[midend-SCCP]bug修复，增加不可达指令（理论来说后端不会出现这条指令，只是为了IR完整性添加），添加相关方法，phi指令方法修复；目前能够跑完所有优化，但是User的析构函数重定义导致全局析构不能正确完成，需要修复

2025-07-31 22:03:35 +08:00
parent 9a53e1b917
commit c5af4f1c49
6 changed files with 73 additions and 88 deletions
--- a/src/midend/IR.cpp
+++ b/src/midend/IR.cpp
@@ -569,7 +569,7 @@ void User::replaceOperand(unsigned index, Value *value) {
 * phi相关函数
 */

- Value* PhiInst::getvalfromBlk(BasicBlock* blk){
+Value* PhiInst::getvalfromBlk(BasicBlock* blk){
  refreshB2VMap();
  if( blk2val.find(blk) != blk2val.end()) {
    return blk2val.at(blk);
@@ -619,11 +619,13 @@ void PhiInst::delBlk(BasicBlock* blk){

 void PhiInst::replaceBlk(BasicBlock* newBlk, unsigned k){
  refreshB2VMap();
-  Value* val = blk2val.at(getBlock(k));
+  BasicBlock* oldBlk = getBlock(k);
+  Value* val = blk2val.at(oldBlk);
+  // Value* val = blk2val.at(getBlock(k));
  // 替换基本块
  setOperand(2 * k + 1, newBlk);
  // 替换blk2val映射
-  blk2val.erase(getBlock(k));
+  blk2val.erase(oldBlk);
  blk2val.emplace(newBlk, val);
 }

--- a/src/midend/Pass/Optimize/SCCP.cpp
+++ b/src/midend/Pass/Optimize/SCCP.cpp
@@ -433,6 +433,7 @@ void SCCPContext::ProcessInstruction(Instruction *inst) {
  case Instruction::kBr:     // 对应 kBr
  case Instruction::kCondBr: // 对应 kCondBr
  case Instruction::kReturn: // 对应 kReturn
+  case Instruction::kUnreachable: // 对应 kUnreachable
    // 终结符指令不产生值
    newState = SSAPValue(); // 保持 Top
    break;
@@ -451,8 +452,10 @@ void SCCPContext::ProcessInstruction(Instruction *inst) {

  // 特殊处理终结符指令，影响 CFG 边的可达性
  if (inst->isTerminator()) {
-    if (auto branchInst = dynamic_cast<CondBrInst *>(inst)) {
-      if (branchInst->isCondBr()) { // 使用 kCondBr
+    if (inst->isBranch()) {
+
+      if (inst->isCondBr()) { // 使用 kCondBr
+        CondBrInst *branchInst = static_cast<CondBrInst *>(inst);
        SSAPValue condVal = GetValueState(branchInst->getOperand(0));
        if (condVal.state == LatticeVal::Constant) {
          bool condition_is_true = false;
@@ -472,7 +475,8 @@ void SCCPContext::ProcessInstruction(Instruction *inst) {
          AddEdgeToWorkList(branchInst->getParent(), branchInst->getElseBlock());
        }
      } else { // 无条件分支 (kBr)
-        AddEdgeToWorkList(branchInst->getParent(), branchInst->getThenBlock());
+        UncondBrInst *branchInst = static_cast<UncondBrInst *>(inst);
+        AddEdgeToWorkList(branchInst->getParent(), branchInst->getBlock());
      }
    }
  }
@@ -560,8 +564,7 @@ bool SCCPContext::PropagateConstants(Function *func) {
        }
        inst->replaceAllUsesWith(constVal);
        instsToDelete.push_back(inst);
-        // it = bb->removeInst(it); // 从块中移除指令
-        it = bb->getInstructions().erase(it);
+        ++it;
        changed = true;
      } else {
        // 如果操作数是常量，直接替换为常量值（常量折叠）
@@ -595,14 +598,7 @@ bool SCCPContext::PropagateConstants(Function *func) {
    // 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。
    if (inst->getParent() != nullptr) {
      // 调用负责完整删除的函数，该函数应负责清除uses并将其从父块中移除。
-      SysYIROptUtils::usedelete_withinstdelte(inst);
-      if (inst->getParent() != nullptr) {
-          // 如果执行到这里，说明 usedelete_withinstdelte 没有成功将其从父块中移除。
-          if (DEBUG) {
-            std::cerr << "Warning: Instruction " << inst->getName()
-                      << " was not fully deleted by usedelete_withinstdelte and is still in parent." << std::endl;
-          }
-        }
+      SysYIROptUtils::usedelete(inst);
    } 
    else {
        // 指令已不属于任何父块，无需再次删除。
@@ -642,8 +638,10 @@ bool SCCPContext::SimplifyControlFlow(Function *func) {
      continue; // 只处理可达块

