public List <Instruction> CodeGen()
{
var code = new List <Instruction>();
if (source.IsConstant())
{
code.AddRange(target.PutFromInt(source.Evaluate()));
}
else
{
var src = source.AsDirectField();
if (src == null)
{
var tgt = target.AsDirectField();
if (tgt == null)
{
var scratch = FieldSRef.ScratchInt();
code.AddRange(source.FetchToField(scratch));
code.AddRange(target.PutFromField(scratch));
}
else
{
code.AddRange(source.FetchToField(tgt));
}
}
else
{
code.AddRange(target.PutFromField(src));
}
}
return(code);
}
public List <Instruction> CodeGen(int truejump, int falsejump)
{
var b = new List <Instruction>();
var f1 = S1.AsDirectField() ?? (S1.IsConstant() ? FieldSRef.Imm1() : null);
if (f1 == null)
{
f1 = FieldSRef.ScratchInt();
b.AddRange(S1.FetchToField(f1));
}
var f2 = S2.AsDirectField() ?? (S2.IsConstant() ? FieldSRef.Imm2() : null);
if (f2 == null)
{
f2 = FieldSRef.ScratchInt();
b.AddRange(S2.FetchToField(f2));
}
b.Add(new Instruction
{
opcode = Opcode.Branch,
op1 = f1,
imm1 = S1.IsConstant() ? new IntSExpr(S1.Evaluate()) : null,
op2 = f2,
imm2 = S2.IsConstant() ? new IntSExpr(S2.Evaluate()) : null,
rjmpeq = this.Op.HasFlag(CompSpec.Equal) ? truejump : falsejump,
rjmplt = this.Op.HasFlag(CompSpec.Less) ? truejump : falsejump,
rjmpgt = this.Op.HasFlag(CompSpec.Greater) ? truejump : falsejump,
});
return(b);
}
public List <Instruction> CodeGen()
{
var b = new List <Instruction>();
if (sreturn != null)
{
b.AddRange(sreturn.FetchToField(FieldSRef.SReturn));
}
if (vreturn != null)
{
b.AddRange(vreturn.FetchToReg(RegVRef.rScratchTab));
}
b.Add(new Jump
{
target = new AddrSExpr("__return"),
relative = true,
});
return(b);
}
public List <Instruction> FetchToField(FieldSRef dest)
{
var code = new List <Instruction>();
var f1 = S1.AsDirectField();
if (f1 == null)
{
if (S1.IsConstant())
{
f1 = FieldSRef.Imm1();
}
else
{
f1 = FieldSRef.ScratchInt();
code.AddRange(S1.FetchToField(f1));
}
}
var f2 = S2.AsDirectField();
if (f2 == null)
{
if (S2.IsConstant())
{
f2 = FieldSRef.Imm2();
}
else
{
f2 = FieldSRef.ScratchInt();
code.AddRange(S2.FetchToField(f2));
}
}
Opcode op;
switch (Op)
{
case ArithSpec.Add:
op = Opcode.Add;
break;
case ArithSpec.Subtract:
op = Opcode.Sub;
break;
case ArithSpec.Multiply:
op = Opcode.Mul;
break;
case ArithSpec.Divide:
op = Opcode.Div;
break;
default:
throw new InvalidOperationException();
}
var tmp = FieldSRef.ScratchInt();
code.Add(new Instruction
{
opcode = op,
op1 = f1,
imm1 = S1.IsConstant() ? S1 : null,
op2 = f2,
imm2 = S2.IsConstant() ? S2 : null,
dest = tmp,
acc = true
});
//TODO: optimize this one day?
code.AddRange(dest.PutFromField(tmp));
return(code);
}