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			119 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			119 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===-- IGNode.h - Represent a node in an interference graph ----*- C++ -*-===//
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| // 
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file was developed by the LLVM research group and is distributed under
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| // the University of Illinois Open Source License. See LICENSE.TXT for details.
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| // 
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| //===----------------------------------------------------------------------===//
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| //
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| // This file represents a node in an interference graph. 
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| //
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| // For efficiency, the AdjList is updated only once - ie. we can add but not
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| // remove nodes from AdjList. 
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| //
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| // The removal of nodes from IG is simulated by decrementing the CurDegree.
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| // If this node is put on stack (that is removed from IG), the CurDegree of all
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| // the neighbors are decremented and this node is marked OnStack. Hence
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| // the effective neighbors in the AdjList are the ones that do not have the
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| // OnStack flag set (therefore, they are in the IG).
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| //
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| // The methods that modify/use the CurDegree must be called only
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| // after all modifications to the IG are over (i.e., all neighbors are fixed).
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| //
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| // The vector representation is the most efficient one for adj list.
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| // Though nodes are removed when coalescing is done, we access it in sequence
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| // for far many times when coloring (colorNode()).
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef IGNODE_H
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| #define IGNODE_H
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| 
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| #include "LiveRange.h"
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| #include <vector>
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| class RegClass;
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| 
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| //----------------------------------------------------------------------------
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| // Class IGNode
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| //
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| // Represents a node in an interference graph.
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| //----------------------------------------------------------------------------
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| 
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| class IGNode {
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|   const unsigned Index;         // index within IGNodeList 
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|   bool OnStack;                 // this has been pushed on to stack for coloring
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|   std::vector<IGNode *> AdjList;// adjacency list for this live range
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| 
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|   int CurDegree;     
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|   //
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|   // set by InterferenceGraph::setCurDegreeOfIGNodes() after calculating
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|   // all adjacency lists.
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|   // Decremented when a neighbor is pushed on to the stack. 
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|   // After that, never incremented/set again nor used.
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| 
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|   LiveRange *const ParentLR;
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| public:
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| 
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|   IGNode(LiveRange *LR, unsigned index) : Index(index), ParentLR(LR) {
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|     OnStack = false;
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|     CurDegree = -1;
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|     ParentLR->setUserIGNode(this);
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|   }
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| 
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|   inline unsigned int getIndex() const { return Index; }
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| 
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|   // adjLists must be updated only once.  However, the CurDegree can be changed
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|   //
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|   inline void addAdjIGNode(IGNode *AdjNode) { AdjList.push_back(AdjNode);  } 
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| 
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|   inline IGNode *getAdjIGNode(unsigned ind) const 
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|     { assert ( ind < AdjList.size()); return AdjList[ind]; }
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| 
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|   // delete a node in AdjList - node must be in the list
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|   // should not be called often
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|   //
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|   void delAdjIGNode(const IGNode *Node); 
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| 
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|   inline unsigned getNumOfNeighbors() const { return AdjList.size(); }
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| 
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|   // Get the number of unique neighbors if these two nodes are merged
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|   unsigned getCombinedDegree(const IGNode* otherNode) const;
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| 
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|   inline bool isOnStack() const { return OnStack; }
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| 
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|   // remove form IG and pushes on to stack (reduce the degree of neighbors)
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|   //
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|   void pushOnStack(); 
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| 
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|   // CurDegree is the effective number of neighbors when neighbors are
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|   // pushed on to the stack during the coloring phase. Must be called
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|   // after all modifications to the IG are over (i.e., all neighbors are
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|   // fixed).
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|   //
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|   inline void setCurDegree() {
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|     assert(CurDegree == -1);
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|     CurDegree = AdjList.size();
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|   }
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| 
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|   inline int getCurDegree() const { return CurDegree; }
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| 
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|   // called when a neigh is pushed on to stack
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|   //
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|   inline void decCurDegree() { assert(CurDegree > 0); --CurDegree; }
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| 
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|   // The following methods call the methods in ParentLR
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|   // They are added to this class for convenience
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|   // If many of these are called within a single scope,
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|   // consider calling the methods directly on LR
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|   inline bool hasColor() const { return ParentLR->hasColor();  }
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| 
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|   inline unsigned int getColor() const { return ParentLR->getColor();  }
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| 
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|   inline void setColor(unsigned Col) { ParentLR->setColor(Col);  }
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| 
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|   inline LiveRange *getParentLR() const { return ParentLR; }
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| };
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| 
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| #endif
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