path: root/crypto/src/math/ec/LongArray.cs

using System;
using System.Text;

using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Math.EC
{
    internal class LongArray
    {
        //private static long DEInterleave_MASK = 0x5555555555555555L;

        /*
         * This expands 8 bit indices into 16 bit contents (high bit 14), by inserting 0s between bits.
         * In a binary field, this operation is the same as squaring an 8 bit number.
         */
        private static readonly int[] INTERLEAVE2_TABLE = new int[]
        {
            0x0000, 0x0001, 0x0004, 0x0005, 0x0010, 0x0011, 0x0014, 0x0015,
            0x0040, 0x0041, 0x0044, 0x0045, 0x0050, 0x0051, 0x0054, 0x0055,
            0x0100, 0x0101, 0x0104, 0x0105, 0x0110, 0x0111, 0x0114, 0x0115,
            0x0140, 0x0141, 0x0144, 0x0145, 0x0150, 0x0151, 0x0154, 0x0155,
            0x0400, 0x0401, 0x0404, 0x0405, 0x0410, 0x0411, 0x0414, 0x0415,
            0x0440, 0x0441, 0x0444, 0x0445, 0x0450, 0x0451, 0x0454, 0x0455,
            0x0500, 0x0501, 0x0504, 0x0505, 0x0510, 0x0511, 0x0514, 0x0515,
            0x0540, 0x0541, 0x0544, 0x0545, 0x0550, 0x0551, 0x0554, 0x0555,
            0x1000, 0x1001, 0x1004, 0x1005, 0x1010, 0x1011, 0x1014, 0x1015,
            0x1040, 0x1041, 0x1044, 0x1045, 0x1050, 0x1051, 0x1054, 0x1055,
            0x1100, 0x1101, 0x1104, 0x1105, 0x1110, 0x1111, 0x1114, 0x1115,
            0x1140, 0x1141, 0x1144, 0x1145, 0x1150, 0x1151, 0x1154, 0x1155,
            0x1400, 0x1401, 0x1404, 0x1405, 0x1410, 0x1411, 0x1414, 0x1415,
            0x1440, 0x1441, 0x1444, 0x1445, 0x1450, 0x1451, 0x1454, 0x1455,
            0x1500, 0x1501, 0x1504, 0x1505, 0x1510, 0x1511, 0x1514, 0x1515,
            0x1540, 0x1541, 0x1544, 0x1545, 0x1550, 0x1551, 0x1554, 0x1555,
            0x4000, 0x4001, 0x4004, 0x4005, 0x4010, 0x4011, 0x4014, 0x4015,
            0x4040, 0x4041, 0x4044, 0x4045, 0x4050, 0x4051, 0x4054, 0x4055,
            0x4100, 0x4101, 0x4104, 0x4105, 0x4110, 0x4111, 0x4114, 0x4115,
            0x4140, 0x4141, 0x4144, 0x4145, 0x4150, 0x4151, 0x4154, 0x4155,
            0x4400, 0x4401, 0x4404, 0x4405, 0x4410, 0x4411, 0x4414, 0x4415,
            0x4440, 0x4441, 0x4444, 0x4445, 0x4450, 0x4451, 0x4454, 0x4455,
            0x4500, 0x4501, 0x4504, 0x4505, 0x4510, 0x4511, 0x4514, 0x4515,
            0x4540, 0x4541, 0x4544, 0x4545, 0x4550, 0x4551, 0x4554, 0x4555,
            0x5000, 0x5001, 0x5004, 0x5005, 0x5010, 0x5011, 0x5014, 0x5015,
            0x5040, 0x5041, 0x5044, 0x5045, 0x5050, 0x5051, 0x5054, 0x5055,
            0x5100, 0x5101, 0x5104, 0x5105, 0x5110, 0x5111, 0x5114, 0x5115,
            0x5140, 0x5141, 0x5144, 0x5145, 0x5150, 0x5151, 0x5154, 0x5155,
            0x5400, 0x5401, 0x5404, 0x5405, 0x5410, 0x5411, 0x5414, 0x5415,
            0x5440, 0x5441, 0x5444, 0x5445, 0x5450, 0x5451, 0x5454, 0x5455,
            0x5500, 0x5501, 0x5504, 0x5505, 0x5510, 0x5511, 0x5514, 0x5515,
            0x5540, 0x5541, 0x5544, 0x5545, 0x5550, 0x5551, 0x5554, 0x5555
        };

        /*
         * This expands 7 bit indices into 21 bit contents (high bit 18), by inserting 0s between bits.
         */
        private static readonly int[] INTERLEAVE3_TABLE = new  int[]
        {
            0x00000, 0x00001, 0x00008, 0x00009, 0x00040, 0x00041, 0x00048, 0x00049,
            0x00200, 0x00201, 0x00208, 0x00209, 0x00240, 0x00241, 0x00248, 0x00249,
            0x01000, 0x01001, 0x01008, 0x01009, 0x01040, 0x01041, 0x01048, 0x01049,
            0x01200, 0x01201, 0x01208, 0x01209, 0x01240, 0x01241, 0x01248, 0x01249,
            0x08000, 0x08001, 0x08008, 0x08009, 0x08040, 0x08041, 0x08048, 0x08049,
            0x08200, 0x08201, 0x08208, 0x08209, 0x08240, 0x08241, 0x08248, 0x08249,
            0x09000, 0x09001, 0x09008, 0x09009, 0x09040, 0x09041, 0x09048, 0x09049,
            0x09200, 0x09201, 0x09208, 0x09209, 0x09240, 0x09241, 0x09248, 0x09249,
            0x40000, 0x40001, 0x40008, 0x40009, 0x40040, 0x40041, 0x40048, 0x40049,
            0x40200, 0x40201, 0x40208, 0x40209, 0x40240, 0x40241, 0x40248, 0x40249,
            0x41000, 0x41001, 0x41008, 0x41009, 0x41040, 0x41041, 0x41048, 0x41049,
            0x41200, 0x41201, 0x41208, 0x41209, 0x41240, 0x41241, 0x41248, 0x41249,
            0x48000, 0x48001, 0x48008, 0x48009, 0x48040, 0x48041, 0x48048, 0x48049,
            0x48200, 0x48201, 0x48208, 0x48209, 0x48240, 0x48241, 0x48248, 0x48249,
            0x49000, 0x49001, 0x49008, 0x49009, 0x49040, 0x49041, 0x49048, 0x49049,
            0x49200, 0x49201, 0x49208, 0x49209, 0x49240, 0x49241, 0x49248, 0x49249
        };

        /*
         * This expands 8 bit indices into 32 bit contents (high bit 28), by inserting 0s between bits.
         */
        private static readonly int[] INTERLEAVE4_TABLE = new int[]
        {
            0x00000000, 0x00000001, 0x00000010, 0x00000011, 0x00000100, 0x00000101, 0x00000110, 0x00000111,
            0x00001000, 0x00001001, 0x00001010, 0x00001011, 0x00001100, 0x00001101, 0x00001110, 0x00001111,
            0x00010000, 0x00010001, 0x00010010, 0x00010011, 0x00010100, 0x00010101, 0x00010110, 0x00010111,
            0x00011000, 0x00011001, 0x00011010, 0x00011011, 0x00011100, 0x00011101, 0x00011110, 0x00011111,
            0x00100000, 0x00100001, 0x00100010, 0x00100011, 0x00100100, 0x00100101, 0x00100110, 0x00100111,
            0x00101000, 0x00101001, 0x00101010, 0x00101011, 0x00101100, 0x00101101, 0x00101110, 0x00101111,
            0x00110000, 0x00110001, 0x00110010, 0x00110011, 0x00110100, 0x00110101, 0x00110110, 0x00110111,
            0x00111000, 0x00111001, 0x00111010, 0x00111011, 0x00111100, 0x00111101, 0x00111110, 0x00111111,
            0x01000000, 0x01000001, 0x01000010, 0x01000011, 0x01000100, 0x01000101, 0x01000110, 0x01000111,
            0x01001000, 0x01001001, 0x01001010, 0x01001011, 0x01001100, 0x01001101, 0x01001110, 0x01001111,
            0x01010000, 0x01010001, 0x01010010, 0x01010011, 0x01010100, 0x01010101, 0x01010110, 0x01010111,
            0x01011000, 0x01011001, 0x01011010, 0x01011011, 0x01011100, 0x01011101, 0x01011110, 0x01011111,
            0x01100000, 0x01100001, 0x01100010, 0x01100011, 0x01100100, 0x01100101, 0x01100110, 0x01100111,
            0x01101000, 0x01101001, 0x01101010, 0x01101011, 0x01101100, 0x01101101, 0x01101110, 0x01101111,
            0x01110000, 0x01110001, 0x01110010, 0x01110011, 0x01110100, 0x01110101, 0x01110110, 0x01110111,
            0x01111000, 0x01111001, 0x01111010, 0x01111011, 0x01111100, 0x01111101, 0x01111110, 0x01111111,
            0x10000000, 0x10000001, 0x10000010, 0x10000011, 0x10000100, 0x10000101, 0x10000110, 0x10000111,
            0x10001000, 0x10001001, 0x10001010, 0x10001011, 0x10001100, 0x10001101, 0x10001110, 0x10001111,
            0x10010000, 0x10010001, 0x10010010, 0x10010011, 0x10010100, 0x10010101, 0x10010110, 0x10010111,
            0x10011000, 0x10011001, 0x10011010, 0x10011011, 0x10011100, 0x10011101, 0x10011110, 0x10011111,
            0x10100000, 0x10100001, 0x10100010, 0x10100011, 0x10100100, 0x10100101, 0x10100110, 0x10100111,
            0x10101000, 0x10101001, 0x10101010, 0x10101011, 0x10101100, 0x10101101, 0x10101110, 0x10101111,
            0x10110000, 0x10110001, 0x10110010, 0x10110011, 0x10110100, 0x10110101, 0x10110110, 0x10110111,
            0x10111000, 0x10111001, 0x10111010, 0x10111011, 0x10111100, 0x10111101, 0x10111110, 0x10111111,
            0x11000000, 0x11000001, 0x11000010, 0x11000011, 0x11000100, 0x11000101, 0x11000110, 0x11000111,
            0x11001000, 0x11001001, 0x11001010, 0x11001011, 0x11001100, 0x11001101, 0x11001110, 0x11001111,
            0x11010000, 0x11010001, 0x11010010, 0x11010011, 0x11010100, 0x11010101, 0x11010110, 0x11010111,
            0x11011000, 0x11011001, 0x11011010, 0x11011011, 0x11011100, 0x11011101, 0x11011110, 0x11011111,
            0x11100000, 0x11100001, 0x11100010, 0x11100011, 0x11100100, 0x11100101, 0x11100110, 0x11100111,
            0x11101000, 0x11101001, 0x11101010, 0x11101011, 0x11101100, 0x11101101, 0x11101110, 0x11101111,
            0x11110000, 0x11110001, 0x11110010, 0x11110011, 0x11110100, 0x11110101, 0x11110110, 0x11110111,
            0x11111000, 0x11111001, 0x11111010, 0x11111011, 0x11111100, 0x11111101, 0x11111110, 0x11111111
        };

