/// <summary>
/// Get the label for a short-circuit
/// </summary>
private static Label GetShortCircuitLabel(AndOrElement current, ShortCircuitInfo info, YaleIlGenerator ilg)
{
// We modify the given stacks so we need to clone them
var cloneOperands = (Stack)info.Operands.Clone();
var cloneOperators = (Stack)info.Operators.Clone();
// Pop all siblings
current.PopRightChild(cloneOperands, cloneOperators);
// Go until we run out of operators
while (cloneOperators.Count > 0)
{
// Get the top operator
var top = (AndOrElement)cloneOperators.Pop();
// Is is a different operation?
if (top.myOperation != current.myOperation)
{
// Yes, so return a label to its right operand
var nextOperand = cloneOperands.Pop();
return(GetLabel(nextOperand, ilg, info));
}
// No, so keep going up the stack
top.PopRightChild(cloneOperands, cloneOperators);
}
// We've reached the end of the stack so return the label for the appropriate true/false terminal
if (current.myOperation == AndOrOperation.And)
{
return(GetLabel(OurFalseTerminalKey, ilg, info));
}
return(GetLabel(OurTrueTerminalKey, ilg, info));
}
/// <summary>
/// Emit a short/long branch for an And/Or element
/// </summary>
private static OpCode GetBranchOpcode(AndOrElement op, bool longBranch)
{
if (op.myOperation == AndOrOperation.And)
{
return(longBranch ? OpCodes.Brfalse : OpCodes.Brfalse_S);
}
return(longBranch ? OpCodes.Brtrue : OpCodes.Brtrue_S);
}
private static void EmitBranch(AndOrElement op, YaleIlGenerator ilg, Label target, ShortCircuitInfo info)
{
if (ilg.IsTemp)
{
info.Branches.AddBranch(ilg, target);
// Temp mode; just emit a short branch and return
var shortBranch = GetBranchOpcode(op, false);
ilg.Emit(shortBranch, target);
return;
}
// Emit the proper branch opcode
// Determine if it is a long branch
var longBranch = info.Branches.IsLongBranch(ilg, target);
// Get the branch opcode
var brOpcode = GetBranchOpcode(op, longBranch);
// Emit the branch
ilg.Emit(brOpcode, target);
}
