- /// GetRegForReload - Helper for the above GetRegForReload(). Add a
- /// 'Rejected' set to remember which registers have been considered and
- /// rejected for the reload. This avoids infinite looping in case like
- /// this:
- /// t1 := op t2, t3
- /// t2 <- assigned r0 for use by the reload but ended up reuse r1
- /// t3 <- assigned r1 for use by the reload but ended up reuse r0
- /// t1 <- desires r1
- /// sees r1 is taken by t2, tries t2's reload register r0
- /// sees r0 is taken by t3, tries t3's reload register r1
- /// sees r1 is taken by t2, tries t2's reload register r0 ...
- unsigned GetRegForReload(unsigned PhysReg, MachineInstr *MI,
- AvailableSpills &Spills,
- std::vector<MachineInstr*> &MaybeDeadStores,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM) {
- SmallSet<unsigned, 8> Rejected;
- return GetRegForReload(PhysReg, MI, Spills, MaybeDeadStores, Rejected,
- RegKills, KillOps, VRM);
- }
- };
-
- // ************************************************************************ //
-
- /// LocalSpiller - This spiller does a simple pass over the machine basic
- /// block to attempt to keep spills in registers as much as possible for
- /// blocks that have low register pressure (the vreg may be spilled due to
- /// register pressure in other blocks).
- class VISIBILITY_HIDDEN LocalSpiller : public Spiller {
- MachineRegisterInfo *RegInfo;
- const TargetRegisterInfo *TRI;
- const TargetInstrInfo *TII;
- DenseMap<MachineInstr*, unsigned> DistanceMap;
- std::vector<MachineInstr*> AddedSpills;
- public:
- bool runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM);
- private:
- void TransferDeadness(MachineBasicBlock *MBB, unsigned CurDist,
- unsigned Reg, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps);
- bool PrepForUnfoldOpti(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- std::vector<MachineInstr*> &MaybeDeadStores,
- AvailableSpills &Spills, BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
- bool CommuteToFoldReload(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- unsigned VirtReg, unsigned SrcReg, int SS,
- AvailableSpills &Spills,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- const TargetRegisterInfo *TRI,
- VirtRegMap &VRM);
- void RemoveDeadStore(MachineInstr *Store,
- MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- SmallSet<MachineInstr*, 4> &ReMatDefs,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
-
- void SpillRegToStackSlot(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MII,
- int Idx, unsigned PhysReg, int StackSlot,
- const TargetRegisterClass *RC,
- bool isAvailable, MachineInstr *&LastStore,
- AvailableSpills &Spills,
- SmallSet<MachineInstr*, 4> &ReMatDefs,
- BitVector &RegKills,
- std::vector<MachineOperand*> &KillOps,
- VirtRegMap &VRM);
- void RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
- AvailableSpills &Spills,
- BitVector &RegKills, std::vector<MachineOperand*> &KillOps);
- };