        /*
         * This expands 7 bit indices into 35 bit contents (high bit 30), by inserting 0s between bits.
         */
        private static readonly int[] INTERLEAVE5_TABLE = new int[] {
            0x00000000, 0x00000001, 0x00000020, 0x00000021, 0x00000400, 0x00000401, 0x00000420, 0x00000421,
            0x00008000, 0x00008001, 0x00008020, 0x00008021, 0x00008400, 0x00008401, 0x00008420, 0x00008421,
            0x00100000, 0x00100001, 0x00100020, 0x00100021, 0x00100400, 0x00100401, 0x00100420, 0x00100421,
            0x00108000, 0x00108001, 0x00108020, 0x00108021, 0x00108400, 0x00108401, 0x00108420, 0x00108421,
            0x02000000, 0x02000001, 0x02000020, 0x02000021, 0x02000400, 0x02000401, 0x02000420, 0x02000421,
            0x02008000, 0x02008001, 0x02008020, 0x02008021, 0x02008400, 0x02008401, 0x02008420, 0x02008421,
            0x02100000, 0x02100001, 0x02100020, 0x02100021, 0x02100400, 0x02100401, 0x02100420, 0x02100421,
            0x02108000, 0x02108001, 0x02108020, 0x02108021, 0x02108400, 0x02108401, 0x02108420, 0x02108421,
            0x40000000, 0x40000001, 0x40000020, 0x40000021, 0x40000400, 0x40000401, 0x40000420, 0x40000421,
            0x40008000, 0x40008001, 0x40008020, 0x40008021, 0x40008400, 0x40008401, 0x40008420, 0x40008421,
            0x40100000, 0x40100001, 0x40100020, 0x40100021, 0x40100400, 0x40100401, 0x40100420, 0x40100421,
            0x40108000, 0x40108001, 0x40108020, 0x40108021, 0x40108400, 0x40108401, 0x40108420, 0x40108421,
            0x42000000, 0x42000001, 0x42000020, 0x42000021, 0x42000400, 0x42000401, 0x42000420, 0x42000421,
            0x42008000, 0x42008001, 0x42008020, 0x42008021, 0x42008400, 0x42008401, 0x42008420, 0x42008421,
            0x42100000, 0x42100001, 0x42100020, 0x42100021, 0x42100400, 0x42100401, 0x42100420, 0x42100421,
            0x42108000, 0x42108001, 0x42108020, 0x42108021, 0x42108400, 0x42108401, 0x42108420, 0x42108421
        };

