llvm-6502/lib/Target/SparcV9/RegAlloc/InterferenceGraph.cpp
2002-10-29 16:51:05 +00:00

253 lines
7.9 KiB
C++

//===-- InterferenceGraph.cpp ---------------------------------------------===//
//
// Interference graph for coloring-based register allocation for LLVM.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/InterferenceGraph.h"
#include "llvm/CodeGen/IGNode.h"
#include "llvm/CodeGen/RegAllocCommon.h"
#include "Support/STLExtras.h"
#include <algorithm>
using std::cerr;
// for asserting this IG node is infact in the IGNodeList of this class
inline static void assertIGNode(const InterferenceGraph *IG,
const IGNode *Node) {
assert(IG->getIGNodeList()[Node->getIndex()] == Node);
}
//-----------------------------------------------------------------------------
// Constructor: Records the RegClass and initalizes IGNodeList.
// The matrix is NOT yet created by the constructor. Call createGraph()
// to create it after adding all IGNodes to the IGNodeList.
//-----------------------------------------------------------------------------
InterferenceGraph::InterferenceGraph(RegClass *const RC) : RegCl(RC),
IGNodeList()
{
IG = NULL;
Size = 0;
if( DEBUG_RA >= RA_DEBUG_Interference) {
cerr << "Interference graph created!\n";
}
}
//-----------------------------------------------------------------------------
// destructor. Deletes the bit matrix and all IGNodes
//-----------------------------------------------------------------------------
InterferenceGraph:: ~InterferenceGraph() {
// delete the matrix
for(unsigned int r=0; r < IGNodeList.size(); ++r)
delete[] IG[r];
delete[] IG;
// delete all IGNodes in the IGNodeList
for_each(IGNodeList.begin(), IGNodeList.end(), deleter<IGNode>);
}
//-----------------------------------------------------------------------------
// Creates (dynamically allocates) the bit matrix necessary to hold the
// interference graph.
//-----------------------------------------------------------------------------
void InterferenceGraph::createGraph()
{
Size = IGNodeList.size();
IG = new char*[Size];
for( unsigned int r=0; r < Size; ++r)
IG[r] = new char[Size];
// init IG matrix
for(unsigned int i=0; i < Size; i++)
for(unsigned int j=0; j < Size; j++)
IG[i][j] = 0;
}
//-----------------------------------------------------------------------------
// creates a new IGNode for the given live range and add to IG
//-----------------------------------------------------------------------------
void InterferenceGraph::addLRToIG(LiveRange *const LR)
{
IGNodeList.push_back(new IGNode(LR, IGNodeList.size()));
}
//-----------------------------------------------------------------------------
// set interference for two live ranges
// update both the matrix and AdjLists of nodes.
// If there is already an interference between LR1 and LR2, adj lists
// are not updated. LR1 and LR2 must be distinct since if not, it suggests
// that there is some wrong logic in some other method.
//-----------------------------------------------------------------------------
void InterferenceGraph::setInterference(const LiveRange *const LR1,
const LiveRange *const LR2 ) {
assert(LR1 != LR2);
IGNode *IGNode1 = LR1->getUserIGNode();
IGNode *IGNode2 = LR2->getUserIGNode();
assertIGNode(this, IGNode1);
assertIGNode(this, IGNode2);
unsigned row = IGNode1->getIndex();
unsigned col = IGNode2->getIndex();
char *val;
if( DEBUG_RA >= RA_DEBUG_Interference)
cerr << "setting intf for: [" << row << "][" << col << "]\n";
( row > col) ? val = &IG[row][col]: val = &IG[col][row];
if( ! (*val) ) { // if this interf is not previously set
*val = 1; // add edges between nodes
IGNode1->addAdjIGNode( IGNode2 );
IGNode2->addAdjIGNode( IGNode1 );
}
}
//----------------------------------------------------------------------------
// return whether two live ranges interfere
//----------------------------------------------------------------------------
unsigned InterferenceGraph::getInterference(const LiveRange *const LR1,
const LiveRange *const LR2 ) const {
assert(LR1 != LR2);
assertIGNode(this, LR1->getUserIGNode());
assertIGNode(this, LR2->getUserIGNode());
const unsigned int row = LR1->getUserIGNode()->getIndex();
const unsigned int col = LR2->getUserIGNode()->getIndex();
char ret;
if (row > col)
ret = IG[row][col];
else
ret = IG[col][row];
return ret;
}
//----------------------------------------------------------------------------
// Merge 2 IGNodes. The neighbors of the SrcNode will be added to the DestNode.
