public void AddExpression(AvailableExpression newExpression, TACInstruction instrution)
{
if (!ExpressionsTable.ContainsKey(newExpression))
{
ExpressionsTable.Add(newExpression, instrution.Result);
}
}
private static void AddUse(string id, TACInstruction c, int num)
{
if (IsId(id))
{
var def = DefList.FindLastIndex(x => x.Id == id);
var use = new Use(num, c);
if (def != -1)
{
use.Parent = DefList[def];
DefList[def].Uses.Add(use);
}
}
}
public override void Run()
{
var i = 1;
while (i < Instructions.Count - 2)
{
if (Instructions[i] != null && Instructions[i].Operation.Equals("if goto"))
{
if (Instructions[i + 1].Operation.Equals("goto"))
{
var tempName = TACGenerationVisitor.GenerateTempName();
var notInstruction = new TACInstruction("!", Instructions[i].Argument1, "", tempName);
Instructions[i].Argument1 = tempName;
Instructions[i].Argument2 = Instructions[i + 1].Argument1;
Instructions[i + 1] = null;
Instructions[i + 2] = null;
Instructions.Insert(i, notInstruction);
++i;
}
}
++i;
}
Instructions = Instructions.Where(x => x != null).ToList();
}
public void AddNewExpression(TACInstruction instruction)
{
GenInstructions.Add(instruction);
GenExpressions.Add(new AvailableExpression(instruction.Argument1, instruction.Argument2, instruction.Operation));
}
public Use(int n, TACInstruction c, Def p = null)
{
Parent = p;
Command = c;
OrderNum = n;
}
public static Tuple <bool, List <TACInstruction> > ReplaceGoTotoGoTo(List <TACInstruction> commands)
{
bool changed = false;
List <GoToScan> list = new List <GoToScan>();
List <TACInstruction> tmpcommands = new List <TACInstruction>();
for (int i = 0; i < commands.Count; i++)
{
tmpcommands.Add(commands[i]);
if (commands[i].Operation == "goto")
{
list.Add(new GoToScan(i, commands[i].Label, commands[i].Argument1));
}
if (commands[i].Operation == "ifgoto")
{
list.Add(new GoToScan(i, commands[i].Label, commands[i].Argument2));
}
}
for (int i = 0; i < tmpcommands.Count; i++)
{
if (tmpcommands[i].Operation == "goto")
{
for (int j = 0; j < list.Count; j++)
{
if (list[j].labelto == tmpcommands[i].Argument1)
{
if (tmpcommands[i].Argument1.ToString() == list[j].labelfrom.ToString())
{
changed |= false;
}
else
{
changed |= true;
tmpcommands[i] = new TACInstruction(tmpcommands[i].Label, "goto", list[j].labelfrom.ToString(), "", "");
}
}
}
}
if (tmpcommands[i].Operation == "ifgoto")
{
for (int j = 0; j < list.Count; j++)
{
if (list[j].labelto == tmpcommands[i].Argument2)
{
if (tmpcommands[i].Argument2.ToString() == list[j].labelfrom.ToString())
{
changed |= false;
}
else
{
tmpcommands[i] = new TACInstruction(tmpcommands[i].Label, "ifgoto", tmpcommands[i].Argument1, list[j].labelfrom.ToString(), "");
changed |= true;
}
}
}
}
}
return(Tuple.Create(changed, tmpcommands));
}
public static Tuple <bool, List <TACInstruction> > RemoveEmptyNodes(List <TACInstruction> commands)
{
if (commands.Count == 0)
{
return(new Tuple <bool, List <TACInstruction> >(false, commands));
}
var result = new List <TACInstruction>();
var changed = false;
var toAddLast = true;
// three cases:
// a) Command = noop without label, in this case just remove it
// b) Command = noop with label, next command - op without label.
// Then just combine current label and next op.
// c) Command = noop with label, in this case,
// rename all GOTO current_label to GOTO next_label
for (var i = 0; i < commands.Count - 1; i++)
{
var currentCommand = commands[i];
if (currentCommand == null)
{
currentCommand = new TACInstruction("noop", "", "", "", "");
}
if (currentCommand.Operation == "noop" && currentCommand.Label == "")
{
changed = true;
}
// we have label here
else if (currentCommand.Operation == "noop")
{
// if next label is empty, we concat current label with next op
if (commands[i + 1].Label == "")
{
var nextCommand = commands[i + 1];
changed = true;
result.Add(
new TACInstruction(
currentCommand.Label,
nextCommand.Operation,
nextCommand.Argument1,
nextCommand.Argument2,
nextCommand.Result
)
);
i += 1;
if (i == commands.Count - 1)
{
toAddLast = false;
}
}
// if next label is not empty, instead of noop + next,
// rename GOTO current_label to GOTO next_label
else
{
var nextCommand = commands[i + 1];
changed = true;
var currentLabel = currentCommand.Label;
var nextLabel = nextCommand.Label;
result = result
.Select(com =>
com.Operation == "goto" && com.Argument1 == currentLabel
? new TACInstruction(com.Label, com.Operation, nextLabel, com.Argument2, com.Result)
: com
).ToList();
for (var j = i + 1; j < commands.Count; j++)
{
commands[j] = commands[j].Operation == "goto" && commands[j].Argument1 == currentLabel
? new TACInstruction(
commands[j].Label,
commands[j].Operation,
nextLabel,
commands[j].Argument2,
commands[j].Result
)
: commands[j];
}
}
}
else
{
result.Add(commands[i]);
}
}
if (toAddLast)
{
var lastCommand = commands[commands.Count - 1];
var toSkip = lastCommand.Operation == "noop" && lastCommand.Label == "";
if (toSkip)
{
changed = true;
}
else
{
result.Add(commands[commands.Count - 1]);
}
}
return(new Tuple <bool, List <TACInstruction> >(changed, result));
}
