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[backend] it works 1.0

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This commit is contained in:
ladev789
2025-06-22 14:06:14 +08:00
parent 232ed6d023
commit 25a8c72a9b
3 changed files with 64 additions and 70 deletions
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102
src/RISCv32Backend.cpp
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@@ -1,7 +1,9 @@
#include "RISCv32Backend.h"
#include <sstream>
#include <algorithm>
namespace sysy {
const std::vector<RISCv32CodeGen::PhysicalReg> RISCv32CodeGen::allocable_regs = {
PhysicalReg::T0, PhysicalReg::T1, PhysicalReg::T2, PhysicalReg::T3,
PhysicalReg::T4, PhysicalReg::T5, PhysicalReg::T6,
@@ -33,16 +35,16 @@ std::string RISCv32CodeGen::code_gen() {
std::string RISCv32CodeGen::module_gen() {
std::stringstream ss;
// 生成全局变量（数据段）
for (auto global : *module->getGlobalValues()) {
for (const auto& global : *module->getGlobalValues()) {
ss << ".data\n";
ss << ".globl " << global->getName() << "\n";
ss << global->getName() << ":\n";
ss << ".globl " << global.second->getName() << "\n";
ss << global.second->getName() << ":\n";
ss << " .word 0\n"; // 假设初始化为0
}
// 生成函数
ss << ".text\n";
for (auto func : *module->getFunctions()) {
ss << function_gen(func);
for (const auto& func : *module->getFunctions()) {
ss << function_gen(func.second);
}
return ss.str();
}
@@ -52,17 +54,17 @@ std::string RISCv32CodeGen::function_gen(Function* func) {
// 函数标签
ss << ".globl " << func->getName() << "\n";
ss << func->getName() << ":\n";
// 序言：保存ra，分配堆栈
bool is_leaf = true; // 简单假设，实际需检查是否调用其他函数
ss << " addi sp, sp, -16\n"; // 分配堆栈空间
ss << " sw ra, 12(sp)\n"; // 保存返回地址
// 序言：保存 ra，分配堆栈
bool is_leaf = true; // 简化假设
ss << " addi sp, sp, -16\n";
ss << " sw ra, 12(sp)\n";
// 寄存器分配
auto alloc = register_allocation(func);
// 生成基本块代码
for (auto bb : func->getBasicBlocks()) {
ss << basicBlock_gen(bb, alloc);
for (const auto& bb : func->getBasicBlocks()) {
ss << basicBlock_gen(bb.get(), alloc);
}
// 结尾：恢复ra，释放堆栈
// 结尾：恢复 ra，释放堆栈
ss << " lw ra, 12(sp)\n";
ss << " addi sp, sp, 16\n";
ss << " ret\n";
@@ -72,23 +74,28 @@ std::string RISCv32CodeGen::function_gen(Function* func) {
std::string RISCv32CodeGen::basicBlock_gen(BasicBlock* bb, const RegAllocResult& alloc) {
std::stringstream ss;
ss << bb->getName() << ":\n";
for (auto inst : bb->getInstructions()) {
auto riscv_insts = instruction_gen(inst);
for (const auto& inst : bb->getInstructions()) {
auto riscv_insts = instruction_gen(inst.get());
for (const auto& riscv_inst : riscv_insts) {
ss << " " << riscv_inst.opcode;
for (size_t i = 0; i < riscv_inst.operands.size(); ++i) {
if (i > 0) ss << ", ";
if (riscv_inst.operands[i].kind == Operand::Reg) {
auto it = alloc.reg_map.find((Value*)riscv_inst.operands[i].value.c_str());
if (riscv_inst.operands[i].kind == Operand::Kind::Reg) {
auto it = alloc.reg_map.find(riscv_inst.operands[i].value);
if (it != alloc.reg_map.end()) {
ss << reg_to_string(it->second);
} else {
// 溢出到堆栈
auto stack_it = alloc.stack_map.find((Value*)riscv_inst.operands[i].value.c_str());
ss << "[sp+" << stack_it->second << "]";
auto stack_it = alloc.stack_map.find(riscv_inst.operands[i].value);
