llvm-6502/lib/CodeGen/RegAlloc/IGNode.cpp
Vikram S. Adve 32f81a3469 Allow copy coalescing in more cases: if sum of node degrees is more than
than #available regs, compute the sum excluding duplicates and if that
is less than #regs, go ahead and coalesce.
Add method IGNode::getCombinedDegree to count excluding duplicates.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3842 91177308-0d34-0410-b5e6-96231b3b80d8
2002-09-20 00:45:47 +00:00

55 lines
1.8 KiB
C++

//===-- IGNode.cpp -------------------------------------------------------===//
//
// class IGNode for coloring-based register allocation for LLVM.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/IGNode.h"
#include <algorithm>
#include <iostream>
using std::cerr;
//-----------------------------------------------------------------------------
// Sets this IGNode on stack and reduce the degree of neighbors
//-----------------------------------------------------------------------------
void IGNode::pushOnStack() {
OnStack = true;
int neighs = AdjList.size();
if (neighs < 0) {
cerr << "\nAdj List size = " << neighs;
assert(0 && "Invalid adj list size");
}
for(int i=0; i < neighs; i++)
AdjList[i]->decCurDegree();
}
//-----------------------------------------------------------------------------
// Deletes an adjacency node. IGNodes are deleted when coalescing merges
// two IGNodes together.
//-----------------------------------------------------------------------------
void IGNode::delAdjIGNode(const IGNode *Node) {
std::vector<IGNode *>::iterator It=find(AdjList.begin(), AdjList.end(), Node);
assert( It != AdjList.end() ); // the node must be there
AdjList.erase(It);
}
//-----------------------------------------------------------------------------
// Get the number of unique neighbors if these two nodes are merged
//-----------------------------------------------------------------------------
unsigned
IGNode::getCombinedDegree(const IGNode* otherNode) const
{
std::vector<IGNode*> nbrs(AdjList);
nbrs.insert(nbrs.end(), otherNode->AdjList.begin(), otherNode->AdjList.end());
sort(nbrs.begin(), nbrs.end());
std::vector<IGNode*>::iterator new_end = unique(nbrs.begin(), nbrs.end());
return new_end - nbrs.begin();
}