private void MultByULong(uint uiMultiplier)
{
int iDataMax = _bLen; // How many UI4s currently in *this
ulong dwlAccum = 0; // accumulated sum
ulong dwlNextAccum = 0; // accumulation past dwlAccum
int iData; // which UI4 in *This we are on.
uint[] rguiData = new uint[4] { _data1, _data2, _data3, _data4 };
for (iData = 0; iData < iDataMax; iData++)
{
Debug.Assert(dwlAccum < s_ulInt32Base);
ulong ulTemp = rguiData[iData];
dwlNextAccum = ulTemp * uiMultiplier;
dwlAccum += dwlNextAccum;
if (dwlAccum < dwlNextAccum) // Overflow of int64 add
dwlNextAccum = s_ulInt32Base; // how much to add to dwlAccum after div x_dwlBaseUI4
else
dwlNextAccum = 0;
rguiData[iData] = (uint)dwlAccum; // equivalent to mod x_dwlBaseUI4
dwlAccum = (dwlAccum >> 32) + dwlNextAccum; // equivalent to div x_dwlBaseUI4
}
// If any carry,
if (dwlAccum != 0)
{
// Either overflowed
Debug.Assert(dwlAccum < s_ulInt32Base, "dwlAccum < x_dwlBaseUI4", "Integer overflow");
if (iDataMax == s_cNumeMax)
throw new OverflowException(SQLResource.s_arithOverflowMessage);
// Or extend length by one uint
rguiData[iDataMax] = (uint)dwlAccum;
_bLen++;
}
if (FGt10_38(rguiData))
throw new OverflowException(SQLResource.s_arithOverflowMessage);
StoreFromWorkingArray(rguiData);
}