JinxRyu/ARMeilleure/Decoders/OpCodeT32AluImm.cs

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using ARMeilleure.Common;
using System.Runtime.Intrinsics;
namespace ARMeilleure.Decoders
{
class OpCodeT32AluImm : OpCodeT32Alu, IOpCode32AluImm
{
public int Immediate { get; }
public bool IsRotated { get; }
public new static OpCode Create(InstDescriptor inst, ulong address, int opCode) => new OpCodeT32AluImm(inst, address, opCode);
private static readonly Vector128<int> _factor = Vector128.Create(1, 0x00010001, 0x01000100, 0x01010101);
public OpCodeT32AluImm(InstDescriptor inst, ulong address, int opCode) : base(inst, address, opCode)
{
int imm8 = (opCode >> 0) & 0xff;
int imm3 = (opCode >> 12) & 7;
int imm1 = (opCode >> 26) & 1;
int imm12 = imm8 | (imm3 << 8) | (imm1 << 11);
if ((imm12 >> 10) == 0)
{
Immediate = imm8 * _factor.GetElement((imm12 >> 8) & 3);
IsRotated = false;
}
else
{
int shift = imm12 >> 7;
Immediate = BitUtils.RotateRight(0x80 | (imm12 & 0x7f), shift, 32);
IsRotated = shift != 0;
}
}
}
}