public void Allocate(BasicBlock <IRInstrList> block)
{
var blockLiveness = liveness[block];
var instrLiveness = LivenessAnalysis.ComputeLiveness(block, blockLiveness);
var pool = RegisterPool.Create(baseOffset, globalVars);
for (var i = 0; i < block.Content.Count; i++)
{
var instr = block.Content[i];
pool.CheckLiveness(instrLiveness[instr]);
// Allocates
if (instr.Operand1 != null)
{
instr.Operand1 = AllocateOperand(instr.Operand1, pool);
}
if (instr.Operand2 != null)
{
instr.Operand2 = AllocateOperand(instr.Operand2, pool);
}
}
if (pool.SpillOffset - 1 > LocalSize)
{
LocalSize = pool.SpillOffset - 1;
}
baseOffset = pool.SpillOffset;
}
public void Initialize()
{
var blocks = transformer.RootScope.GetBasicBlocks().Cast <BasicBlock <IRInstrList> >().ToList();
liveness = LivenessAnalysis.ComputeLiveness(blocks);
var stackVars = new HashSet <IRVariable>();
foreach (var blockLiveness in liveness)
{
foreach (var instr in blockLiveness.Key.Content)
{
if (instr.OpCode != IROpCode.__LEA)
{
continue;
}
var variable = (IRVariable)instr.Operand2;
if (variable.VariableType != IRVariableType.Argument)
{
stackVars.Add(variable);
}
}
stackVars.UnionWith(blockLiveness.Value.OutLive);
}
// [BP - 2] = last argument
// [BP - 1] = return address
// [BP ] = old BP
// [BP + 1] = first local
var offset = 1;
globalVars = stackVars.ToDictionary(var => var, var => new StackSlot(offset++, var));
baseOffset = offset;
LocalSize = baseOffset - 1;
offset = -2;
var parameters = transformer.Context.GetParameters();
for (var i = parameters.Length - 1; i >= 0; i--)
{
var paramVar = parameters[i];
globalVars[paramVar] = new StackSlot(offset--, paramVar);
}
allocation = globalVars.ToDictionary(pair => pair.Key, pair => (object)pair.Value);
}
