//--------------------------------------------------------------
// Purpose: Computes the value of operand2 in data processing instructions
// Returns: The uint value of the instruction's operand2
//--------------------------------------------------------------
private static uint ComputeValue(Data instr)
{
op2Type op2 = Operation.CheckOperand2(instr);
shiftType shift = Operation.CheckShiftType(instr);
Memory registers = Computer.GetCPU().registers;
uint value = 0, adjustPC = 0;
if (instr.RM * 4 == (int)regs.PC || instr.RS * 4 == (int)regs.PC)
{
adjustPC = 4;
}
switch (op2)
{
case op2Type.imm:
value = BarrelShifter.rotateVal((uint)instr.immediateVal, (byte)shiftType.ror, (uint)instr.rotateVal * 2);
break;
case op2Type.reg_imm:
value = BarrelShifter.rotateVal(registers.ReadWord((uint)instr.RM * 4) + adjustPC, instr.shiftType, instr.shiftVal);
break;
case op2Type.reg_reg:
value = BarrelShifter.rotateVal(registers.ReadWord((uint)instr.RM * 4) + adjustPC, instr.shiftType, registers.ReadWord((uint)instr.RS * 4) + adjustPC);
break;
}
return(value);
}
//--------------------------------------------------------------
// Purpose: Creates disassembly for data processing instructions and sets it
// Returns: Nothing
//--------------------------------------------------------------
private static void SetDataDisassembly(Data instr, uint value, bool isMov)
{
op2Type op2 = Operation.CheckOperand2(instr);
shiftType shift = Operation.CheckShiftType(instr);
if (isMov)
{
switch (op2)
{
case op2Type.imm:
instr.disasm.value = Disassembly.ImmMov(instr, value);
break;
case op2Type.reg_imm:
instr.disasm.value = Disassembly.RegImmMov(instr);
break;
case op2Type.reg_reg:
instr.disasm.value = Disassembly.RegRegMov(instr);
break;
}
}
else
{
switch (op2)
{
case op2Type.imm:
instr.disasm.value = Disassembly.ImmData(instr, value);
break;
case op2Type.reg_imm:
instr.disasm.value = Disassembly.RegImmData(instr);
break;
case op2Type.reg_reg:
instr.disasm.value = Disassembly.RegRegData(instr);
break;
}
}
}