// Truncate - Truncate the numeric to a specific digit
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal Truncate(SqlDecimal n, int position)
{
n.AssertValid();
return Round(n, position, true);
}
// Power - Compute the power of a numeric
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal Power(SqlDecimal n, double exp)
{
n.AssertValid();
if (n.IsNull)
return SqlDecimal.Null;
byte prec = n.Precision;
int scale = n.Scale;
double dBaseNum = n.ToDouble();
n = new SqlDecimal(Math.Pow(dBaseNum, exp));
n.AdjustScale(scale - (int)n.Scale, true);
n.m_bPrec = MaxPrecision;
return n;
}
private static SqlDecimal Round(SqlDecimal n, int lPosition, bool fTruncate)
{
if (n.IsNull)
return SqlDecimal.Null;
if (lPosition >= 0)
{
//If round to the right of decimal number
lPosition = Math.Min(s_NUMERIC_MAX_PRECISION, lPosition);
if (lPosition >= n.m_bScale)
return n; //No need to round
}
else
{
//If round to the left of the decimal point
lPosition = Math.Max(-s_NUMERIC_MAX_PRECISION, lPosition);
//Return +0.00 if truncation of integer part
if (lPosition < n.m_bScale - n.m_bPrec)
{
n.SetToZero();
return n;
}
}
uint ulRem = 0; // Remainder: the highest significant digit to be truncated
int lAdjust = Math.Abs(lPosition - (int)n.m_bScale); // Precision adjustment
uint ulLastDivBase = 1; //
//Compute the integral part of the numeric
while (lAdjust > 0)
{
if (lAdjust >= 9)
{
ulRem = n.DivByULong(s_rgulShiftBase[8]);
ulLastDivBase = s_rgulShiftBase[8];
lAdjust -= 9;
}
else
{
ulRem = n.DivByULong(s_rgulShiftBase[lAdjust - 1]);
ulLastDivBase = s_rgulShiftBase[lAdjust - 1];
lAdjust = 0;
}
}
// The rounding only depends on the first digit after the rounding position
if (ulLastDivBase > 1)
{
ulRem /= (ulLastDivBase / 10);
}
//If result is zero, return
if (n.FZero() && (fTruncate || ulRem < 5))
{
n.SetPositive();
n.AssertValid();
return n;
}
// Adjust by adding 1 if remainder is larger than 5
if (ulRem >= 5 && !fTruncate)
n.AddULong(1);
// Convert back to original scale
lAdjust = Math.Abs(lPosition - n.m_bScale);
while (lAdjust-- > 0)
{
n.MultByULong(s_ulBase10);
}
n.AssertValid();
return n;
}
// Round - Round the numeric to a specific digit
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal Round(SqlDecimal n, int position)
{
n.AssertValid();
return Round(n, position, false);
}
// Floor - next largest integer smaller or equal to the numeric
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal Floor(SqlDecimal n)
{
n.AssertValid();
if (n.IsNull)
return SqlDecimal.Null;
if (n.m_bScale == 0)
return n;
bool fFraction; //Fractional flag
n.MakeInteger(out fFraction);
//When the numeric has fraction and is negative, subtract 1 by calling AddULong(1)
//Otherwise return the integral part.
