common/ttcn3float.hh

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Copyright (c) 2000-2015 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 #ifndef TTCN3FLOAT_HH_
   9 #define TTCN3FLOAT_HH_
  10
  11 #include <math.h>
  12
  13 /* TTCN-3 float values that have absolute value smaller than this
  14    are displayed in exponential notation. */
  15 #define MIN_DECIMAL_FLOAT               1.0E-4
  16 /* TTCN-3 float values that have absolute value larger or equal than this
  17    are displayed in exponential notation. */
  18 #define MAX_DECIMAL_FLOAT               1.0E+10
  19
  20 #ifndef signbit
  21 // Probably Solaris.
  22 // Thankfully, IEEE Std 1003.1, 2004 Edition says that signbit is a macro,
  23 // hence it's safe to use ifdef.
  24
  25 #ifdef __sparc
  26 // Big endian
  27
  28 inline int signbitfunc(double d)
  29 {
  30   return *((unsigned char*)&d) & 0x80;
  31 }
  32
  33 #else
  34 // Probably Intel, assume little endian
  35 inline int signbitfunc(double d)
  36 {
  37   return ((unsigned char*)&d)[sizeof(double)-1] & 0x80;
  38 }
  39
  40 #endif
  41
  42 #define signbit(d) signbitfunc(d)
  43
  44 #endif // def signbit
  45
  46 /** A class which behaves almost, but not quite, entirely unlike
  47  *  a floating-point value.
  48  *
  49  *  It is used as a member of a union (in Value.hh);
  50  *  it MUST NOT have a constructor.
  51  */
  52 struct ttcn3float {
  53   /// Implicit conversion
  54   operator double() const { return value; }
  55
  56   /// Assignment from a proper double
  57   const ttcn3float& operator=(double d) {
  58     value = d;
  59     return *this;
  60   }
  61
  62   /// Address-of, for scanf
  63   double* operator&() { return &value; }
  64
  65   const ttcn3float& operator+=(double d) {
  66     value += d;
  67     return *this;
  68   }
  69
  70   const ttcn3float& operator-=(double d) {
  71     value -= d;
  72     return *this;
  73   }
  74
  75   const ttcn3float& operator*=(double d) {
  76     value *= d;
  77     return *this;
  78   }
  79
  80   const ttcn3float& operator/=(double d) {
  81     value /= d;
  82     return *this;
  83   }
  84
  85   bool operator<(double d) const {
  86     if (isnan(value)) {
  87       return false; // TTCN-3 special: NaN is bigger than anything except NaN
  88     }
  89     else if (isnan(d)) {
  90       return true; // TTCN-3 special: NaN is bigger than anything except NaN
  91     }
  92     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
  93       return signbit(value) && !signbit(d); // value negative, d positive
  94     }
  95     else { // finally, the sensible behavior
  96       return value < d;
  97     }
  98   }
  99
 100   bool operator>(double d) const {
 101     if (isnan(value)) {
 102       return true; // TTCN-3 special: NaN is bigger than anything except NaN
 103     }
 104     else if (isnan(d)) {
 105       return false; // TTCN-3 special: NaN is bigger than anything except NaN
 106     }
 107     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 108       return !signbit(value) && signbit(d); // value positive, d negative
 109     }
 110     else { // finally, the sensible behavior
 111       return value > d;
 112     }
 113   }
 114
 115   bool operator==(double d) const {
 116     if (isnan(value)) {
 117       return !!isnan(d); // TTCN-3 special: NaN is bigger than anything except NaN
 118     }
 119     else if (isnan(d)) {
 120       return false;
 121     }
 122     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 123       return signbit(value) == signbit(d);
 124     }
 125     else { // finally, the sensible behavior
 126       return value == d;
 127     }
 128   }
 129 public:
 130   double value;
 131 };
 132
 133 /** Replacement for a user-defined constructor that ttcn3float can't have */
 134 inline ttcn3float make_ttcn3float(double f) {
 135   ttcn3float retval = { f };
 136   return retval;
 137 }
 138
 139 #endif /* TTCN3FLOAT_HH_ */