        /*
         * This expands 9 bit indices into 63 bit (long) contents (high bit 56), by inserting 0s between bits.
         */
        private static readonly long[] INTERLEAVE7_TABLE = new long[]
        {
            0x0000000000000000L, 0x0000000000000001L, 0x0000000000000080L, 0x0000000000000081L,
            0x0000000000004000L, 0x0000000000004001L, 0x0000000000004080L, 0x0000000000004081L,
            0x0000000000200000L, 0x0000000000200001L, 0x0000000000200080L, 0x0000000000200081L,
            0x0000000000204000L, 0x0000000000204001L, 0x0000000000204080L, 0x0000000000204081L,
            0x0000000010000000L, 0x0000000010000001L, 0x0000000010000080L, 0x0000000010000081L,
            0x0000000010004000L, 0x0000000010004001L, 0x0000000010004080L, 0x0000000010004081L,
            0x0000000010200000L, 0x0000000010200001L, 0x0000000010200080L, 0x0000000010200081L,
            0x0000000010204000L, 0x0000000010204001L, 0x0000000010204080L, 0x0000000010204081L,
            0x0000000800000000L, 0x0000000800000001L, 0x0000000800000080L, 0x0000000800000081L,
            0x0000000800004000L, 0x0000000800004001L, 0x0000000800004080L, 0x0000000800004081L,
            0x0000000800200000L, 0x0000000800200001L, 0x0000000800200080L, 0x0000000800200081L,
            0x0000000800204000L, 0x0000000800204001L, 0x0000000800204080L, 0x0000000800204081L,
            0x0000000810000000L, 0x0000000810000001L, 0x0000000810000080L, 0x0000000810000081L,
            0x0000000810004000L, 0x0000000810004001L, 0x0000000810004080L, 0x0000000810004081L,
            0x0000000810200000L, 0x0000000810200001L, 0x0000000810200080L, 0x0000000810200081L,
            0x0000000810204000L, 0x0000000810204001L, 0x0000000810204080L, 0x0000000810204081L,
            0x0000040000000000L, 0x0000040000000001L, 0x0000040000000080L, 0x0000040000000081L,
            0x0000040000004000L, 0x0000040000004001L, 0x0000040000004080L, 0x0000040000004081L,
            0x0000040000200000L, 0x0000040000200001L, 0x0000040000200080L, 0x0000040000200081L,
            0x0000040000204000L, 0x0000040000204001L, 0x0000040000204080L, 0x0000040000204081L,
            0x0000040010000000L, 0x0000040010000001L, 0x0000040010000080L, 0x0000040010000081L,
            0x0000040010004000L, 0x0000040010004001L, 0x0000040010004080L, 0x0000040010004081L,
            0x0000040010200000L, 0x0000040010200001L, 0x0000040010200080L, 0x0000040010200081L,
            0x0000040010204000L, 0x0000040010204001L, 0x0000040010204080L, 0x0000040010204081L,
            0x0000040800000000L, 0x0000040800000001L, 0x0000040800000080L, 0x0000040800000081L,
            0x0000040800004000L, 0x0000040800004001L, 0x0000040800004080L, 0x0000040800004081L,
            0x0000040800200000L, 0x0000040800200001L, 0x0000040800200080L, 0x0000040800200081L,
            0x0000040800204000L, 0x0000040800204001L, 0x0000040800204080L, 0x0000040800204081L,
            0x0000040810000000L, 0x0000040810000001L, 0x0000040810000080L, 0x0000040810000081L,
            0x0000040810004000L, 0x0000040810004001L, 0x0000040810004080L, 0x0000040810004081L,
            0x0000040810200000L, 0x0000040810200001L, 0x0000040810200080L, 0x0000040810200081L,
            0x0000040810204000L, 0x0000040810204001L, 0x0000040810204080L, 0x0000040810204081L,
            0x0002000000000000L, 0x0002000000000001L, 0x0002000000000080L, 0x0002000000000081L,
            0x0002000000004000L, 0x0002000000004001L, 0x0002000000004080L, 0x0002000000004081L,
            0x0002000000200000L, 0x0002000000200001L, 0x0002000000200080L, 0x0002000000200081L,
            0x0002000000204000L, 0x0002000000204001L, 0x0002000000204080L, 0x0002000000204081L,
            0x0002000010000000L, 0x0002000010000001L, 0x0002000010000080L, 0x0002000010000081L,
            0x0002000010004000L, 0x0002000010004001L, 0x0002000010004080L, 0x0002000010004081L,
            0x0002000010200000L, 0x0002000010200001L, 0x0002000010200080L, 0x0002000010200081L,
            0x0002000010204000L, 0x0002000010204001L, 0x0002000010204080L, 0x0002000010204081L,
            0x0002000800000000L, 0x0002000800000001L, 0x0002000800000080L, 0x0002000800000081L,
            0x0002000800004000L, 0x0002000800004001L, 0x0002000800004080L, 0x0002000800004081L,
            0x0002000800200000L, 0x0002000800200001L, 0x0002000800200080L, 0x0002000800200081L,
            0x0002000800204000L, 0x0002000800204001L, 0x0002000800204080L, 0x0002000800204081L,
            0x0002000810000000L, 0x0002000810000001L, 0x0002000810000080L, 0x0002000810000081L,
            0x0002000810004000L, 0x0002000810004001L, 0x0002000810004080L, 0x0002000810004081L,
            0x0002000810200000L, 0x0002000810200001L, 0x0002000810200080L, 0x0002000810200081L,
            0x0002000810204000L, 0x0002000810204001L, 0x0002000810204080L, 0x0002000810204081L,
            0x0002040000000000L, 0x0002040000000001L, 0x0002040000000080L, 0x0002040000000081L,
            0x0002040000004000L, 0x0002040000004001L, 0x0002040000004080L, 0x0002040000004081L,
            0x0002040000200000L, 0x0002040000200001L, 0x0002040000200080L, 0x0002040000200081L,
            0x0002040000204000L, 0x0002040000204001L, 0x0002040000204080L, 0x0002040000204081L,
            0x0002040010000000L, 0x0002040010000001L, 0x0002040010000080L, 0x0002040010000081L,
            0x0002040010004000L, 0x0002040010004001L, 0x0002040010004080L, 0x0002040010004081L,
            0x0002040010200000L, 0x0002040010200001L, 0x0002040010200080L, 0x0002040010200081L,
            0x0002040010204000L, 0x0002040010204001L, 0x0002040010204080L, 0x0002040010204081L,
            0x0002040800000000L, 0x0002040800000001L, 0x0002040800000080L, 0x0002040800000081L,
            0x0002040800004000L, 0x0002040800004001L, 0x0002040800004080L, 0x0002040800004081L,
            0x0002040800200000L, 0x0002040800200001L, 0x0002040800200080L, 0x0002040800200081L,
            0x0002040800204000L, 0x0002040800204001L, 0x0002040800204080L, 0x0002040800204081L,
            0x0002040810000000L, 0x0002040810000001L, 0x0002040810000080L, 0x0002040810000081L,
            0x0002040810004000L, 0x0002040810004001L, 0x0002040810004080L, 0x0002040810004081L,
            0x0002040810200000L, 0x0002040810200001L, 0x0002040810200080L, 0x0002040810200081L,
            0x0002040810204000L, 0x0002040810204001L, 0x0002040810204080L, 0x0002040810204081L,
            0x0100000000000000L, 0x0100000000000001L, 0x0100000000000080L, 0x0100000000000081L,
            0x0100000000004000L, 0x0100000000004001L, 0x0100000000004080L, 0x0100000000004081L,
            0x0100000000200000L, 0x0100000000200001L, 0x0100000000200080L, 0x0100000000200081L,
            0x0100000000204000L, 0x0100000000204001L, 0x0100000000204080L, 0x0100000000204081L,
            0x0100000010000000L, 0x0100000010000001L, 0x0100000010000080L, 0x0100000010000081L,
            0x0100000010004000L, 0x0100000010004001L, 0x0100000010004080L, 0x0100000010004081L,
            0x0100000010200000L, 0x0100000010200001L, 0x0100000010200080L, 0x0100000010200081L,
            0x0100000010204000L, 0x0100000010204001L, 0x0100000010204080L, 0x0100000010204081L,
            0x0100000800000000L, 0x0100000800000001L, 0x0100000800000080L, 0x0100000800000081L,
            0x0100000800004000L, 0x0100000800004001L, 0x0100000800004080L, 0x0100000800004081L,
            0x0100000800200000L, 0x0100000800200001L, 0x0100000800200080L, 0x0100000800200081L,
            0x0100000800204000L, 0x0100000800204001L, 0x0100000800204080L, 0x0100000800204081L,
            0x0100000810000000L, 0x0100000810000001L, 0x0100000810000080L, 0x0100000810000081L,
            0x0100000810004000L, 0x0100000810004001L, 0x0100000810004080L, 0x0100000810004081L,
            0x0100000810200000L, 0x0100000810200001L, 0x0100000810200080L, 0x0100000810200081L,
            0x0100000810204000L, 0x0100000810204001L, 0x0100000810204080L, 0x0100000810204081L,
            0x0100040000000000L, 0x0100040000000001L, 0x0100040000000080L, 0x0100040000000081L,
            0x0100040000004000L, 0x0100040000004001L, 0x0100040000004080L, 0x0100040000004081L,
            0x0100040000200000L, 0x0100040000200001L, 0x0100040000200080L, 0x0100040000200081L,
            0x0100040000204000L, 0x0100040000204001L, 0x0100040000204080L, 0x0100040000204081L,
            0x0100040010000000L, 0x0100040010000001L, 0x0100040010000080L, 0x0100040010000081L,
            0x0100040010004000L, 0x0100040010004001L, 0x0100040010004080L, 0x0100040010004081L,
            0x0100040010200000L, 0x0100040010200001L, 0x0100040010200080L, 0x0100040010200081L,
            0x0100040010204000L, 0x0100040010204001L, 0x0100040010204080L, 0x0100040010204081L,
            0x0100040800000000L, 0x0100040800000001L, 0x0100040800000080L, 0x0100040800000081L,
            0x0100040800004000L, 0x0100040800004001L, 0x0100040800004080L, 0x0100040800004081L,
            0x0100040800200000L, 0x0100040800200001L, 0x0100040800200080L, 0x0100040800200081L,
            0x0100040800204000L, 0x0100040800204001L, 0x0100040800204080L, 0x0100040800204081L,
            0x0100040810000000L, 0x0100040810000001L, 0x0100040810000080L, 0x0100040810000081L,
            0x0100040810004000L, 0x0100040810004001L, 0x0100040810004080L, 0x0100040810004081L,
            0x0100040810200000L, 0x0100040810200001L, 0x0100040810200080L, 0x0100040810200081L,
            0x0100040810204000L, 0x0100040810204001L, 0x0100040810204080L, 0x0100040810204081L,
            0x0102000000000000L, 0x0102000000000001L, 0x0102000000000080L, 0x0102000000000081L,
            0x0102000000004000L, 0x0102000000004001L, 0x0102000000004080L, 0x0102000000004081L,
            0x0102000000200000L, 0x0102000000200001L, 0x0102000000200080L, 0x0102000000200081L,
            0x0102000000204000L, 0x0102000000204001L, 0x0102000000204080L, 0x0102000000204081L,
            0x0102000010000000L, 0x0102000010000001L, 0x0102000010000080L, 0x0102000010000081L,
            0x0102000010004000L, 0x0102000010004001L, 0x0102000010004080L, 0x0102000010004081L,
            0x0102000010200000L, 0x0102000010200001L, 0x0102000010200080L, 0x0102000010200081L,
            0x0102000010204000L, 0x0102000010204001L, 0x0102000010204080L, 0x0102000010204081L,
            0x0102000800000000L, 0x0102000800000001L, 0x0102000800000080L, 0x0102000800000081L,
            0x0102000800004000L, 0x0102000800004001L, 0x0102000800004080L, 0x0102000800004081L,
            0x0102000800200000L, 0x0102000800200001L, 0x0102000800200080L, 0x0102000800200081L,
            0x0102000800204000L, 0x0102000800204001L, 0x0102000800204080L, 0x0102000800204081L,
            0x0102000810000000L, 0x0102000810000001L, 0x0102000810000080L, 0x0102000810000081L,
            0x0102000810004000L, 0x0102000810004001L, 0x0102000810004080L, 0x0102000810004081L,
            0x0102000810200000L, 0x0102000810200001L, 0x0102000810200080L, 0x0102000810200081L,
            0x0102000810204000L, 0x0102000810204001L, 0x0102000810204080L, 0x0102000810204081L,
            0x0102040000000000L, 0x0102040000000001L, 0x0102040000000080L, 0x0102040000000081L,
            0x0102040000004000L, 0x0102040000004001L, 0x0102040000004080L, 0x0102040000004081L,
            0x0102040000200000L, 0x0102040000200001L, 0x0102040000200080L, 0x0102040000200081L,
            0x0102040000204000L, 0x0102040000204001L, 0x0102040000204080L, 0x0102040000204081L,
            0x0102040010000000L, 0x0102040010000001L, 0x0102040010000080L, 0x0102040010000081L,
            0x0102040010004000L, 0x0102040010004001L, 0x0102040010004080L, 0x0102040010004081L,
            0x0102040010200000L, 0x0102040010200001L, 0x0102040010200080L, 0x0102040010200081L,
            0x0102040010204000L, 0x0102040010204001L, 0x0102040010204080L, 0x0102040010204081L,
            0x0102040800000000L, 0x0102040800000001L, 0x0102040800000080L, 0x0102040800000081L,
            0x0102040800004000L, 0x0102040800004001L, 0x0102040800004080L, 0x0102040800004081L,
            0x0102040800200000L, 0x0102040800200001L, 0x0102040800200080L, 0x0102040800200081L,
            0x0102040800204000L, 0x0102040800204001L, 0x0102040800204080L, 0x0102040800204081L,
            0x0102040810000000L, 0x0102040810000001L, 0x0102040810000080L, 0x0102040810000081L,
            0x0102040810004000L, 0x0102040810004001L, 0x0102040810004080L, 0x0102040810004081L,
            0x0102040810200000L, 0x0102040810200001L, 0x0102040810200080L, 0x0102040810200081L,
            0x0102040810204000L, 0x0102040810204001L, 0x0102040810204080L, 0x0102040810204081L
        };

        // For toString(); must have length 64
        private const string ZEROES = "0000000000000000000000000000000000000000000000000000000000000000";

        internal static readonly byte[] BitLengths =
        {
            0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
            5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
            6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
            6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
            7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
            8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
        };

