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!");
}
}
}
private List <TreeStm> CanonStm(TreeStm s)
{
switch (s)
{
case StmMove move:
{
if (move.Dest is ExpMem mem)
{
TreeExp addr = ((ExpMem)move.Dest).Address;
CanonExpression(addr);
return(CanonizedExp.ToStm(CanonNoTopCall(addr), CanonNoTopCall(move.Source),
(eaddr, esrc) => new StmMove(new ExpMem(eaddr), esrc)));
}
else if (move.Dest is ExpTemp)
{
return(CanonExpression(move.Source).ToStm(esrc => new StmMove(move.Dest, esrc)));
}
else if (move.Dest is ExpParam)
{
return(CanonExpression(move.Source).ToStm(esrc => new StmMove(move.Dest, esrc)));
}
else if (move.Dest is ExpESeq dst)
{
return(CanonStm(new StmSeq(new List <TreeStm> {
dst.Stm, new StmMove(dst.Exp, move.Source)
})));
}
else
{
throw new Exception("Left-hand side of MOVE must be TEMP, PARAM, MEM or ESEQ.");
}
}
case StmJump jump:
{
return(CanonNoTopCall(jump.Dest).ToStm(e => new StmJump(e, jump.PossibleTargets)));
}
case StmCJump cjump:
{
return(CanonizedExp.ToStm(CanonNoTopCall(cjump.Left), CanonNoTopCall(cjump.Right),
(l, r) => new StmCJump(cjump.Rel, l, r, cjump.LabelTrue, cjump.LabelFalse)));
}
case StmSeq seq:
{
List <TreeStm> cstms = new List <TreeStm>();
foreach (var stat in seq.Stms)
{
cstms.AddRange(CanonStm(stat));
}
return(cstms);
}
case StmLabel label:
{
List <TreeStm> stms = new List <TreeStm>();
stms.Add(label);
return(stms);
}
default: throw new Exception("Ya know, did not match any Statement.");
}
}
private static bool Commute(TreeStm s, TreeExp e)
{
return((e is ExpName) || (e is ExpConst));
}
public ExpESeq(TreeStm stm, TreeExp exp)
{
Stm = stm;
Exp = exp;
}