    Instruction *terminator = bb->terminator()->get();
-    if (auto branchInst = dynamic_cast<CondBrInst *>(terminator)) {
-      if (branchInst->isCondBr()) { // 检查是否是条件分支 (kCondBr)
+    if (terminator->isBranch()) {
+
+      if (terminator->isCondBr()) { // 检查是否是条件分支 (kCondBr)
+        CondBrInst *branchInst = static_cast<CondBrInst *>(terminator);
        SSAPValue condVal = GetValueState(branchInst->getOperand(0));
        if (condVal.state == LatticeVal::Constant) {
          bool condition_is_true = false;
@@ -680,8 +678,9 @@ std::unordered_set<BasicBlock *> SCCPContext::FindReachableBlocks(Function *func
    if (!terminator)
      continue;

-    if (auto branchInst = dynamic_cast<CondBrInst *>(terminator)) {
-      if (branchInst->isCondBr()) { // 检查是否是条件分支 (kCondBr)
+    if (terminator->isBranch()) {
+      if (terminator->isCondBr()) { // 检查是否是条件分支 (kCondBr)
+        CondBrInst *branchInst = static_cast<CondBrInst *>(terminator);
        SSAPValue condVal = GetValueState(branchInst->getOperand(0));
        if (condVal.state == LatticeVal::Constant) {
          bool condition_is_true = false;
@@ -713,14 +712,16 @@ std::unordered_set<BasicBlock *> SCCPContext::FindReachableBlocks(Function *func
          }
        }
      } else { // 无条件分支 (kBr)
-        BasicBlock *targetBlock = branchInst->getThenBlock();
+        UncondBrInst *branchInst = static_cast<UncondBrInst *>(terminator);
+        BasicBlock *targetBlock = branchInst->getBlock();
        if (reachable.find(targetBlock) == reachable.end()) {
          reachable.insert(targetBlock);
          q.push(targetBlock);
        }
      }
-    } else if (auto retInst = dynamic_cast<ReturnInst *>(terminator)) {
+    } else if (terminator->isReturn() || terminator->isUnreachable()) {
      // ReturnInst 没有后继，不需要处理
+      // UnreachableInst 也没有后继，不需要处理
    }
  }
  return reachable;
@@ -771,16 +772,12 @@ void SCCPContext::SimplifyBranch(CondBrInst *brInst, bool condVal) {
  if (condVal) {                            // 条件为真，跳转到真分支
    builder->createUncondBrInst(trueBlock); // 插入无条件分支 kBr
    SysYIROptUtils::usedelete(brInst);      // 移除旧的条件分支指令
-    // TODO now： 移出指令
-
    parentBB->removeSuccessor(falseBlock);
    falseBlock->removePredecessor(parentBB);
    RemovePhiIncoming(falseBlock, parentBB);
  } else {                                   // 条件为假，跳转到假分支
    builder->createUncondBrInst(falseBlock); // 插入无条件分支 kBr
    SysYIROptUtils::usedelete(brInst);       // 移除旧的条件分支指令
-    // TODO now： 移出指令
-
    parentBB->removeSuccessor(trueBlock);
    trueBlock->removePredecessor(parentBB);
    RemovePhiIncoming(trueBlock, parentBB);
@@ -793,8 +790,9 @@ void SCCPContext::UpdateTerminator(BasicBlock *predBB, BasicBlock *removedSucc)
  if (!terminator)
    return;