        // TODO make m fixed for the LongArray, and hence compute T once and for all

        private long[] m_ints;

        public LongArray(int intLen)
        {
            m_ints = new long[intLen];
        }

        public LongArray(long[] ints)
        {
            m_ints = ints;
        }

        public LongArray(long[] ints, int off, int len)
        {
            if (off == 0 && len == ints.Length)
            {
                m_ints = ints;
            }
            else
            {
                m_ints = new long[len];
                Array.Copy(ints, off, m_ints, 0, len);
            }
        }

        public LongArray(BigInteger bigInt)
        {
            if (bigInt == null || bigInt.SignValue < 0)
            {
                throw new ArgumentException("invalid F2m field value", "bigInt");
            }

            if (bigInt.SignValue == 0)
            {
                m_ints = new long[] { 0L };
                return;
            }

            byte[] barr = bigInt.ToByteArray();
            int barrLen = barr.Length;
            int barrStart = 0;
            if (barr[0] == 0)
            {
                // First byte is 0 to enforce highest (=sign) bit is zero.
                // In this case ignore barr[0].
                barrLen--;
                barrStart = 1;
            }
            int intLen = (barrLen + 7) / 8;
            m_ints = new long[intLen];

            int iarrJ = intLen - 1;
            int rem = barrLen % 8 + barrStart;
            long temp = 0;
            int barrI = barrStart;
            if (barrStart < rem)
            {
                for (; barrI < rem; barrI++)
                {
                    temp <<= 8;
                    uint barrBarrI = barr[barrI];
                    temp |= barrBarrI;
                }
                m_ints[iarrJ--] = temp;
            }

            for (; iarrJ >= 0; iarrJ--)
            {
                temp = 0;
                for (int i = 0; i < 8; i++)
                {
                    temp <<= 8;
                    uint barrBarrI = barr[barrI++];
                    temp |= barrBarrI;
                }
                m_ints[iarrJ] = temp;
            }
        }

        public bool IsOne()
        {
            long[] a = m_ints;
            if (a[0] != 1L)
            {
                return false;
            }
            for (int i = 1; i < a.Length; ++i)
            {
                if (a[i] != 0L)
                {
                    return false;
                }
            }
            return true;
        }

        public bool IsZero()
        {
            long[] a = m_ints;
            for (int i = 0; i < a.Length; ++i)
            {
                if (a[i] != 0L)
                {
                    return false;
                }
            }
            return true;
        }

        public int GetUsedLength()
        {
            return GetUsedLengthFrom(m_ints.Length);
        }

        public int GetUsedLengthFrom(int from)
        {
            long[] a = m_ints;
            from = System.Math.Min(from, a.Length);

            if (from < 1)
            {
                return 0;
            }

            // Check if first element will act as sentinel
            if (a[0] != 0)
            {
                while (a[--from] == 0)
                {
                }
                return from + 1;
            }

            do
            {
                if (a[--from] != 0)
                {
                    return from + 1;
                }
            }
            while (from > 0);

            return 0;
        }

        public int Degree()
        {
            int i = m_ints.Length;
            long w;
            do
            {
                if (i == 0)
                {
                    return 0;
                }
                w = m_ints[--i];
            }
            while (w == 0);

            return (i << 6) + BitLength(w);
        }

        private int DegreeFrom(int limit)
        {
            int i = (int)(((uint)limit + 62) >> 6);
            long w;
            do
            {
                if (i == 0)
                {
                    return 0;
                }
                w = m_ints[--i];
            }
            while (w == 0);

            return (i << 6) + BitLength(w);
        }

    //    private int lowestCoefficient()
    //    {
    //        for (int i = 0; i < m_ints.Length; ++i)
    //        {
    //            long mi = m_ints[i];
    //            if (mi != 0)
    //            {
    //                int j = 0;
    //                while ((mi & 0xFFL) == 0)
    //                {
    //                    j += 8;
    //                    mi >>>= 8;
    //                }
    //                while ((mi & 1L) == 0)
    //                {
    //                    ++j;
    //                    mi >>>= 1;
    //                }
    //                return (i << 6) + j;
    //            }
    //        }
    //        return -1;
    //    }

        private static int BitLength(long w)
        {
            int u = (int)((ulong)w >> 32), b;
            if (u == 0)
            {
                u = (int)w;
                b = 0;
            }
            else
            {
                b = 32;
            }

            int t = (int)((uint)u >> 16), k;
            if (t == 0)
            {
                t = (int)((uint)u >> 8);
                k = (t == 0) ? BitLengths[u] : 8 + BitLengths[t];
            }
            else
            {
                int v = (int)((uint)t >> 8);
                k = (v == 0) ? 16 + BitLengths[t] : 24 + BitLengths[v];
            }

            return b + k;
        }

        private long[] ResizedInts(int newLen)
        {
            long[] newInts = new long[newLen];
            Array.Copy(m_ints, 0, newInts, 0, System.Math.Min(m_ints.Length, newLen));
            return newInts;
        }

        public BigInteger ToBigInteger()
        {
            int usedLen = GetUsedLength();
            if (usedLen == 0)
            {
                return BigInteger.Zero;
            }

            long highestInt = m_ints[usedLen - 1];
            byte[] temp = new byte[8];
            int barrI = 0;
            bool trailingZeroBytesDone = false;
            for (int j = 7; j >= 0; j--)
            {
                byte thisByte = (byte)((ulong)highestInt >> (8 * j));
                if (trailingZeroBytesDone || (thisByte != 0))
                {
                    trailingZeroBytesDone = true;
                    temp[barrI++] = thisByte;
                }
            }

            int barrLen = 8 * (usedLen - 1) + barrI;
            byte[] barr = new byte[barrLen];
            for (int j = 0; j < barrI; j++)
            {
                barr[j] = temp[j];
            }
            // Highest value int is done now

            for (int iarrJ = usedLen - 2; iarrJ >= 0; iarrJ--)
            {
                long mi = m_ints[iarrJ];
                for (int j = 7; j >= 0; j--)
                {
                    barr[barrI++] = (byte)((ulong)mi >> (8 * j));
                }
            }
            return new BigInteger(1, barr);
        }

    //    private static long shiftUp(long[] x, int xOff, int count)
    //    {
    //        long prev = 0;
    //        for (int i = 0; i < count; ++i)
    //        {
    //            long next = x[xOff + i];
    //            x[xOff + i] = (next << 1) | prev;
    //            prev = next >>> 63;
    //        }
    //        return prev;
    //    }

        private static long ShiftUp(long[] x, int xOff, int count, int shift)
        {
            int shiftInv = 64 - shift;
            long prev = 0;
            for (int i = 0; i < count; ++i)
            {
                long next = x[xOff + i];
                x[xOff + i] = (next << shift) | prev;
                prev = (long)((ulong)next >> shiftInv);
            }
            return prev;
        }

        private static long ShiftUp(long[] x, int xOff, long[] z, int zOff, int count, int shift)
        {
            int shiftInv = 64 - shift;
            long prev = 0;
            for (int i = 0; i < count; ++i)
            {
                long next = x[xOff + i];
                z[zOff + i] = (next << shift) | prev;
                prev = (long)((ulong)next >> shiftInv);
            }
            return prev;
        }

        public LongArray AddOne()
        {
            if (m_ints.Length == 0)
            {
                return new LongArray(new long[]{ 1L });
            }

            int resultLen = System.Math.Max(1, GetUsedLength());
            long[] ints = ResizedInts(resultLen);
            ints[0] ^= 1L;
            return new LongArray(ints);
        }

    //    private void addShiftedByBits(LongArray other, int bits)
    //    {
    //        int words = bits >>> 6;
    //        int shift = bits & 0x3F;
    //
    //        if (shift == 0)
    //        {
    //            addShiftedByWords(other, words);
    //            return;
    //        }
    //
    //        int otherUsedLen = other.GetUsedLength();
    //        if (otherUsedLen == 0)
    //        {
    //            return;
    //        }
    //
    //        int minLen = otherUsedLen + words + 1;
    //        if (minLen > m_ints.Length)
    //        {
    //            m_ints = resizedInts(minLen);
    //        }
    //
    //        long carry = addShiftedByBits(m_ints, words, other.m_ints, 0, otherUsedLen, shift);
    //        m_ints[otherUsedLen + words] ^= carry;
    //    }

        private void AddShiftedByBitsSafe(LongArray other, int otherDegree, int bits)
        {
            int otherLen = (int)((uint)(otherDegree + 63) >> 6);

            int words = (int)((uint)bits >> 6);
            int shift = bits & 0x3F;

            if (shift == 0)
            {
                Add(m_ints, words, other.m_ints, 0, otherLen);
                return;
            }

            long carry = AddShiftedUp(m_ints, words, other.m_ints, 0, otherLen, shift);
            if (carry != 0L)
            {
                m_ints[otherLen + words] ^= carry;
            }
        }

        private static long AddShiftedUp(long[] x, int xOff, long[] y, int yOff, int count, int shift)
        {
            int shiftInv = 64 - shift;
            long prev = 0;
            for (int i = 0; i < count; ++i)
            {
                long next = y[yOff + i];
                x[xOff + i] ^= (next << shift) | prev;
                prev = (long)((ulong)next >> shiftInv);
            }
            return prev;
        }

        private static long AddShiftedDown(long[] x, int xOff, long[] y, int yOff, int count, int shift)
        {
            int shiftInv = 64 - shift;
            long prev = 0;
            int i = count;
            while (--i >= 0)
            {
                long next = y[yOff + i];
                x[xOff + i] ^= (long)((ulong)next >> shift) | prev;
                prev = next << shiftInv;
            }
            return prev;
        }

        public void AddShiftedByWords(LongArray other, int words)
        {
            int otherUsedLen = other.GetUsedLength();
            if (otherUsedLen == 0)
            {
                return;
            }

            int minLen = otherUsedLen + words;
            if (minLen > m_ints.Length)
            {
                m_ints = ResizedInts(minLen);
            }

