Added comments, destructors where necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1491 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAlloc/LiveRange.h b/lib/CodeGen/RegAlloc/LiveRange.h
index 3ef627e..778e070 100644
--- a/lib/CodeGen/RegAlloc/LiveRange.h
+++ b/lib/CodeGen/RegAlloc/LiveRange.h
@@ -14,56 +14,88 @@
#include "llvm/Analysis/LiveVar/ValueSet.h"
#include "llvm/Type.h"
-
-
-
class RegClass;
class IGNode;
+//----------------------------------------------------------------------------
+// Class LiveRange
+//
+// Implements a live range using a ValueSet. A LiveRange is a simple set
+// of Values.
+//----------------------------------------------------------------------------
+
class LiveRange : public ValueSet
{
private:
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;
- // does this live range span across calls?
+ bool 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 ***TODO REMOVE this
+
bool mustSaveAcrossCalls;
-
- // bool mustLoadFromStack; // must load from stack at start of method
-
-
+ //
+ // whether this LR must be saved accross calls ***TODO REMOVE this
+
int SuggestedColor; // The suggested color for this LR
-
+ //
// 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.
bool 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)
+ int SpilledStackOffsetFromFP;
+ //
// if this LR is spilled, its stack offset from *FP*. The spilled offsets
// must always be relative to the FP.
- int SpilledStackOffsetFromFP;
+
bool HasSpillOffset;
+ //
+ // Whether this live range has a spill offset
+
+ unsigned SpillCost;
+ //
+ // The spill cost of this live range. Calculated using loop depth of
+ // each reference to each Value in the live range
public:
+ // constructor
+ //
+ LiveRange() : ValueSet() {
+ Color = SuggestedColor = -1; // not yet colored
+ mustSpill = mustSaveAcrossCalls = false;
+ MyRegClass = NULL;
+ UserIGNode = NULL;
+ doesSpanAcrossCalls = false;
+ CanUseSuggestedCol = true;
+ HasSpillOffset = false;
+ SpillCost = 0;
+ }
- ~LiveRange() {} // empty destructor
+ // empty destructor since there are nothing to be deleted
+ //
+ ~LiveRange() {}
+
void setRegClass(RegClass *const RC)
{ MyRegClass = RC; }
@@ -90,7 +122,6 @@
return (doesSpanAcrossCalls == 1);
}
-
inline void markForSpill() { mustSpill = true; }
inline bool isMarkedForSpill() { return mustSpill; }
@@ -122,9 +153,7 @@
inline void markForSaveAcrossCalls() { mustSaveAcrossCalls = true; }
- // inline void markForLoadFromStack() { mustLoadFromStack = true;
-
-
+
inline void setUserIGNode( IGNode *const IGN)
{ assert( !UserIGNode); UserIGNode = IGN; }
@@ -169,22 +198,13 @@
CanUseSuggestedCol = val;
}
+ inline void addSpillCost(unsigned cost) {
+ SpillCost += cost;
+ }
-
-
-
-
-
- inline LiveRange() : ValueSet() /* , CallInterferenceList() */
- {
- Color = SuggestedColor = -1; // not yet colored
- mustSpill = mustSaveAcrossCalls = false;
- MyRegClass = NULL;
- UserIGNode = NULL;
- doesSpanAcrossCalls = false;
- CanUseSuggestedCol = true;
- HasSpillOffset = false;
- }
+ inline unsigned getSpillCost() const {
+ return SpillCost;
+ }
};