1  // Symbols and macros to supply platform-independent interfaces to mathematical
       2  // functions and constants.
       3  
       4  #ifndef Py_PYMATH_H
       5  #define Py_PYMATH_H
       6  
       7  /* High precision definition of pi and e (Euler)
       8   * The values are taken from libc6's math.h.
       9   */
      10  #ifndef Py_MATH_PIl
      11  #define Py_MATH_PIl 3.1415926535897932384626433832795029L
      12  #endif
      13  #ifndef Py_MATH_PI
      14  #define Py_MATH_PI 3.14159265358979323846
      15  #endif
      16  
      17  #ifndef Py_MATH_El
      18  #define Py_MATH_El 2.7182818284590452353602874713526625L
      19  #endif
      20  
      21  #ifndef Py_MATH_E
      22  #define Py_MATH_E 2.7182818284590452354
      23  #endif
      24  
      25  /* Tau (2pi) to 40 digits, taken from tauday.com/tau-digits. */
      26  #ifndef Py_MATH_TAU
      27  #define Py_MATH_TAU 6.2831853071795864769252867665590057683943L
      28  #endif
      29  
      30  // Py_IS_NAN(X)
      31  // Return 1 if float or double arg is a NaN, else 0.
      32  #define Py_IS_NAN(X) isnan(X)
      33  
      34  // Py_IS_INFINITY(X)
      35  // Return 1 if float or double arg is an infinity, else 0.
      36  #define Py_IS_INFINITY(X) isinf(X)
      37  
      38  // Py_IS_FINITE(X)
      39  // Return 1 if float or double arg is neither infinite nor NAN, else 0.
      40  #define Py_IS_FINITE(X) isfinite(X)
      41  
      42  /* HUGE_VAL is supposed to expand to a positive double infinity.  Python
      43   * uses Py_HUGE_VAL instead because some platforms are broken in this
      44   * respect.  We used to embed code in pyport.h to try to worm around that,
      45   * but different platforms are broken in conflicting ways.  If you're on
      46   * a platform where HUGE_VAL is defined incorrectly, fiddle your Python
      47   * config to #define Py_HUGE_VAL to something that works on your platform.
      48   */
      49  #ifndef Py_HUGE_VAL
      50  #  define Py_HUGE_VAL HUGE_VAL
      51  #endif
      52  
      53  // Py_NAN: Value that evaluates to a quiet Not-a-Number (NaN).
      54  #if !defined(Py_NAN)
      55  #  if _Py__has_builtin(__builtin_nan)
      56       // Built-in implementation of the ISO C99 function nan(): quiet NaN.
      57  #    define Py_NAN (__builtin_nan(""))
      58  #else
      59       // Use C99 NAN constant: quiet Not-A-Number.
      60       // NAN is a float, Py_NAN is a double: cast to double.
      61  #    define Py_NAN ((double)NAN)
      62  #  endif
      63  #endif
      64  
      65  #endif /* Py_PYMATH_H */