if (stack_it != alloc.stack_map.end()) {
ss << stack_it->second << "(sp)";
} else {
ss << "%" << riscv_inst.operands[i].value->getName();
}
}
} else if (riscv_inst.operands[i].kind == Operand::Kind::Imm) {
ss << riscv_inst.operands[i].label;
} else {
ss << riscv_inst.operands[i].value;
ss << riscv_inst.operands[i].label;
}
}
ss << "\n";
@@ -101,69 +108,50 @@ std::vector<RISCv32CodeGen::RISCv32Inst> RISCv32CodeGen::instruction_gen(Instruc
std::vector<RISCv32Inst> insts;
if (auto bin = dynamic_cast<BinaryInst*>(inst)) {
std::string opcode;
if (bin->getOpcode() == BinaryInst::Add) opcode = "add";
else if (bin->getOpcode() == BinaryInst::Sub) opcode = "sub";
else if (bin->getOpcode() == BinaryInst::Mul) opcode = "mul";
else return insts; // 未实现其他操作
if (bin->getKind() == BinaryInst::kAdd) opcode = "add";
else if (bin->getKind() == BinaryInst::kSub) opcode = "sub";
else if (bin->getKind() == BinaryInst::kMul) opcode = "mul";
else return insts; // 其他操作未实现
insts.emplace_back(opcode, std::vector<Operand>{
{Operand::Reg, std::string((const char*)bin->getResult())},
{Operand::Reg, std::string((const char*)bin->getLHS())},
{Operand::Reg, std::string((const char*)bin->getRHS())}
{Operand::Kind::Reg, bin},
{Operand::Kind::Reg, bin->getLhs()},
{Operand::Kind::Reg, bin->getRhs()}
});
} else if (auto load = dynamic_cast<LoadInst*>(inst)) {
insts.emplace_back("lw", std::vector<Operand>{
{Operand::Reg, std::string((const char*)load->getResult())},
{Operand::Label, load->getPointer()->getName()}
{Operand::Kind::Reg, load},
{Operand::Kind::Label, load->getPointer()->getName()}
});
} else if (auto store = dynamic_cast<StoreInst*>(inst)) {
insts.emplace_back("sw", std::vector<Operand>{
{Operand::Reg, std::string((const char*)store->getValue())},
{Operand::Label, store->getPointer()->getName()}
{Operand::Kind::Reg, store->getValue()},
{Operand::Kind::Label, store->getPointer()->getName()}
});
} // 其他指令类型待实现
}
return insts;
}
void RISCv32CodeGen::eliminate_phi(Function* func) {
// 简单实现：假设CopyInst存在
for (auto bb : func->getBasicBlocks()) {
for (auto inst : bb->getInstructions()) {
if (/* inst is PhiInst */) {
// 插入CopyInst到前驱块
// 移除phi指令
}
}
}
// TODO: 实现 phi 指令消除
}
std::map<Instruction*, std::set<Value*>> RISCv32CodeGen::liveness_analysis(Function* func) {
std::map<Instruction*, std::set<Value*>> live_sets;
// 简单实现：需实际计算活跃性
// TODO: 实现活跃性分析
return live_sets;
}
std::map<Value*, std::set<Value*>> RISCv32CodeGen::build_interference_graph(
const std::map<Instruction*, std::set<Value*>>& live_sets) {
std::map<Value*, std::set<Value*>> graph;
// 简单实现：需实际构建干扰图
// TODO: 实现干扰图构建
return graph;
}
RISCv32CodeGen::RegAllocResult RISCv32CodeGen::register_allocation(Function* func) {
RegAllocResult result;
eliminate_phi(func);
auto live_sets = liveness_analysis(func);
auto graph = build_interference_graph(live_sets);
// 图着色算法
std::vector<Value*> stack;
std::map<Value*, int> degrees;
for (const auto& pair : graph) {
degrees[pair.first] = pair.second.size();
if (degrees[pair.first] < allocable_regs.size()) {
stack.push_back(pair.first);
}
}
// 简单实现：需完成图着色和溢出处理
// TODO: 实现寄存器分配
return result;
}
}
} // namespace sysy