public void Emit(Format5OpCode opCode, Register rd, Register rs, string nopExplanation=null)
{
string fluentComment;
var rsIsHigh=rs is HighRegister;
var rdIsHigh=rd is HighRegister;
if(opCode==Format5OpCode.BX) {
//rd is ignored on BX instruction
rd=Register.R0;
fluentComment="BX "+rs;
} else if(!rsIsHigh && !rdIsHigh) {
throw new Exception("illegal use of this instruction");
} else if(rd.EqualTo(rs)) {
fluentComment="NOP";
} else {
fluentComment=opCode.ToHumanReadable().MyConcat(" ", rd, ",", rs);
}
if(nopExplanation!=null) {
fluentComment=fluentComment+" ("+nopExplanation+")";
}
var maskedRs=rs.Index&7;
var maskedRd=rd.Index&7;
var h1Bits=rdIsHigh ? 1 : 0;
var h2Bits=rsIsHigh ? 1 : 0;
EmitHelper(rd, 5, fluentComment, 17, 6, (int)opCode, 2, h1Bits, 1, h2Bits, 1, maskedRs, 3, maskedRd, 3);
}
public void Emit(Format5OpCode opCode, Register rd, Register rs, string nopExplanation = null)
{
string fluentComment;
var rsIsHigh = rs is HighRegister;
var rdIsHigh = rd is HighRegister;
if (opCode == Format5OpCode.BX)
{
//rd is ignored on BX instruction
rd = Register.R0;
fluentComment = "BX " + rs;
}
else if (!rsIsHigh && !rdIsHigh)
{
throw new Exception("illegal use of this instruction");
}
else if (rd.EqualTo(rs))
{
fluentComment = "NOP";
}
else
{
fluentComment = opCode.ToHumanReadable().MyConcat(" ", rd, ",", rs);
}
if (nopExplanation != null)
{
fluentComment = fluentComment + " (" + nopExplanation + ")";
}
var maskedRs = rs.Index & 7;
var maskedRd = rd.Index & 7;
var h1Bits = rdIsHigh ? 1 : 0;
var h2Bits = rsIsHigh ? 1 : 0;
EmitHelper(rd, 5, fluentComment, 17, 6, (int)opCode, 2, h1Bits, 1, h2Bits, 1, maskedRs, 3, maskedRd, 3);
}
public static string ToHumanReadable(this Format5OpCode opCode)
{
return("ADDCMPMOVBX ".Substring((int)opCode * 3, 3));
}