protected:
   }
 
 public:
-  // unsigned getNumDims() const  { return numDims; }                     ///< 获取维度数量
-  // Value* getDim(unsigned index) const { return getOperand(index); }  ///< 获取位置为index的维度
-  // auto getDims() const { return getOperands(); }                              ///< 获取维度列表
   unsigned getNumIndices() const {
     return numDims;
   } ///< 获取维度数量
@@ -1430,13 +1443,19 @@ class ConstantVariable : public Value {
   ValueCounter initValues;  ///< 值
 
  protected:
-  ConstantVariable(Module *parent, Type *type, const std::string &name, const ValueCounter &init,
-                   const std::vector<Value *> &dims = {})
+  ConstantVariable(Module *parent, Type *type, const std::string &name, const ValueCounter &init)
       : Value(type, name), parent(parent) {
     assert(type->isPointer());
-    numDims = dims.size();
+    // numDims = dims.size();
+    numDims = 0;
+    if(type->as<PointerType>()->getBaseType()->isArray()) {
+      auto arrayType = type->as<ArrayType>();
+      while (arrayType) {
+        numDims++;
+        arrayType = arrayType->getElementType()->as<ArrayType>();
+      }
+    }
     initValues = init;
-    // addOperands(dims); 同GlobalValue，维度信息已经被记录到Type中，dim只是为了方便初始化
   }
 
  public:
@@ -1468,9 +1487,6 @@ class ConstantVariable : public Value {
 
     return getByIndex(index);
   }                                                        ///< 通过多维索引indices获取初始值
-  // unsigned getNumDims() const { return numDims; }  ///< 获取维度数量
-  // Value* getDim(unsigned index) const { return getOperand(index); }  ///< 获取位置为index的维度
-  // auto getDims() const { return getOperands(); }                              ///< 获取维度列表
   const ValueCounter& getInitValues() const { return initValues; }                           ///< 获取初始值
 };
 
@@ -1529,13 +1545,12 @@ class Module {
     return result.first->second.get();
   }  ///< 创建外部函数
   ///< 变量创建伴随着符号表的更新
-  GlobalValue* createGlobalValue(const std::string &name, Type *type, const std::vector<Value *> &dims = {},
-                         const ValueCounter &init = {}) {
+  GlobalValue* createGlobalValue(const std::string &name, Type *type, const ValueCounter &init = {}) {
     bool isFinished = variableTable.isCurNodeNull();
     if (isFinished) {
       variableTable.enterGlobalScope();
     }
-    auto result = variableTable.addVariable(name, new GlobalValue(this, type, name, dims, init));
+    auto result = variableTable.addVariable(name, new GlobalValue(this, type, name, init));
     if (isFinished) {
       variableTable.leaveScope();
     }
@@ -1544,9 +1559,8 @@ class Module {
     }
     return dynamic_cast<GlobalValue *>(result);
   }  ///< 创建全局变量
-  ConstantVariable* createConstVar(const std::string &name, Type *type, const ValueCounter &init,
-                      const std::vector<Value *> &dims = {}) {
-    auto result = variableTable.addVariable(name, new ConstantVariable(this, type, name, init, dims));
+  ConstantVariable* createConstVar(const std::string &name, Type *type, const ValueCounter &init) {
+    auto result = variableTable.addVariable(name, new ConstantVariable(this, type, name, init));
     if (result == nullptr) {
       return nullptr;
     }

