[optimze]添加基础的除法指令优化，目前只对除以2的幂数生效

src/include/backend/RISCv64/Optimize/DivStrengthReduction.h

@@ -0,0 +1,30 @@
+#ifndef RISCV64_DIV_STRENGTH_REDUCTION_H
+#define RISCV64_DIV_STRENGTH_REDUCTION_H
+
+#include "RISCv64LLIR.h"
+#include "Pass.h"
+
+namespace sysy {
+
+/**
+ * @class DivStrengthReduction
+ * @brief 除法强度削弱优化器
+ * * 将除法运算转换为乘法运算，使用magic number算法
+ * 适用于除数为常数的情况，可以显著提高性能
+ */
+class DivStrengthReduction : public Pass {
+public:
+    static char ID;
+    
+    DivStrengthReduction() : Pass("div-strength-reduction", Granularity::Function, PassKind::Optimization) {}
+    
+    void *getPassID() const override { return &ID; }
+    
+    bool runOnFunction(Function *F, AnalysisManager& AM) override;
+    
+    void runOnMachineFunction(MachineFunction* mfunc);
+};
+
+} // namespace sysy
+
+#endif // RISCV64_DIV_STRENGTH_REDUCTION_H

src/include/backend/RISCv64/RISCv64Passes.h

@@ -9,6 +9,8 @@
 #include "LegalizeImmediates.h"
 #include "PrologueEpilogueInsertion.h"
 #include "Pass.h"
+#include "DivStrengthReduction.h"
+
 
 namespace sysy {
 

src/include/midend/IR.h

@@ -708,6 +708,8 @@ class Instruction : public User {
     kPhi = 0x1UL << 39,
     kBitItoF = 0x1UL << 40,
     kBitFtoI = 0x1UL << 41,
+    kSRA = 0x1UL << 42,
+    kMulh = 0x1UL << 43,
   };
 
 protected:
@@ -804,6 +806,12 @@ public:
         return "Memset";
       case kPhi:
         return "Phi";
+      case kBitItoF:
+        return "BitItoF";
+      case kBitFtoI:
+        return "BitFtoI";
+      case kSRA:
+        return "SRA";
       default:
         return "Unknown";
     }
@@ -815,11 +823,15 @@ public:
 
   bool isBinary() const {
     static constexpr uint64_t BinaryOpMask =
-        (kAdd | kSub | kMul | kDiv | kRem | kAnd | kOr) |
-        (kICmpEQ | kICmpNE | kICmpLT | kICmpGT | kICmpLE | kICmpGE) |
+        (kAdd | kSub | kMul | kDiv | kRem | kAnd | kOr | kSRA) |
+        (kICmpEQ | kICmpNE | kICmpLT | kICmpGT | kICmpLE | kICmpGE);
+    return kind & BinaryOpMask;
+  }
+  bool isFPBinary() const {
+    static constexpr uint64_t FPBinaryOpMask =
         (kFAdd | kFSub | kFMul | kFDiv) |
         (kFCmpEQ | kFCmpNE | kFCmpLT | kFCmpGT | kFCmpLE | kFCmpGE);
-    return kind & BinaryOpMask;
+    return kind & FPBinaryOpMask;
   }
   bool isUnary() const {
     static constexpr uint64_t UnaryOpMask = 

src/include/midend/IRBuilder.h

@@ -217,6 +217,9 @@ class IRBuilder {
   BinaryInst * createOrInst(Value *lhs, Value *rhs, const std::string &name = "") {
     return createBinaryInst(Instruction::kOr, Type::getIntType(), lhs, rhs, name);
   }  ///< 创建按位或指令
+  BinaryInst * createSRAInst(Value *lhs, Value *rhs, const std::string &name = "") {
+    return createBinaryInst(Instruction::kSRA, Type::getIntType(), lhs, rhs, name);
+  }  ///< 创建算术右移指令
   CallInst * createCallInst(Function *callee, const std::vector<Value *> &args, const std::string &name = "") {
     std::string newName;
     if (name.empty() && callee->getReturnType() != Type::getVoidType()) {