if (fFraction && !n.IsPositive)
{
n.AddULong(1);
}
if (n.FZero())//if result is zero, sign should be positive
n.SetPositive();
n.AssertValid();
return n;
}
// Sign - 1 if positive, -1 if negative
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlInt32 Sign(SqlDecimal n)
{
n.AssertValid();
if (n.IsNull)
return SqlInt32.Null;
if (n == new SqlDecimal(0))
return SqlInt32.Zero;
else
return n.IsNull ? SqlInt32.Null :
(n.IsPositive ? new SqlInt32(1) : new SqlInt32(-1));
}
// CmpCompareNm()
//
// Compare the value of two numerics
//
// Complexity: O(pn) p: precision n: length
//
// Parameters:
// this - IN Operand1
// snumOp - IN operand2
//
// Returns:
// EComparison.LT - this < snumOp
// EComparison.EQ - this = snumOp
// EComparison.GT - this > snumOp
//
private EComparison CompareNm
(
SqlDecimal snumOp
)
{
AssertValid();
snumOp.AssertValid();
//Signs of the two numeric operands
int Sign1;
int Sign2;
int iFinalResult; //Final result of comparison: positive = greater
//than, 0 = equal, negative = less than
//Initialize the sign values to be 1(positive) or -1(negative)
Sign1 = IsPositive ? 1 : -1;
Sign2 = snumOp.IsPositive ? 1 : -1;
if (Sign1 != Sign2) //If different sign, the positive one is greater
return Sign1 == 1 ? EComparison.GT : EComparison.LT;
else
{ //same sign, have to compare absolute values
//Temporary memory to hold the operand since it is const
//but its scale may get adjusted during comparison
int ScaleDiff;
SqlDecimal snumArg1 = this;
SqlDecimal snumArg2 = snumOp;
//First make the two operands the same scale if necessary
ScaleDiff = ((int)m_bScale) - ((int)snumOp.m_bScale);
if (ScaleDiff < 0)
{
//If increasing the scale of operand1 caused an overflow,
//then its absolute value is greater than that of operand2.
try
{
snumArg1.AdjustScale(-ScaleDiff, true);
}
catch (OverflowException)
{
return (Sign1 > 0) ? EComparison.GT : EComparison.LT;
}
}
else if (ScaleDiff > 0)
{
//If increasing the scale of operand2 caused an overflow, then
//operand1's absolute value is less than that of operand2.
try
{
snumArg2.AdjustScale(ScaleDiff, true);
}
catch (OverflowException)
{
return (Sign1 > 0) ? EComparison.LT : EComparison.GT;
}
}
//Compare the absolute value of the two numerics
//Note: We are sure that scale of arguments is the same,
// so LAbsCmp() will not modify its argument.
int lResult = snumArg1.LAbsCmp(snumArg2);
if (0 == lResult)
return EComparison.EQ;
//if both positive, result same as result from LAbsCmp;
//if both negative, result reverse of result from LAbsCmp
iFinalResult = Sign1 * lResult;
if (iFinalResult < 0)
return EComparison.LT;
else
return EComparison.GT;
}
}
// Builtin functions
// Abs - absolute value
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal Abs(SqlDecimal n)
{
n.AssertValid();
if (n.IsNull)
return SqlDecimal.Null;
n.SetPositive();
n.AssertValid();
return n;
}
// Convert to a specific precision and scale
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal ConvertToPrecScale(SqlDecimal n, int precision, int scale)
{
CheckValidPrecScale(precision, scale);
n.AssertValid();
if (n.IsNull)
return SqlDecimal.Null;
SqlDecimal ret = n;
int lPrecAdjust = precision - (int)ret.m_bPrec;//Adjustment to precision
int lScaleAdjust = scale - (int)ret.m_bScale;//Adjustment to scale
//Adjust scale
ret.AdjustScale(lScaleAdjust, true);
// devnote: is that still true?
//Shouldn't truncate the integer digits; BActualPrec() is an expensive
//function call, so test the data length first to eliminate majority
//of cases
//The number of bytes storage required by the new precision
byte cbWithNewPrec = CLenFromPrec((byte)precision);
if (cbWithNewPrec < ret.m_bLen)
{
//if current actual length greater than length corresponding to bNewPrec
//there must be truncating
throw new SqlTruncateException();
}
else if (cbWithNewPrec == ret.m_bLen)
{
//if the two lengths equal, need to check the actual precision
if (precision < ret.CalculatePrecision())
throw new SqlTruncateException();
}
//Adjust precision
ret.m_bPrec = (byte)precision;
ret.AssertValid();
return ret;
}
//-----------------------------------------------------------
//DivNm():
// Divide numeric by numeric.