src/include/midend/IRBuilder.h

@@ -239,31 +239,30 @@ class IRBuilder {
     block->getInstructions().emplace(position, inst);
     return inst;
   }  ///< 创建return指令
-  UncondBrInst * createUncondBrInst(BasicBlock *thenBlock, const std::vector<Value *> &args) {
-    auto inst = new UncondBrInst(thenBlock, args, block);
+  UncondBrInst * createUncondBrInst(BasicBlock *thenBlock) {
+    auto inst = new UncondBrInst(thenBlock, block);
     assert(inst);
     block->getInstructions().emplace(position, inst);
     return inst;
   }  ///< 创建无条件指令
-  CondBrInst * createCondBrInst(Value *condition, BasicBlock *thenBlock, BasicBlock *elseBlock,
-                        const std::vector<Value *> &thenArgs, const std::vector<Value *> &elseArgs) {
-    auto inst = new CondBrInst(condition, thenBlock, elseBlock, thenArgs, elseArgs, block);
+  CondBrInst * createCondBrInst(Value *condition, BasicBlock *thenBlock, BasicBlock *elseBlock) {
+    auto inst = new CondBrInst(condition, thenBlock, elseBlock, block);
     assert(inst);
     block->getInstructions().emplace(position, inst);
     return inst;
   }  ///< 创建条件跳转指令
-  AllocaInst * createAllocaInst(Type *type, const std::vector<Value *> &dims = {}, const std::string &name = "") {
-    auto inst = new AllocaInst(type, dims, block, name);
+  UnreachableInst * createUnreachableInst(const std::string &name = "") {
+    auto inst = new UnreachableInst(name, block);
+    assert(inst);
+    block->getInstructions().emplace(position, inst);
+    return inst;
+  }  ///< 创建不可达指令
+  AllocaInst * createAllocaInst(Type *type, const std::string &name = "") {
+    auto inst = new AllocaInst(type, block, name);
     assert(inst);
     block->getInstructions().emplace(position, inst);
     return inst;
   }  ///< 创建分配指令
-  AllocaInst * createAllocaInstWithoutInsert(Type *type, const std::vector<Value *> &dims = {}, BasicBlock *parent = nullptr,
-                                     const std::string &name = "") {
-    auto inst = new AllocaInst(type, dims, parent, name);
-    assert(inst);
-    return inst;
-  }  ///< 创建不插入指令列表的分配指令[仅用于phi指令]
   LoadInst * createLoadInst(Value *pointer, const std::vector<Value *> &indices = {}, const std::string &name = "") {
     std::string newName;
     if (name.empty()) {
@@ -275,7 +274,7 @@ class IRBuilder {
       newName = name;
     }
 
-    auto inst = new LoadInst(pointer, indices, block, newName);
+    auto inst = new LoadInst(pointer, block, newName);
     assert(inst);
     block->getInstructions().emplace(position, inst);
     return inst;
@@ -286,9 +285,8 @@ class IRBuilder {
     block->getInstructions().emplace(position, inst);
     return inst;
   }  ///< 创建memset指令
-  StoreInst * createStoreInst(Value *value, Value *pointer, const std::vector<Value *> &indices = {},
-                       const std::string &name = "") {
-    auto inst = new StoreInst(value, pointer, indices, block, name);
+  StoreInst * createStoreInst(Value *value, Value *pointer, const std::string &name = "") {
+    auto inst = new StoreInst(value, pointer, block, name);
     assert(inst);
     block->getInstructions().emplace(position, inst);
     return inst;
@@ -308,24 +306,6 @@ class IRBuilder {
     block->getInstructions().emplace(block->begin(), inst);
     return inst;
   }  ///< 创建Phi指令
-  // GetElementPtrInst* createGetElementPtrInst(Value *basePointer,
-  //                                const std::vector<Value *> &indices = {},
-  //                                const std::string &name = "") {
-  //   std::string newName;
-  //   if (name.empty()) {
-  //     std::stringstream ss;
-  //     ss << tmpIndex;
-  //     newName = ss.str();
-  //     tmpIndex++;
-  //   } else {
-  //     newName = name;
-  //   }
-
-  //   auto inst = new GetElementPtrInst(basePointer, indices, block, newName);
-  //   assert(inst);
-  //   block->getInstructions().emplace(position, inst);
-  //   return inst;
-  // }
   /**
      * @brief 根据 LLVM 设计模式创建 GEP 指令。
      * 它会自动推断返回类型，无需手动指定。

