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[backend]去除了错误的寄存器分配机制

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This commit is contained in:
Lixuanwang
2025-07-18 18:50:21 +08:00
parent fc62446b40
commit 1bcb5eba2a
1 changed files with 4 additions and 135 deletions
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139
src/RISCv64Backend.cpp
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@ -1339,8 +1339,6 @@ RISCv64CodeGen::RegAllocResult RISCv64CodeGen::register_allocation(Function* fun
}
}
}
// 清空临时指令存储
temp_instructions_storage.clear();
}
RegAllocResult alloc_result;
@ -1379,7 +1377,8 @@ RISCv64CodeGen::RegAllocResult RISCv64CodeGen::register_allocation(Function* fun
alloc_result.stack_map[alloca] = current_stack_offset;
current_stack_offset += total_size;
}
alloc_result.stack_size = current_stack_offset + 16; // 为 ra 和 s0 预留16字节
// RV64 修改: 为保存的 ra 和 s0 (各8字节) 预留16字节空间
alloc_result.stack_size = current_stack_offset + 16;
// 活跃性分析
std::map<Instruction*, std::set<std::string>> live_sets = liveness_analysis(func);
@ -1387,138 +1386,8 @@ RISCv64CodeGen::RegAllocResult RISCv64CodeGen::register_allocation(Function* fun
// 构建干扰图
std::map<std::string, std::set<std::string>> interference_graph = build_interference_graph(live_sets);
// 增强生命周期跟踪：记录每个虚拟寄存器的活跃范围
std::map<std::string, std::pair<Instruction*, Instruction*>> vreg_lifetimes; // <开始指令, 结束指令>
for (const auto& bb_ptr : func->getBasicBlocks()) {
for (const auto& inst_ptr : bb_ptr->getInstructions()) {
Instruction* inst = inst_ptr.get();
if (value_vreg_map.count(inst) && !dynamic_cast<AllocaInst*>(inst)) {
std::string vreg = value_vreg_map.at(inst);
if (vreg_lifetimes.find(vreg) == vreg_lifetimes.end()) {
vreg_lifetimes[vreg].first = inst; // 定义点作为生命周期开始
}
}
for (const auto& operand_use : inst->getOperands()) {
Value* operand = operand_use->getValue();
if (value_vreg_map.count(operand) && !dynamic_cast<AllocaInst*>(operand)) {
std::string vreg = value_vreg_map.at(operand);
vreg_lifetimes[vreg].second = inst; // 使用点更新生命周期结束
}
}
}
}
// 图着色，基于生命周期优化寄存器分配
std::map<std::string, PhysicalReg>& vreg_to_preg = alloc_result.vreg_to_preg;
vreg_to_preg.clear();
std::vector<PhysicalReg> int_regs = {
PhysicalReg::T0, PhysicalReg::T1, PhysicalReg::T2, PhysicalReg::T3,
PhysicalReg::T4, PhysicalReg::T5, PhysicalReg::T6,
PhysicalReg::A0, PhysicalReg::A1, PhysicalReg::A2, PhysicalReg::A3,
PhysicalReg::A4, PhysicalReg::A5, PhysicalReg::A6, PhysicalReg::A7,
PhysicalReg::S0, PhysicalReg::S1, PhysicalReg::S2, PhysicalReg::S3,
PhysicalReg::S4, PhysicalReg::S5, PhysicalReg::S6, PhysicalReg::S7,
PhysicalReg::S8, PhysicalReg::S9, PhysicalReg::S10, PhysicalReg::S11
};
std::vector<PhysicalReg> float_regs = {
PhysicalReg::F0, PhysicalReg::F1, PhysicalReg::F2, PhysicalReg::F3,
PhysicalReg::F4, PhysicalReg::F5, PhysicalReg::F6, PhysicalReg::F7,
PhysicalReg::F8, PhysicalReg::F9, PhysicalReg::F10, PhysicalReg::F11,
PhysicalReg::F12, PhysicalReg::F13, PhysicalReg::F14, PhysicalReg::F15,
PhysicalReg::F16, PhysicalReg::F17, PhysicalReg::F18, PhysicalReg::F19,