            Add(m_ints, words, other.m_ints, 0, otherUsedLen);
        }

        private static void Add(long[] x, int xOff, long[] y, int yOff, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                x[xOff + i] ^= y[yOff + i];
            }
        }

        private static void Add(long[] x, int xOff, long[] y, int yOff, long[] z, int zOff, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                z[zOff + i] = x[xOff + i] ^ y[yOff + i];
            }
        }

        private static void AddBoth(long[] x, int xOff, long[] y1, int y1Off, long[] y2, int y2Off, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                x[xOff + i] ^= y1[y1Off + i] ^ y2[y2Off + i];
            }
        }

        private static void Distribute(long[] x, int src, int dst1, int dst2, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                long v = x[src + i];
                x[dst1 + i] ^= v;
                x[dst2 + i] ^= v;
            }
        }

        public int Length
        {
            get { return m_ints.Length; }
        }

        private static void FlipWord(long[] buf, int off, int bit, long word)
        {
            int n = off + (int)((uint)bit >> 6);
            int shift = bit & 0x3F;
            if (shift == 0)
            {
                buf[n] ^= word;
            }
            else
            {
                buf[n] ^= word << shift;
                word = (long)((ulong)word >> (64 - shift));
                if (word != 0)
                {
                    buf[++n] ^= word;
                }
            }
        }

    //    private static long getWord(long[] buf, int off, int len, int bit)
    //    {
    //        int n = off + (bit >>> 6);
    //        int shift = bit & 0x3F;
    //        if (shift == 0)
    //        {
    //            return buf[n];
    //        }
    //        long result = buf[n] >>> shift;
    //        if (++n < len)
    //        {
    //            result |= buf[n] << (64 - shift);
    //        }
    //        return result;
    //    }

        public bool TestBitZero()
        {
            return m_ints.Length > 0 && (m_ints[0] & 1L) != 0;
        }

        private static bool TestBit(long[] buf, int off, int n)
        {
            // theInt = n / 64
            int theInt = (int)((uint)n >> 6);
            // theBit = n % 64
            int theBit = n & 0x3F;
            long tester = 1L << theBit;
            return (buf[off + theInt] & tester) != 0;
        }

        private static void FlipBit(long[] buf, int off, int n)
        {
            // theInt = n / 64
            int theInt = (int)((uint)n >> 6);
            // theBit = n % 64
            int theBit = n & 0x3F;
            long flipper = 1L << theBit;
            buf[off + theInt] ^= flipper;
        }

    //    private static void SetBit(long[] buf, int off, int n)
    //    {
    //        // theInt = n / 64
    //        int theInt = n >>> 6;
    //        // theBit = n % 64
    //        int theBit = n & 0x3F;
    //        long setter = 1L << theBit;
    //        buf[off + theInt] |= setter;
    //    }
    //
    //    private static void ClearBit(long[] buf, int off, int n)
    //    {
    //        // theInt = n / 64
    //        int theInt = n >>> 6;
    //        // theBit = n % 64
    //        int theBit = n & 0x3F;
    //        long setter = 1L << theBit;
    //        buf[off + theInt] &= ~setter;
    //    }

        private static void MultiplyWord(long a, long[] b, int bLen, long[] c, int cOff)
        {
            if ((a & 1L) != 0L)
            {
                Add(c, cOff, b, 0, bLen);
            }
            int k = 1;
            while ((a = (long)((ulong)a >> 1)) != 0L)
            {
                if ((a & 1L) != 0L)
                {
                    long carry = AddShiftedUp(c, cOff, b, 0, bLen, k);
                    if (carry != 0L)
                    {
                        c[cOff + bLen] ^= carry;
                    }
                }
                ++k;
            }
        }

        public LongArray ModMultiplyLD(LongArray other, int m, int[] ks)
        {
            /*
             * Find out the degree of each argument and handle the zero cases
             */
            int aDeg = Degree();
            if (aDeg == 0)
            {
                return this;
            }
            int bDeg = other.Degree();
            if (bDeg == 0)
            {
                return other;
            }

            /*
             * Swap if necessary so that A is the smaller argument
             */
            LongArray A = this, B = other;
            if (aDeg > bDeg)
            {
                A = other; B = this;
                int tmp = aDeg; aDeg = bDeg; bDeg = tmp;
            }

            /*
             * Establish the word lengths of the arguments and result
             */
            int aLen = (int)((uint)(aDeg + 63) >> 6);
            int bLen = (int)((uint)(bDeg + 63) >> 6);
            int cLen = (int)((uint)(aDeg + bDeg + 62) >> 6);

            if (aLen == 1)
            {
                long a0 = A.m_ints[0];
                if (a0 == 1L)
                {
                    return B;
                }

                /*
                 * Fast path for small A, with performance dependent only on the number of set bits
                 */
                long[] c0 = new long[cLen];
                MultiplyWord(a0, B.m_ints, bLen, c0, 0);

                /*
                 * Reduce the raw answer against the reduction coefficients
                 */
                return ReduceResult(c0, 0, cLen, m, ks);
            }

            /*
             * Determine if B will get bigger during shifting
             */
            int bMax = (int)((uint)(bDeg + 7 + 63) >> 6);

            /*
             * Lookup table for the offset of each B in the tables
             */
            int[] ti = new int[16];

            /*
             * Precompute table of all 4-bit products of B
             */
            long[] T0 = new long[bMax << 4];
            int tOff = bMax;
            ti[1] = tOff;
            Array.Copy(B.m_ints, 0, T0, tOff, bLen);
            for (int i = 2; i < 16; ++i)
            {
                ti[i] = (tOff += bMax);
                if ((i & 1) == 0)
                {
                    ShiftUp(T0, (int)((uint)tOff >> 1), T0, tOff, bMax, 1);
                }
                else
                {
                    Add(T0, bMax, T0, tOff - bMax, T0, tOff, bMax);
                }
            }

            /*
             * Second table with all 4-bit products of B shifted 4 bits
             */
            long[] T1 = new long[T0.Length];
            ShiftUp(T0, 0, T1, 0, T0.Length, 4);
    //        shiftUp(T0, bMax, T1, bMax, tOff, 4);

            long[] a = A.m_ints;
            long[] c = new long[cLen];

            int MASK = 0xF;

            /*
             * Lopez-Dahab algorithm
             */

            for (int k = 56; k >= 0; k -= 8)
            {
                for (int j = 1; j < aLen; j += 2)
                {
                    int aVal = (int)((ulong)a[j] >> k);
                    int u = aVal & MASK;
                    int v = (int)((uint)aVal >> 4) & MASK;
                    AddBoth(c, j - 1, T0, ti[u], T1, ti[v], bMax);
                }
                ShiftUp(c, 0, cLen, 8);
            }

            for (int k = 56; k >= 0; k -= 8)
            {
                for (int j = 0; j < aLen; j += 2)
                {
                    int aVal = (int)((ulong)a[j] >> k);
                    int u = aVal & MASK;
                    int v = (int)((uint)aVal >> 4) & MASK;
                    AddBoth(c, j, T0, ti[u], T1, ti[v], bMax);
                }
                if (k > 0)
                {
                    ShiftUp(c, 0, cLen, 8);
                }
            }

            /*
             * Finally the raw answer is collected, reduce it against the reduction coefficients
             */
            return ReduceResult(c, 0, cLen, m, ks);
        }

        public LongArray ModMultiply(LongArray other, int m, int[] ks)
        {
            /*
             * Find out the degree of each argument and handle the zero cases
             */
            int aDeg = Degree();
            if (aDeg == 0)
            {
                return this;
            }
            int bDeg = other.Degree();
            if (bDeg == 0)
            {
                return other;
            }

            /*
             * Swap if necessary so that A is the smaller argument
             */
            LongArray A = this, B = other;
            if (aDeg > bDeg)
            {
                A = other; B = this;
                int tmp = aDeg; aDeg = bDeg; bDeg = tmp;
            }

            /*
             * Establish the word lengths of the arguments and result
             */
            int aLen = (int)((uint)(aDeg + 63) >> 6);
            int bLen = (int)((uint)(bDeg + 63) >> 6);
            int cLen = (int)((uint)(aDeg + bDeg + 62) >> 6);

            if (aLen == 1)
            {
                long a0 = A.m_ints[0];
                if (a0 == 1L)
                {
                    return B;
                }

                /*
                 * Fast path for small A, with performance dependent only on the number of set bits
                 */
                long[] c0 = new long[cLen];
                MultiplyWord(a0, B.m_ints, bLen, c0, 0);

                /*
                 * Reduce the raw answer against the reduction coefficients
                 */
                return ReduceResult(c0, 0, cLen, m, ks);
            }

            /*
             * Determine if B will get bigger during shifting
             */
            int bMax = (int)((uint)(bDeg + 7 + 63) >> 6);

            /*
             * Lookup table for the offset of each B in the tables
             */
            int[] ti = new int[16];

            /*
             * Precompute table of all 4-bit products of B
             */
            long[] T0 = new long[bMax << 4];
            int tOff = bMax;
            ti[1] = tOff;
            Array.Copy(B.m_ints, 0, T0, tOff, bLen);
            for (int i = 2; i < 16; ++i)
            {
                ti[i] = (tOff += bMax);
                if ((i & 1) == 0)
                {
                    ShiftUp(T0, (int)((uint)tOff >> 1), T0, tOff, bMax, 1);
                }
                else
                {
                    Add(T0, bMax, T0, tOff - bMax, T0, tOff, bMax);
                }
            }

            /*
             * Second table with all 4-bit products of B shifted 4 bits
             */
            long[] T1 = new long[T0.Length];
            ShiftUp(T0, 0, T1, 0, T0.Length, 4);
    //        ShiftUp(T0, bMax, T1, bMax, tOff, 4);

            long[] a = A.m_ints;
            long[] c = new long[cLen << 3];

            int MASK = 0xF;

