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
76 PhyRegAlloc(Function *F, const TargetMachine& TM, FunctionLiveVarInfo *Lvi,
77 LoopInfo *LoopDepthCalc);
80 // main method called for allocating registers
82 void allocateRegisters();
85 // access to register classes by class ID
87 const RegClass* getRegClassByID(unsigned int id) const {
88 return RegClassList[id];
90 RegClass* getRegClassByID(unsigned int id) {
91 return RegClassList[id];
95 void addInterference(const Value *Def, const ValueSet *LVSet,
98 void addInterferencesForArgs();
99 void createIGNodeListsAndIGs();
100 void buildInterferenceGraphs();
102 void setCallInterferences(const MachineInstr *MInst,
103 const ValueSet *LVSetAft );
105 void move2DelayedInstr(const MachineInstr *OrigMI,
106 const MachineInstr *DelayedMI );
108 void markUnusableSugColors();
109 void allocateStackSpace4SpilledLRs();
111 void insertCode4SpilledLR (const LiveRange *LR,
113 const BasicBlock *BB,
114 const unsigned OpNum);
116 inline void constructLiveRanges() { LRI.constructLiveRanges(); }
118 void colorIncomingArgs();
119 void colorCallRetArgs();
120 void updateMachineCode();
121 void updateInstruction(MachineInstr* MInst, BasicBlock* BB);
123 void printLabel(const Value *const Val);
124 void printMachineCode();
127 friend class UltraSparcRegInfo; // FIXME: remove this
129 int getUsableUniRegAtMI(int RegType,
130 const ValueSet *LVSetBef,
132 std::vector<MachineInstr*>& MIBef,
133 std::vector<MachineInstr*>& MIAft);
135 int getUnusedUniRegAtMI(RegClass *RC, const int RegType,
136 const MachineInstr *MInst, const ValueSet *LVSetBef);
138 void setRelRegsUsedByThisInst(RegClass *RC, const int RegType,
139 const MachineInstr *MInst );
141 int getUniRegNotUsedByThisInst(RegClass *RC, const int RegType,
142 const MachineInstr *MInst);
144 void addInterf4PseudoInstr(const MachineInstr *MInst);