common/ttcn3float.hh

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Copyright (c) 2000-2014 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 #ifndef signbit
  14 // Probably Solaris.
  15 // Thankfully, IEEE Std 1003.1, 2004 Edition says that signbit is a macro,
  16 // hence it's safe to use ifdef.
  17
  18 #ifdef __sparc
  19 // Big endian
  20
  21 inline int signbitfunc(double d)
  22 {
  23   return *((unsigned char*)&d) & 0x80;
  24 }
  25
  26 #else
  27 // Probably Intel, assume little endian
  28 inline int signbitfunc(double d)
  29 {
  30   return ((unsigned char*)&d)[sizeof(double)-1] & 0x80;
  31 }
  32
  33 #endif
  34
  35 #define signbit(d) signbitfunc(d)
  36
  37 #endif // def signbit
  38
  39 /** A class which behaves almost, but not quite, entirely unlike
  40  *  a floating-point value.
  41  *
  42  *  It is used as a member of a union (in Value.hh);
  43  *  it MUST NOT have a constructor.
  44  */
  45 struct ttcn3float {
  46   /// Implicit conversion
  47   operator double() const { return value; }
  48
  49   /// Assignment from a proper double
  50   const ttcn3float& operator=(double d) {
  51     value = d;
  52     return *this;
  53   }
  54
  55   /// Address-of, for scanf
  56   double* operator&() { return &value; }
  57
  58   const ttcn3float& operator+=(double d) {
  59     value += d;
  60     return *this;
  61   }
  62
  63   const ttcn3float& operator-=(double d) {
  64     value -= d;
  65     return *this;
  66   }
  67
  68   const ttcn3float& operator*=(double d) {
  69     value *= d;
  70     return *this;
  71   }
  72
  73   const ttcn3float& operator/=(double d) {
  74     value /= d;
  75     return *this;
  76   }
  77
  78   bool operator<(double d) const {
  79     if (isnan(value)) {
  80       return false; // TTCN-3 special: NaN is bigger than anything except NaN
  81     }
  82     else if (isnan(d)) {
  83       return true; // TTCN-3 special: NaN is bigger than anything except NaN
  84     }
  85     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
  86       return signbit(value) && !signbit(d); // value negative, d positive
  87     }
  88     else { // finally, the sensible behavior
  89       return value < d;
  90     }
  91   }
  92
  93   bool operator>(double d) const {
  94     if (isnan(value)) {
  95       return true; // TTCN-3 special: NaN is bigger than anything except NaN
  96     }
  97     else if (isnan(d)) {
  98       return false; // TTCN-3 special: NaN is bigger than anything except NaN
  99     }
 100     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 101       return !signbit(value) && signbit(d); // value positive, d negative
 102     }
 103     else { // finally, the sensible behavior
 104       return value > d;
 105     }
 106   }
 107
 108   bool operator==(double d) const {
 109     if (isnan(value)) {
 110       return !!isnan(d); // TTCN-3 special: NaN is bigger than anything except NaN
 111     }
 112     else if (isnan(d)) {
 113       return false;
 114     }
 115     else if (value==0.0 && d==0.0) { // does not distinguish -0.0
 116       return signbit(value) == signbit(d);
 117     }
 118     else { // finally, the sensible behavior
 119       return value == d;
 120     }
 121   }
 122 public:
 123   double value;
 124 };
 125
 126 /** Replacement for a user-defined constructor that ttcn3float can't have */
 127 inline ttcn3float make_ttcn3float(double f) {
 128   ttcn3float retval = { f };
 129   return retval;
 130 }
 131
 132 #endif /* TTCN3FLOAT_HH_ */