1 /* Title: PhyRegAlloc.h -*- C++ -*-
2 Author: Ruchira Sasanka
4 Purpose: This is the main entry point for register allocation.
9 * RegisterClasses: Each RegClass accepts a
10 TargetRegClass which contains machine specific info about that register
11 class. The code in the RegClass is machine independent and they use
12 access functions in the TargetRegClass object passed into it to get
13 machine specific info.
15 * Machine dependent work: All parts of the register coloring algorithm
16 except coloring of an individual node are machine independent.
19 #ifndef PHY_REG_ALLOC_H
20 #define PHY_REG_ALLOC_H
22 #include "llvm/CodeGen/LiveRangeInfo.h"
23 #include "Support/NonCopyable.h"
26 class MachineFunction;
28 class FunctionLiveVarInfo;
33 //----------------------------------------------------------------------------
34 // Class AddedInstrns:
35 // When register allocator inserts new instructions in to the existing
36 // instruction stream, it does NOT directly modify the instruction stream.
37 // Rather, it creates an object of AddedInstrns and stick it in the
38 // AddedInstrMap for an existing instruction. This class contains two vectors
39 // to store such instructions added before and after an existing instruction.
40 //----------------------------------------------------------------------------
43 std::vector<MachineInstr*> InstrnsBefore;//Insts added BEFORE an existing inst
44 std::vector<MachineInstr*> InstrnsAfter; //Insts added AFTER an existing inst
47 //----------------------------------------------------------------------------
49 // Main class the register allocator. Call allocateRegisters() to allocate
50 // registers for a Function.
51 //----------------------------------------------------------------------------
53 class PhyRegAlloc : public NonCopyable {
54 std::vector<RegClass *> RegClassList; // vector of register classes
55 const TargetMachine &TM; // target machine
56 const Function *Fn; // name of the function we work on
57 MachineFunction &MF; // descriptor for method's native code
58 FunctionLiveVarInfo *const LVI; // LV information for this method
59 // (already computed for BBs)
60 LiveRangeInfo LRI; // LR info (will be computed)
61 const TargetRegInfo &MRI; // Machine Register information
62 const unsigned NumOfRegClasses; // recorded here for efficiency
64 // Map to indicate whether operands of each MachineInstr have been updated
65 // according to their assigned colors. This is primarily for debugging and
66 // could be removed in the long run.
67 std::map<const MachineInstr *, bool> OperandsColoredMap;
69 // AddedInstrMap - Used to store instrns added in this phase
70 std::map<const MachineInstr *, AddedInstrns> AddedInstrMap;
72 AddedInstrns AddedInstrAtEntry; // to store instrns added at entry
73 LoopInfo *LoopDepthCalc; // to calculate loop depths
74 std::vector<unsigned> ResColList; // A set of reserved regs if desired.
78 PhyRegAlloc(Function *F, const TargetMachine& TM, FunctionLiveVarInfo *Lvi,
79 LoopInfo *LoopDepthCalc);
82 // main method called for allocating registers
84 void allocateRegisters();
87 // access to register classes by class ID
89 const RegClass* getRegClassByID(unsigned int id) const {
90 return RegClassList[id];
92 RegClass* getRegClassByID(unsigned int id) {
93 return RegClassList[id]; }
97 void addInterference(const Value *Def, const ValueSet *LVSet,
100 void addInterferencesForArgs();
101 void createIGNodeListsAndIGs();
102 void buildInterferenceGraphs();
104 void setCallInterferences(const MachineInstr *MInst,
105 const ValueSet *LVSetAft );
107 void move2DelayedInstr(const MachineInstr *OrigMI,
108 const MachineInstr *DelayedMI );
110 void markUnusableSugColors();
111 void allocateStackSpace4SpilledLRs();
113 void insertCode4SpilledLR (const LiveRange *LR,
115 const BasicBlock *BB,
116 const unsigned OpNum);
118 inline void constructLiveRanges() { LRI.constructLiveRanges(); }
120 void colorIncomingArgs();
121 void colorCallRetArgs();
122 void updateMachineCode();
123 void updateInstruction(MachineInstr* MInst, BasicBlock* BB);
125 void printLabel(const Value *const Val);
126 void printMachineCode();
129 friend class UltraSparcRegInfo; // FIXME: remove this
131 int getUsableUniRegAtMI(int RegType,
132 const ValueSet *LVSetBef,
134 std::vector<MachineInstr*>& MIBef,
135 std::vector<MachineInstr*>& MIAft);
137 int getUnusedUniRegAtMI(RegClass *RC, const MachineInstr *MInst,
138 const ValueSet *LVSetBef);
140 void setRelRegsUsedByThisInst(RegClass *RC, const MachineInstr *MInst );
141 int getUniRegNotUsedByThisInst(RegClass *RC, const MachineInstr *MInst);
143 void addInterf4PseudoInstr(const MachineInstr *MInst);