src/include/midend/Pass/Optimize/SCCP.h

@@ -1,196 +1,139 @@
 #pragma once
 
 #include "IR.h"
+#include "Pass.h"
+#include "SysYIROptUtils.h"
+#include <cassert>
+#include <iostream>
+#include <map>
+#include <queue>
+#include <set>
+#include <unordered_set>
+#include <vector>
+#include <variant>
+#include <functional>
 
 namespace sysy {
 
-// 稀疏条件常量传播类
-// Sparse Conditional Constant Propagation
-/*
-伪代码
-function SCCP_Optimization(Module):
-    for each Function in Module:
-        changed = true
-        while changed:
-            changed = false
-            // 阶段1: 常量传播与折叠
-            changed |= PropagateConstants(Function)
-            // 阶段2: 控制流简化
-            changed |= SimplifyControlFlow(Function)
-        end while
-    end for
-
-function PropagateConstants(Function):
-    // 初始化
-    executableBlocks = {entryBlock}
-    valueState = map<Value, State> // 值->状态映射
-    instWorkList = Queue()
-    edgeWorkList = Queue()
-    
-    // 初始化工作列表
-    for each inst in entryBlock:
-        instWorkList.push(inst)
-    
-    // 迭代处理
-    while !instWorkList.empty() || !edgeWorkList.empty():
-        // 处理指令工作列表
-        while !instWorkList.empty():
-            inst = instWorkList.pop()
-            // 如果指令是可执行基本块中的
-            if executableBlocks.contains(inst.parent):
-                ProcessInstruction(inst)
-        
-        // 处理边工作列表
-        while !edgeWorkList.empty():
-            edge = edgeWorkList.pop()
-            ProcessEdge(edge)
-    
-    // 应用常量替换
-    for each inst in Function:
-        if valueState[inst] == CONSTANT:
-            ReplaceWithConstant(inst, valueState[inst].constant)
-            changed = true
-    
-    return changed
-
-function ProcessInstruction(Instruction inst):
-    switch inst.type:
-        //二元操作
-        case BINARY_OP:
-            lhs = GetValueState(inst.operands[0])
-            rhs = GetValueState(inst.operands[1])
-            if lhs == CONSTANT && rhs == CONSTANT:
-                newState = ComputeConstant(inst.op, lhs.value, rhs.value)
-                UpdateState(inst, newState)
-            else if lhs == BOTTOM || rhs == BOTTOM:
-                UpdateState(inst, BOTTOM)
-        //phi
-        case PHI:
-            mergedState = ⊤
-            for each incoming in inst.incomings:
-            // 检查每个输入的状态
-                if executableBlocks.contains(incoming.block):
-                    incomingState = GetValueState(incoming.value)
-                    mergedState = Meet(mergedState, incomingState)
-            UpdateState(inst, mergedState)
-        // 条件分支
-        case COND_BRANCH:
-            cond = GetValueState(inst.condition)
-            if cond == CONSTANT:
-                // 判断条件分支
-                if cond.value == true:
