-/* Title: LiveRange.h
- Author: Ruchira Sasanka
- Date: July 25, 01
- Purpose: To keep info about a live range.
- Asuumptions:
-
- Since the Value pointed by a use is the same as of its def, it is sufficient
- to keep only defs in a LiveRange.
-*/
+//===-- LiveRange.h - Store info about a live range --------------*- C++ -*--=//
+//
+// Implements a live range using a ValueSet. A LiveRange is a simple set
+// of Values.
+//
+// Since the Value pointed by a use is the same as of its def, it is sufficient
+// to keep only defs in a LiveRange.
+//
+//===----------------------------------------------------------------------===//
#ifndef LIVE_RANGE_H
#define LIVE_RANGE_H
#include "llvm/Analysis/LiveVar/ValueSet.h"
-#include "llvm/Type.h"
-
-
-
+#include "llvm/Value.h"
class RegClass;
class IGNode;
+class Type;
-
-class LiveRange : public ValueSet
-{
- private:
-
+class LiveRange : public ValueSet {
RegClass *MyRegClass; // register classs (e.g., int, FP) for this LR
- // a list of call instructions that interferes with this live range
- vector<const Instruction *> CallInterferenceList;
+ // doesSpanAcrossCalls - Does this live range span across calls?
+ // This information is used by graph
+ // coloring algo to avoid allocating volatile colors to live ranges
+ // that span across calls (since they have to be saved/restored)
+ //
+ bool doesSpanAcrossCalls;
IGNode *UserIGNode; // IGNode which uses this LR
int Color; // color assigned to this live range
bool mustSpill; // whether this LR must be spilt
- // whether this LR must be saved accross calls
+ // mustSaveAcrossCalls - whether this LR must be saved accross calls
+ // ***TODO REMOVE this
+ //
bool mustSaveAcrossCalls;
+
+ // SuggestedColor - if this LR has a suggested color, can it be
+ // really alloated? A suggested color cannot be allocated when the
+ // suggested color is volatile and when there are call
+ // interferences.
+ //
+ int SuggestedColor; // The suggested color for this LR
+
+ // CanUseSuggestedCol - It is possible that a suggested color for
+ // this live range is not available before graph coloring (e.g., it
+ // can be allocated to another live range which interferes with
+ // this)
+ //
+ bool CanUseSuggestedCol;
+
+ // SpilledStackOffsetFromFP - If this LR is spilled, its stack
+ // offset from *FP*. The spilled offsets must always be relative to
+ // the FP.
+ //
+ int SpilledStackOffsetFromFP;
+
+ // HasSpillOffset 0 Whether this live range has a spill offset
+ //
+ bool HasSpillOffset;
+
+ // The spill cost of this live range. Calculated using loop depth of
+ // each reference to each Value in the live range
+ //
+ unsigned SpillCost;
+
+public:
+ LiveRange() {
+ Color = SuggestedColor = -1; // not yet colored
+ mustSpill = mustSaveAcrossCalls = false;
+ MyRegClass = 0;
+ UserIGNode = 0;
+ doesSpanAcrossCalls = false;
+ CanUseSuggestedCol = true;
+ HasSpillOffset = false;
+ SpillCost = 0;
+ }
- // bool mustLoadFromStack; // must load from stack at start of method
-
- public:
+ void setRegClass(RegClass *RC) { MyRegClass = RC; }
+ RegClass *getRegClass() const { assert(MyRegClass); return MyRegClass; }
- ~LiveRange() {} // empty destructor
+ bool hasColor() const { return Color != -1; }
+
+ unsigned getColor() const { assert(Color != -1); return (unsigned)Color; }
- void setRegClass(RegClass *const RC)
- { MyRegClass = RC; }
+ void setColor(unsigned Col) { Color = (int)Col; }
