sc/inc/math.hxx

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  19
  20 #ifndef INCLUDED_SC_INC_MATH_HXX
  21 #define INCLUDED_SC_INC_MATH_HXX
  22
  23 #include <formula/errorcodes.hxx>
  24
  25 namespace sc {
  26
  27 /** Return fNumerator/fDenominator if fDenominator!=0 else #DIV/0! error coded
  28     into double.
  29  */
  30 inline double div( const double& fNumerator, const double& fDenominator )
  31 {
  32     return (fDenominator != 0.0) ? (fNumerator / fDenominator) :
  33         CreateDoubleError( FormulaError::DivisionByZero);
  34 }
  35
  36 /** Return fNumerator/fDenominator if fDenominator!=0 else +-Infinity if
  37     fNumerator!=0 or NaN if fNumerator==0.
  38
  39     This allows to build/run with -fsanitize=float-divide-by-zero and have a
  40     defined behavior for the otherwise undefined division by zero case ("If the
  41     second operand of / or % is zero the behavior is undefined."
  42     ([expr.mul]/4)).
  43
  44     The Calc interpreter gracefully handles Infinity or NaN double values
  45     encountered as interim or final results, using this function we can ensure
  46     defined behavior where desired.
  47
  48     Use where the double coded error creating div() is not wanted.
  49  */
  50 inline double divide( const double& fNumerator, const double& fDenominator )
  51 {
  52     if (fDenominator == 0.0)
  53     {
  54         double fVal;
  55         if (rtl::math::isFinite( fNumerator) && fNumerator != 0.0)
  56         {
  57             rtl::math::setInf( &fVal, rtl::math::isSignBitSet( fNumerator));
  58         }
  59         else
  60         {
  61             rtl::math::setNan( &fVal);
  62         }
  63         return fVal;
  64     }
  65     return fNumerator / fDenominator;
  66 }
  67
  68 }
  69
  70 #endif
  71
  72 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */