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合并backend、backend-IRC到midend

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This commit is contained in:
Lixuanwang
2025-08-03 15:18:52 +08:00
parent 5b43f208ac
commit f8e423f579
17 changed files with 1966 additions and 1135 deletions
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145
src/backend/RISCv64/Handler/PrologueEpilogueInsertion.cpp
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@@ -1,17 +1,22 @@
#include "PrologueEpilogueInsertion.h"
#include "RISCv64LLIR.h" // 假设包含了 PhysicalReg, RVOpcodes 等定义
#include "RISCv64ISel.h"
#include "RISCv64RegAlloc.h" // 需要访问RegAlloc的结果
#include <algorithm>
#include <vector>
#include <set>
namespace sysy {
char PrologueEpilogueInsertionPass::ID = 0;
void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc) {
StackFrameInfo& frame_info = mfunc->getFrameInfo();
Function* F = mfunc->getFunc();
RISCv64ISel* isel = mfunc->getISel();
// 1. 清理 KEEPALIVE 伪指令
for (auto& mbb : mfunc->getBlocks()) {
auto& instrs = mbb->getInstructions();
// 使用标准的 Erase-Remove Idiom 来删除满足条件的元素
instrs.erase(
std::remove_if(instrs.begin(), instrs.end(),
[](const std::unique_ptr<MachineInstr>& instr) {
@@ -22,39 +27,49 @@ void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc)
);
}
StackFrameInfo& frame_info = mfunc->getFrameInfo();
Function* F = mfunc->getFunc();
RISCv64ISel* isel = mfunc->getISel();
// [关键] 获取寄存器分配的结果 (vreg -> preg 的映射)
// RegAlloc Pass 必须已经运行过
// 2. 确定需要保存的被调用者保存寄存器 (callee-saved)
auto& vreg_to_preg_map = frame_info.vreg_to_preg_map;
std::set<PhysicalReg> used_callee_saved_regs_set;
const auto& callee_saved_int = getCalleeSavedIntRegs();
const auto& callee_saved_fp = getCalleeSavedFpRegs();
// 完全遵循 AsmPrinter 中的计算逻辑
for (const auto& pair : vreg_to_preg_map) {
PhysicalReg preg = pair.second;
bool is_int_cs = std::find(callee_saved_int.begin(), callee_saved_int.end(), preg) != callee_saved_int.end();
bool is_fp_cs = std::find(callee_saved_fp.begin(), callee_saved_fp.end(), preg) != callee_saved_fp.end();
if ((is_int_cs && preg != PhysicalReg::S0) || is_fp_cs) {
used_callee_saved_regs_set.insert(preg);
}
}
frame_info.callee_saved_regs_to_store.assign(
used_callee_saved_regs_set.begin(), used_callee_saved_regs_set.end()
);
std::sort(frame_info.callee_saved_regs_to_store.begin(), frame_info.callee_saved_regs_to_store.end());
frame_info.callee_saved_size = frame_info.callee_saved_regs_to_store.size() * 8;
// 3. 计算最终的栈帧总大小
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
16;
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 ---
// --- 4. 插入完整的序言 ---
MachineBasicBlock* entry_block = mfunc->getBlocks().front().get();
auto& entry_instrs = entry_block->getInstructions();
std::vector<std::unique_ptr<MachineInstr>> prologue_instrs;
// 1. addi sp, sp, -aligned_stack_size
// 4.1. 分配栈帧
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)
// 4.2. 保存 ra 和 s0
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>(
@@ -62,8 +77,6 @@ void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc)
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>(
@@ -72,66 +85,54 @@ void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc)
));
prologue_instrs.push_back(std::move(save_fp));
// 4. addi s0, sp, aligned_stack_size
// 4.3. 设置新的帧指针 s0
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));
// --- 在s0设置完毕后，使用物理寄存器加载栈参数 ---
if (F && isel) {
int arg_idx = 0;
for (Argument* arg : F->getArguments()) {
if (arg_idx >= 8) {