// The Quotient will be returned in *this
//
//Result scale & precision:
// NOTE: same as in Hydra but different from SQL Server Manual,
// where scale = max(s1+p2-s2+1,x_cNumeDivScaleMin)):
// scale = max(s1 + p2 + 1, x_cNumeDivScaleMin);
// precision = max(s1 + p2 + 1, x_cNumeDivScaleMin) + p1 + p2 + 1;
//
//Overflow Rules:
// If scale is greater than NUMERIC_MAX_PRECISION it is set to
// NUMERIC_MAX_PRECISION. If precision is greater than NUMERIC_MAX_PRECISION
// it's set to NUMERIC_MAX_PRECISION, then scale is reduced to keep the
// integer part untruncated but keeping a minimum value of x_cNumeDivScaleMin.
// For example, if using the above formula, the resulting precision is 46 and
// scale is 10, the precision will be reduced to 38, to keep the integral part
// untruncated the scale needs be reduced to 2, but since x_cNumeDivScaleMin
// is set to 6 currently, resulting scale will be 6.
// OverflowException is thrown only if the actual precision is greater than
// NUMERIC_MAX_PRECISION or actual length is greater than x_cbNumeBuf
//
//Algorithm
// Call general purpose arbitrary precision division routine with scale = 0.
// Scale,prec adjusted later.
//
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal operator /(SqlDecimal x, SqlDecimal y)
{
if (x.IsNull || y.IsNull)
return Null;
x.AssertValid();
y.AssertValid();
// Variables for figuring prec,scale
int bScaleD; // Input Scale of dividend (output scale of remainder)
int bPrecD; // Input Prec of dividend (output prec of remainder)
int ResScale; // Final scale we will force quotient to
int ResPrec; // Final precision we will force quotient to
int ResInteger; // # of digits in integer part of result (prec-scale)
int MinScale; // Temp to help compute ResScale
int lScaleAdjust; // How much result scale will be adjusted
bool fResSignPos; // sign of result
// Steps:
// 1) Figure result prec,scale; adjust scale of dividend
// 2) Compute result remainder/quotient in 0 scale numbers
// 3) Set result prec,scale and adjust as necessary
// 0) Check for Div by 0
if (y.FZero())
throw new DivideByZeroException(SQLResource.DivideByZeroMessage);
// 1) Figure out result prec,scale,sign..
fResSignPos = (x.IsPositive == y.IsPositive);//sign of result
//scale = max(s1 + p2 + 1, x_cNumeDivScaleMin);
//precision = max(s1 + p2 + 1, x_cNumeDivScaleMin) + p1 + p2 + 1;
//For backward compatibility, use exactly the same scheme as in Hydra
bScaleD = x.m_bScale;
bPrecD = x.m_bPrec;
ResScale = Math.Max(x.m_bScale + y.m_bPrec + 1, s_cNumeDivScaleMin);
ResInteger = x.m_bPrec - x.m_bScale + y.m_bScale;
MinScale = Math.Min(ResScale, s_cNumeDivScaleMin);
ResInteger = Math.Min(ResInteger, s_NUMERIC_MAX_PRECISION);
ResPrec = ResInteger + ResScale;
if (ResPrec > s_NUMERIC_MAX_PRECISION)
ResPrec = s_NUMERIC_MAX_PRECISION;
// If overflow, reduce the scale to avoid truncation of data
ResScale = Math.Min((ResPrec - ResInteger), ResScale);
ResScale = Math.Max(ResScale, MinScale);
//Adjust the scale of the dividend
lScaleAdjust = ResScale - (int)x.m_bScale + (int)y.m_bScale;
x.AdjustScale(lScaleAdjust, true);
// Step2: Actual Computation
uint[] rgulData1 = new uint[4] { x.m_data1, x.m_data2, x.m_data3, x.m_data4 };
uint[] rgulData2 = new uint[4] { y.m_data1, y.m_data2, y.m_data3, y.m_data4 };
// Buffers for arbitrary precision divide
uint[] rgulR = new uint[s_cNumeMax + 1];
uint[] rgulQ = new uint[s_cNumeMax];
// # of ULONGs in result
int culQ, culR;
// Divide mantissas. V is not zero - already checked.