- inline RegClass *const getRegClass() const
- { assert(MyRegClass); return MyRegClass; }
+ inline void setCallInterference() {
+ doesSpanAcrossCalls = 1;
+ }
+ inline void clearCallInterference() {
+ doesSpanAcrossCalls = 0;
+ }
- inline bool hasColor() const
- { return Color != -1; }
+ inline bool isCallInterference() const {
+ return doesSpanAcrossCalls == 1;
+ }
- inline unsigned int getColor() const
- { assert( Color != -1); return (unsigned) Color ; }
+ inline void markForSpill() { mustSpill = true; }
- inline void setColor(unsigned int Col)
- { Color = (int) Col ; }
+ inline bool isMarkedForSpill() { return mustSpill; }
-
- inline void addCallInterference(const Instruction *const Inst)
- { CallInterferenceList.push_back( Inst ); }
+ inline void setSpillOffFromFP(int StackOffset) {
+ assert(mustSpill && "This LR is not spilled");
+ SpilledStackOffsetFromFP = StackOffset;
+ HasSpillOffset = true;
+ }
- inline const Instruction *const getCallInterference(const unsigned i) const {
- assert( i < CallInterferenceList.size() );
- return CallInterferenceList[i];
+ inline void modifySpillOffFromFP(int StackOffset) {
+ assert(mustSpill && "This LR is not spilled");
+ SpilledStackOffsetFromFP = StackOffset;
+ HasSpillOffset = true;
}
- inline unsigned int getNumOfCallInterferences() const
- { return CallInterferenceList.size(); }
+ inline bool hasSpillOffset() const {
+ return HasSpillOffset;
+ }
-
- inline void markForSpill() { mustSpill = true; }
+ inline int getSpillOffFromFP() const {
+ assert(HasSpillOffset && "This LR is not spilled");
+ return SpilledStackOffsetFromFP;
+ }
inline void markForSaveAcrossCalls() { mustSaveAcrossCalls = true; }
+
+ inline void setUserIGNode(IGNode *IGN) {
+ assert(!UserIGNode); UserIGNode = IGN;
+ }
- // inline void markForLoadFromStack() { mustLoadFromStack = true;
+ // getUserIGNode - NULL if the user is not allocated
+ inline IGNode *getUserIGNode() const { return UserIGNode; }
+ inline const Type *getType() const {
+ return (*begin())->getType(); // set's don't have a front
+ }
+
+ inline void setSuggestedColor(int Col) {
+ if (SuggestedColor == -1)
+ SuggestedColor = Col;
+ }
- inline void setUserIGNode( IGNode *const IGN)
- { assert( !UserIGNode); UserIGNode = IGN; }
+ inline unsigned getSuggestedColor() const {
+ assert(SuggestedColor != -1); // only a valid color is obtained
+ return (unsigned)SuggestedColor;
+ }
- inline IGNode * getUserIGNode() const
- { return UserIGNode; } // NULL if the user is not allocated
+ inline bool hasSuggestedColor() const {
+ return SuggestedColor != -1;
+ }
- inline Type::PrimitiveID getTypeID() const {
- const Value *val = *begin();
- assert(val && "Can't find type - Live range is empty" );
- return (val->getType())->getPrimitiveID();
+ inline bool isSuggestedColorUsable() const {
+ assert(hasSuggestedColor() && "No suggested color");
+ return CanUseSuggestedCol;
}
+ inline void setSuggestedColorUsable(bool val) {
+ assert(hasSuggestedColor() && "No suggested color");
+ CanUseSuggestedCol = val;
+ }
- inline LiveRange() : ValueSet() , CallInterferenceList()
- {
- Color = -1; // not yet colored
- mustSpill = mustSaveAcrossCalls = false;
- MyRegClass = NULL;
- UserIGNode = NULL;
- }
+ inline void addSpillCost(unsigned cost) {
+ SpillCost += cost;
+ }
+ inline unsigned getSpillCost() const {
+ return SpillCost;
+ }
};
-
-
-
-
#endif
-