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Remove some analysis warnings from 6809 implementation

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Adrian Conlon committed 2026-06-05 20:13:02 +01:00
1 parent 7d99e8162f
commit ff31ac05de
1 file changed
+77 -11
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MC6809/MC6809.cs
+77 -11
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@@ -422,7 +422,11 @@ namespace MC6809
protected byte AdjustZero(ushort datum) => ClearBit(this.CC, StatusBits.ZF, datum);
protected byte AdjustZero(Register16 datum) => this.AdjustZero(datum.Joined);
protected byte AdjustZero(Register16 datum)
{
Debug.Assert(datum is not null);
return this.AdjustZero(datum.Joined);
}
protected byte AdjustNegative(byte datum) => SetBit(this.CC, StatusBits.NF, datum & (byte)Bits.Bit7);
@@ -440,16 +444,25 @@ namespace MC6809
return this.AdjustNegative(datum);
}
protected byte AdjustNZ(Register16 datum) => this.AdjustNZ(datum.Joined);
protected byte AdjustNZ(Register16 datum)
{
Debug.Assert(datum is not null);
return this.AdjustNZ(datum.Joined);
}
protected byte AdjustCarry(ushort datum) => SetBit(this.CC, StatusBits.CF, datum & (ushort)Bits.Bit8); // 8-bit addition
protected byte AdjustCarry(uint datum) => SetBit(this.CC, StatusBits.CF, (int)(datum & (uint)Bits.Bit16)); // 16-bit addition
protected byte AdjustCarry(Register16 datum) => this.AdjustCarry(datum.Joined);
protected byte AdjustCarry(Register16 datum)
{
Debug.Assert(datum is not null);
return this.AdjustCarry(datum.Joined);
}
protected byte AdjustOverflow(byte before, byte data, Register16 after)
{
Debug.Assert(after is not null);
var lowAfter = after.Low;
var highAfter = after.High;
return SetBit(this.CC, StatusBits.VF, (before ^ data ^ lowAfter ^ highAfter << 7) & (int)Bits.Bit7);
@@ -466,6 +479,7 @@ namespace MC6809
protected byte AdjustAddition(byte before, byte data, Register16 after)
{
Debug.Assert(after is not null);
var result = after.Low;
this.CC = this.AdjustNZ(result);
this.CC = this.AdjustCarry(after);
@@ -481,10 +495,16 @@ namespace MC6809
return this.AdjustOverflow(before, data, after);
}
protected byte AdjustAddition(Register16 before, Register16 data, uint after) => this.AdjustAddition(before.Joined, data.Joined, after);
protected byte AdjustAddition(Register16 before, Register16 data, uint after)
{
Debug.Assert(before is not null);
Debug.Assert(data is not null);
return this.AdjustAddition(before.Joined, data.Joined, after);
}
protected byte AdjustSubtraction(byte before, byte data, Register16 after)
{
Debug.Assert(after is not null);
var result = after.Low;
this.CC = this.AdjustNZ(result);
this.CC = this.AdjustCarry(after);
@@ -499,7 +519,12 @@ namespace MC6809
return this.AdjustOverflow(before, data, after);
}
protected byte AdjustSubtraction(Register16 before, Register16 data, uint after) => this.AdjustSubtraction(before.Joined, data.Joined, after);
protected byte AdjustSubtraction(Register16 before, Register16 data, uint after)
{
Debug.Assert(before is not null);
Debug.Assert(data is not null);
return this.AdjustSubtraction(before.Joined, data.Joined, after);
}
#endregion
@@ -599,6 +624,7 @@ namespace MC6809
protected void Push(Register16 stack, byte value)
{
Debug.Assert(stack is not null);
stack.Decrement();
this.MemoryWrite(stack, value);
}
@@ -607,12 +633,15 @@ namespace MC6809
protected void Push(Register16 stack, Register16 value)
{
Debug.Assert(stack is not null);
Debug.Assert(value is not null);
this.Push(stack, value.Low);
this.Push(stack, value.High);
}
protected void Pop(Register16 stack)
{
Debug.Assert(stack is not null);
this.MemoryRead(stack);
stack.Increment();
}
@@ -860,6 +889,7 @@ namespace MC6809