PhysicalReg::F20, PhysicalReg::F21, PhysicalReg::F22, PhysicalReg::F23,
PhysicalReg::F24, PhysicalReg::F25, PhysicalReg::F26, PhysicalReg::F27,
PhysicalReg::F28, PhysicalReg::F29, PhysicalReg::F30, PhysicalReg::F31
};
auto is_float_vreg = [&](const std::string& vreg) -> bool {
for (const auto& pair : value_vreg_map) {
if (pair.second == vreg) {
if (auto inst = dynamic_cast<Instruction*>(pair.first)) {
if (inst->isUnary()) {
switch (inst->getKind()) {
case Instruction::kFNeg:
case Instruction::kFNot:
case Instruction::kFtoI:
case Instruction::kItoF:
case Instruction::kBitFtoI:
case Instruction::kBitItoF:
return true;
default:
return inst->getType()->isFloat();
}
}
return inst->getType()->isFloat();
} else if (auto constant = dynamic_cast<ConstantValue*>(pair.first)) {
return constant->isFloat();
}
}
}
return false;
};
// 按活跃范围长度排序虚拟寄存器，优先分配长生命周期的寄存器
std::vector<std::pair<std::string, int>> vreg_priorities;
for (const auto& vreg_life : vreg_lifetimes) {
const std::string& vreg = vreg_life.first;
int lifetime_length = std::distance(
func->getBasicBlocks().begin(),
std::find_if(func->getBasicBlocks().begin(), func->getBasicBlocks().end(),
[&](const auto& bb) {
return std::find_if(bb->getInstructions().begin(), bb->getInstructions().end(),
[&](const auto& inst) { return inst.get() == vreg_life.second.second; }) != bb->getInstructions().end();
})) -
std::distance(
func->getBasicBlocks().begin(),
std::find_if(func->getBasicBlocks().begin(), func->getBasicBlocks().end(),
[&](const auto& bb) {
return std::find_if(bb->getInstructions().begin(), bb->getInstructions().end(),
[&](const auto& inst) { return inst.get() == vreg_life.second.first; }) != bb->getInstructions().end();
}));
vreg_priorities.push_back({vreg, lifetime_length});
}
std::sort(vreg_priorities.begin(), vreg_priorities.end(),
[](const auto& a, const auto& b) { return a.second > b.second; });
// 分配寄存器，考虑生命周期重叠
for (const auto& vreg_prio : vreg_priorities) {
const std::string& vreg = vreg_prio.first;
std::set<PhysicalReg> used_colors;
bool is_float = is_float_vreg(vreg);
// 检查干扰图和生命周期重叠
if (interference_graph.count(vreg)) {
for (const auto& neighbor_vreg : interference_graph.at(vreg)) {
if (vreg_to_preg.count(neighbor_vreg)) {
Instruction* neighbor_start = vreg_lifetimes[neighbor_vreg].first;
Instruction* neighbor_end = vreg_lifetimes[neighbor_vreg].second;
Instruction* current_start = vreg_lifetimes[vreg].first;
Instruction* current_end = vreg_lifetimes[vreg].second;
// 判断生命周期是否重叠
if (!(current_end < neighbor_start || current_start > neighbor_end)) {
used_colors.insert(vreg_to_preg.at(neighbor_vreg));
}
}
}
}
const auto& available_regs = is_float ? float_regs : int_regs;
bool colored = false;
for (PhysicalReg preg : available_regs) {
if (used_colors.find(preg) == used_colors.end()) {
vreg_to_preg[vreg] = preg;
colored = true;
break;
}
}
if (!colored) {
std::cerr << "警告: 无法为 " << vreg << " 分配" << (is_float ? "浮点" : "整数") << "寄存器，将溢出到栈。\n";
// 溢出处理逻辑待完善
}
}
// 图着色
color_graph(alloc_result.vreg_to_preg, interference_graph);
if (DEBUG) {
std::cerr << "=== 寄存器分配结果 (vreg_to_preg) ===\n";