[backend]重构了后端

src/include/RISCv64AsmPrinter.h

@@ -0,0 +1,38 @@
+#ifndef RISCV64_ASMPRINTER_H
+#define RISCV64_ASMPRINTER_H
+
+#include "RISCv64LLIR.h"
+#include <iostream>
+
+namespace sysy {
+
+class RISCv64AsmPrinter {
+public:
+    // 主入口，将整个MachineFunction打印到指定的输出流
+    void runOnMachineFunction(MachineFunction* mfunc, std::ostream& os);
+
+private:
+    // 打印单个基本块
+    void printBasicBlock(MachineBasicBlock* mbb);
+
+    // 打印单条指令
+    void printInstruction(MachineInstr* instr, MachineBasicBlock* parent_bb);
+
+    // 打印函数序言
+    void printPrologue(MachineFunction* mfunc);
+    
+    // 打印函数尾声
+    void printEpilogue(MachineFunction* mfunc);
+    
+    // 将物理寄存器枚举转换为字符串 (从原RISCv64Backend迁移)
+    std::string regToString(PhysicalReg reg);
+
+    // 打印单个操作数
+    void printOperand(MachineOperand* op);
+
+    std::ostream* OS; // 指向当前输出流
+};
+
+} // namespace sysy
+
+#endif // RISCV64_ASMPRINTER_H