6502/EightBitNet
1
0
Fork 0
mirror of https://github.com/MoleskiCoder/EightBitNet.git synced 2025-08-15 11:27:27 +00:00
Code Issues Projects Releases Wiki Activity

Interesting, makes pretty much no difference to just calculate 16 bit values, rather than relying on byte layout.

Browse Source 
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon
2019-02-18 22:28:20 +00:00
parent 9ac2c53685
commit 23489b7127
1 changed files with 19 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
EightBit/Register16.cs
View File

@@ -6,30 +6,21 @@ namespace EightBit
{ {
using System.Runtime.InteropServices; using System.Runtime.InteropServices;
// This'll only work for little endian host processors...
[StructLayout(LayoutKind.Explicit)]
public struct Register16 public struct Register16
{ {
[FieldOffset(0)]
public byte Low; public byte Low;
[FieldOffset(1)]
public byte High; public byte High;
[FieldOffset(0)]
public ushort Word;
public Register16(byte low, byte high) public Register16(byte low, byte high)
{ {
this.Word = 0;
this.Low = low; this.Low = low;
this.High = high; this.High = high;
} }
public Register16(ushort value) public Register16(ushort value)
{ {
this.Low = this.High = 0; this.Low = Chip.LowByte(value);
this.Word = value; this.High = Chip.HighByte(value);
} }
public Register16(int value) public Register16(int value)
@@ -44,9 +35,22 @@ namespace EightBit
public Register16(Register16 rhs) public Register16(Register16 rhs)
{ {
this.Low = 0; this.Low = rhs.Low;
this.High = 0; this.High = rhs.High;
this.Word = rhs.Word; }
public ushort Word
{
get
{
return (ushort)(this.Low | Chip.PromoteByte(this.High));
}
set
{
this.Low = Chip.LowByte(value);
this.High = Chip.HighByte(value);
}
} }
public static Register16 operator ++(Register16 value) => Increment(value); public static Register16 operator ++(Register16 value) => Increment(value);
@@ -77,7 +81,7 @@ namespace EightBit
} }
var rhs = (Register16)obj; var rhs = (Register16)obj;
return rhs.Word == this.Word; return rhs.Low == this.Low && rhs.High == this.High;
} }
public override int GetHashCode() => this.Word; public override int GetHashCode() => this.Word;