public void AllocateRegisters(InterferenceGraph graph)
{
SpilledRegisters.Clear();
RegistersColoring.Clear();
mapping = InterferenceGraph.copyGraph(graph);
Initialize(graph);
do
{
if (toSimplify.Count > 0)
{
Simplify();
}
else if (toFreeze.Count > 0)
{
Freeze();
}
else if (toSpill.Count > 0)
{
Spill();
}
UpdateVertexPartition(graph);
} while(toSimplify.Count > 0 || toSpill.Count > 0 || toFreeze.Count > 0);
AssignColors();
}
private void AssignColors()
{
while (stack.Count > 0)
{
var vertex = stack.Pop();
var forbidden = new HashSet <HardwareRegisterNode> ();
foreach (Vertex neigh in vertex.NonCopyNeighbors)
{
if (RegistersColoring.ContainsKey(neigh.Register))
{
forbidden.Add(RegistersColoring [neigh.Register]);
}
}
var occurs = new Dictionary <HardwareRegisterNode, int> ();
foreach (Vertex neigh in vertex.CopyNeighbors)
{
if (RegistersColoring.ContainsKey(neigh.Register))
{
if (!occurs.ContainsKey(RegistersColoring [neigh.Register]))
{
occurs [RegistersColoring [neigh.Register]] = 1;
}
else
{
occurs [RegistersColoring [neigh.Register]]++;
}
}
}
if (forbidden.Count >= registers.Count)
{
SpilledRegisters.Add(vertex.Register);
}
else
{
int mostOccurs = 0;
HardwareRegisterNode choice = null;
foreach (HardwareRegisterNode reg in registers)
{
if (!forbidden.Contains(reg))
{
var tmp = occurs.ContainsKey(reg) ? occurs[reg] : 0;
if (tmp >= mostOccurs)
{
mostOccurs = tmp;
choice = reg;
}
}
}
RegistersColoring [vertex.Register] = choice;
}
}
}