-                    AddEdgeToWorkList(inst.parent, inst.trueTarget)
-                else:
-                    AddEdgeToWorkList(inst.parent, inst.falseTarget)
-            else if cond == BOTTOM:
-                AddEdgeToWorkList(inst.parent, inst.trueTarget)
-                AddEdgeToWorkList(inst.parent, inst.falseTarget)
-        
-        case UNCOND_BRANCH:
-            AddEdgeToWorkList(inst.parent, inst.target)
-        
-        // 其他指令处理...
-
-function ProcessEdge(Edge edge):
-    fromBB, toBB = edge
-    if !executableBlocks.contains(toBB):
-        executableBlocks.add(toBB)
-        for each inst in toBB:
-            if inst is PHI:
-                instWorkList.push(inst)
-            else:
-                instWorkList.push(inst) // 非PHI指令
-    
-    // 更新PHI节点的输入
-    for each phi in toBB.phis:
-        instWorkList.push(phi)
-
-function SimplifyControlFlow(Function):
-    changed = false
-    // 标记可达基本块
-    ReachableBBs = FindReachableBlocks(Function.entry)
-    
-    // 删除不可达块
-    for each bb in Function.blocks:
-        if !ReachableBBs.contains(bb):
-            RemoveDeadBlock(bb)
-            changed = true
-    
-    // 简化条件分支
-    for each bb in Function.blocks:
-        terminator = bb.terminator
-        if terminator is COND_BRANCH:
-            cond = GetValueState(terminator.condition)
-            if cond == CONSTANT:
-                SimplifyBranch(terminator, cond.value)
-                changed = true
-    
-    return changed
-
-function RemoveDeadBlock(BasicBlock bb):
-    // 1. 更新前驱块的分支指令
-    for each pred in bb.predecessors:
-        UpdateTerminator(pred, bb)
-    
-    // 2. 更新后继块的PHI节点
-    for each succ in bb.successors:
-        RemovePhiIncoming(succ, bb)
-    
-    // 3. 删除块内所有指令
-    for each inst in bb.instructions:
-        inst.remove()
-    
-    // 4. 从函数中移除基本块
-    Function.removeBlock(bb)
-
-function Meet(State a, State b):
-    if a == ⊤: return b
-    if b == ⊤: return a
-    if a == ⊥ || b == ⊥: return ⊥
-    if a.value == b.value: return a
-    return ⊥
-
-function UpdateState(Value v, State newState):
-    oldState = valueState.get(v, ⊤)
-    if newState != oldState:
-        valueState[v] = newState
-        for each user in v.users:
-            if user is Instruction:
-                instWorkList.push(user)
-
-*/
-
-enum class LatticeValue {
-  Top,       // ⊤ (Unknown)
-  Constant,  // c (Constant)
-  Bottom     // ⊥ (Undefined / Varying)
+// 定义三值格 (Three-valued Lattice) 的状态
+enum class LatticeVal {
+  Top,      // ⊤ (未知 / 未初始化)
+  Constant, // c (常量)
+  Bottom    // ⊥ (不确定 / 变化 / 未定义)
 };
-// LatticeValue: 用于表示值的状态，Top表示未知，Constant表示常量，Bottom表示未定义或变化的值。
-// 这里的LatticeValue用于跟踪每个SSA值（变量、指令结果）的状态，
-// 以便在SCCP过程中进行常量传播和控制流简化。
 