// Cannot overflow, as Q <= U, R <= V. (and both are positive)
MpDiv(rgulData1, x.m_bLen, rgulData2, y.m_bLen, rgulQ, out culQ, rgulR, out culR);
// Construct the result from Q
ZeroToMaxLen(rgulQ, culQ);
SqlDecimal ret = new SqlDecimal(rgulQ, (byte)culQ, (byte)ResPrec, (byte)ResScale, fResSignPos);
if (ret.FZero())
ret.SetPositive();
ret.AssertValid();
return ret;
}
// MultNm()
//
// Multiply two numerics.
//
// Parameters:
// x - IN Multiplier
// y - IN Multiplicand
//
// Result scale and precision(same as in SQL Server Manual and Hydra):
// scale = s1 + s2
// precision = s1 + s2 + (p1 - s1) + (p2 - s2) + 1
//
// Overflow Rules:
// If scale is greater than NUMERIC_MAX_PRECISION it is set to
// NUMERIC_MAX_PRECISION. If precision is greater than NUMERIC_MAX_PRECISION
// it is set to NUMERIC_MAX_PRECISION, then scale is reduced to keep the
// integer part untruncated but keeping a minimum value of x_cNumeDivScaleMin.
// For example, if using the above formula, the resulting precision is 46 and
// scale is 10, the precision will be reduced to 38. To keep the integral part
// untruncated the scale needs be reduced to 2, but since x_cNumeDivScaleMin
// is set to 6 currently, resulting scale will be 6.
// O_OVERFLOW is returned only if the actual precision is greater than
// NUMERIC_MAX_PRECISION or the actual length is greater than x_cbNumeBuf.
//
// Algorithm:
// Starting from the lowest significant UI4, for each UI4 of the multiplier
// iterate through the UI4s of the multiplicand starting from
// the least significant UI4s, multiply the multiplier UI4 with
// multiplicand UI4, update the result buffer with the product modulo
// x_dwlBaseUI4 at the same index as the multiplicand, and carry the quotient to
// add to the next multiplicand UI4. Until the end of the multiplier data
// array is reached.
//
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal operator *(SqlDecimal x, SqlDecimal y)
{
x.AssertValid();
y.AssertValid();
if (x.IsNull || y.IsNull)
return Null;
//Implementation:
// I) Figure result scale,prec
// II) Perform mult.
// III) Adjust product to result scale,prec
// Local variables for actual multiplication
int iulPlier; //index of UI4 in the Multiplier
uint ulPlier; //current multiplier UI4
ulong dwlAccum; //accumulated sum
ulong dwlNextAccum; //overflow of accumulated sum
int culCand = y.m_bLen; //length of multiplicand in UI4s
//Local variables to track scale,precision
int ActualScale; // Scale after mult done
int ResScale; // Final scale we will force result to
int ResPrec; // Final precision we will force result to
int ResInteger; // # of digits in integer part of result (prec-scale)
int lScaleAdjust; //How much result scale will be adjusted
bool fResPositive; // Result sign
SqlDecimal ret;
//I) Figure result prec,scale
ActualScale = x.m_bScale + y.m_bScale;
ResScale = ActualScale;
ResInteger = (x.m_bPrec - x.m_bScale) + (y.m_bPrec - y.m_bScale) + 1;
//result precision = s1 + s2 + (p1 - s1) + (p2 - s2) + 1
ResPrec = ResScale + ResInteger;
// Downward adjust res prec,scale if either larger than NUMERIC_MAX_PRECISION
if (ResPrec > s_NUMERIC_MAX_PRECISION)
ResPrec = s_NUMERIC_MAX_PRECISION;
if (ResScale > s_NUMERIC_MAX_PRECISION)
ResScale = s_NUMERIC_MAX_PRECISION;
//
// It is possible when two large numbers are being multiplied the scale
// can be reduced to 0 to keep data untruncated; the fix here is to
// preserve a minimum scale of 6.