-  if (auto branchInst = dynamic_cast<CondBrInst *>(terminator)) {
-    if (branchInst->isCondBr()) { // 如果是条件分支
+  if (terminator->isBranch()) {
+    if (terminator->isCondBr()) { // 如果是条件分支
+      CondBrInst *branchInst = static_cast<CondBrInst *>(terminator);
      if (branchInst->getThenBlock() == removedSucc) {
        if (DEBUG) {
          std::cout << "Updating cond br in " << predBB->getName() << ": True block (" << removedSucc->getName()
@@ -802,7 +800,7 @@ void SCCPContext::UpdateTerminator(BasicBlock *predBB, BasicBlock *removedSucc)
        }
        builder->setPosition(predBB, predBB->findInstIterator(branchInst));
        builder->createUncondBrInst(branchInst->getElseBlock());
-        SysYIROptUtils::usedelete_withinstdelte(branchInst);
+        SysYIROptUtils::usedelete(branchInst);
        predBB->removeSuccessor(removedSucc);
      } else if (branchInst->getElseBlock() == removedSucc) {
        if (DEBUG) {
@@ -811,16 +809,17 @@ void SCCPContext::UpdateTerminator(BasicBlock *predBB, BasicBlock *removedSucc)
        }
        builder->setPosition(predBB, predBB->findInstIterator(branchInst));
        builder->createUncondBrInst(branchInst->getThenBlock());
-        SysYIROptUtils::usedelete_withinstdelte(branchInst);
+        SysYIROptUtils::usedelete(branchInst);
        predBB->removeSuccessor(removedSucc);
      }
    } else { // 无条件分支 (kBr)
-      if (branchInst->getThenBlock() == removedSucc) {
+      UncondBrInst *branchInst = static_cast<UncondBrInst *>(terminator);
+      if (branchInst->getBlock() == removedSucc) {
        if (DEBUG) {
          std::cout << "Updating unconditional br in " << predBB->getName() << ": Target block ("
                    << removedSucc->getName() << ") removed. Replacing with Unreachable." << std::endl;
        }
-        SysYIROptUtils::usedelete_withinstdelte(branchInst);
+        SysYIROptUtils::usedelete(branchInst);
        predBB->removeSuccessor(removedSucc);
        builder->setPosition(predBB, predBB->end());
        builder->createUnreachableInst();
--- a/src/midend/Pass/Pass.cpp
+++ b/src/midend/Pass/Pass.cpp
@@ -83,11 +83,19 @@ void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR

      this->clearPasses();
      this->addPass(&Mem2Reg::ID);
+      this->run();
+
+      if(DEBUG) {
+        std::cout << "=== IR After Mem2Reg Optimizations ===\n";
+        printPasses();
+      }
+
+      this->clearPasses();
      this->addPass(&SCCP::ID);
      this->run();

      if(DEBUG) {
-        std::cout << "=== IR After Mem2Reg And SCCP Optimizations ===\n";
+        std::cout << "=== IR After SCCP Optimizations ===\n";
        printPasses();
      }

--- a/src/midend/SysYIRPrinter.cpp
+++ b/src/midend/SysYIRPrinter.cpp
@@ -400,7 +400,12 @@ void SysYPrinter::printInst(Instruction *pInst) {
      }
      std::cout << std::endl;
    } break;
-    
+
+    case Kind::kUnreachable: {
+      std::cout << "Unreachable" << std::endl;
+      
+    } break;
+
    case Kind::kAlloca: {
      auto allocaInst = dynamic_cast<AllocaInst *>(pInst);
      std::cout << "%" << allocaInst->getName() << " = alloca ";