private void AddRtsInfo(JsrInfo info)
{
info.ReturnAddr = _cpu.RPC;
info.CyclesAfterRts = _cpu.Cycles;
info.RtsOpcodeAddr = _cpu.OpcodeRPC;
info.CallDepthAfterRts = CallDepth;
}
public void cpu_OnJSR(Cpu cpu)
{
Debug.Assert(cpu.OpCode == 0x20); // JSR
// 6502 JSR semantics
StackByte jsrReturnAddrH = _stackBytes[StackPtr + 2];
StackByte jsrReturnAddrL = _stackBytes[StackPtr + 1];
JsrInfo info = new JsrInfo {
JsrOpcodeAddr = cpu.OpcodeRPC,
JsrTargetAddr = cpu.RPC,
StackPtrAfterJsr = StackPtr,
CyclesAfterJsr = cpu.Cycles,
JsrReturnAddrH = jsrReturnAddrH,
JsrReturnAddrL = jsrReturnAddrL,
CallDepthAtJsr = CallDepth,
};
// check integrity of JsrInfo (ReturnAddrOnStack is calculated property)
Debug.Assert((jsrReturnAddrL.Value | jsrReturnAddrH.Value << 8) == info.ReturnAddrOnStack);
_jsrInfoStack.Push(info);
jsrReturnAddrH.NotifyNewJsrInfo(info, AddressPart.High, cpu.Cycles);
jsrReturnAddrL.NotifyNewJsrInfo(info, AddressPart.Low, cpu.Cycles);
OnJSR?.Invoke(info);
}
public JsrInfo NotifyJsrInfoRetired(long cycles)
{
Debug.Assert(IsPartOfReturnAddr);
JsrInfo jsrInfoToRetire = JsrInfo;
_retiredJsrInfos.Push(jsrInfoToRetire);
LastRetiredCycles = cycles;
ClearJsrPartInfo();
TraceLine("retired", StackPtr.ToHex(), _retiredJsrInfos.Count);
return(jsrInfoToRetire);
}
public void NotifyNewJsrInfo(JsrInfo info, AddressPart addressPart, long cycles)
{
Debug.Assert(info != null);
Debug.Assert(JsrInfo == null);
Debug.Assert(addressPart != AddressPart.NA);
Debug.Assert(addressPart == AddressPart.High ? info.JsrReturnAddrH == this : info.JsrReturnAddrL == this);
Debug.Assert(cycles == info.CyclesAfterJsr);
JsrInfo = info;
ReturnAddrPart = addressPart;
LastAssignedCycles = cycles;
}
public void cpu_OnPL(Cpu cpu)
{
OnPL?.Invoke(null);
if (CurrentStackByte.IsPartOfReturnAddr)
{
JsrInfo info = CurrentStackByte.JsrInfo;
TraceLine($"PL, retire{info.JsrOpcodeAddr.ToHex()}, {StackPtr.ToHex()}");
info.JsrReturnAddrL.NotifyJsrInfoRetired(cpu.Cycles);
info.JsrReturnAddrH.NotifyJsrInfoRetired(cpu.Cycles);
info.CyclesAtRetire = cpu.Cycles;
info.Retired = true;
}
else
{
// ignore PL from stack which doesn't affect any return address on the stack
}
}
public void cpu_OnRTS(Cpu cpu)
{
Debug.Assert(cpu.OpCode == 0x60); // RTS
// RTS adds 1 to RPC, so return address needs to be one byte less than target RPC
// this how RTS is defined, so we can safely assert (6502 semantics, not StackWrapper semantics)
StackByte highRtsPart = _stackBytes[StackPtr];
StackByte lowRtsPart = _stackBytes[StackPtr - 1];
Debug.Assert(lowRtsPart.Value + (highRtsPart.Value << 8) + 1 == cpu.RPC);
if (StackPtr == TopStackPtrH)
{
// StackPtr is at the level where the matching JSR happened
JsrInfo info = PopJsrInfo(i => {
// TraceLine( $"<- RTS /{CallDepth} {cpu.RPC.ToHex()}" + (i.Retired ? $" (retired {i.JsrOpcodeAddr.ToHex()})" : "" ) );
});
AddRtsInfo(info);
OnRTS?.Invoke(info);
}
else
{
Debug.Assert(false, "UNTESTED");
if (StackPtr < TopStackPtrH)
{
// probably a RTS jump table
// nothing to do for us here
// we could probably assert that StackPtr is 2 below exectedStackPtr, but maybe caller wants to pass sth on the stack?
}
else
{
// probably an "exception", i.e. returning not to the caller but to the caller's caller
Debug.Assert(StackPtr > TopStackPtrH);
while (_jsrInfoStack.Count > 0 && StackPtr > TopStackPtrH)
{
JsrInfo info = PopJsrInfo(i => {
// TraceLine( $"<- ignored RTS /{CallDepth} {cpu.RPC.ToHex()}" + (i.Retired ? $" (retired {i.JsrOpcodeAddr.ToHex()})" : "") );
});
info.Ignored = true;
AddRtsInfo(info);
OnRTS?.Invoke(info);
}
}
}
}
private JsrInfo PopJsrInfo(Action <JsrInfo> action)
{
JsrInfo info = _jsrInfoStack.Pop();
if (info.Retired)
{
JsrInfo retiredInfoL = info.JsrReturnAddrL._retiredJsrInfos.Pop();
JsrInfo retiredInfoH = info.JsrReturnAddrH._retiredJsrInfos.Pop();
Debug.Assert(retiredInfoL == retiredInfoH && retiredInfoL == info);
}
else
{
info.JsrReturnAddrH.ClearJsrPartInfo();
info.JsrReturnAddrL.ClearJsrPartInfo();
}
action?.Invoke(info);
return(info);
}
public void wrapper_OnTXS(JsrInfo info)
{
return;
}
public void wrapper_OnRts(JsrInfo info)
{
return;
}
public void wrapper_OnJsr(JsrInfo info)
{
_jsrInfoList.Add(info);
}