System.Numerics.BigIntegerBuilder.Trim C# (CSharp) Method

        private void Trim() {
            if ((this._iuLast > 0) && (this._rgu[this._iuLast] == 0)) {
                this._uSmall = this._rgu[0];
                while ((--this._iuLast > 0) && (this._rgu[this._iuLast] == 0)) {
                }
            }
        }

 private static void ModDivCore(ref BigIntegerBuilder regNum, ref BigIntegerBuilder regDen, bool fQuo, ref BigIntegerBuilder regQuo)
 {
     regQuo.Set((uint)0);
     if (regNum._iuLast >= regDen._iuLast)
     {
         int num   = regDen._iuLast + 1;
         int num2  = regNum._iuLast - regDen._iuLast;
         int cu    = num2;
         int index = regNum._iuLast;
         while (true)
         {
             if (index < num2)
             {
                 cu++;
                 break;
             }
             if (regDen._rgu[index - num2] != regNum._rgu[index])
             {
                 if (regDen._rgu[index - num2] < regNum._rgu[index])
                 {
                     cu++;
                 }
                 break;
             }
             index--;
         }
         if (cu != 0)
         {
             if (fQuo)
             {
                 regQuo.SetSizeLazy(cu);
             }
             uint u    = regDen._rgu[num - 1];
             uint num6 = regDen._rgu[num - 2];
             int  num7 = NumericsHelpers.CbitHighZero(u);
             int  num8 = 0x20 - num7;
             if (num7 > 0)
             {
                 u    = (u << num7) | (num6 >> num8);
                 num6 = num6 << num7;
                 if (num > 2)
                 {
                     num6 |= regDen._rgu[num - 3] >> num8;
                 }
             }
             regNum.EnsureWritable();
             int num9 = cu;
             while (--num9 >= 0)
             {
                 uint  uHi   = ((num9 + num) <= regNum._iuLast) ? regNum._rgu[num9 + num] : 0;
                 ulong num11 = NumericsHelpers.MakeUlong(uHi, regNum._rgu[(num9 + num) - 1]);
                 uint  uLo   = regNum._rgu[(num9 + num) - 2];
                 if (num7 > 0)
                 {
                     num11 = (num11 << num7) | (uLo >> num8);
                     uLo   = uLo << num7;
                     if ((num9 + num) >= 3)
                     {
                         uLo |= regNum._rgu[(num9 + num) - 3] >> num8;
                     }
                 }
                 ulong num13 = num11 / ((ulong)u);
                 ulong num14 = (uint)(num11 % ((ulong)u));
                 if (num13 > 0xffffffffL)
                 {
                     num14 += (ulong)u * (num13 - 0xffffffffL);
                     num13  = 0xffffffffL;
                 }
                 while ((num14 <= 0xffffffffL) && ((num13 * num6) > NumericsHelpers.MakeUlong((uint)num14, uLo)))
                 {
                     num13 -= (ulong)1L;
                     num14 += (ulong)u;
                 }
                 if (num13 > 0L)
                 {
                     ulong num15 = 0L;
                     for (int i = 0; i < num; i++)
                     {
                         num15 += regDen._rgu[i] * num13;
                         uint num17 = (uint)num15;
                         num15 = num15 >> 0x20;
                         if (regNum._rgu[num9 + i] < num17)
                         {
                             num15 += (ulong)1L;
                         }
                         regNum._rgu[num9 + i] -= num17;
                     }
                     if (uHi < num15)
                     {
                         uint uCarry = 0;
                         for (int j = 0; j < num; j++)
                         {
                             uCarry = AddCarry(ref regNum._rgu[num9 + j], regDen._rgu[j], uCarry);
                         }
                         num13 -= (ulong)1L;
                     }
                     regNum._iuLast = (num9 + num) - 1;
                 }
                 if (fQuo)
                 {
                     if (cu == 1)
                     {
                         regQuo._uSmall = (uint)num13;
                     }
                     else
                     {
                         regQuo._rgu[num9] = (uint)num13;
                     }
                 }
             }
             regNum._iuLast = num - 1;
             regNum.Trim();
         }
     }
 }