[midend-SCCP]修改BaiscBlock的析构逻辑，将CFG修改的职责交给优化遍,注释Mem2Reg的调试信息。

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:

src/midend/Pass/Optimize/Mem2Reg.cpp

@@ -240,7 +240,9 @@ void Mem2RegContext::renameVariables(AllocaInst *currentAlloca, BasicBlock *curr
           // loadInst->getPointer() 返回 AllocaInst*
           // 将 LoadInst 的所有用途替换为当前 alloca 值栈顶部的 SSA 值
           assert(!allocaToValueStackMap[alloca].empty() && "Value stack empty for alloca during load replacement!");
+          if(DEBUG){
             std::cout << "Mem2Reg: Replacing load " << loadInst->getPointer()->getName() << " with SSA value." << std::endl;
+          }
           loadInst->replaceAllUsesWith(allocaToValueStackMap[alloca].top());
           instIter = SysYIROptUtils::usedelete(instIter);
           instDeleted = true;
@@ -256,7 +258,9 @@ void Mem2RegContext::renameVariables(AllocaInst *currentAlloca, BasicBlock *curr
         if (storeInst->getPointer() == alloca) { 
           // 假设 storeInst->getPointer() 返回 AllocaInst*
           // 将 StoreInst 存储的值作为新的 SSA 值，压入值栈
+          if(DEBUG){
             std::cout << "Mem2Reg: Replacing store to " << storeInst->getPointer()->getName() << " with SSA value." << std::endl;
+          }
           allocaToValueStackMap[alloca].push(storeInst->getValue());
           localStackPushed.push(storeInst->getValue());          // 记录以便弹出
           instIter = SysYIROptUtils::usedelete(instIter);
@@ -297,7 +301,9 @@ void Mem2RegContext::renameVariables(AllocaInst *currentAlloca, BasicBlock *curr
   if(dominatedBlocks){
     for (auto dominatedBB : *dominatedBlocks) {
       if (dominatedBB) {
+        if(DEBUG){
           std::cout << "Mem2Reg: Recursively renaming variables in dominated block: " << dominatedBB->getName() << std::endl;
+        }
         renameVariables(currentAlloca, dominatedBB);
       }
     }

src/midend/Pass/Optimize/SCCP.cpp

@@ -1,4 +1,6 @@
 #include "SCCP.h"
+#include "Dom.h"
+#include "Liveness.h"
 #include <algorithm>
 #include <cassert>
 #include <cmath>  // For std::fmod, std::fabs
@@ -236,6 +238,8 @@ SSAPValue SCCPContext::ComputeConstant(UnaryInst *unaryInst, SSAPValue operandVa
   if (operandVal.constant_type == ValueType::Integer) {
     int val = std::get<int>(operandVal.constantVal);
     switch (unaryInst->getKind()) {
+    case Instruction::kAdd:
+      return SSAPValue(val);
     case Instruction::kNeg:
       return SSAPValue(-val);
     case Instruction::kNot:
@@ -246,6 +250,8 @@ SSAPValue SCCPContext::ComputeConstant(UnaryInst *unaryInst, SSAPValue operandVa
   } else if (operandVal.constant_type == ValueType::Float) {
     float val = std::get<float>(operandVal.constantVal);
     switch (unaryInst->getKind()) {
+    case Instruction::kAdd:
+      return SSAPValue(val);
     case Instruction::kFNeg:
       return SSAPValue(-val);
     case Instruction::kFNot:
@@ -593,6 +599,7 @@ bool SCCPContext::PropagateConstants(Function *func) {
   }
 
   // 实际删除指令
+  // TODO: 删除的逻辑需要考虑修改
   for (Instruction *inst : instsToDelete) {
     // 在尝试删除之前，先检查指令是否仍然附加到其父基本块。
     // 如果它已经没有父块，可能说明它已被其他方式处理或已处于无效状态。
@@ -752,6 +759,7 @@ void SCCPContext::RemoveDeadBlock(BasicBlock *bb, Function *func) {
   }
   for (BasicBlock *succ : succs_to_update) {
     RemovePhiIncoming(succ, bb);
+    succ->removePredecessor(bb);
   }
 
   func->removeBasicBlock(bb); // 从函数中移除基本块
@@ -864,7 +872,9 @@ bool SCCP::runOnFunction(Function *F, AnalysisManager &AM) {
 }
 
 void SCCP::getAnalysisUsage(std::set<void *> &analysisDependencies, std::set<void *> &analysisInvalidations) const {
-  analysisInvalidations.insert(nullptr); // 表示使所有默认分析失效
+  // analysisInvalidations.insert(nullptr); // 表示使所有默认分析失效
+  analysisInvalidations.insert(&DominatorTreeAnalysisPass::ID); // 支配树可能受影响
+  analysisInvalidations.insert(&LivenessAnalysisPass::ID); // 活跃性分析很可能失效
 }
 
 } // namespace sysy