2019-02-14 23:01:31 +00:00
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// <copyright file="Register16.cs" company="Adrian Conlon">
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// Copyright (c) Adrian Conlon. All rights reserved.
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// </copyright>
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namespace EightBit
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{
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using System.Runtime.InteropServices;
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// This'll only work for little endian host processors...
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[StructLayout(LayoutKind.Explicit)]
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public struct Register16
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{
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[FieldOffset(0)]
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public byte Low;
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[FieldOffset(1)]
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public byte High;
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[FieldOffset(0)]
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public ushort Word;
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public Register16(byte low, byte high)
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{
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this.Word = 0;
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this.Low = low;
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this.High = high;
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}
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public Register16(ushort value)
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{
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2019-02-15 09:08:44 +00:00
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this.Low = this.High = 0;
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this.Word = value;
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2019-02-14 23:01:31 +00:00
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}
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public Register16(int value)
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: this((ushort)value)
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{
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}
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public Register16(byte low)
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: this(low, 0)
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{
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}
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public Register16(Register16 rhs)
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{
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this.Low = 0;
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this.High = 0;
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this.Word = rhs.Word;
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}
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2019-02-14 23:51:32 +00:00
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public static Register16 operator ++(Register16 value) => Increment(value);
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2019-02-14 23:01:31 +00:00
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2019-02-14 23:51:32 +00:00
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public static Register16 operator --(Register16 value) => Decrement(value);
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2019-02-14 23:01:31 +00:00
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2019-02-14 23:51:32 +00:00
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public static bool operator ==(Register16 left, Register16 right) => left.Equals(right);
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2019-02-14 23:01:31 +00:00
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2019-02-14 23:51:32 +00:00
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public static bool operator !=(Register16 left, Register16 right) => !(left == right);
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2019-02-14 23:01:31 +00:00
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public static Register16 Increment(Register16 value)
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{
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++value.Word;
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return value;
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}
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public static Register16 Decrement(Register16 value)
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{
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--value.Word;
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return value;
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}
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public override bool Equals(object obj)
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{
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if (!(obj is Register16))
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{
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return false;
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}
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2019-02-16 21:32:34 +00:00
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var rhs = (Register16)obj;
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2019-02-14 23:01:31 +00:00
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return rhs.Word == this.Word;
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}
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2019-02-14 23:51:32 +00:00
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public override int GetHashCode() => this.Word;
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2019-02-14 23:01:31 +00:00
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}
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}
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