private static void UnconditionalJumpAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
const Boolean Condition = true;
DoJump(Condition, operand, registerSet.PR);
}
private static void JumpOnNonZeroAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
Boolean condition = !registerSet.FR.ZF;
DoJump(condition, operand, registerSet.PR);
}
private static void JumpOnOverflowAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
Boolean condition = registerSet.FR.OF;
DoJump(condition, operand, registerSet.PR);
}
/// <summary>
/// 命令を実行します。
/// </summary>
/// <param name="rR1Field">命令語の中の r/r1 フィールドの値です。</param>
/// <param name="xR2Field">命令語の中の x/r2 フィールドの値です。</param>
/// <param name="registerSet">COMET II の一そろいのレジスタです。</param>
/// <param name="memory">COMET II の主記憶です。</param>
internal void Execute(UInt16 rR1Field, UInt16 xR2Field, CpuRegisterSet registerSet, Memory memory)
{
CpuRegister r = m_registerHandler.GetRegister(rR1Field, registerSet);
Word operand = m_operandHandler.GetOperand(xR2Field, registerSet, memory);
m_operator.Operate(r, operand, registerSet, memory);
}
private static Word DoGetRegister(UInt16 xR2Field, CpuRegisterSet registerSet)
{
ArgChecker.CheckRange(xR2Field, 0, RegisterDef.GrCount - 1, "x/r2");
CpuRegister x = registerSet.GR[xR2Field];
return(x.Value);
}
private static void LoadWithFrAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
r.Value = operand;
const Boolean OverflowFlag = false;
registerSet.FR.SetFlags(r, OverflowFlag);
}
private static void JumpOnPlusAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
FlagRegister fr = registerSet.FR;
Boolean condition = (!fr.SF && !fr.ZF);
DoJump(condition, operand, registerSet.PR);
}
private static void CallSubroutineAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
CpuRegister pr = registerSet.PR;
PushValue(registerSet.SP, memory, pr.Value);
pr.Value = operand;
}
private static Word GetEaContents(UInt16 xR2Field, CpuRegisterSet registerSet, Memory memory)
{
// 実効アドレスの内容を取得します。
Word effectiveAddress = GetEffectiveAddress(xR2Field, registerSet, memory);
Word eaContents = memory.Read(effectiveAddress);
return(eaContents);
}
private void SetupRegisterSet(MemoryAddress execStartAddress)
{
// PR をプログラムの開始アドレスに、SP をスタック領域の最後のアドレス + 1 に、それぞれ設定する。
CpuRegisterSet registerSet = m_cpu.RegisterSet;
registerSet.Reset();
registerSet.PR.Value = execStartAddress.GetValueAsWord();
registerSet.SP.Value = InitialSp;
}
private static Word GetAddressOffset(UInt16 xR2Field, CpuRegisterSet registerSet)
{
if (xR2Field == 0)
{
return(Word.Zero);
}
else
{
return(DoGetRegister(xR2Field, registerSet));
}
}
private static void ReturnFromSubroutineAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
Boolean cancel = OnReturningFromSubroutine(registerSet.SP);
if (!cancel)
{
CpuRegister pr = registerSet.PR;
pr.Value = PopValue(registerSet.SP, memory);
}
}
private static Word GetEffectiveAddress(UInt16 xR2Field, CpuRegisterSet registerSet, Memory memory)
{
// プログラムカウンタの指すアドレスより adr を取得します。
Word adr = Fetcher.Fetch(registerSet.PR, memory);
// x/r2 フィールドの値よりオフセット x の値を取得し、実効アドレス adr +L x を計算します。
Word x = GetAddressOffset(xR2Field, registerSet);
Word effectiveAddress = Alu.AddLogical(adr, x);
return(effectiveAddress);
}
private static void LoadWithoutFrAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
r.Value = operand;
}
/// <summary>
/// 演算を実行します。
/// </summary>
/// <param name="r">演算に使用するレジスタです。</param>
/// <param name="operand">演算対象の値を保持する語です。</param>
/// <param name="registerSet">COMET II の一そろいのレジスタです。</param>
/// <param name="memory">COMET II の主記憶です。</param>
internal void Operate(CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
m_operateAction(r, operand, registerSet, memory);
}
private static void StoreAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
memory.Write(operand, r.Value);
}
private static void NoOperationAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
//
}
private static void SuperVisorCallAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
OnCallingSuperVisor(operand);
}
private static void CompareArithmeticAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoCompare(Alu.CompareArithmetic, r, operand, registerSet.FR);
}
private static void XorAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoLogic(Alu.Xor, r, operand, registerSet.FR, memory);
}
private static void CompareLogicalAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoCompare(Alu.CompareLogical, r, operand, registerSet.FR);
}
private static void SubtractArithmeticAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoOperation(Alu.SubtractArithmetic, r, operand, registerSet.FR, memory);
}
private static void ShiftLeftArithmeticAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoShift(Alu.ShiftLeftArithmetic, r, operand, registerSet.FR);
}
private static CpuRegister GetNoRegister(UInt16 rR1Field, CpuRegisterSet registerSet)
{
return(null);
}
/// <summary>
/// 命令で指定するレジスタを取得します。
/// </summary>
/// <param name="rR1Field">命令語の中の r/r1 フィールドの値です。</param>
/// <param name="registerSet">COMET II の一そろいのレジスタです。</param>
/// <returns>
/// 命令で指定するレジスタを返します。
/// 指定するレジスタがない場合は <see langword="null"/> を返します。
/// </returns>
internal CpuRegister GetRegister(UInt16 rR1Field, CpuRegisterSet registerSet)
{
CpuRegister r = m_getRegisterAction(rR1Field, registerSet);
return(r);
}
private static void ShiftRightLogicalAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoShift(Alu.ShiftRightLogical, r, operand, registerSet.FR);
}
private static void AddLogicalAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
DoOperation(Alu.AddLogical, r, operand, registerSet.FR, memory);
}
private static void PushAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
PushValue(registerSet.SP, memory, operand);
}
private static void PopAction(
CpuRegister r, Word operand, CpuRegisterSet registerSet, Memory memory)
{
r.Value = PopValue(registerSet.SP, memory);
}
/// <summary>
/// 指定の主記憶を使って <see cref="Cpu"/> のインスタンスを初期化します。
/// </summary>
/// <param name="memory">COMET II の主記憶です。</param>
internal Cpu(Memory memory)
{
m_registerSet = new CpuRegisterSet();
m_memory = memory;
}