protected Register16 Through(Register16 data)
{
Debug.Assert(data is not null);
this.Through(data.Joined);
return data;
}
@@ -1794,6 +1824,9 @@ namespace MC6809
protected void Add(Register16 operand, Register16 data, int carry, Register16 result)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
Debug.Assert(result is not null);
var addition = operand.Joined + data.Joined + carry;
this.CC = this.AdjustAddition(operand, data, (uint)addition);
result.Joined = (ushort)addition;
@@ -1813,7 +1846,13 @@ namespace MC6809
protected ushort And(ushort operand, ushort data) => this.Through((ushort)(operand & data));
protected void And(Register16 operand, Register16 data, Register16 destination) => destination.Joined = this.And(operand.Joined, data.Joined);
protected void And(Register16 operand, Register16 data, Register16 destination)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
Debug.Assert(destination is not null);
destination.Joined = this.And(operand.Joined, data.Joined);
}
protected byte And(byte operand, byte data) => this.Through((byte)(operand & data));
@@ -1886,7 +1925,12 @@ namespace MC6809
protected void Compare(ushort operand, ushort data) => this.Subtract(operand, data);
protected void Compare(Register16 operand, Register16 data) => this.Compare(operand.Joined, data.Joined);
protected void Compare(Register16 operand, Register16 data)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
this.Compare(operand.Joined, data.Joined);
}
protected void Compare(byte operand, byte data) => this.Subtract(operand, data);
@@ -1957,7 +2001,13 @@ namespace MC6809
protected ushort ExclusiveOr(ushort operand, ushort data) => this.Through((ushort)(operand ^ data));
protected void ExclusiveOr(Register16 operand, Register16 data, Register16 destination) => destination.Joined = this.ExclusiveOr(operand.Joined, data.Joined);
protected void ExclusiveOr(Register16 operand, Register16 data, Register16 destination)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
Debug.Assert(destination is not null);
destination.Joined = this.ExclusiveOr(operand.Joined, data.Joined);
}
protected byte ExclusiveOr(byte operand, byte data) => this.Through((byte)(operand ^ data));
@@ -2070,7 +2120,13 @@ namespace MC6809
protected ushort Or(ushort operand, ushort data) => this.Through((ushort)(operand | data));
protected void Or(Register16 operand, Register16 data, Register16 destination) => destination.Joined = this.Or(operand.Joined, data.Joined);
protected void Or(Register16 operand, Register16 data, Register16 destination)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
Debug.Assert(destination is not null);
destination.Joined = this.Or(operand.Joined, data.Joined);
}
protected byte Or(byte operand, byte data) => this.Through((byte)(operand | data));
@@ -2156,7 +2212,13 @@ namespace MC6809
return (ushort)subtraction;
}
protected void Subtract(Register16 operand, Register16 data, int carry, Register16 result) => result.Joined = this.Subtract(operand.Joined, data.Joined, carry);
protected void Subtract(Register16 operand, Register16 data, int carry, Register16 result)
{
Debug.Assert(operand is not null);
Debug.Assert(data is not null);
Debug.Assert(result is not null);
result.Joined = this.Subtract(operand.Joined, data.Joined, carry);
}
protected void Subtract(Register16 operand, Register16 data, Register16 result) => this.Subtract(operand, data, 0, result);
@@ -2236,7 +2298,11 @@ namespace MC6809
this.SwallowRead();
}
protected void LEA(Register16 register) => register.Assign(this.EA);
protected void LEA(Register16 register)
{
Debug.Assert(register is not null);
register.Assign(this.EA);
}
private void ABX()
{