private static void Search(IRBlock block, DominatorTree dominatorTree, Dictionary <Ident, int> count, Dictionary <Ident, Stack <int> > stack)
{
// Algorithm from Ron Cytron et al to rename variables into SSA form
foreach (IRTuple irt in block.GetStatements())
{
Console.Write("Type: " + irt.GetType() + " ");
irt.Print();
Console.WriteLine();
if (irt.getOp() != IrOp.PHI)
{
foreach (Ident v in irt.GetUsedVars())
{
Console.WriteLine("Renaming variable: " + v);
int i = stack[v].Peek();
RenameTupleSourcesHelper(irt, v, i); // replace uses of v with vi in statement
}
}
foreach (Ident a in irt.GetDefinedVars())
{
count[a] = count[a] + 1;
int i = count[a];
stack[a].Push(i);
irt.setDest(RenameVar(a, i)); // replace definitions of a with ai in statement
}
}
// rename Phi function arguments in the successors
List <IRBlock> successors = block.GetSuccessors();
for (int i = 0; i < successors.Count; i++)
{
foreach (IRTuple stmt in block.GetStatements())
{
if (stmt.getOp() == IrOp.PHI)
{
IRTupleManyOp phi = (IRTupleManyOp)stmt;
Ident v = phi.GetSources()[i];
int numbering = stack[v].Peek();
phi.SetSource(i, RenameVar(v, numbering));
}
}
}
// for each descendant do the Search(X) renaming process
DominatorTreeNode node = dominatorTree.GetNode(block);
foreach (DominatorTreeNode descendant in node.GetDescendants())
{
Search(descendant.GetBlock(), dominatorTree, count, stack);
}
// pop stack phase
foreach (IRTuple irt in block.GetStatements())
{
foreach (Ident v in irt.GetDefinedVars())
{
stack[v].Pop();
}
}
}
private static void InsertPhiFunctions(IRGraph graph, DominatorTree dominatorTree)
{
foreach (IRBlock block in graph.GetSetOfAllBlocks())
{
Console.WriteLine();
Console.WriteLine("***");
Console.WriteLine("Block: " + block.GetIndex());
block.PrintStatements();
Console.Write("Predecessors: ");
foreach (IRBlock pred in graph.GetPredecessors(block))
{
Console.Write(pred.GetIndex() + ", ");
}
Console.WriteLine();
Console.Write("Live in : ");
foreach (Ident ident in block.GetLiveIn())
{
Console.Write(ident + ", ");
}
Console.WriteLine();
Console.Write("Defined vars: ");
foreach (Ident ident in block.GetDefinedVars())
{
Console.Write(ident + ", ");
}
Console.WriteLine();
}
foreach (Ident v in graph.GetDefinedVars())
{
// A(v) = blocks containing an assignment to v
HashSet <IRBlock> Av = new HashSet <IRBlock>();
foreach (IRBlock block in graph.GetSetOfAllBlocks())
{
if (block.GetDefinedVars().Contains(v) && block.GetLiveIn().Contains(v))
{
Av.Add(block);
}
}
// place Phi tuple for each v in the iterated dominance frontier of A(v)
HashSet <IRBlock> needsPhiFunction = new HashSet <IRBlock>();
foreach (IRBlock Avblock in Av)
{
// create set of blocks that need phi functions
foreach (IRBlock block in dominatorTree.GetDominanceFrontier(Avblock))
{
needsPhiFunction.Add(block);
}
}
// only want one phi function per block for each variable where appropiate
foreach (IRBlock block in needsPhiFunction)
{
// Phi function should have as many arguments as it does predecessors
List <Ident> sources = new List <Ident>();
foreach (IRBlock b in graph.GetPredecessors(block))
{
sources.Add(v);
}
IRTupleManyOp phi = new IRTupleManyOp(IrOp.PHI, v, sources);
block.InsertStatement(phi, 0);
Console.WriteLine("** SSA: Inserting phi function: " + phi.toString() + " into block " + block.GetIndex());
}
}
}
private static void InsertPhiFunctions(IRGraph graph, DominatorTree dominatorTree)
{
foreach (IRBlock block in graph.GetSetOfAllBlocks())
{
Console.WriteLine();
Console.WriteLine("***");
Console.WriteLine("Block: " + block.GetIndex());
block.PrintStatements();
Console.Write("Predecessors: ");
foreach (IRBlock pred in graph.GetPredecessors(block))
Console.Write(pred.GetIndex() + ", ");
Console.WriteLine();
Console.Write("Live in : ");
foreach (Ident ident in block.GetLiveIn())
Console.Write(ident + ", ");
Console.WriteLine();
Console.Write("Defined vars: ");
foreach (Ident ident in block.GetDefinedVars())
Console.Write(ident + ", ");
Console.WriteLine();
}
foreach (Ident v in graph.GetDefinedVars())
{
// A(v) = blocks containing an assignment to v
HashSet<IRBlock> Av = new HashSet<IRBlock>();
foreach (IRBlock block in graph.GetSetOfAllBlocks())
{
if (block.GetDefinedVars().Contains(v) && block.GetLiveIn().Contains(v))
Av.Add(block);
}
// place Phi tuple for each v in the iterated dominance frontier of A(v)
HashSet<IRBlock> needsPhiFunction = new HashSet<IRBlock>();
foreach (IRBlock Avblock in Av)
{
// create set of blocks that need phi functions
foreach (IRBlock block in dominatorTree.GetDominanceFrontier(Avblock))
{
needsPhiFunction.Add(block);
}
}
// only want one phi function per block for each variable where appropiate
foreach (IRBlock block in needsPhiFunction)
{
// Phi function should have as many arguments as it does predecessors
List<Ident> sources = new List<Ident>();
foreach (IRBlock b in graph.GetPredecessors(block))
sources.Add(v);
IRTupleManyOp phi = new IRTupleManyOp(IrOp.PHI, v, sources);
block.InsertStatement(phi, 0);
Console.WriteLine("** SSA: Inserting phi function: " + phi.toString() + " into block " + block.GetIndex());
}
}
}