            /*
             * Lopez-Dahab (Modified) algorithm
             */

            for (int aPos = 0; aPos < aLen; ++aPos)
            {
                long aVal = a[aPos];
                int cOff = aPos;
                for (;;)
                {
                    int u = (int)aVal & MASK;
                    aVal = (long)((ulong)aVal >> 4);
                    int v = (int)aVal & MASK;
                    AddBoth(c, cOff, T0, ti[u], T1, ti[v], bMax);
                    aVal = (long)((ulong)aVal >> 4);
                    if (aVal == 0L)
                    {
                        break;
                    }
                    cOff += cLen;
                }
            }

            {
                int cOff = c.Length;
                while ((cOff -= cLen) != 0)
                {
                    AddShiftedUp(c, cOff - cLen, c, cOff, cLen, 8);
                }
            }

            /*
             * Finally the raw answer is collected, reduce it against the reduction coefficients
             */
            return ReduceResult(c, 0, cLen, m, ks);
        }

        public LongArray ModMultiplyAlt(LongArray other, int m, int[] ks)
        {
            /*
             * Find out the degree of each argument and handle the zero cases
             */
            int aDeg = Degree();
            if (aDeg == 0)
            {
                return this;
            }
            int bDeg = other.Degree();
            if (bDeg == 0)
            {
                return other;
            }

            /*
             * Swap if necessary so that A is the smaller argument
             */
            LongArray A = this, B = other;
            if (aDeg > bDeg)
            {
                A = other; B = this;
                int tmp = aDeg; aDeg = bDeg; bDeg = tmp;
            }

            /*
             * Establish the word lengths of the arguments and result
             */
            int aLen = (int)((uint)(aDeg + 63) >> 6);
            int bLen = (int)((uint)(bDeg + 63) >> 6);
            int cLen = (int)((uint)(aDeg + bDeg + 62) >> 6);

            if (aLen == 1)
            {
                long a0 = A.m_ints[0];
                if (a0 == 1L)
                {
                    return B;
                }

                /*
                 * Fast path for small A, with performance dependent only on the number of set bits
                 */
                long[] c0 = new long[cLen];
                MultiplyWord(a0, B.m_ints, bLen, c0, 0);

                /*
                 * Reduce the raw answer against the reduction coefficients
                 */
                return ReduceResult(c0, 0, cLen, m, ks);
            }

            // NOTE: This works, but is slower than width 4 processing
    //        if (aLen == 2)
    //        {
    //            /*
    //             * Use common-multiplicand optimization to save ~1/4 of the adds
    //             */
    //            long a1 = A.m_ints[0], a2 = A.m_ints[1];
    //            long aa = a1 & a2; a1 ^= aa; a2 ^= aa;
    //
    //            long[] b = B.m_ints;
    //            long[] c = new long[cLen];
    //            multiplyWord(aa, b, bLen, c, 1);
    //            add(c, 0, c, 1, cLen - 1);
    //            multiplyWord(a1, b, bLen, c, 0);
    //            multiplyWord(a2, b, bLen, c, 1);
    //
    //            /*
    //             * Reduce the raw answer against the reduction coefficients
    //             */
    //            return ReduceResult(c, 0, cLen, m, ks);
    //        }

            /*
             * Determine the parameters of the Interleaved window algorithm: the 'width' in bits to
             * process together, the number of evaluation 'positions' implied by that width, and the
             * 'top' position at which the regular window algorithm stops.
             */
            int width, positions, top, banks;

            // NOTE: width 4 is the fastest over the entire range of sizes used in current crypto 
    //        width = 1; positions = 64; top = 64; banks = 4;
    //        width = 2; positions = 32; top = 64; banks = 4;
    //        width = 3; positions = 21; top = 63; banks = 3;
            width = 4; positions = 16; top = 64; banks = 8;
    //        width = 5; positions = 13; top = 65; banks = 7;
    //        width = 7; positions = 9; top = 63; banks = 9;
    //        width = 8; positions = 8; top = 64; banks = 8;

            /*
             * Determine if B will get bigger during shifting
             */
            int shifts = top < 64 ? positions : positions - 1;
            int bMax = (int)((uint)(bDeg + shifts + 63) >> 6);

            int bTotal = bMax * banks, stride = width * banks;

            /*
             * Create a single temporary buffer, with an offset table to find the positions of things in it 
             */
            int[] ci = new int[1 << width];
            int cTotal = aLen;
            {
                ci[0] = cTotal;
                cTotal += bTotal;
                ci[1] = cTotal;
                for (int i = 2; i < ci.Length; ++i)
                {
                    cTotal += cLen;
                    ci[i] = cTotal;
                }
                cTotal += cLen;
            }
            // NOTE: Provide a safe dump for "high zeroes" since we are adding 'bMax' and not 'bLen'
            ++cTotal;

            long[] c = new long[cTotal];

            // Prepare A in Interleaved form, according to the chosen width
            Interleave(A.m_ints, 0, c, 0, aLen, width);

            // Make a working copy of B, since we will be shifting it
            {
                int bOff = aLen;
                Array.Copy(B.m_ints, 0, c, bOff, bLen);
                for (int bank = 1; bank < banks; ++bank)
                {
                    ShiftUp(c, aLen, c, bOff += bMax, bMax, bank);
                }
            }

            /*
             * The main loop analyzes the Interleaved windows in A, and for each non-zero window
             * a single word-array XOR is performed to a carefully selected slice of 'c'. The loop is
             * breadth-first, checking the lowest window in each word, then looping again for the
             * next higher window position.
             */
            int MASK = (1 << width) - 1;

            int k = 0;
            for (;;)
            {
                int aPos = 0;
                do
                {
                    long aVal = (long)((ulong)c[aPos] >> k);
                    int bank = 0, bOff = aLen;
                    for (;;)
                    {
                        int index = (int)(aVal) & MASK;
                        if (index != 0)
                        {
                            /*
                             * Add to a 'c' buffer based on the bit-pattern of 'index'. Since A is in
                             * Interleaved form, the bits represent the current B shifted by 0, 'positions',
                             * 'positions' * 2, ..., 'positions' * ('width' - 1)
                             */
                            Add(c, aPos + ci[index], c, bOff, bMax);
                        }
                        if (++bank == banks)
                        {
                            break;
                        }
                        bOff += bMax;
                        aVal = (long)((ulong)aVal >> width);
                    }
                }
                while (++aPos < aLen);

                if ((k += stride) >= top)
                {
                    if (k >= 64)
                    {
                        break;
                    }

                    /*
                     * Adjustment for window setups with top == 63, the final bit (if any) is processed
                     * as the top-bit of a window
                     */
                    k = 64 - width;
                    MASK &= MASK << (top - k);
                }

                /*
                 * After each position has been checked for all words of A, B is shifted up 1 place
                 */
                ShiftUp(c, aLen, bTotal, banks);
            }

            int ciPos = ci.Length;
            while (--ciPos > 1)
            {
                if ((ciPos & 1L) == 0L)
                {
                    /*
                     * For even numbers, shift contents and add to the half-position
                     */
                    AddShiftedUp(c, ci[(uint)ciPos >> 1], c, ci[ciPos], cLen, positions);
                }
                else
                {
                    /*
                     * For odd numbers, 'distribute' contents to the result and the next-lowest position
                     */
                    Distribute(c, ci[ciPos], ci[ciPos - 1], ci[1], cLen);
                }
            }

            /*
             * Finally the raw answer is collected, reduce it against the reduction coefficients
             */
            return ReduceResult(c, ci[1], cLen, m, ks);
        }

        private static LongArray ReduceResult(long[] buf, int off, int len, int m, int[] ks)
        {
            int rLen = ReduceInPlace(buf, off, len, m, ks);
            return new LongArray(buf, off, rLen);
        }

    //    private static void deInterleave(long[] x, int xOff, long[] z, int zOff, int count, int rounds)
    //    {
    //        for (int i = 0; i < count; ++i)
    //        {
    //            z[zOff + i] = deInterleave(x[zOff + i], rounds);
    //        }
    //    }
    //
    //    private static long deInterleave(long x, int rounds)
    //    {
    //        while (--rounds >= 0)
    //        {
    //            x = deInterleave32(x & DEInterleave_MASK) | (deInterleave32((x >>> 1) & DEInterleave_MASK) << 32);
    //        }
    //        return x;
    //    }
    //
    //    private static long deInterleave32(long x)
    //    {
    //        x = (x | (x >>> 1)) & 0x3333333333333333L;
    //        x = (x | (x >>> 2)) & 0x0F0F0F0F0F0F0F0FL;
    //        x = (x | (x >>> 4)) & 0x00FF00FF00FF00FFL;
    //        x = (x | (x >>> 8)) & 0x0000FFFF0000FFFFL;
    //        x = (x | (x >>> 16)) & 0x00000000FFFFFFFFL;
    //        return x;
    //    }

        private static int ReduceInPlace(long[] buf, int off, int len, int m, int[] ks)
        {
            int mLen = (int)((uint)(m + 63) >> 6);
            if (len < mLen)
            {
                return len;
            }

            int numBits = System.Math.Min(len << 6, (m << 1) - 1); // TODO use actual degree?
            int excessBits = (len << 6) - numBits;
            while (excessBits >= 64)
            {
                --len;
                excessBits -= 64;
            }

            int kLen = ks.Length, kMax = ks[kLen - 1], kNext = kLen > 1 ? ks[kLen - 2] : 0;
            int wordWiseLimit = System.Math.Max(m, kMax + 64);
            int vectorableWords = (excessBits + System.Math.Min(numBits - wordWiseLimit, m - kNext)) >> 6;
            if (vectorableWords > 1)
            {
                int vectorWiseWords = len - vectorableWords;
                ReduceVectorWise(buf, off, len, vectorWiseWords, m, ks);
                while (len > vectorWiseWords)
                {
                    buf[off + --len] = 0L;
                }
                numBits = vectorWiseWords << 6;
            }

