Accessing Inner Decimal Fields

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;
using BenchmarkDotNet.Attributes;

namespace TestApp
{
    [MemoryDiagnoser]
    public class DecimalConverter
    {
        decimal value = 123.567m;
        
        private ulong _a;
        private ulong _low;
        private ulong _b;
        private uint _high;
        private uint _signScale;

        [Benchmark(Baseline = true)]
        public void GetBits()
        {
            int[] bits = decimal.GetBits(value);
            _a = ((ulong)bits[1]) << 32;
            _b = ((ulong)bits[0]) & 0xFFFFFFFFL;
            _low = _a | _b;
            _high = (uint)bits[2];
            _signScale = (uint)(((bits[3] >> 15) & 0x01FE) | ((bits[3] >> 31) & 0x0001));
        }

        [Benchmark]
        public void StructConversion()
        {
            var dec = new DecimalAccessor(value);

            _a = ((ulong)dec.Mid) << 32;
            _b = ((ulong)dec.Lo) & 0xFFFFFFFFL;
            _low = _a | _b;
            _high = (uint)dec.Hi;
            _signScale = (uint)(((dec.Flags >> 15) & 0x01FE) | ((dec.Flags >> 31) & 0x0001));
        }

        [StructLayout(LayoutKind.Explicit)]
        public struct DecimalAccessor
        {
            [FieldOffset(0)]
            public int Flags;
            [FieldOffset(4)]
            public int Hi;
            [FieldOffset(8)]
            public int Lo;
            [FieldOffset(12)]
            public int Mid;

            [FieldOffset(0)]
            public decimal Decimal;

            public DecimalAccessor(decimal value)
            {
                Flags = 0;
                Hi = 0;
                Lo = 0;
                Mid = 0;
                Decimal = value;
            }
        }
    }
}