//
// If overflow, reduce the scale to avoid truncation of data
ResScale = Math.Min((ResPrec - ResInteger), ResScale);
// But keep a minimum scale of NUMERIC_MIN_DVSCALE
ResScale = Math.Max(ResScale, Math.Min(ActualScale, s_cNumeDivScaleMin));
lScaleAdjust = ResScale - ActualScale;
fResPositive = (x.IsPositive == y.IsPositive);//positive if both signs same.
// II) Perform multiplication
uint[] rglData1 = new uint[4] { x.m_data1, x.m_data2, x.m_data3, x.m_data4 };
uint[] rglData2 = new uint[4] { y.m_data1, y.m_data2, y.m_data3, y.m_data4 };
//Local buffer to hold the result of multiplication.
//Longer than CReNumeBuf because full precision of multiplication is carried out
const int x_culNumeMultRes = 9; // Maximum # UI4s in result buffer in multiplication
uint[] rgulRes = new uint[x_culNumeMultRes]; //new [] are already initialized to zero
int culRes; // # of UI4s in result
int idRes = 0;
//Iterate over the bytes of multiplier
for (iulPlier = 0; iulPlier < x.m_bLen; iulPlier++)
{
ulPlier = rglData1[iulPlier];
dwlAccum = 0;
//Multiply each UI4 of multiCand by ulPliear and accumulate into result buffer
// Start on correct place in result
idRes = iulPlier;
for (int iulCand = 0; iulCand < culCand; iulCand++)
{
// dwlAccum = dwlAccum + rgulRes[idRes] + ulPlier*rglData2[iulCand]
// use dwlNextAccum to detect overflow of DWORDLONG
dwlNextAccum = dwlAccum + rgulRes[idRes];
ulong ulTemp = (ulong)rglData2[iulCand];
dwlAccum = (ulong)ulPlier * ulTemp;
dwlAccum += dwlNextAccum;
if (dwlAccum < dwlNextAccum) // indicates dwl addition overflowed
dwlNextAccum = s_ulInt32Base; // = maxUI64/x_dwlBaseUI4
else
dwlNextAccum = 0;
// Update result and accum
rgulRes[idRes++] = (uint)(dwlAccum);// & x_ulInt32BaseForMod); // equiv to mod x_lInt32Base
dwlAccum = (dwlAccum >> 32) + dwlNextAccum; // equiv to div BaseUI4 + dwlNAccum
// dwlNextAccum can't overflow next iteration
Debug.Assert(dwlAccum < s_ulInt32Base * 2);
}
Debug.Assert(dwlAccum < s_ulInt32Base); // can never final accum > 1 more UI4
if (dwlAccum != 0)
rgulRes[idRes++] = (uint)dwlAccum;
}
// Skip leading 0s (may exist if we are multiplying by 0)
for (; (rgulRes[idRes] == 0) && (idRes > 0); idRes--)
;
// Calculate actual result length
culRes = idRes + 1;
// III) Adjust precision,scale to result prec,scale
if (lScaleAdjust != 0)
{
// If need to decrease scale
if (lScaleAdjust < 0)
{
Debug.Assert(s_NUMERIC_MAX_PRECISION == ResPrec);
// have to adjust - might yet end up fitting.
// Cannot call AdjustScale - number cannot fit in a numeric, so
// have to duplicate code here
uint ulRem; //Remainder when downshifting
uint ulShiftBase; //What to multiply by to effect scale adjust
do
{
if (lScaleAdjust <= -9)
{
ulShiftBase = s_rgulShiftBase[8];
lScaleAdjust += 9;
}
else
{
ulShiftBase = s_rgulShiftBase[-lScaleAdjust - 1];
lScaleAdjust = 0;
}
MpDiv1(rgulRes, ref culRes, ulShiftBase, out ulRem);
}
while (lScaleAdjust != 0);
// Still do not fit?
if (culRes > s_cNumeMax)
throw new OverflowException(SQLResource.ArithOverflowMessage);
for (idRes = culRes; idRes < s_cNumeMax; idRes++)
rgulRes[idRes] = 0;
ret = new SqlDecimal(rgulRes, (byte)culRes, (byte)ResPrec, (byte)ResScale, fResPositive);
// Is it greater than 10**38?
if (ret.FGt10_38())
throw new OverflowException(SQLResource.ArithOverflowMessage);
ret.AssertValid();
// If remainder is 5 or above, increment/decrement by 1.
if (ulRem >= ulShiftBase / 2)
ret.AddULong(1);
// After adjusting, if the result is 0 and remainder is less than 5,
// set the sign to be positive
if (ret.FZero())
ret.SetPositive();
return ret;
}
// Otherwise call AdjustScale
if (culRes > s_cNumeMax) // Do not fit now, so will not fit after adjustment
throw new OverflowException(SQLResource.ArithOverflowMessage);
// NOTE: Have not check for value in the range (10**38..2**128),
// as we'll call AdjustScale with positive argument, and it'll
// return "normal" overflow
for (idRes = culRes; idRes < s_cNumeMax; idRes++)
rgulRes[idRes] = 0;
ret = new SqlDecimal(rgulRes, (byte)culRes, (byte)ResPrec, (byte)ActualScale, fResPositive);
if (ret.FZero())
ret.SetPositive();
ret.AssertValid();
ret.AdjustScale(lScaleAdjust, true);
return ret;
}
else
{
if (culRes > s_cNumeMax)
throw new OverflowException(SQLResource.ArithOverflowMessage);
for (idRes = culRes; idRes < s_cNumeMax; idRes++)
rgulRes[idRes] = 0;
ret = new SqlDecimal(rgulRes, (byte)culRes, (byte)ResPrec, (byte)ResScale, fResPositive);
// Is it greater than 10**38?
if (ret.FGt10_38())
throw new OverflowException(SQLResource.ArithOverflowMessage);
if (ret.FZero())
ret.SetPositive();
ret.AssertValid();
return ret;
}
}
// Binary operators
// Arithmetic operators
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public static SqlDecimal operator +(SqlDecimal x, SqlDecimal y)
{
if (x.IsNull || y.IsNull)
return Null;
ulong dwlAccum; //accumulated sum
bool fMySignPos; //sign of x was positive at start
bool fOpSignPos; // sign of y positive at start
bool fResSignPos = true; //sign of result should be positive
int MyScale; //scale of x
int OpScale; //scale of y
int ResScale; //scale of result
int ResPrec; //precision of result
int ResInteger; //number of digits for the integer part of result
int culOp1; //# of UI4s in x
int culOp2; //# of UI4s in y
int iulData; //which UI4 we are operating on in x, y
byte bLen; // length for the result
x.AssertValid();
y.AssertValid();
fMySignPos = x.IsPositive;
fOpSignPos = y.IsPositive;
//result scale = max(s1,s2)
//result precision = max(s1,s2) + max(p1-s1,p2-s2)
MyScale = x.m_bScale;
OpScale = y.m_bScale;
// Calculate the integer part of the result.
ResInteger = Math.Max((int)x.m_bPrec - MyScale, (int)y.m_bPrec - OpScale);
Debug.Assert(ResInteger <= MaxPrecision);
// Calculate the scale of the result.
ResScale = Math.Max(MyScale, OpScale);
Debug.Assert(ResScale <= MaxScale);
// Calculate the precision of the result.
// Add 1 for final carry.
ResPrec = ResInteger + ResScale + 1;
ResPrec = Math.Min(MaxPrecision, ResPrec);
// If precision adjusted, scale is reduced to keep the integer part untruncated.
// But discard the extra carry, only keep the integer part as ResInteger, not ResInteger + 1.
Debug.Assert(ResPrec - ResInteger >= 0);
if (ResPrec - ResInteger < ResScale)
ResScale = ResPrec - ResInteger;
// Adjust both operands to be the same scale as ResScale.
if (MyScale != ResScale)
x.AdjustScale(ResScale - MyScale, true);
if (OpScale != ResScale)
y.AdjustScale(ResScale - OpScale, true);
// When sign of first operand is negative
// negate all operands including result.
if (!fMySignPos)
{
fMySignPos = !fMySignPos;
fOpSignPos = !fOpSignPos;
fResSignPos = !fResSignPos;
}
// Initialize operand lengths and pointer.
