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; }
private static SqlDecimal Round(SqlDecimal n, int lPosition, bool fTruncate) { if (n.IsNull) { return Null; } if (lPosition >= 0) { lPosition = Math.Min(NUMERIC_MAX_PRECISION, lPosition); if (lPosition >= n.m_bScale) { return n; } } else { lPosition = Math.Max(-NUMERIC_MAX_PRECISION, lPosition); if (lPosition < (n.m_bScale - n.m_bPrec)) { n.SetToZero(); return n; } } uint num2 = 0; int num = Math.Abs((int) (lPosition - n.m_bScale)); uint num3 = 1; while (num > 0) { if (num >= 9) { num2 = n.DivByULong(x_rgulShiftBase[8]); num3 = x_rgulShiftBase[8]; num -= 9; } else { num2 = n.DivByULong(x_rgulShiftBase[num - 1]); num3 = x_rgulShiftBase[num - 1]; num = 0; } } if (num3 > 1) { num2 /= num3 / 10; } if (n.FZero() && (fTruncate || (num2 < 5))) { n.SetPositive(); return n; } if ((num2 >= 5) && !fTruncate) { n.AddULong(1); } num = Math.Abs((int) (lPosition - n.m_bScale)); while (num-- > 0) { n.MultByULong(x_ulBase10); } return n; }