common/ttcn3float.hh

   1 /******************************************************************************
   2  * Copyright (c) 2000-2016 Ericsson Telecom AB
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *   Balasko, Jeno
  10  *   Baranyi, Botond
  11  *   Raduly, Csaba
  12  *
  13  ******************************************************************************/
  14 #ifndef TTCN3FLOAT_HH_
  15 #define TTCN3FLOAT_HH_
  16
  17 #include <math.h>
  18
  19 /* TTCN-3 float values that have absolute value smaller than this
  20    are displayed in exponential notation. */
  21 #define MIN_DECIMAL_FLOAT               1.0E-4
  22 /* TTCN-3 float values that have absolute value larger or equal than this
  23    are displayed in exponential notation. */
  24 #define MAX_DECIMAL_FLOAT               1.0E+10
  25
  26 #ifndef signbit
  27 // Probably Solaris.
  28 // Thankfully, IEEE Std 1003.1, 2004 Edition says that signbit is a macro,
  29 // hence it's safe to use ifdef.
  30
  31 #ifdef __sparc
  32 // Big endian
  33
  34 inline int signbitfunc(double d)
  35 {
  36   return *((unsigned char*)&d) & 0x80;
  37 }
  38
  39 #else
  40 // Probably Intel, assume little endian
  41 inline int signbitfunc(double d)
  42 {
  43   return ((unsigned char*)&d)[sizeof(double)-1] & 0x80;
  44 }
  45
  46 #endif
  47
  48 #define signbit(d) signbitfunc(d)
  49
  50 #endif // def signbit
  51
  52 /** A class which behaves almost, but not quite, entirely unlike
  53  *  a floating-point value.
  54  *
  55  *  It is used as a member of a union (in Value.hh);
  56  *  it MUST NOT have a constructor.
  57  */
  58 struct ttcn3float {
  59   /// Implicit conversion
  60   operator double() const { return value; }
  61
  62   /// Assignment from a proper double
  63   const ttcn3float& operator=(double d) {
  64     value = d;
  65     return *this;
  66   }
  67
  68   /// Address-of, for scanf
  69   double* operator&() { return &value; }
  70
  71   const ttcn3float& operator+=(double d) {
  72     value += d;
  73     return *this;
  74   }
  75
  76   const ttcn3float& operator-=(double d) {
  77     value -= d;
  78     return *this;
  79   }
  80
  81   const ttcn3float& operator*=(double d) {
  82     value *= d;
  83     return *this;
  84   }
  85
  86   const ttcn3float& operator/=(double d) {
  87     value /= d;
  88     return *this;
  89   }
  90
  91   bool operator<(double d) const {
  92     if (isnan(value)) {
  93       return false; // TTCN-3 special: NaN is bigger than anything except NaN
  94     }
  95     else if (isnan(d)) {
  96       return true; // TTCN-3 special: NaN is bigger than anything except NaN
  97     }
  98     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
  99       return signbit(value) && !signbit(d); // value negative, d positive
 100     }
 101     else { // finally, the sensible behavior
 102       return value < d;
 103     }
 104   }
 105
 106   bool operator>(double d) const {
 107     if (isnan(value)) {
 108       return true; // TTCN-3 special: NaN is bigger than anything except NaN
 109     }
 110     else if (isnan(d)) {
 111       return false; // TTCN-3 special: NaN is bigger than anything except NaN
 112     }
 113     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 114       return !signbit(value) && signbit(d); // value positive, d negative
 115     }
 116     else { // finally, the sensible behavior
 117       return value > d;
 118     }
 119   }
 120
 121   bool operator==(double d) const {
 122     if (isnan(value)) {
 123       return !!isnan(d); // TTCN-3 special: NaN is bigger than anything except NaN
 124     }
 125     else if (isnan(d)) {
 126       return false;
 127     }
 128     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 129       return signbit(value) == signbit(d);
 130     }
 131     else { // finally, the sensible behavior
 132       return value == d;
 133     }
 134   }
 135 public:
 136   double value;
 137 };
 138
 139 /** Replacement for a user-defined constructor that ttcn3float can't have */
 140 inline ttcn3float make_ttcn3float(double f) {
 141   ttcn3float retval = { f };
 142   return retval;
 143 }
 144
 145 #endif /* TTCN3FLOAT_HH_ */