culOp1 = x.m_bLen;
culOp2 = y.m_bLen;
uint[] rglData1 = new uint[4] { x.m_data1, x.m_data2, x.m_data3, x.m_data4 };
uint[] rglData2 = new uint[4] { y.m_data1, y.m_data2, y.m_data3, y.m_data4 };
if (fOpSignPos)
{
dwlAccum = 0;
// CONSIDER: Call AddUlong when possible
// Loop through UI4s adding operands and putting result in *this
// of the operands and put result in *this
for (iulData = 0; iulData < culOp1 || iulData < culOp2; iulData++)
{
// None of these DWORDLONG additions can overflow, as dwlAccum comes in < x_lInt32Base
if (iulData < culOp1)
dwlAccum += rglData1[iulData];
if (iulData < culOp2)
dwlAccum += rglData2[iulData];
rglData1[iulData] = (uint)dwlAccum; // equiv to mod x_lInt32Base
dwlAccum >>= 32; // equiv to div x_lInt32Base
}
//If carry
if (dwlAccum != 0)
{
Debug.Assert(dwlAccum < s_ulInt32Base);
//Either overflowed
if (iulData == s_cNumeMax)
throw new OverflowException(SQLResource.ArithOverflowMessage);
// Or extended length
rglData1[iulData] = (uint)dwlAccum;
iulData++;
}
// Set result length
bLen = (byte)iulData;
}
else
{
int iulLastNonZero = 0; // The last nonzero UI
// When second operand is negative, switch operands
// if operand2 is greater than operand1
if (x.LAbsCmp(y) < 0)
{
fResSignPos = !fResSignPos;
uint[] rguiTemp = rglData2;
rglData2 = rglData1;
rglData1 = rguiTemp;
culOp1 = culOp2;
culOp2 = x.m_bLen;
}
dwlAccum = s_ulInt32Base;
for (iulData = 0; iulData < culOp1 || iulData < culOp2; iulData++)
{
if (iulData < culOp1)
dwlAccum += rglData1[iulData];
if (iulData < culOp2)
dwlAccum -= rglData2[iulData];
rglData1[iulData] = (uint)dwlAccum; // equiv to mod BaseUI4
if (rglData1[iulData] != 0)
iulLastNonZero = iulData;
dwlAccum >>= 32; // equiv to /= BaseUI4
dwlAccum += s_ulInt32BaseForMod; // equiv to BaseUI4 - 1
}
// Set length based on highest non-zero ULONG
bLen = (byte)(iulLastNonZero + 1);
}
SqlDecimal ret = new SqlDecimal(rglData1, bLen, (byte)ResPrec, (byte)ResScale, fResSignPos);
if (ret.FGt10_38() || ret.CalculatePrecision() > s_NUMERIC_MAX_PRECISION)
throw new OverflowException(SQLResource.ArithOverflowMessage);
if (ret.FZero())
ret.SetPositive();
ret.AssertValid();
return ret;
}
// Convert to a specific precision and scale
public static SqlDecimal ConvertToPrecScale(SqlDecimal n, int precision, int scale)
{
CheckValidPrecScale(precision, scale);
n.AssertValid();
if (n.IsNull)
return SqlDecimal.Null;
SqlDecimal ret = n;
int lPrecAdjust = precision - ret._bPrec;//Adjustment to precision
int lScaleAdjust = scale - ret._bScale;//Adjustment to scale
//Adjust scale
ret.AdjustScale(lScaleAdjust, true);
//The number of bytes storage required by the new precision
byte cbWithNewPrec = CLenFromPrec((byte)precision);
if (cbWithNewPrec < ret._bLen)
{
//if current actual length greater than length corresponding to bNewPrec
//there must be truncating
throw new SqlTruncateException();
}
else if (cbWithNewPrec == ret._bLen)
{
//if the two lengths equal, need to check the actual precision
if (precision < ret.CalculatePrecision())
throw new SqlTruncateException();
}
//Adjust precision
ret._bPrec = (byte)precision;
ret.AssertValid();
return ret;
}