-//TODO: 下列数据结构考虑集成到类中，避免重命名问题
-static std::set<Instruction *> Worklist;
-static std::unordered_set<BasicBlock*> Executable_Blocks;
-static std::queue<std::pair<BasicBlock *, BasicBlock *> > Executable_Edges;
-static std::map<Value*, LatticeValue> valueState;
+// 新增枚举来区分常量的实际类型
+enum class ValueType {
+  Integer,
+  Float,
+  Unknown // 用于 Top 和 Bottom 状态
+};
 
-class SCCP {
+// 用于表示 SSA 值的具体状态（包含格值和常量值）
+struct SSAPValue {
+  LatticeVal state;
+  std::variant<int, float> constantVal; // 使用 std::variant 存储 int 或 float
+  ValueType constant_type; // 记录常量是整数还是浮点数
+
+  // 默认构造函数，初始化为 Top
+  SSAPValue() : state(LatticeVal::Top), constantVal(0), constant_type(ValueType::Unknown) {}
+  // 构造函数，用于创建 Bottom 状态
+  SSAPValue(LatticeVal s) : state(s), constantVal(0), constant_type(ValueType::Unknown) {
+    assert((s == LatticeVal::Top || s == LatticeVal::Bottom) && "SSAPValue(LatticeVal) only for Top/Bottom");
+  }
+  // 构造函数，用于创建 int Constant 状态
+  SSAPValue(int c) : state(LatticeVal::Constant), constantVal(c), constant_type(ValueType::Integer) {}
+  // 构造函数，用于创建 float Constant 状态
+  SSAPValue(float c) : state(LatticeVal::Constant), constantVal(c), constant_type(ValueType::Float) {}
+
+  // 比较操作符，用于判断状态是否改变
+  bool operator==(const SSAPValue &other) const {
+    if (state != other.state)
+      return false;
+    if (state == LatticeVal::Constant) {
+        if (constant_type != other.constant_type) return false; // 类型必须匹配
+        return constantVal == other.constantVal; // std::variant 会比较内部值
+    }
+    return true; // Top == Top, Bottom == Bottom
+  }
+  bool operator!=(const SSAPValue &other) const { return !(*this == other); }
+};
+
+// SCCP 上下文类，持有每个函数运行时的状态
+class SCCPContext {
 private:
-  Module *pModule;
+  IRBuilder *builder; // IR 构建器，用于插入指令和创建常量
+
+  // 工作列表
+  // 存储需要重新评估的指令
+  std::queue<Instruction *> instWorkList;
+  // 存储需要重新评估的控制流边 (pair: from_block, to_block)
+  std::queue<std::pair<BasicBlock *, BasicBlock *>> edgeWorkList;
+
+  // 格值映射：SSA Value 到其当前状态
+  std::map<Value *, SSAPValue> valueState;
+  // 可执行基本块集合
+  std::unordered_set<BasicBlock *> executableBlocks;
+  // 追踪已访问的CFG边，防止重复添加，使用 SysYIROptUtils::PairHash
+  std::unordered_set<std::pair<BasicBlock*, BasicBlock*>, SysYIROptUtils::PairHash> visitedCFGEdges;
+
+  // 辅助函数：格操作 Meet
+  SSAPValue Meet(const SSAPValue &a, const SSAPValue &b);
+  // 辅助函数：获取值的当前状态，如果不存在则默认为 Top
+  SSAPValue GetValueState(Value *v);
+  // 辅助函数：更新值的状态，如果状态改变，将所有用户加入指令工作列表
+  void UpdateState(Value *v, SSAPValue newState);
+  // 辅助函数：将边加入边工作列表，并更新可执行块
+  void AddEdgeToWorkList(BasicBlock *fromBB, BasicBlock *toBB);
+  // 辅助函数：标记一个块为可执行
+  void MarkBlockExecutable(BasicBlock* block);
+
+  // 辅助函数：对二元操作进行常量折叠
+  SSAPValue ComputeConstant(BinaryInst *binaryinst, SSAPValue lhsVal, SSAPValue rhsVal);
+  // 辅助函数：对一元操作进行常量折叠
+  SSAPValue ComputeConstant(UnaryInst *unaryInst, SSAPValue operandVal);
+
+  // 主要优化阶段
+  // 阶段1: 常量传播与折叠
+  bool PropagateConstants(Function *func);
+  // 阶段2: 控制流简化
+  bool SimplifyControlFlow(Function *func);
+
+  // 辅助函数：处理单条指令
+  void ProcessInstruction(Instruction *inst);
+  // 辅助函数：处理单条控制流边
+  void ProcessEdge(const std::pair<BasicBlock *, BasicBlock *> &edge);
+
+  // 控制流简化辅助函数
+  // 查找所有可达的基本块 (基于常量条件)
+  std::unordered_set<BasicBlock *> FindReachableBlocks(Function *func);
+  // 移除死块
+  void RemoveDeadBlock(BasicBlock *bb, Function *func);
+  // 简化分支（将条件分支替换为无条件分支）
+  void SimplifyBranch(CondBrInst*brInst, bool condVal); // 保持 BranchInst
+  // 更新前驱块的终结指令（当一个后继块被移除时）
+  void UpdateTerminator(BasicBlock *predBB, BasicBlock *removedSucc);
+  // 移除 Phi 节点的入边（当其前驱块被移除时）
+  void RemovePhiIncoming(BasicBlock *phiParentBB, BasicBlock *removedPred);
 
 public:
-  SCCP(Module *pMoudle) : pModule(pMoudle) {}
+  SCCPContext(IRBuilder *builder) : builder(builder) {}
 
