sal/qa/inc/valueequal.hxx

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  19
  20 #ifndef INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX
  21 #define INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX
  22
  23 #include <sal/config.h>
  24
  25 #include <cmath>
  26
  27 #define PREC_float 1
  28 #define PREC_double 2
  29 #define PREC_long_double 3
  30
  31 template<class T>
  32 bool is_equal(T x, T y, sal_Int16 _nPrec)
  33 {
  34     if (!(std::isfinite(x) && std::isfinite(y))) {
  35         return x == y;
  36     }
  37
  38     // due to the fact that this check looks only if both values are equal
  39     // we only need to look on one value
  40
  41     // 14 digits will announce the checkPrecisionSize
  42
  43     sal_Int32 nPRECISION;
  44     switch(_nPrec)
  45     {
  46     case PREC_float:
  47         nPRECISION = 6;
  48         break;
  49     case PREC_double:
  50         nPRECISION = 14;
  51         break;
  52     case PREC_long_double:
  53         nPRECISION = 20;
  54         break;
  55     default:
  56         nPRECISION = 2;
  57     }
  58
  59     if (x < 0)
  60     {
  61         x = -x;
  62     }
  63     if (y < 0)
  64     {
  65         y = -y;
  66     }
  67
  68     if (_nPrec != PREC_long_double)
  69     {
  70         printf("double equal: %.20f\n", x);
  71         printf("              %.20f\n", y);
  72     }
  73     //here nPrecOfN is the number after dot
  74     sal_Int32 nBeforeDot = sal_Int32( log10(x) );
  75     if ( nBeforeDot < 0)
  76     {
  77          nBeforeDot = 0;
  78     }
  79     //printf("nPRECISION is  %d\n", nPRECISION);
  80     sal_Int32 nPrecOfN = -nPRECISION + nBeforeDot;
  81
  82     if (_nPrec != PREC_long_double)
  83         printf("nPrecOfN is  %" SAL_PRIdINT32 "\n", nPrecOfN);
  84
  85     double nPrec = pow(0.1, -nPrecOfN);
  86
  87     if (_nPrec != PREC_long_double)
  88         printf("        prec: %.20f\n", nPrec);
  89
  90     double nDelta = fabs( x - y ) ;
  91
  92     if (_nPrec != PREC_long_double)
  93     {
  94         printf("       delta: %.20f\n", nDelta);
  95         printf("       nPrec: %.20f\n", nPrec);
  96         printf("delta must be less or equal to prec\n\n");
  97     }
  98
  99     if (nDelta > nPrec)
 100     {
 101         // values are not equal
 102         return false;
 103     }
 104
 105     // values are equal
 106     return true;
 107 }
 108
 109 bool is_float_equal(float x, float y)
 110 {
 111     return is_equal<float>(x, y, PREC_float);
 112 }
 113 bool is_double_equal(double x, double y)
 114 {
 115     return is_equal<double>(x, y, PREC_double);
 116 }
 117
 118 #endif // INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX
 119
 120 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */