81 lines
2.1 KiB
C++
81 lines
2.1 KiB
C++
#ifndef RISCV64_LINEARSCAN_H
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#define RISCV64_LINEARSCAN_H
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#include "RISCv64LLIR.h"
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#include "RISCv64ISel.h"
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#include <vector>
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#include <map>
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#include <set>
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#include <algorithm>
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namespace sysy {
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// 前向声明
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class MachineBasicBlock;
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class MachineFunction;
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class RISCv64ISel;
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/**
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* @brief 表示一个虚拟寄存器的活跃区间。
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* 包含起始和结束指令编号。为了简化，我们不处理有“洞”的区间。
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*/
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struct LiveInterval {
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unsigned vreg = 0;
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int start = -1;
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int end = -1;
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bool crosses_call = false;
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LiveInterval(unsigned vreg) : vreg(vreg) {}
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// 用于排序，按起始点从小到大
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bool operator<(const LiveInterval& other) const {
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return start < other.start;
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}
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};
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class RISCv64LinearScan {
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public:
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RISCv64LinearScan(MachineFunction* mfunc);
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bool run();
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private:
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// --- 核心算法流程 ---
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void linearizeBlocks();
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void computeLiveIntervals();
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bool linearScan();
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void rewriteProgram();
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void applyAllocation();
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void spillAtInterval(LiveInterval* current);
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// --- 辅助函数 ---
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bool isFPVReg(unsigned vreg) const;
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void collectUsedCalleeSavedRegs();
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MachineFunction* MFunc;
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RISCv64ISel* ISel;
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// --- 线性扫描数据结构 ---
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std::vector<MachineBasicBlock*> linear_order_blocks;
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std::map<const MachineInstr*, int> instr_numbering;
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std::map<unsigned, LiveInterval> live_intervals;
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std::vector<LiveInterval*> unhandled;
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std::vector<LiveInterval*> active; // 活跃且已分配物理寄存器的区间
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std::set<unsigned> spilled_vregs; // 记录在本轮被决定溢出的vreg
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bool conservative_spill_mode = false;
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const PhysicalReg SPILL_TEMP_REG = PhysicalReg::T4;
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// --- 寄存器池和分配结果 ---
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std::vector<PhysicalReg> allocable_int_regs;
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std::vector<PhysicalReg> allocable_fp_regs;
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std::map<unsigned, PhysicalReg> vreg_to_preg_map;
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std::map<unsigned, PhysicalReg> abi_vreg_map;
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const std::map<unsigned, Type*>& vreg_type_map;
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};
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} // namespace sysy
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#endif // RISCV64_LINEARSCAN_H
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