/// <summary>
/// Creates a RegisterLiveness for an output register
/// </summary>
/// <param name="nRegister"></param>
/// <param name="transformed_from"></param>
public RegisterLiveness(int nRegister, RegisterLiveness transformed_from)
{
NumRegister = nRegister;
FromInstruction = -9999;// transformed_from.FromInstruction;
ToInstruction = -9999;// transformed_from.ToInstruction;
transformed_from.Transformed = this;
TransformedFrom = new List<RegisterLiveness>();
TransformedFrom.Add(transformed_from);
}
/// <summary>
/// Update the liveness for a given register, to include this instruction
/// </summary>
/// <param name="dict"></param>
/// <param name="nRegister"></param>
/// <param name="at_instruction"></param>
/// <returns></returns>
RegisterLiveness TouchRegister(Dictionary<int, RegisterLiveness> dict, int nRegister, int at_instruction)
{
RegisterLiveness rl;
if (!dict.TryGetValue(nRegister, out rl))
{
rl = new RegisterLiveness(nRegister, at_instruction);
dict[nRegister] = rl;
return rl;
}
rl.Touch(at_instruction);
return rl;
}
/// <summary>
/// Selects an output register number, given an input register number
/// An improved implementation might be more picky about the selection, this one grabs the next available off a stack.
/// </summary>
/// <param name="nInputRegister"></param>
/// <param name="nInstruction"></param>
/// <returns></returns>
int GetOutputRegister(int nInputRegister, int nInstruction)
{
RegisterLiveness irl = InputRegisters[nInputRegister];
if (irl.Transformed != null)
return irl.Transformed.NumRegister;
int nOutputRegister = Derp.GetOutputRegister(nInputRegister,this);
RegisterLiveness rl;
if (OutputRegisters.TryGetValue(nOutputRegister, out rl))
{
rl.Touch(nInstruction);
irl.Transformed = rl;
rl.TransformedFrom.Add(irl);
}
else
{
rl = new RegisterLiveness(nOutputRegister, irl);
rl.Touch(nInstruction);
OutputRegisters.Add(nOutputRegister, rl);
}
return nOutputRegister;
}
public bool Intersects(RegisterLiveness other)
{
if (other.FromInstruction >= ToInstruction)
return false;
if (FromInstruction >= other.ToInstruction)
return false;
return true;
}
public void Dispose()
{
_Transformed = null;
if (TransformedFrom != null)
{
TransformedFrom.Clear();
TransformedFrom = null;
}
}
/// <summary>
/// Creates a RegisterLiveness for an output register
/// </summary>
/// <param name="nRegister"></param>
/// <param name="transformed_from"></param>
public RegisterLiveness(int nRegister, RegisterLiveness transformed_from)
{
NumRegister = nRegister;
Transformed = transformed_from;
}
/// <summary>
/// Selects an output register number, given an input register number
/// An improved implementation might be more picky about the selection, this one grabs the next available off a stack.
/// </summary>
/// <param name="nInputRegister"></param>
/// <param name="nInstruction"></param>
/// <returns></returns>
int GetOutputRegister(int nInputRegister, int nInstruction)
{
// see if it's already transformed
RegisterLiveness input = InputRegisters[nInputRegister];
RegisterLiveness transformed = input.Transformed;
if (transformed != null)
return transformed.NumRegister;
// not already transformed, pick an available register
if (AvailableRegisters.Count == 0)
{
throw new NotImplementedException("Out of registers!");
}
int nOutputRegister = AvailableRegisters.Pop();
// are we reusing a register?
if (!OutputRegisters.TryGetValue(nOutputRegister, out transformed))
{
transformed = new RegisterLiveness(nOutputRegister, input);
OutputRegisters[nOutputRegister] = transformed;
}
input.Transformed = transformed;
UnavailableRegisters.Add(transformed);
return nOutputRegister;
}
