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
diff --git a/lib/CodeGen/RegAlloc/IGNode.cpp b/lib/CodeGen/RegAlloc/IGNode.cpp
index c8fca7a..caee296 100644
--- a/lib/CodeGen/RegAlloc/IGNode.cpp
+++ b/lib/CodeGen/RegAlloc/IGNode.cpp
@@ -36,3 +36,19 @@
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();
+}
+
+