1 //===-- LiveRange.h - Store info about a live range --------------*- C++ -*--=//
3 // Implements a live range using a ValueSet. A LiveRange is a simple set
6 // Since the Value pointed by a use is the same as of its def, it is sufficient
7 // to keep only defs in a LiveRange.
9 //===----------------------------------------------------------------------===//
14 #include "llvm/Analysis/LiveVar/ValueSet.h"
15 #include "llvm/Type.h"
21 class LiveRange : public ValueSet {
22 RegClass *MyRegClass; // register classs (e.g., int, FP) for this LR
24 // doesSpanAcrossCalls - Does this live range span across calls?
25 // This information is used by graph
26 // coloring algo to avoid allocating volatile colors to live ranges
27 // that span across calls (since they have to be saved/restored)
29 bool doesSpanAcrossCalls;
31 IGNode *UserIGNode; // IGNode which uses this LR
32 int Color; // color assigned to this live range
33 bool mustSpill; // whether this LR must be spilt
35 // mustSaveAcrossCalls - whether this LR must be saved accross calls
36 // ***TODO REMOVE this
38 bool mustSaveAcrossCalls;
40 // SuggestedColor - if this LR has a suggested color, can it be
41 // really alloated? A suggested color cannot be allocated when the
42 // suggested color is volatile and when there are call
45 int SuggestedColor; // The suggested color for this LR
47 // CanUseSuggestedCol - It is possible that a suggested color for
48 // this live range is not available before graph coloring (e.g., it
49 // can be allocated to another live range which interferes with
52 bool CanUseSuggestedCol;
54 // SpilledStackOffsetFromFP - If this LR is spilled, its stack
55 // offset from *FP*. The spilled offsets must always be relative to
58 int SpilledStackOffsetFromFP;
60 // HasSpillOffset 0 Whether this live range has a spill offset
64 // The spill cost of this live range. Calculated using loop depth of
65 // each reference to each Value in the live range
71 Color = SuggestedColor = -1; // not yet colored
72 mustSpill = mustSaveAcrossCalls = false;
75 doesSpanAcrossCalls = false;
76 CanUseSuggestedCol = true;
77 HasSpillOffset = false;
81 void setRegClass(RegClass *RC) { MyRegClass = RC; }
83 RegClass *getRegClass() const { assert(MyRegClass); return MyRegClass; }
85 bool hasColor() const { return Color != -1; }
87 unsigned getColor() const { assert(Color != -1); return (unsigned)Color; }
89 void setColor(unsigned Col) { Color = (int)Col; }
91 inline void setCallInterference() {
92 doesSpanAcrossCalls = 1;
95 inline bool isCallInterference() const {
96 return doesSpanAcrossCalls == 1;
99 inline void markForSpill() { mustSpill = true; }
101 inline bool isMarkedForSpill() { return mustSpill; }
103 inline void setSpillOffFromFP(int StackOffset) {
104 assert(mustSpill && "This LR is not spilled");
105 SpilledStackOffsetFromFP = StackOffset;
106 HasSpillOffset = true;
109 inline void modifySpillOffFromFP(int StackOffset) {
110 assert(mustSpill && "This LR is not spilled");
111 SpilledStackOffsetFromFP = StackOffset;
112 HasSpillOffset = true;
115 inline bool hasSpillOffset() const {
116 return HasSpillOffset;
119 inline int getSpillOffFromFP() const {
120 assert(HasSpillOffset && "This LR is not spilled");
121 return SpilledStackOffsetFromFP;
124 inline void markForSaveAcrossCalls() { mustSaveAcrossCalls = true; }
126 inline void setUserIGNode(IGNode *IGN) {
127 assert(!UserIGNode); UserIGNode = IGN;
130 // getUserIGNode - NULL if the user is not allocated
131 inline IGNode *getUserIGNode() const { return UserIGNode; }
133 inline const Type *getType() const {
134 return (*begin())->getType(); // set's don't have a front
137 inline Type::PrimitiveID getTypeID() const {
138 return getType()->getPrimitiveID();
141 inline void setSuggestedColor(int Col) {
142 if (SuggestedColor == -1)
143 SuggestedColor = Col;
146 std::cerr << "Already has a suggested color " << Col << "\n";
150 inline unsigned getSuggestedColor() const {
151 assert(SuggestedColor != -1); // only a valid color is obtained
152 return (unsigned)SuggestedColor;
155 inline bool hasSuggestedColor() const {
156 return SuggestedColor != -1;
159 inline bool isSuggestedColorUsable() const {
160 assert(hasSuggestedColor() && "No suggested color");
161 return CanUseSuggestedCol;
164 inline void setSuggestedColorUsable(bool val) {
165 assert(hasSuggestedColor() && "No suggested color");
166 CanUseSuggestedCol = val;
169 inline void addSpillCost(unsigned cost) {
173 inline unsigned getSpillCost() const {