using System;
using System.Diagnostics;
using System.Security;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;

using alib;
using alib.Enumerable;
using alib.Debugging;

namespace ConsoleApp5
{
    [SuppressUnmanagedCodeSecurity]
    public static class _test_B
    {
        static _test_B()
        {
            highest_one_16 = init_highest_1s();
        }

        [DebuggerBrowsable(DebuggerBrowsableState.Never)]
        static readonly sbyte[] highest_one_16;

        static sbyte[] init_highest_1s()
        {
            int i, c, j;
            sbyte n;
            var p = new sbyte[0x10000];

            p[0] = -1;
            j = 1;
            for (n = 0, c = 1; n < 16; c <<= 1, n++)
                for (i = 0; i < c; i++)
                    p[j++] = n;

            return p;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne0(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 35
            int i = *(ushort*)(pb + 6) == 0 ?
                    *(ushort*)(pb + 4) == 0 ?
                    *(ushort*)(pb + 2) == 0 ? 0 : 2 : 4 : 6;
            return (i << 3) + highest_one_16[*(ushort*)(pb + i)];
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne1(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            // this one is more sensitive to the data, performance varies more widely than the others, even more with the neg-check
            byte* pb = (byte*)&ul + 6;      // CIL: 3B

            if (*(int*)(pb - 2) == 0)
                pb -= 4;

            if (*(ushort*)pb == 0)
                pb -= 2;

            return ((int)(pb - (long)&ul) << 3) + highest_one_16[*(ushort*)pb];
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne2(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 3A

            return highest_one_16[
                *(ushort*)((*(int*)(pb + 4) != 0 ?
                    (*(ushort*)(pb += 6)) :
                    (*(ushort*)(pb += 2))) != 0 ?
                        pb : (pb -= 2))] + ((int)(pb - (long)&ul) << 3);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne3(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 44

            return highest_one_16[
                *(ushort*)
                    (*(int*)(pb + 4) != 0 ?
                        (*(ushort*)(pb + 6) != 0 ?
                             (pb += 6) :
                             (pb += 4)) :
                        (*(ushort*)(pb + 2) != 0 ?
                             (pb += 2) :
                             pb))
                             ] + ((int)(pb - (long)&ul) << 3);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne4(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 41

            int v;
            return highest_one_16[
                *(*(int*)(pb + 4) != 0 ?
                        (*(ushort*)(pb + 6) != 0 ?
                             (ushort*)(pb + (v = 6)) :
                             (ushort*)(pb + (v = 4))) :
                        (*(ushort*)(pb + 2) != 0 ?
                             (ushort*)(pb + (v = 2)) :
                             (ushort*)(pb + (v = 0))))
                             ] + (v << 3);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne5(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 3C

            pb += (*(int*)(pb + 4) != 0 ?
                (*(ushort*)(pb + 6) != 0 ? 6 : 4) :
                (*(ushort*)(pb + 2) != 0 ? 2 : 0));

            return highest_one_16[*(ushort*)pb] + ((int)(pb - (long)&ul) << 3);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne6(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 35

            return highest_one_16[*(ushort*)
                                  (*(ushort*)(pb += (*(int*)(pb + 4) != 0 ? 6 : 2)) == 0 ?
                                        pb -= 2 :
                                        pb)] + ((int)(pb - (long)&ul) << 3);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe int HighestOne7(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            byte* pb = (byte*)&ul;          // CIL: 34

            return ((int)(-(long)pb +
                            (*(ushort*)(pb += *(int*)(pb + 4) != 0 ? 6 : 2) == 0 ?
                                pb -= 2 :
                                pb)) << 3) + highest_one_16[*(ushort*)pb];
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int HighestOne8(ulong ul)
        {
            if ((long)ul <= 0)
                return (int)((ul >> 57) & 64) - 1;

            int i, j;
            return
                (i = highest_one_16[ul >> (j = 48)]) < 0 &&
                (i = highest_one_16[ul >> (j = 32)]) < 0 &&
                (i = highest_one_16[ul >> (j = 16)]) < 0 ?
                    highest_one_16[(ushort)ul] :
                    (i + j);
        }
    };
}