// Emit a short/long branch for an And/Or element
private static OpCode GetBranchOpcode(AndOrElement op, bool longBranch)
{
if (op.MyOperation == AndOrOperation.And)
{
if (longBranch == true)
{
return OpCodes.Brfalse;
}
else
{
return OpCodes.Brfalse_S;
}
}
else
{
if (longBranch == true)
{
return OpCodes.Brtrue;
}
else
{
return OpCodes.Brtrue_S;
}
}
}
// Get the label for a short-circuit
private static Label GetShortCircuitLabel(AndOrElement current, ShortCircuitInfo info, FleeILGenerator ilg)
{
// We modify the given stacks so we need to clone them
Stack cloneOperands = (Stack)info.Operands.Clone();
Stack 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
AndOrElement top = (AndOrElement)cloneOperators.Pop();
// Is is a different operation?
if (top.MyOperation != current.MyOperation)
{
// Yes, so return a label to its right operand
object nextOperand = cloneOperands.Pop();
return GetLabel(nextOperand, ilg, info);
}
else
{
// 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);
}
else
{
return GetLabel(OurTrueTerminalKey, ilg, info);
}
}
private static void EmitBranch(AndOrElement op, FleeILGenerator ilg, Label target, ShortCircuitInfo info)
{
if (ilg.IsTemp == true)
{
info.Branches.AddBranch(ilg, target);
// Temp mode; just emit a short branch and return
OpCode shortBranch = GetBranchOpcode(op, false);
ilg.Emit(shortBranch, target);
return;
}
// Emit the proper branch opcode
// Determine if it is a long branch
bool longBranch = info.Branches.IsLongBranch(ilg, target);
// Get the branch opcode
OpCode brOpcode = GetBranchOpcode(op, longBranch);
// Emit the branch
ilg.Emit(brOpcode, target);
}