unsigned vreg = isel->getVReg(arg);
if (frame_info.alloca_offsets.count(vreg) && vreg_to_preg_map.count(vreg)) {
int offset = frame_info.alloca_offsets.at(vreg);
PhysicalReg dest_preg = vreg_to_preg_map.at(vreg);
Type* arg_type = arg->getType();
if (arg_type->isFloat()) {
auto load_arg = std::make_unique<MachineInstr>(RVOpcodes::FLW);
load_arg->addOperand(std::make_unique<RegOperand>(dest_preg));
load_arg->addOperand(std::make_unique<MemOperand>(
std::make_unique<RegOperand>(PhysicalReg::S0),
std::make_unique<ImmOperand>(offset)
));
prologue_instrs.push_back(std::move(load_arg));
} else {
RVOpcodes load_op = arg_type->isPointer() ? RVOpcodes::LD : RVOpcodes::LW;
auto load_arg = std::make_unique<MachineInstr>(load_op);
load_arg->addOperand(std::make_unique<RegOperand>(dest_preg));
load_arg->addOperand(std::make_unique<MemOperand>(
std::make_unique<RegOperand>(PhysicalReg::S0),
std::make_unique<ImmOperand>(offset)
));
prologue_instrs.push_back(std::move(load_arg));
}
}
}
arg_idx++;
}
}
// 确定插入点
auto insert_pos = entry_instrs.begin();
// 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()));
// 4.4. 保存所有使用到的被调用者保存寄存器
int next_available_offset = -(16 + frame_info.locals_size + frame_info.spill_size);
for (const auto& reg : frame_info.callee_saved_regs_to_store) {
// 采用“先使用，后更新”逻辑
RVOpcodes store_op = isFPR(reg) ? RVOpcodes::FSD : RVOpcodes::SD;
auto save_cs_reg = std::make_unique<MachineInstr>(store_op);
save_cs_reg->addOperand(std::make_unique<RegOperand>(reg));
save_cs_reg->addOperand(std::make_unique<MemOperand>(
std::make_unique<RegOperand>(PhysicalReg::S0),
std::make_unique<ImmOperand>(next_available_offset) // 使用当前偏移
));
prologue_instrs.push_back(std::move(save_cs_reg));
next_available_offset -= 8; // 为下一个寄存器准备偏移
}
// --- 2. 插入尾声 (此部分逻辑保持不变) ---
// 4.5. 将所有生成的序言指令一次性插入到函数入口
entry_instrs.insert(entry_instrs.begin(),
std::make_move_iterator(prologue_instrs.begin()),
std::make_move_iterator(prologue_instrs.end()));
// --- 5. 插入完整的尾声 ---
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;
// 5.1. 恢复被调用者保存寄存器
int next_available_offset_restore = -(16 + frame_info.locals_size + frame_info.spill_size);
for (const auto& reg : frame_info.callee_saved_regs_to_store) {
RVOpcodes load_op = isFPR(reg) ? RVOpcodes::FLD : RVOpcodes::LD;
auto restore_cs_reg = std::make_unique<MachineInstr>(load_op);
restore_cs_reg->addOperand(std::make_unique<RegOperand>(reg));
restore_cs_reg->addOperand(std::make_unique<MemOperand>(
std::make_unique<RegOperand>(PhysicalReg::S0),
std::make_unique<ImmOperand>(next_available_offset_restore) // 使用当前偏移
));
epilogue_instrs.push_back(std::move(restore_cs_reg));
next_available_offset_restore -= 8; // 为下一个寄存器准备偏移
}
// 1. ld ra
// 5.2. 恢复 ra 和 s0
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>(
@@ -139,8 +140,6 @@ void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc)
std::make_unique<ImmOperand>(aligned_stack_size - 8)
));
epilogue_instrs.push_back(std::move(restore_ra));
// 2. ld s0
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>(
@@ -149,18 +148,18 @@ void PrologueEpilogueInsertionPass::runOnMachineFunction(MachineFunction* mfunc)
));
epilogue_instrs.push_back(std::move(restore_fp));
// 3. addi sp, sp, aligned_stack_size
// 5.3. 释放栈帧
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()));
}
// 将尾声指令插入到 RET 指令之前
mbb->getInstructions().insert(it,
std::make_move_iterator(epilogue_instrs.begin()),
std::make_move_iterator(epilogue_instrs.end()));
goto next_block;
}
}