            if (numBits > wordWiseLimit)
            {
                ReduceWordWise(buf, off, len, wordWiseLimit, m, ks);
                numBits = wordWiseLimit;
            }

            if (numBits > m)
            {
                ReduceBitWise(buf, off, numBits, m, ks);
            }

            return mLen;
        }

        private static void ReduceBitWise(long[] buf, int off, int BitLength, int m, int[] ks)
        {
            while (--BitLength >= m)
            {
                if (TestBit(buf, off, BitLength))
                {
                    ReduceBit(buf, off, BitLength, m, ks);
                }
            }
        }

        private static void ReduceBit(long[] buf, int off, int bit, int m, int[] ks)
        {
            FlipBit(buf, off, bit);
            int n = bit - m;
            int j = ks.Length;
            while (--j >= 0)
            {
                FlipBit(buf, off, ks[j] + n);
            }
            FlipBit(buf, off, n);
        }

        private static void ReduceWordWise(long[] buf, int off, int len, int toBit, int m, int[] ks)
        {
            int toPos = (int)((uint)toBit >> 6);

            while (--len > toPos)
            {
                long word = buf[off + len];
                if (word != 0)
                {
                    buf[off + len] = 0;
                    ReduceWord(buf, off, (len << 6), word, m, ks);
                }
            }

            {
                int partial = toBit & 0x3F;
                long word = (long)((ulong)buf[off + toPos] >> partial);
                if (word != 0)
                {
                    buf[off + toPos] ^= word << partial;
                    ReduceWord(buf, off, toBit, word, m, ks);
                }
            }
        }

        private static void ReduceWord(long[] buf, int off, int bit, long word, int m, int[] ks)
        {
            int offset = bit - m;
            int j = ks.Length;
            while (--j >= 0)
            {
                FlipWord(buf, off, offset + ks[j], word);
            }
            FlipWord(buf, off, offset, word);
        }

        private static void ReduceVectorWise(long[] buf, int off, int len, int words, int m, int[] ks)
        {
            /*
             * NOTE: It's important we go from highest coefficient to lowest, because for the highest
             * one (only) we allow the ranges to partially overlap, and therefore any changes must take
             * effect for the subsequent lower coefficients.
             */
            int baseBit = (words << 6) - m;
            int j = ks.Length;
            while (--j >= 0)
            {
                FlipVector(buf, off, buf, off + words, len - words, baseBit + ks[j]);
            }
            FlipVector(buf, off, buf, off + words, len - words, baseBit);
        }

        private static void FlipVector(long[] x, int xOff, long[] y, int yOff, int yLen, int bits)
        {
            xOff += (int)((uint)bits >> 6);
            bits &= 0x3F;

            if (bits == 0)
            {
                Add(x, xOff, y, yOff, yLen);
            }
            else
            {
                long carry = AddShiftedDown(x, xOff + 1, y, yOff, yLen, 64 - bits);
                x[xOff] ^= carry;
            }
        }

        public LongArray ModSquare(int m, int[] ks)
        {
            int len = GetUsedLength();
            if (len == 0)
            {
                return this;
            }

            int _2len = len << 1;
            long[] r = new long[_2len];

            int pos = 0;
            while (pos < _2len)
            {
                long mi = m_ints[(uint)pos >> 1];
                r[pos++] = Interleave2_32to64((int)mi);
                r[pos++] = Interleave2_32to64((int)((ulong)mi >> 32));
            }

            return new LongArray(r, 0, ReduceInPlace(r, 0, r.Length, m, ks));
        }

    //    private LongArray modSquareN(int n, int m, int[] ks)
    //    {
    //        int len = GetUsedLength();
    //        if (len == 0)
    //        {
    //            return this;
    //        }
    //
    //        int mLen = (m + 63) >>> 6;
    //        long[] r = new long[mLen << 1];
    //        Array.Copy(m_ints, 0, r, 0, len);
    //
    //        while (--n >= 0)
    //        {
    //            squareInPlace(r, len, m, ks);
    //            len = reduceInPlace(r, 0, r.Length, m, ks);
    //        }
    //
    //        return new LongArray(r, 0, len);
    //    }
    //
    //    private static void squareInPlace(long[] x, int xLen, int m, int[] ks)
    //    {
    //        int pos = xLen << 1;
    //        while (--xLen >= 0)
    //        {
    //            long xVal = x[xLen];
    //            x[--pos] = Interleave2_32to64((int)(xVal >>> 32));
    //            x[--pos] = Interleave2_32to64((int)xVal);
    //        }
    //    }

        private static void Interleave(long[] x, int xOff, long[] z, int zOff, int count, int width)
        {
            switch (width)
            {
            case 3:
                Interleave3(x, xOff, z, zOff, count);
                break;
            case 5:
                Interleave5(x, xOff, z, zOff, count);
                break;
            case 7:
                Interleave7(x, xOff, z, zOff, count);
                break;
            default:
                Interleave2_n(x, xOff, z, zOff, count, BitLengths[width] - 1);
                break;
            }
        }

        private static void Interleave3(long[] x, int xOff, long[] z, int zOff, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                z[zOff + i] = Interleave3(x[xOff + i]);
            }
        }

        private static long Interleave3(long x)
        {
            long z = x & (1L << 63);
            return z
                | Interleave3_21to63((int)x & 0x1FFFFF)
                | Interleave3_21to63((int)((ulong)x >> 21) & 0x1FFFFF) << 1
                | Interleave3_21to63((int)((ulong)x >> 42) & 0x1FFFFF) << 2;

    //        int zPos = 0, wPos = 0, xPos = 0;
    //        for (;;)
    //        {
    //            z |= ((x >>> xPos) & 1L) << zPos;
    //            if (++zPos == 63)
    //            {
    //                String sz2 = Long.toBinaryString(z);
    //                return z;
    //            }
    //            if ((xPos += 21) >= 63)
    //            {
    //                xPos = ++wPos;
    //            }
    //        }
        }

        private static long Interleave3_21to63(int x)
        {
            int r00 = INTERLEAVE3_TABLE[x & 0x7F];
            int r21 = INTERLEAVE3_TABLE[((uint)x >> 7) & 0x7F];
            int r42 = INTERLEAVE3_TABLE[(uint)x >> 14];
            return (r42 & 0xFFFFFFFFL) << 42 | (r21 & 0xFFFFFFFFL) << 21 | (r00 & 0xFFFFFFFFL);
        }

        private static void Interleave5(long[] x, int xOff, long[] z, int zOff, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                z[zOff + i] = Interleave5(x[xOff + i]);
            }
        }

        private static long Interleave5(long x)
        {
            return Interleave3_13to65((int)x & 0x1FFF)
                | Interleave3_13to65((int)((ulong)x >> 13) & 0x1FFF) << 1
                | Interleave3_13to65((int)((ulong)x >> 26) & 0x1FFF) << 2
                | Interleave3_13to65((int)((ulong)x >> 39) & 0x1FFF) << 3
                | Interleave3_13to65((int)((ulong)x >> 52) & 0x1FFF) << 4;

    //        long z = 0;
    //        int zPos = 0, wPos = 0, xPos = 0;
    //        for (;;)
    //        {
    //            z |= ((x >>> xPos) & 1L) << zPos;
    //            if (++zPos == 64)
    //            {
    //                return z;
    //            }
    //            if ((xPos += 13) >= 64)
    //            {
    //                xPos = ++wPos;
    //            }
    //        }
        }

        private static long Interleave3_13to65(int x)
        {
            int r00 = INTERLEAVE5_TABLE[x & 0x7F];
            int r35 = INTERLEAVE5_TABLE[(uint)x >> 7];
            return (r35 & 0xFFFFFFFFL) << 35 | (r00 & 0xFFFFFFFFL);
        }

        private static void Interleave7(long[] x, int xOff, long[] z, int zOff, int count)
        {
            for (int i = 0; i < count; ++i)
            {
                z[zOff + i] = Interleave7(x[xOff + i]);
            }
        }

        private static long Interleave7(long x)
        {
            long z = x & (1L << 63);
            return z
                | INTERLEAVE7_TABLE[(int)x & 0x1FF]
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 9) & 0x1FF] << 1
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 18) & 0x1FF] << 2
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 27) & 0x1FF] << 3
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 36) & 0x1FF] << 4
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 45) & 0x1FF] << 5
                | INTERLEAVE7_TABLE[(int)((ulong)x >> 54) & 0x1FF] << 6;