// Then the IGNode2L will be deleted. Necessary for coalescing.
// IMPORTANT: The live ranges are NOT merged by this method. Use
// LiveRangeInfo::unionAndUpdateLRs for that purpose.
//----------------------------------------------------------------------------
void InterferenceGraph::mergeIGNodesOfLRs(const LiveRange *LR1,
LiveRange *LR2) {
assert( LR1 != LR2); // cannot merge the same live range
IGNode *const DestNode = LR1->getUserIGNode();
IGNode *SrcNode = LR2->getUserIGNode();
assertIGNode(this, DestNode);
assertIGNode(this, SrcNode);
if( DEBUG_RA >= RA_DEBUG_Interference) {
cerr << "Merging LRs: \""; printSet(*LR1);
cerr << "\" and \""; printSet(*LR2);
cerr << "\"\n";
}
unsigned SrcDegree = SrcNode->getNumOfNeighbors();
const unsigned SrcInd = SrcNode->getIndex();
// for all neighs of SrcNode
for(unsigned i=0; i < SrcDegree; i++) {
IGNode *NeighNode = SrcNode->getAdjIGNode(i);
LiveRange *const LROfNeigh = NeighNode->getParentLR();
// delete edge between src and neigh - even neigh == dest
NeighNode->delAdjIGNode(SrcNode);
// set the matrix posn to 0 betn src and neigh - even neigh == dest
const unsigned NInd = NeighNode->getIndex();
( SrcInd > NInd) ? (IG[SrcInd][NInd]=0) : (IG[NInd][SrcInd]=0) ;
if( LR1 != LROfNeigh) { // if the neigh != dest
// add edge betwn Dest and Neigh - if there is no current edge
setInterference(LR1, LROfNeigh );
}
}
IGNodeList[ SrcInd ] = NULL;
// SrcNode is no longer necessary - LR2 must be deleted by the caller
delete( SrcNode );
}
//----------------------------------------------------------------------------
// must be called after modifications to the graph are over but before
// pushing IGNodes on to the stack for coloring.
//----------------------------------------------------------------------------
void InterferenceGraph::setCurDegreeOfIGNodes()
{
unsigned Size = IGNodeList.size();
for( unsigned i=0; i < Size; i++) {
IGNode *Node = IGNodeList[i];
if( Node )
Node->setCurDegree();
}
}
//--------------------- debugging (Printing) methods -----------------------
//----------------------------------------------------------------------------
// Print the IGnodes
//----------------------------------------------------------------------------
void InterferenceGraph::printIG() const
{
for(unsigned int i=0; i < Size; i++) {
const IGNode *const Node = IGNodeList[i];
if(Node) {
cerr << " [" << i << "] ";
for( unsigned int j=0; j < i; j++) {
if(IG[i][j])
cerr << "(" << i << "," << j << ") ";
}
cerr << "\n";
}
}
}
//----------------------------------------------------------------------------
// Print the IGnodes in the IGNode List
//----------------------------------------------------------------------------
void InterferenceGraph::printIGNodeList() const
{
for(unsigned i=0; i < IGNodeList.size() ; ++i) {
const IGNode *const Node = IGNodeList[i];
if (Node) {
cerr << " [" << Node->getIndex() << "] ";
printSet(*Node->getParentLR());
//int Deg = Node->getCurDegree();
cerr << "\t <# of Neighs: " << Node->getNumOfNeighbors() << ">\n";
}
}
}