[midend-LICM]优化了特征分析中对循环不变量的识别，实现了LICM遍，格式化副作用分析代码

src/include/midend/Pass/Analysis/LoopCharacteristics.h

@@ -38,8 +38,8 @@ struct LoopCharacteristics {
   std::map<Value*, int> inductionSteps;         // 归纳变量的步长（简化）
   
   // ========== 基础循环不变量分析 ==========
-  std::set<Value*> loopInvariants;              // 循环不变量
-  std::set<Instruction*> invariantInsts;       // 可提升的不变指令
+  std::unordered_set<Value*> loopInvariants;              // 循环不变量
+  std::unordered_set<Instruction*> invariantInsts;       // 可提升的不变指令
   
   // ========== 基础边界分析 ==========
   std::optional<int> staticTripCount;          // 静态循环次数（如果可确定）
@@ -293,7 +293,7 @@ private:
   // 基础归纳变量识别
   void identifyBasicInductionVariables(Loop* loop, LoopCharacteristics* characteristics);
   
-  // 基础循环不变量识别
+  // 循环不变量识别
   void identifyBasicLoopInvariants(Loop* loop, LoopCharacteristics* characteristics);
   
   // 基础边界分析
@@ -306,8 +306,8 @@ private:
   void evaluateBasicOptimizationOpportunities(Loop* loop, LoopCharacteristics* characteristics);
   
   // ========== 辅助方法 ==========
+  bool isClassicLoopInvariant(Value* val, Loop* loop, const std::unordered_set<Value*>& invariants);
   bool isBasicInductionVariable(Value* val, Loop* loop);
-  bool isBasicLoopInvariant(Value* val, Loop* loop);
   bool hasSimpleMemoryPattern(Loop* loop); // 简单的内存模式检查
 };
 

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

@@ -0,0 +1,40 @@
+#pragma once
+#include "Pass.h"
+#include "Loop.h"
+#include "LoopCharacteristics.h"
+#include "Dom.h"
+#include <unordered_set>
+#include <vector>
+
+namespace sysy{
+
+class LICMContext {
+public:
+  LICMContext(Function* func, Loop* loop, IRBuilder* builder, const LoopCharacteristics* chars)
+    : func(func), loop(loop), builder(builder), chars(chars) {}
+    // 运行LICM主流程，返回IR是否被修改
+    bool run();
+
+private:
+    Function* func;
+    Loop* loop;
+    IRBuilder* builder;
+    const LoopCharacteristics* chars; // 特征分析结果
+
+    // 外提所有可提升指令
+    bool hoistInstructions();
+};
+
+
+class LICM : public OptimizationPass{
+private:
+	IRBuilder *builder; ///< IR构建器，用于插入指令
+public:
+	static void *ID;
+	LICM(IRBuilder *builder = nullptr) : OptimizationPass("LICM", Granularity::Function) , builder(builder) {}
+	bool runOnFunction(Function *F, AnalysisManager &AM) override;
+	void getAnalysisUsage(std::set<void *> &, std::set<void *> &) const override;
+	void *getPassID() const override { return &ID; }
+};
+
+} // namespace sysy