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Some performance updates

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This commit is contained in:
Adrian Conlon
2025-10-13 17:36:32 +01:00
parent ceacac4741
commit 33fce45cc8
3 changed files with 33 additions and 10 deletions
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34
EightBit/MemoryMapping.cs
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@@ -4,21 +4,43 @@
namespace EightBit namespace EightBit
{ {
public sealed class MemoryMapping(Memory memory, ushort begin, ushort mask, AccessLevel access) public sealed class MemoryMapping
{ {
public MemoryMapping(Memory memory, ushort begin, ushort mask, AccessLevel access)
{
this._memory = memory;
this._begin = begin;
this._mask = mask;
this._access = access;
for (int i = ushort.MinValue; i < ushort.MaxValue + 1; ++i)
{
System.Diagnostics.Debug.Assert(i >= ushort.MinValue);
System.Diagnostics.Debug.Assert(i <= ushort.MaxValue);
this._offsets[i] = this.CalculateOffset((ushort)i);
}
}
public MemoryMapping(Memory memory, ushort begin, Mask mask, AccessLevel access) public MemoryMapping(Memory memory, ushort begin, Mask mask, AccessLevel access)
: this(memory, begin, (ushort)mask, access) : this(memory, begin, (ushort)mask, access)
{ {
} }
public Memory Memory { get; set; } = memory; private readonly int[] _offsets = new int[ushort.MaxValue + 1];
private readonly Memory _memory;
private readonly ushort _begin;
private readonly ushort _mask;
private readonly AccessLevel _access;
public ushort Begin { get; set; } = begin; public Memory Memory => this._memory;
public ushort Mask { get; set; } = mask; public ushort Begin => this._begin;
public AccessLevel Access { get; set; } = access; public ushort Mask => this._mask;
public int Offset(ushort absolute) => (absolute - this.Begin) & this.Mask; public AccessLevel Access => this._access;
private int CalculateOffset(ushort absolute) => (absolute - this.Begin) & this.Mask;
public int Offset(ushort absolute) => this._offsets[absolute];
} }
} }

3
EightBit/Register16.cs
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@@ -89,7 +89,8 @@ namespace EightBit
public void Assign(Register16 from) public void Assign(Register16 from)
{ {
this.Assign(from.Low, from.High); this.Low = from.Low;
this.High = from.High;
} }
[MethodImpl(MethodImplOptions.AggressiveInlining)] [MethodImpl(MethodImplOptions.AggressiveInlining)]

6
M6502/Core.cs
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@@ -972,11 +972,11 @@ namespace M6502
private void JSR() private void JSR()
{ {
this.Intermediate.Low = this.FetchByte(); var low = this.FetchByte();
this.SwallowPop(); this.SwallowPop();
this.PushWord(this.PC); this.PushWord(this.PC);
this.PC.High = this.FetchByte(); var high = this.FetchByte();
this.PC.Low = this.Intermediate.Low; this.PC.Assign(low, high);
} }
private void PHP() => this.Push(SetBit(this.P, StatusBits.BF)); private void PHP() => this.Push(SetBit(this.P, StatusBits.BF));