RyuKen/ARMeilleure/Decoders/OpCodeT16MemStack.cs

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2022-02-17 22:39:45 +00:00
using ARMeilleure.Instructions;
using ARMeilleure.State;
using System;
using System.Numerics;
namespace ARMeilleure.Decoders
{
class OpCodeT16MemStack : OpCodeT16, IOpCode32MemMult
{
public int Rn => RegisterAlias.Aarch32Sp;
public int RegisterMask { get; }
public int PostOffset { get; }
public bool IsLoad { get; }
public int Offset { get; }
public new static OpCode Create(InstDescriptor inst, ulong address, int opCode) => new OpCodeT16MemStack(inst, address, opCode);
public OpCodeT16MemStack(InstDescriptor inst, ulong address, int opCode) : base(inst, address, opCode)
{
int extra = (opCode >> 8) & 1;
int regCount = BitOperations.PopCount((uint)opCode & 0x1ff);
switch (inst.Name)
{
case InstName.Push:
RegisterMask = (opCode & 0xff) | (extra << 14);
IsLoad = false;
Offset = -4 * regCount;
PostOffset = -4 * regCount;
break;
case InstName.Pop:
RegisterMask = (opCode & 0xff) | (extra << 15);
IsLoad = true;
Offset = 0;
PostOffset = 4 * regCount;
break;
default:
throw new InvalidOperationException();
}
}
}
}