1 //===-- LiveRangeInfo.h - Track all LiveRanges for a Method ------*- C++ -*-==//
3 // This file contains the class LiveRangeInfo which constructs and keeps
4 // the LiveRangMap which contains all the live ranges used in a method.
8 // All variables (llvm Values) are defined before they are used. However, a
9 // constant may not be defined in the machine instruction stream if it can be
10 // used as an immediate value within a machine instruction. However, register
11 // allocation does not have to worry about immediate constants since they
12 // do not require registers.
14 // Since an llvm Value has a list of uses associated, it is sufficient to
15 // record only the defs in a Live Range.
17 //===----------------------------------------------------------------------===//
19 #ifndef LIVE_RANGE_INFO_H
20 #define LIVE_RANGE_INFO_H
22 #include "Support/HashExtras.h"
23 #include "llvm/Analysis/LiveVar/ValueSet.h"
34 typedef std::hash_map<const Value*, LiveRange*> LiveRangeMapType;
35 typedef std::vector<const MachineInstr*> CallRetInstrListType;
37 //----------------------------------------------------------------------------
38 // Class LiveRangeInfo
40 // Constructs and keeps the LiveRangMap which contains all the live
41 // ranges used in a method. Also contain methods to coalesce live ranges.
42 //----------------------------------------------------------------------------
45 const Method *const Meth; // Method for which live range info is held
46 LiveRangeMapType LiveRangeMap; // A map from Value * to LiveRange * to
47 // record all live ranges in a method
48 // created by constructLiveRanges
50 const TargetMachine& TM; // target machine description
52 std::vector<RegClass *> & RegClassList;// vector containing register classess
54 const MachineRegInfo& MRI; // machine reg info
56 CallRetInstrListType CallRetInstrList; // a list of all call/ret instrs
59 //------------ Private methods (see LiveRangeInfo.cpp for description)-------
61 void unionAndUpdateLRs(LiveRange *L1, LiveRange *L2);
63 void addInterference(const Instruction *Inst, const ValueSet *LVSet);
65 void suggestRegs4CallRets();
67 const Method* getMethod() { return Meth; }
71 LiveRangeInfo(const Method *M,
72 const TargetMachine& tm,
73 std::vector<RegClass *> & RCList);
76 // Destructor to destroy all LiveRanges in the LiveRange Map
79 // Main entry point for live range construction
81 void constructLiveRanges();
83 // This method is used to add a live range created elsewhere (e.g.,
84 // in machine specific code) to the common live range map
86 inline void addLRToMap(const Value *Val, LiveRange *LR) {
87 assert(Val && LR && "Val/LR is NULL!\n");
88 assert((!LiveRangeMap[Val]) && "LR already set in map");
89 LiveRangeMap[Val] = LR;
92 // return the common live range map for this method
94 inline const LiveRangeMapType *const getLiveRangeMap() const
95 { return &LiveRangeMap; }
97 // Method sed to get the corresponding live range of a Value
99 inline LiveRange *getLiveRangeForValue( const Value *const Val)
100 { return LiveRangeMap[Val]; }
102 // Method used to get the Call and Return instruction list
104 inline CallRetInstrListType &getCallRetInstrList() {
105 return CallRetInstrList;
108 // Method for coalescing live ranges. Called only after interference info
113 // debugging method to print the live ranges
115 void printLiveRanges();