private static bool PropagatePhi(PhiNode phi)
{
// If all phi sources are the same, we can propagate it and remove the phi.
Operand firstSrc = phi.GetSource(0);
for (int index = 1; index < phi.SourcesCount; index++)
{
if (!IsSameOperand(firstSrc, phi.GetSource(index)))
{
return(false);
}
}
// All sources are equal, we can propagate the value.
Operand dest = phi.Dest;
INode[] uses = dest.UseOps.ToArray();
foreach (INode useNode in uses)
{
for (int index = 0; index < useNode.SourcesCount; index++)
{
if (useNode.GetSource(index) == dest)
{
useNode.SetSource(index, firstSrc);
}
}
}
return(true);
}
private static void AddPhi(BasicBlock block, PhiNode phi)
{
LinkedListNode <INode> node = block.Operations.First;
if (node != null)
{
while (node.Next?.Value is PhiNode)
{
node = node.Next;
}
}
if (node?.Value is PhiNode)
{
block.Operations.AddAfter(node, phi);
}
else
{
block.Operations.AddFirst(phi);
}
}
private static void AddPhi(BasicBlock block, PhiNode phi)
{
Node node = block.Operations.First;
if (node != null)
{
while (node.ListNext is PhiNode)
{
node = node.ListNext;
}
}
if (node is PhiNode)
{
block.Operations.AddAfter(node, phi);
}
else
{
block.Operations.AddFirst(phi);
}
}
private static Operand InsertPhi(DefMap[] globalDefs, BasicBlock block, Register reg)
{
// This block has a Phi that has not been materialized yet, but that
// would define a new version of the variable we're looking for. We need
// to materialize the Phi, add all the block/operand pairs into the Phi, and
// then use the definition from that Phi.
Operand local = Local();
PhiNode phi = new PhiNode(local);
AddPhi(block, phi);
globalDefs[block.Index].TryAddOperand(reg, local);
foreach (BasicBlock predecessor in block.Predecessors)
{
Definition def = FindDefinition(globalDefs, predecessor, reg);
phi.AddSource(def.Block, def.Local);
}
return(local);
}
private static Operand InsertPhi(DefMap[] globalDefs, BasicBlock block, Operand operand)
{
// This block has a Phi that has not been materialized yet, but that
// would define a new version of the variable we're looking for. We need
// to materialize the Phi, add all the block/operand pairs into the Phi, and
// then use the definition from that Phi.
Operand local = Local(operand.Type);
PhiNode phi = new PhiNode(local, block.Predecessors.Count);
AddPhi(block, phi);
globalDefs[block.Index].TryAddOperand(operand.GetRegister(), local);
for (int index = 0; index < block.Predecessors.Count; index++)
{
BasicBlock predecessor = block.Predecessors[index];
phi.SetBlock(index, predecessor);
phi.SetSource(index, FindDefOnPred(globalDefs, predecessor, operand));
}
return(local);
}
