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  1. #include <cmath>
  2. #include <iomanip>
  3. #include <iostream>
  4. #include <sstream>
  5. #include <stdint.h>
  6. #include <string>
  7.  
  8. #define MAX(A, B) ((A) > (B) ? (A) : (B))
  9. #define MIN(A, B) ((A) < (B) ? (A) : (B))
  10.  
  11. namespace Astrome
  12. {
  13. typedef uint8_t BitCountType;
  14. typedef uint64_t IntegerDataType;
  15.  
  16. class FixedPoint
  17. {
  18.   const BitCountType _totalBits;
  19.   const BitCountType _integerBits;
  20.   const bool _isSigned;
  21.   const IntegerDataType _constant; // This is the number of possible states
  22.   const IntegerDataType _factor;   // This is the scaling factor
  23.   const IntegerDataType _mask;
  24.  
  25.   IntegerDataType _integerValue;
  26.  
  27. public:
  28.   FixedPoint(BitCountType totalBits,
  29.              BitCountType integerBits,
  30.              bool isSigned,
  31.              IntegerDataType integerValue = 0) :
  32.     _totalBits(totalBits),
  33.     _integerBits(integerBits), _isSigned(isSigned), _constant(1 << _totalBits),
  34.     _factor(1 << (_totalBits - _integerBits)), _mask(_constant - 1),
  35.     _integerValue(integerValue & _mask)
  36.   {
  37.   }
  38.  
  39.   FixedPoint(BitCountType totalBits, BitCountType integerBits, bool isSigned, double floatValue) :
  40.     FixedPoint(totalBits, integerBits, isSigned, floatToInt(floatValue))
  41.   {
  42.   }
  43.  
  44.  
  45.   IntegerDataType floatToInt(const double &value)
  46.   {
  47.     if (_isSigned)
  48.     {
  49.       if (value < 0)
  50.         return (round(_constant + value * _factor));
  51.       else
  52.         return round(value * _factor);
  53.     }
  54.     else
  55.     {
  56.       return round(value * _factor);
  57.     }
  58.   }
  59.  
  60.   bool isNegative() const
  61.   {
  62.     if (_isSigned)
  63.       return _integerValue >> (_totalBits - 1);
  64.     return false;
  65.   }
  66.  
  67.   double floatValue() const
  68.   {
  69.     if (isNegative())
  70.       return (_integerValue - _constant) * 1.0 / _factor;
  71.     return _integerValue * 1.0 / _factor;
  72.   }
  73.  
  74.   FixedPoint &operator=(const FixedPoint &other)
  75.   {
  76.     _integerValue = floatToInt(other.floatValue());
  77.     return *this;
  78.   }
  79.  
  80.   FixedPoint operator>>(const BitCountType &bits)
  81.   {
  82.     return FixedPoint(_totalBits, _integerBits, _isSigned, _integerValue >> bits);
  83.   }
  84.  
  85.   FixedPoint operator<<(const BitCountType &bits)
  86.   {
  87.     IntegerDataType integerValue = _integerValue << bits;
  88.     return FixedPoint(_totalBits, _integerBits, _isSigned, integerValue);
  89.   }
  90.  
  91.   FixedPoint operator-() const
  92.   {
  93.     return FixedPoint(_totalBits, _integerBits, _isSigned, (~_integerValue) + 1); // Error
  94.   }
  95.  
  96.   FixedPoint operator+(const FixedPoint &other) const
  97.   {
  98.     return FixedPoint(_totalBits, _integerBits, _isSigned, floatValue() + other.floatValue());
  99.   }
  100.  
  101.   FixedPoint operator-(const FixedPoint &other) const
  102.   {
  103.     return (*this) + (-other);
  104.   }
  105.  
  106.  
  107.   std::string hexValue() const
  108.   {
  109.     std::stringstream stream;
  110.     stream << "0x" << std::setfill('0') << std::setw(_totalBits / 4) << std::hex << _integerValue;
  111.     return (stream.str());
  112.   }
  113. };
  114.  
  115. }
  116.  
  117. #ifdef DEBUG
  118. #define PRINT(t, x, f)                                                                \
  119.   std::cout << t << "\033[20G" << x.floatValue() << " " << x.hexValue() << "\033[50G" \
  120.             << (fabs(x.floatValue() - f) < 1e-4 ? "OK" : "FAIL") << std::endl;
  121. #else
  122. #define PRINT(t, x, f) std::cout << x.floatValue() << " " << x.hexValue() << std::endl;
  123. #endif
  124.  
  125.  
  126. #define TEST(x)                      \
  127.   {                                  \
  128.     FixedPoint g(16, 1, true, x);    \
  129.     PRINT("X", g, x)                 \
  130.                                      \
  131.     FixedPoint h = g >> 1;           \
  132.     PRINT("X>>1", h, x / 2)          \
  133.                                      \
  134.     FixedPoint i = h << 1;           \
  135.     PRINT("(X>>1)<<1", i, x)         \
  136.                                      \
  137.     FixedPoint j = -g;               \
  138.     PRINT("-X", j, -x)               \
  139.                                      \
  140.     FixedPoint k = g + h;            \
  141.     PRINT("X + (X>>1)", k, 1.5 * x); \
  142.                                      \
  143.     FixedPoint l = g - h;            \
  144.     PRINT("X - (X>>1)", l, 0.5 * x); \
  145.     std::cout << "-" << std::endl;   \
  146.   }
  147.  
  148. int main()
  149. {
  150.   using namespace Astrome;
  151.  
  152.   TEST(1.0)
  153.   TEST(-1.0)
  154.   TEST(-0.5)
  155.  
  156.   TEST(0.7)
  157.   TEST(-0.7)
  158.   TEST(M_PI / 4)
  159. }
Success #stdin #stdout 0s 5284KB
comments (?)
stdin
copy 
Standard input is empty
stdout
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0 0x0000
0 0x0000
0 0x0000
0 0x0000
0 0x0000
0 0x0000
-
5.6295e+14 0x8000
0.5 0x4000
5.6295e+14 0x8000
5.6295e+14 0x8000
5.6295e+14 0xc000
0 0x0000
-
5.6295e+14 0xc000
0.75 0x6000
5.6295e+14 0xc000
0.5 0x4000
0 0x0000
0 0x0000
-
0.700012 0x599a
0.350006 0x2ccd
0.700012 0x599a
5.6295e+14 0xa666
5.6295e+14 0x8667
0 0x0000
-
5.6295e+14 0xa666
0.649994 0x5333
5.6295e+14 0xa666
0.700012 0x599a
5.6295e+14 0xf800
0 0x0000
-
0.7854 0x6488
0.3927 0x3244
0.7854 0x6488
5.6295e+14 0x9b78
5.6295e+14 0x96cc
0 0x0000
-
https://ideone.com/cJ33JD
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

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