[midend]重构了src目录

src/backend/RISCv64/Handler/PrologueEpilogueInsertion.cpp

@@ -0,0 +1,118 @@
+#include "PrologueEpilogueInsertion.h"
+
+namespace sysy {
+
+char PrologueEpilogueInsertionPass::ID = 0;
+
+void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc) {
+    StackFrameInfo& frame_info = mfunc->getFrameInfo();
+    
+    // 完全遵循 AsmPrinter 中的计算逻辑
+    int total_stack_size = frame_info.locals_size + 
+                           frame_info.spill_size + 
+                           frame_info.callee_saved_size + 
+                           16; // 为 ra 和 s0 固定的16字节
+    
+    int aligned_stack_size = (total_stack_size + 15) & ~15;
+    frame_info.total_size = aligned_stack_size;
+
+    // 只有在需要分配栈空间时才生成指令
+    if (aligned_stack_size > 0) {
+        // --- 1. 插入序言 ---
+        MachineBasicBlock* entry_block = mfunc->getBlocks().front().get();
+        auto& entry_instrs = entry_block->getInstructions();
+
+        std::vector<std::unique_ptr<MachineInstr>> prologue_instrs;
+
+        // 严格按照 AsmPrinter 的打印顺序来创建和组织指令
+        // 1. addi sp, sp, -aligned_stack_size
+        auto alloc_stack = std::make_unique<MachineInstr>(RVOpcodes::ADDI);
+        alloc_stack->addOperand(std::make_unique<RegOperand>(PhysicalReg::SP));
+        alloc_stack->addOperand(std::make_unique<RegOperand>(PhysicalReg::SP));
+        alloc_stack->addOperand(std::make_unique<ImmOperand>(-aligned_stack_size));
+        prologue_instrs.push_back(std::move(alloc_stack));
+
+        // 2. sd ra, (aligned_stack_size - 8)(sp)
+        auto save_ra = std::make_unique<MachineInstr>(RVOpcodes::SD);
+        save_ra->addOperand(std::make_unique<RegOperand>(PhysicalReg::RA));
+        save_ra->addOperand(std::make_unique<MemOperand>(
+            std::make_unique<RegOperand>(PhysicalReg::SP),
+            std::make_unique<ImmOperand>(aligned_stack_size - 8)
+        ));
+        prologue_instrs.push_back(std::move(save_ra));
+
+        // 3. sd s0, (aligned_stack_size - 16)(sp)
+        auto save_fp = std::make_unique<MachineInstr>(RVOpcodes::SD);
+        save_fp->addOperand(std::make_unique<RegOperand>(PhysicalReg::S0));
+        save_fp->addOperand(std::make_unique<MemOperand>(
+            std::make_unique<RegOperand>(PhysicalReg::SP),
+            std::make_unique<ImmOperand>(aligned_stack_size - 16)
+        ));
+        prologue_instrs.push_back(std::move(save_fp));
+        
+        // 4. addi s0, sp, aligned_stack_size
+        auto set_fp = std::make_unique<MachineInstr>(RVOpcodes::ADDI);
+        set_fp->addOperand(std::make_unique<RegOperand>(PhysicalReg::S0));
+        set_fp->addOperand(std::make_unique<RegOperand>(PhysicalReg::SP));
+        set_fp->addOperand(std::make_unique<ImmOperand>(aligned_stack_size));
+        prologue_instrs.push_back(std::move(set_fp));
+
+        // 确定插入点（在函数名标签之后）
+        auto insert_pos = entry_instrs.begin();
+        // [重要] 这里我们不再需要跳过LABEL，因为AsmPrinter将不再打印函数名标签
+        // 第一个基本块的标签就是函数入口
+        
+        // 一次性将所有序言指令插入
+        if (!prologue_instrs.empty()) {
+            entry_instrs.insert(insert_pos, 
+                                std::make_move_iterator(prologue_instrs.begin()),
+                                std::make_move_iterator(prologue_instrs.end()));
+        }
+
+        // --- 2. 插入尾声 ---
+        for (auto& mbb : mfunc->getBlocks()) {
+            for (auto it = mbb->getInstructions().begin(); it != mbb->getInstructions().end(); ++it) {
+                if ((*it)->getOpcode() == RVOpcodes::RET) {
+                    std::vector<std::unique_ptr<MachineInstr>> epilogue_instrs;
+
+                    // 同样严格按照 AsmPrinter 的打印顺序
+                    // 1. ld ra, (aligned_stack_size - 8)(sp)
+                    auto restore_ra = std::make_unique<MachineInstr>(RVOpcodes::LD);
+                    restore_ra->addOperand(std::make_unique<RegOperand>(PhysicalReg::RA));
+                    restore_ra->addOperand(std::make_unique<MemOperand>(
+                        std::make_unique<RegOperand>(PhysicalReg::SP),
+                        std::make_unique<ImmOperand>(aligned_stack_size - 8)
+                    ));
+                    epilogue_instrs.push_back(std::move(restore_ra));
+
+                    // 2. ld s0, (aligned_stack_size - 16)(sp)
+                    auto restore_fp = std::make_unique<MachineInstr>(RVOpcodes::LD);
+                    restore_fp->addOperand(std::make_unique<RegOperand>(PhysicalReg::S0));
+                    restore_fp->addOperand(std::make_unique<MemOperand>(
+                        std::make_unique<RegOperand>(PhysicalReg::SP),
+                        std::make_unique<ImmOperand>(aligned_stack_size - 16)
+                    ));
+                    epilogue_instrs.push_back(std::move(restore_fp));
+
+                    // 3. addi sp, sp, aligned_stack_size
+                    auto dealloc_stack = std::make_unique<MachineInstr>(RVOpcodes::ADDI);
+                    dealloc_stack->addOperand(std::make_unique<RegOperand>(PhysicalReg::SP));
+                    dealloc_stack->addOperand(std::make_unique<RegOperand>(PhysicalReg::SP));
+                    dealloc_stack->addOperand(std::make_unique<ImmOperand>(aligned_stack_size));
+                    epilogue_instrs.push_back(std::move(dealloc_stack));
+
+                    if (!epilogue_instrs.empty()) {
+                        mbb->getInstructions().insert(it, 
+                                                    std::make_move_iterator(epilogue_instrs.begin()),
+                                                    std::make_move_iterator(epilogue_instrs.end()));
+                    }
+                    // 处理完一个基本块中的RET后，迭代器已失效，需跳出
+                    goto next_block;
+                }
+            }
+            next_block:;
+        }
+    }
+}
+
+} // namespace sysy