-  void run();
-  bool PropagateConstants(Function *function);
-  bool SimplifyControlFlow(Function *function);
-  void ProcessInstruction(Instruction *inst);
-  void ProcessEdge(const std::pair<BasicBlock *, BasicBlock *> &edge);
-  void RemoveDeadBlock(BasicBlock *bb);
-  void UpdateState(Value *v, LatticeValue newState);
-  LatticeValue Meet(LatticeValue a, LatticeValue b);
-  LatticeValue GetValueState(Value *v);
+  // 运行 SCCP 优化
+  void run(Function *func, AnalysisManager &AM);
 };
 
-}  // namespace sysy
+// SCCP 优化遍类，继承自 OptimizationPass
+class SCCP : public OptimizationPass {
+private:
+  IRBuilder *builder; // IR 构建器，作为 Pass 的成员，传入 Context
+
+public:
+  SCCP(IRBuilder *builder) : OptimizationPass("SCCP", Granularity::Function), builder(builder) {}
+  static void *ID;
+  bool runOnFunction(Function *F, AnalysisManager &AM) override;
+  void getAnalysisUsage(std::set<void *> &analysisDependencies, std::set<void *> &analysisInvalidations) const override;
+  void *getPassID() const override { return &ID; }
+};
+
+} // namespace sysy

src/include/midend/Pass/Optimize/SysYIROptUtils.h

@@ -2,6 +2,7 @@
 
 #include "IR.h"
 
+extern int DEBUG;
 namespace sysy {
 
 // 优化工具类，包含一些通用的优化方法
@@ -10,13 +11,88 @@ namespace sysy {
 class SysYIROptUtils{
 
 public:
-  // 仅仅删除use关系
-  static void usedelete(Instruction *instr) {
-    for (auto &use : instr->getOperands()) {
-      Value* val = use->getValue();
-      val->removeUse(use);
+  struct PairHash {
+      template <class T1, class T2>
+      std::size_t operator () (const std::pair<T1, T2>& p) const {
+          auto h1 = std::hash<T1>{}(p.first);
+          auto h2 = std::hash<T2>{}(p.second);
+
+          // 简单的组合哈希值，可以更复杂以减少冲突
+          // 使用 boost::hash_combine 的简化版本
+          return h1 ^ (h2 << 1); 
+      }
+  };
+
+  static void RemoveUserOperandUses(User *user) {
+    if (!user) {
+        return;
     }
+
+    // 遍历 User 的 operands 列表。
+    // 由于 operands 是 protected 成员，我们需要一个临时方法来访问它，
+    // 或者在 User 类中添加一个 friend 声明。
+    // 假设 User 内部有一个像 getOperands() 这样的公共方法返回 operands 的引用，
+    // 或者将 SysYIROptUtils 声明为 User 的 friend。
+    // 为了示例，我将假设可以直接访问 user->operands 或通过一个getter。
+    // 如果无法直接访问，请在 IR.h 的 User 类中添加：
+    // public: const std::vector<std::shared_ptr<Use>>& getOperands() const { return operands; }
+
+    // 迭代 copies of shared_ptr to avoid issues if removeUse modifies the list
+    // (though remove should handle it, iterating a copy is safer or reverse iteration).
+    // Since we'll clear the vector at the end, iterating forward is fine.
+    for (const auto& use_ptr : user->getOperands()) { // 假设 getOperands() 可用
+        if (use_ptr) {
+            Value *val = use_ptr->getValue(); // 获取 Use 指向的 Value (如 AllocaInst)
+            if (val) {
+                val->removeUse(use_ptr); // 通知 Value 从其 uses 列表中移除此 Use 关系
+            }
+        }
+    }
+    // 清空 User 的 operands 向量。这会递减 User 持有的 shared_ptr<Use> 的引用计数。
+    // 当引用计数降为 0 时，Use 对象本身将被销毁。
+    // User::operands.clear(); // 这个步骤会在 Instruction 的析构函数中自动完成，因为它是 vector 成员
+                             // 或者我们可以在 User::removeOperand 方法中确保 Use 对象从 operands 中移除。
+                             // 实际上，只要 Value::removeUse(use_ptr) 被调用了，
+                             // 当 Instruction 所在的 unique_ptr 销毁时，它的 operands vector 也会被销毁。
+                             // 所以这里不需要显式 clear()
   }
+  static void usedelete(Instruction *inst) {
+    assert(inst && "Instruction to delete cannot be null.");
+    BasicBlock *parentBlock = inst->getParent();
+    assert(parentBlock && "Instruction must have a parent BasicBlock to be deleted.");
+
+    // 步骤1: 处理所有使用者，将他们从使用 inst 变为使用 UndefinedValue
+    // 这将清理 inst 作为 Value 时的 uses 列表
+    if (!inst->getUses().empty()) {
+        inst->replaceAllUsesWith(UndefinedValue::get(inst->getType()));
+    }
+
+    // 步骤2: 清理 inst 作为 User 时的操作数关系
+    // 通知 inst 所使用的所有 Value (如 AllocaInst)，移除对应的 Use 关系。
+    // 这里的 inst 实际上是一个 User*，所以可以安全地向下转型。
+    RemoveUserOperandUses(static_cast<User*>(inst));
+
+    // 步骤3: 物理删除指令
+    // 这会导致 Instruction 对象的 unique_ptr 销毁，从而调用其析构函数链。
+    parentBlock->removeInst(inst);
+}
+
+  static BasicBlock::iterator usedelete(BasicBlock::iterator inst_it) {
+    Instruction *inst_to_delete = inst_it->get();
+    BasicBlock *parentBlock = inst_to_delete->getParent();
+    assert(parentBlock && "Instruction must have a parent BasicBlock for iterator deletion.");
+
+    // 步骤1: 处理所有使用者
+    if (!inst_to_delete->getUses().empty()) {
+        inst_to_delete->replaceAllUsesWith(UndefinedValue::get(inst_to_delete->getType()));
+    }
+
+    // 步骤2: 清理操作数关系
+    RemoveUserOperandUses(static_cast<User*>(inst_to_delete));
+
+    // 步骤3: 物理删除指令并返回下一个迭代器
+    return parentBlock->removeInst(inst_it);
+}
 
   // 判断是否是全局变量
   static bool isGlobal(Value *val) {
@@ -26,7 +102,17 @@ public:
   // 判断是否是数组
   static bool isArr(Value *val) {
     auto aval = dynamic_cast<AllocaInst *>(val);
-  return aval != nullptr && aval->getNumDims() != 0;
+    // 如果是 AllocaInst 且通过Type::isArray()判断为数组类型
+    return aval && aval->getType()->as<PointerType>()->getBaseType()->isArray();
+  }
+  // 判断是否是指向数组的指针
+  static bool isArrPointer(Value *val) {
+    auto aval = dynamic_cast<AllocaInst *>(val);
+    // 如果是 AllocaInst 且通过Type::isPointer()判断为指针;
+    auto baseType = aval->getType()->as<PointerType>()->getBaseType();
+    // 在sysy中，函数的数组参数会退化成指针
+    // 所以当AllocaInst的basetype是PointerType时（一维数组）或者是指向ArrayType的PointerType（多位数组）时，返回true
+    return aval && (baseType->isPointer() || baseType->as<PointerType>()->getBaseType()->isArray());
   }
 };