public Type Visit(IfStatement ifStatement, FunctionGeneratorEnvironment arg)
{
var labelno_end = arg.GetNextLabelNumber();
var end = $"{arg.FunctionName}_LABEL{labelno_end}";
ifStatement.expr.Accept(this, arg);
Program.Emit(T42Instruction.BRF(end));
ifStatement.stmt.Accept(this, arg);
Program.Emit(T42Instruction.LABEL(end));
return(null);
}
public Type Visit(BinOperatorStatement binOperatorStatement, FunctionGeneratorEnvironment arg)
{
var left = binOperatorStatement.left;
var right = binOperatorStatement.right;
var type = binOperatorStatement.type;
var opType = MapOpExpr[binOperatorStatement.type];
switch (opType)
{
case OperatorExpression.INTEGER:
left.Accept(this, arg);
right.Accept(this, arg);
switch (type)
{
case BinOperatorStatement.Type.ADD:
Program.Emit(T42Instruction.ADD);
break;
case BinOperatorStatement.Type.SUB:
Program.Emit(T42Instruction.SUB);
break;
case BinOperatorStatement.Type.MUL:
Program.Emit(T42Instruction.MUL);
break;
case BinOperatorStatement.Type.DIV:
Program.Emit(T42Instruction.DIV);
break;
}
break;
case OperatorExpression.LOGICAL:
var labelno_next = arg.GetNextLabelNumber();
var labelno_end = arg.GetNextLabelNumber();
var end = $"{arg.FunctionName}_LABEL{labelno_end}";
var next = $"{arg.FunctionName}_LABEL{labelno_next}";
switch (binOperatorStatement.type)
{
case BinOperatorStatement.Type.OR:
left.Accept(this, arg);
Program.Emit(T42Instruction.BRF(next));
Program.Emit(T42Instruction.PUSHBOOL(1));
Program.Emit(T42Instruction.BRA(end));
Program.Emit(T42Instruction.LABEL(next));
right.Accept(this, arg);
Program.Emit(T42Instruction.LABEL(end));
break;
case BinOperatorStatement.Type.AND:
left.Accept(this, arg);
Program.Emit(T42Instruction.BRF(next));
right.Accept(this, arg);
Program.Emit(T42Instruction.BRA(end));
Program.Emit(T42Instruction.LABEL(next));
Program.Emit(T42Instruction.PUSHBOOL(0));
Program.Emit(T42Instruction.LABEL(end));
break;
}
break;
case OperatorExpression.INEQUALITY:
left.Accept(this, arg);
right.Accept(this, arg);
switch (type)
{
case BinOperatorStatement.Type.LE:
case BinOperatorStatement.Type.GEQ:
Program.Emit(T42Instruction.LTINT);
if (type == BinOperatorStatement.Type.GEQ)
{
Program.Emit(T42Instruction.NOT);
}
break;
case BinOperatorStatement.Type.GR:
case BinOperatorStatement.Type.LEQ:
Program.Emit(T42Instruction.GTINT);
if (type == BinOperatorStatement.Type.LEQ)
{
Program.Emit(T42Instruction.NOT);
}
break;
}
break;
case OperatorExpression.EQUALITY:
var t = left.Accept(this, arg);
right.Accept(this, arg);
if (t.GetType() == typeof(IntType))
{
Program.Emit(T42Instruction.EQINT);
}
else
{
Program.Emit(T42Instruction.EQBOOL);
}
if (type == BinOperatorStatement.Type.NEQ)
{
Program.Emit(T42Instruction.NOT);
}
break;
default:
throw new Exception();
}
return(new BoolType());
}