151 lines
4.2 KiB
C++
151 lines
4.2 KiB
C++
/* Title: IGNode.h -*- C++ -*-
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Author: Ruchira Sasanka
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Date: July 25, 01
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Purpose: Represents a node in an interference graph.
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Notes:
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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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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 OnSack. 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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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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The vector representation is the most efficient one for adj list.
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Though nodes are removed when coalsing 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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#ifndef IG_NODE_H
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#define IG_NODE_H
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#include "llvm/CodeGen/RegAllocCommon.h"
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#include "llvm/CodeGen/LiveRange.h"
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class LiveRange;
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class RegClass;
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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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class IGNode {
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const int 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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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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LiveRange *const ParentLR; // parent LR (cannot be a const)
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public:
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// constructor
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//
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IGNode(LiveRange *const LR, unsigned int index);
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// an empty destructor
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//
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~IGNode() { }
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inline unsigned int getIndex() const
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{ return Index; }
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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 *const AdjNode)
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{ AdjList.push_back(AdjNode); }
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inline IGNode * getAdjIGNode(unsigned int ind) const
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{ assert ( ind < AdjList.size()); return AdjList[ ind ]; }
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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 *const Node);
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inline unsigned int getNumOfNeighbors() const
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{ return AdjList.size() ; }
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inline bool isOnStack() const
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{ return OnStack; }
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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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// 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); CurDegree = AdjList.size(); }
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inline int getCurDegree() const
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{ return CurDegree; }
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// called when a neigh is pushed on to stack
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//
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inline void decCurDegree()
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{ assert( CurDegree > 0 ); --CurDegree; }
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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 void setRegClass(RegClass *const RC)
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{ ParentLR->setRegClass(RC); }
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inline RegClass *const getRegClass() const {
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return ParentLR->getRegClass();
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}
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inline bool hasColor() const
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{ return ParentLR->hasColor(); }
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inline unsigned int getColor() const
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{ return ParentLR->getColor(); }
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inline void setColor(unsigned int Col)
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{ ParentLR->setColor(Col); }
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inline void markForSpill()
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{ ParentLR->markForSpill(); }
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inline void markForSaveAcrossCalls()
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{ ParentLR->markForSaveAcrossCalls(); }
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inline unsigned int isCallInterference() const
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{ return ParentLR->isCallInterference(); }
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inline LiveRange *getParentLR() const
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{ return ParentLR; }
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inline Type::PrimitiveID getTypeID() const
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{ return ParentLR->getTypeID(); }
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};
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#endif
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