    //        int zPos = 0, wPos = 0, xPos = 0;
    //        for (;;)
    //        {
    //            z |= ((x >>> xPos) & 1L) << zPos;
    //            if (++zPos == 63)
    //            {
    //                return z;
    //            }
    //            if ((xPos += 9) >= 63)
    //            {
    //                xPos = ++wPos;
    //            }
    //        }
        }

        private static void Interleave2_n(long[] x, int xOff, long[] z, int zOff, int count, int rounds)
        {
            for (int i = 0; i < count; ++i)
            {
                z[zOff + i] = Interleave2_n(x[xOff + i], rounds);
            }
        }

        private static long Interleave2_n(long x, int rounds)
        {
            while (rounds > 1)
            {
                rounds -= 2;
                x = Interleave4_16to64((int)x & 0xFFFF)
                    | Interleave4_16to64((int)((ulong)x >> 16) & 0xFFFF) << 1
                    | Interleave4_16to64((int)((ulong)x >> 32) & 0xFFFF) << 2
                    | Interleave4_16to64((int)((ulong)x >> 48) & 0xFFFF) << 3;
            }
            if (rounds > 0)
            {
                x = Interleave2_32to64((int)x) | Interleave2_32to64((int)((ulong)x >> 32)) << 1;
            }
            return x;
        }

        private static long Interleave4_16to64(int x)
        {
            int r00 = INTERLEAVE4_TABLE[x & 0xFF];
            int r32 = INTERLEAVE4_TABLE[(uint)x >> 8];
            return (r32 & 0xFFFFFFFFL) << 32 | (r00 & 0xFFFFFFFFL);
        }

        private static long Interleave2_32to64(int x)
        {
            int r00 = INTERLEAVE2_TABLE[x & 0xFF] | INTERLEAVE2_TABLE[((uint)x >> 8) & 0xFF] << 16;
            int r32 = INTERLEAVE2_TABLE[((uint)x >> 16) & 0xFF] | INTERLEAVE2_TABLE[(uint)x >> 24] << 16;
            return (r32 & 0xFFFFFFFFL) << 32 | (r00 & 0xFFFFFFFFL);
        }

    //    private static LongArray ExpItohTsujii2(LongArray B, int n, int m, int[] ks)
    //    {
    //        LongArray t1 = B, t3 = new LongArray(new long[]{ 1L });
    //        int scale = 1;
    //
    //        int numTerms = n;
    //        while (numTerms > 1)
    //        {
    //            if ((numTerms & 1) != 0)
    //            {
    //                t3 = t3.ModMultiply(t1, m, ks);
    //                t1 = t1.modSquareN(scale, m, ks);
    //            }
    //
    //            LongArray t2 = t1.modSquareN(scale, m, ks);
    //            t1 = t1.ModMultiply(t2, m, ks);
    //            numTerms >>>= 1; scale <<= 1;
    //        }
    //
    //        return t3.ModMultiply(t1, m, ks);
    //    }
    //
    //    private static LongArray ExpItohTsujii23(LongArray B, int n, int m, int[] ks)
    //    {
    //        LongArray t1 = B, t3 = new LongArray(new long[]{ 1L });
    //        int scale = 1;
    //
    //        int numTerms = n;
    //        while (numTerms > 1)
    //        {
    //            bool m03 = numTerms % 3 == 0;
    //            bool m14 = !m03 && (numTerms & 1) != 0;
    //
    //            if (m14)
    //            {
    //                t3 = t3.ModMultiply(t1, m, ks);
    //                t1 = t1.modSquareN(scale, m, ks);
    //            }
    //
    //            LongArray t2 = t1.modSquareN(scale, m, ks);
    //            t1 = t1.ModMultiply(t2, m, ks);
    //
    //            if (m03)
    //            {
    //                t2 = t2.modSquareN(scale, m, ks);
    //                t1 = t1.ModMultiply(t2, m, ks);
    //                numTerms /= 3; scale *= 3;
    //            }
    //            else
    //            {
    //                numTerms >>>= 1; scale <<= 1;
    //            }
    //        }
    //
    //        return t3.ModMultiply(t1, m, ks);
    //    }
    //
    //    private static LongArray ExpItohTsujii235(LongArray B, int n, int m, int[] ks)
    //    {
    //        LongArray t1 = B, t4 = new LongArray(new long[]{ 1L });
    //        int scale = 1;
    //
    //        int numTerms = n;
    //        while (numTerms > 1)
    //        {
    //            if (numTerms % 5 == 0)
    //            {
    ////                t1 = ExpItohTsujii23(t1, 5, m, ks);
    //
    //                LongArray t3 = t1;
    //                t1 = t1.modSquareN(scale, m, ks);
    //
    //                LongArray t2 = t1.modSquareN(scale, m, ks);
    //                t1 = t1.ModMultiply(t2, m, ks);
    //                t2 = t1.modSquareN(scale << 1, m, ks);
    //                t1 = t1.ModMultiply(t2, m, ks);
    //
    //                t1 = t1.ModMultiply(t3, m, ks);
    //
    //                numTerms /= 5; scale *= 5;
    //                continue;
    //            }
    //
    //            bool m03 = numTerms % 3 == 0;
    //            bool m14 = !m03 && (numTerms & 1) != 0;
    //
    //            if (m14)
    //            {
    //                t4 = t4.ModMultiply(t1, m, ks);
    //                t1 = t1.modSquareN(scale, m, ks);
    //            }
    //
    //            LongArray t2 = t1.modSquareN(scale, m, ks);
    //            t1 = t1.ModMultiply(t2, m, ks);
    //
    //            if (m03)
    //            {
    //                t2 = t2.modSquareN(scale, m, ks);
    //                t1 = t1.ModMultiply(t2, m, ks);
    //                numTerms /= 3; scale *= 3;
    //            }
    //            else
    //            {
    //                numTerms >>>= 1; scale <<= 1;
    //            }
    //        }
    //
    //        return t4.ModMultiply(t1, m, ks);
    //    }

        public LongArray ModInverse(int m, int[] ks)
        {
            /*
             * Fermat's Little Theorem
             */
    //        LongArray A = this;
    //        LongArray B = A.modSquare(m, ks);
    //        LongArray R0 = B, R1 = B;
    //        for (int i = 2; i < m; ++i)
    //        {
    //            R1 = R1.modSquare(m, ks);
    //            R0 = R0.ModMultiply(R1, m, ks);
    //        }
    //
    //        return R0;

            /*
             * Itoh-Tsujii
             */
    //        LongArray B = modSquare(m, ks);
    //        switch (m)
    //        {
    //        case 409:
    //            return ExpItohTsujii23(B, m - 1, m, ks);
    //        case 571:
    //            return ExpItohTsujii235(B, m - 1, m, ks);
    //        case 163:
    //        case 233:
    //        case 283:
    //        default:
    //            return ExpItohTsujii2(B, m - 1, m, ks);
    //        }

            /*
             * Inversion in F2m using the extended Euclidean algorithm
             * 
             * Input: A nonzero polynomial a(z) of degree at most m-1
             * Output: a(z)^(-1) mod f(z)
             */
            int uzDegree = Degree();
            if (uzDegree == 0)
            {
                throw new InvalidOperationException();
            }
            if (uzDegree == 1)
            {
                return this;
            }

            // u(z) := a(z)
            LongArray uz = (LongArray)Copy();

            int t = (int)((uint)(m + 63) >> 6);

            // v(z) := f(z)
            LongArray vz = new LongArray(t);
            ReduceBit(vz.m_ints, 0, m, m, ks);

            // g1(z) := 1, g2(z) := 0
            LongArray g1z = new LongArray(t);
            g1z.m_ints[0] = 1L;
            LongArray g2z = new LongArray(t);

            int[] uvDeg = new int[]{ uzDegree, m + 1 };
            LongArray[] uv = new LongArray[]{ uz, vz };

            int[] ggDeg = new int[]{ 1, 0 };
            LongArray[] gg = new LongArray[]{ g1z, g2z };

            int b = 1;
            int duv1 = uvDeg[b];
            int dgg1 = ggDeg[b];
            int j = duv1 - uvDeg[1 - b];

            for (;;)
            {
                if (j < 0)
                {
                    j = -j;
                    uvDeg[b] = duv1;
                    ggDeg[b] = dgg1;
                    b = 1 - b;
                    duv1 = uvDeg[b];
                    dgg1 = ggDeg[b];
                }

                uv[b].AddShiftedByBitsSafe(uv[1 - b], uvDeg[1 - b], j);

                int duv2 = uv[b].DegreeFrom(duv1);
                if (duv2 == 0)
                {
                    return gg[1 - b];
                }

                {
                    int dgg2 = ggDeg[1 - b];
                    gg[b].AddShiftedByBitsSafe(gg[1 - b], dgg2, j);
                    dgg2 += j;

                    if (dgg2 > dgg1)
                    {
                        dgg1 = dgg2;
                    }
                    else if (dgg2 == dgg1)
                    {
                        dgg1 = gg[b].DegreeFrom(dgg1);
                    }
                }

                j += (duv2 - duv1);
                duv1 = duv2;
            }
        }

        public override bool Equals(object obj)
        {
            return Equals(obj as LongArray);
        }

        public virtual bool Equals(LongArray other)
        {
            if (this == other)
                return true;
            if (null == other)
                return false;
            int usedLen = GetUsedLength();
            if (other.GetUsedLength() != usedLen)
            {
                return false;
            }
            for (int i = 0; i < usedLen; i++)
            {
                if (m_ints[i] != other.m_ints[i])
                {
                    return false;
                }
            }
            return true;
        }

        public override int GetHashCode()
        {
            int usedLen = GetUsedLength();
            int hash = 1;
            for (int i = 0; i < usedLen; i++)
            {
                long mi = m_ints[i];
                hash *= 31;
                hash ^= (int)mi;
                hash *= 31;
                hash ^= (int)((ulong)mi >> 32);
            }
            return hash;
        }

        public LongArray Copy()
        {
            return new LongArray(Arrays.Clone(m_ints));
        }

        public override string ToString()
        {
            int i = GetUsedLength();
            if (i == 0)
            {
                return "0";
            }

            StringBuilder sb = new StringBuilder(Convert.ToString(m_ints[--i], 2));
            while (--i >= 0)
            {
                string s = Convert.ToString(m_ints[i], 2);

                // Add leading zeroes, except for highest significant word
                int len = s.Length;
                if (len < 64)
                {
                    sb.Append(ZEROES.Substring(len));
                }

                sb.Append(s);
            }
            return sb.ToString();
        }
    }
}