/// <summary>
/// Retrieves the local stack operand at the specified <paramref name="index"/>.
/// </summary>
/// <param name="index">The index of the stack operand to retrieve.</param>
/// <returns>The operand at the specified index.</returns>
/// <exception cref="System.ArgumentOutOfRangeException">The <paramref name="index"/> is not valid.</exception>
public Operand GetLocalOperand(int index)
{
// HACK: Returning a new instance here breaks object identity. We should reuse operands,
// which represent the same memory location. If we need to move a variable in an optimization
// stage to a different memory location, it should actually be a new one so sharing object
// only saves runtime space/perf.
Debug.Assert(_localsSig != null, "Method doesn't have _locals.");
Debug.Assert(index <= _localsSig.Types.Length, "Invalid local index requested.");
if (_localsSig == null || _localsSig.Types.Length <= index)
{
throw new ArgumentOutOfRangeException("index", index, "Invalid parameter index");
}
Operand local = null;
if (_locals.Count > index)
{
local = _locals[index];
}
if (local == null)
{
local = new LocalVariableOperand(_architecture.StackFrameRegister, String.Format("L_{0}", index), index, _localsSig.Types[index]);
_locals[index] = local;
}
return(local);
}
/// <summary>
/// Retrieves the local stack operand at the specified <paramref name="index"/>.
/// </summary>
/// <param name="index">The index of the stack operand to retrieve.</param>
/// <returns>The operand at the specified index.</returns>
/// <exception cref="System.ArgumentOutOfRangeException">The <paramref name="index"/> is not valid.</exception>
public Operand GetLocalOperand(int index)
{
// HACK: Returning a new instance here breaks object identity. We should reuse operands,
// which represent the same memory location. If we need to move a variable in an optimization
// stage to a different memory location, it should actually be a new one so sharing object
// only saves runtime space/perf.
// PG: Isn't that implemented below? Comment seems out of date with code
Debug.Assert(localsSig != null, @"Method doesn't have locals.");
Debug.Assert(index < localsSig.Locals.Length, @"Invalid local index requested.");
if (localsSig == null || localsSig.Locals.Length < index)
{
throw new ArgumentOutOfRangeException(@"index", index, @"Invalid parameter index");
}
Operand local = locals[index];
if (local == null)
{
VariableSignature localVariable = localsSig.Locals[index];
//ScheduleDependencyForCompilation(localVariable.Type);
local = new LocalVariableOperand(architecture.StackFrameRegister, String.Format("L_{0}", index), index, localVariable.Type);
locals[index] = local;
}
return(local);
}
/// <summary>
/// Collects all local variables assignments into a list.
/// </summary>
/// <param name="locals">Holds all locals found by the stage.</param>
/// <param name="block">The block.</param>
private void CollectLocalVariables(List <StackOperand> locals, BasicBlock block)
{
for (Context ctx = new Context(InstructionSet, block); !ctx.EndOfInstruction; ctx.GotoNext())
{
// Does this instruction define a new stack variable?
foreach (Operand op in ctx.Results)
{
// The instruction list may not be in SSA form, so we have to check existence again here unfortunately.
// FIXME: Allow us to detect the state of blocks
LocalVariableOperand lvop = op as LocalVariableOperand;
if (lvop != null && !locals.Contains(lvop))
{
locals.Add(lvop);
}
}
}
}
