void MunchStm(TreeStm stm)
{
switch (stm)
{
case StmCJump cjump:
{
if (cjump.Left is ExpConst c)
{
Temp constTemp = new Temp();
Emit(new InstrBinary(InstrBinary.Kind.MOV, new Operand.Reg(constTemp), new Operand.Imm(c.Value)));
Emit(new InstrBinary(InstrBinary.Kind.CMP, new Operand.Reg(constTemp), MunchExp(cjump.Right)));
}
else
{
Operand op1 = MunchExp(cjump.Left);
Operand op2 = MunchExp(cjump.Right);
if (op1 is Operand.Mem && op2 is Operand.Mem)
{
Operand.Reg memTemp = new Operand.Reg(new Temp());
Emit(new InstrBinary(InstrBinary.Kind.MOV, memTemp, op1));
Emit(new InstrBinary(InstrBinary.Kind.CMP, memTemp, op2));
}
else
{
Emit(new InstrBinary(InstrBinary.Kind.CMP, op1, op2));
}
//Emit(new InstrBinary(InstrBinary.Kind.CMP, MunchExp(cjump.Left), MunchExp(cjump.Right)));
}
InstrJump.Cond cond;
switch (cjump.Rel)
{
case StmCJump.Relation.EQ:
{
cond = InstrJump.Cond.NE;
break;
}
case StmCJump.Relation.GE:
{
cond = InstrJump.Cond.L;
break;
}
case StmCJump.Relation.GT:
{
cond = InstrJump.Cond.LE;
break;
}
case StmCJump.Relation.LE:
{
cond = InstrJump.Cond.G;
break;
}
case StmCJump.Relation.LT:
{
cond = InstrJump.Cond.GE;
break;
}
case StmCJump.Relation.NE:
{
cond = InstrJump.Cond.E;
break;
}
default: throw new Exception("No Relation matched!");
}
Emit(new InstrJump(cond, cjump.LabelFalse));
break;
}
case StmJump jump:
{
Emit(new InstrJump(InstrJump.Kind.JMP, jump.PossibleTargets[0]));
break;
}
case StmLabel label:
{
Emit(new InstrLabel(label.Label));
break;
}
case StmMove move:
{
Operand op1 = MunchExp(move.Dest);
Operand op2 = MunchExp(move.Source);
if (op1 is Operand.Mem && op2 is Operand.Mem)
{
Operand.Reg t = new Operand.Reg(new Temp());
Emit(new InstrBinary(InstrBinary.Kind.MOV, t, op2));
Emit(new InstrBinary(InstrBinary.Kind.MOV, op1, t));
}
else
{
Emit(new InstrBinary(InstrBinary.Kind.MOV, op1, op2));
}
break;
}
case StmSeq seq:
{
throw new Exception("No Sequences allowed!");
}
default:
{
throw new Exception("No case matched!");
}
}
}
Operand MunchExp(TreeExp exp)
{
switch (exp)
{
case ExpBinOp binop:
{
InstrBinary.Kind operation;
switch (binop.Operator)
{
case ExpBinOp.Op.AND:
{
operation = InstrBinary.Kind.AND;
break;
}
case ExpBinOp.Op.ARSHIFT:
{
operation = InstrBinary.Kind.SHR;
break;
}
case ExpBinOp.Op.DIV:
{
Emit(new InstrBinary(InstrBinary.Kind.MOV, new Operand.Reg(EAX), MunchExp(binop.Left)));
Operand op = MunchExp(binop.Right);
Operand.Reg temp = new Operand.Reg(new Temp());
if (op is Operand.Reg)
{
Emit(new InstrNullary(InstrNullary.Kind.CDQ));
Emit(new InstrUnary(InstrUnary.Kind.IDIV, op));
}
else
{
Emit(new InstrBinary(InstrBinary.Kind.MOV, temp, op));
Emit(new InstrNullary(InstrNullary.Kind.CDQ));
Emit(new InstrUnary(InstrUnary.Kind.IDIV, temp));
}
return(new Operand.Reg(EAX));
}
case ExpBinOp.Op.LSHIFT:
{
operation = InstrBinary.Kind.SHL;
break;
}
case ExpBinOp.Op.MINUS:
{
operation = InstrBinary.Kind.SUB;
break;
}
case ExpBinOp.Op.MUL:
{
operation = InstrBinary.Kind.IMUL;
break;
}
case ExpBinOp.Op.OR:
{
operation = InstrBinary.Kind.OR;
break;
}
case ExpBinOp.Op.PLUS:
{
operation = InstrBinary.Kind.ADD;
break;
}
default: throw new Exception("not matched");
}
Operand tempOp = new Operand.Reg(new Temp());
Emit(new InstrBinary(InstrBinary.Kind.MOV, tempOp, MunchExp(binop.Left)));
Emit(new InstrBinary(operation, tempOp, MunchExp(binop.Right)));
return(tempOp);
}
case ExpCall call:
{
ExpName name;
if (call.Function is ExpName n)
{
name = n;
}
else
{
throw new Exception("No label");
}
for (int i = 0; i < call.Args.Count; i++)
{
Temp argTemp = new Temp();
Emit(new InstrBinary(InstrBinary.Kind.MOV, new Operand.Reg(argTemp), MunchExp(call.Args[i])));
Emit(new InstrUnary(InstrUnary.Kind.PUSH, new Operand.Reg(argTemp)));
}
//Emit(new InstrBinary(InstrBinary.Kind.SUB, ))
Emit(new InstrJump(InstrJump.Kind.CALL, name.Label, new List <RegTemp> {
(RegTemp)EAX, (RegTemp)ECX, (RegTemp)EDX
}));
Emit(new InstrBinary(InstrBinary.Kind.ADD, new Operand.Reg(ESP), new Operand.Imm(call.Args.Count * 4)));
return(new Operand.Reg(EAX));
}
case ExpConst con:
{
return(new Operand.Imm(con.Value));
}
case ExpMem mem:
{
// very confusing
Temp bas = new Temp(); Temp index = new Temp();
Emit(new InstrBinary(InstrBinary.Kind.MOV, new Operand.Reg(bas), MunchExp(mem.Address)));
return(new Operand.Mem(bas));
}
case ExpName name:
{
Emit(new InstrLabel(name.Label));
return(new Operand.Reg(new Temp()));
}
case ExpParam param:
{
//Temp parTemp = new Temp();
//Emit(new InstrBinary(InstrBinary.Kind.MOV, new Operand.Reg(parTemp), new Operand.Mem(EBP, 0, null, (currentParamCount - param.Number) * 4 + 8)));
//return new Operand.Reg(parTemp);
return(new Operand.Mem(EBP, 0, null, (currentParamCount - param.Number) * 4 + 8));
}
case ExpTemp temp:
{
return(new Operand.Reg(temp.Temp));
}
default: throw new Exception("No expression matched.");
}
}