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cpython/Include/pymath.h
Victor Stinner 1b2611eb02
bpo-46656: Remove Py_NO_NAN macro (GH-31160)
Building Python now requires support for floating point Not-a-Number
(NaN): remove the Py_NO_NAN macro.
2022-02-25 01:32:57 +01:00

66 lines
1.9 KiB
C

// Symbols and macros to supply platform-independent interfaces to mathematical
// functions and constants.
#ifndef Py_PYMATH_H
#define Py_PYMATH_H
/* High precision definition of pi and e (Euler)
* The values are taken from libc6's math.h.
*/
#ifndef Py_MATH_PIl
#define Py_MATH_PIl 3.1415926535897932384626433832795029L
#endif
#ifndef Py_MATH_PI
#define Py_MATH_PI 3.14159265358979323846
#endif
#ifndef Py_MATH_El
#define Py_MATH_El 2.7182818284590452353602874713526625L
#endif
#ifndef Py_MATH_E
#define Py_MATH_E 2.7182818284590452354
#endif
/* Tau (2pi) to 40 digits, taken from tauday.com/tau-digits. */
#ifndef Py_MATH_TAU
#define Py_MATH_TAU 6.2831853071795864769252867665590057683943L
#endif
// Py_IS_NAN(X)
// Return 1 if float or double arg is a NaN, else 0.
#define Py_IS_NAN(X) isnan(X)
// Py_IS_INFINITY(X)
// Return 1 if float or double arg is an infinity, else 0.
#define Py_IS_INFINITY(X) isinf(X)
// Py_IS_FINITE(X)
// Return 1 if float or double arg is neither infinite nor NAN, else 0.
#define Py_IS_FINITE(X) isfinite(X)
/* HUGE_VAL is supposed to expand to a positive double infinity. Python
* uses Py_HUGE_VAL instead because some platforms are broken in this
* respect. We used to embed code in pyport.h to try to worm around that,
* but different platforms are broken in conflicting ways. If you're on
* a platform where HUGE_VAL is defined incorrectly, fiddle your Python
* config to #define Py_HUGE_VAL to something that works on your platform.
*/
#ifndef Py_HUGE_VAL
# define Py_HUGE_VAL HUGE_VAL
#endif
// Py_NAN: Value that evaluates to a quiet Not-a-Number (NaN).
#if !defined(Py_NAN)
# if _Py__has_builtin(__builtin_nan)
// Built-in implementation of the ISO C99 function nan(): quiet NaN.
# define Py_NAN (__builtin_nan(""))
#else
// Use C99 NAN constant: quiet Not-A-Number.
// NAN is a float, Py_NAN is a double: cast to double.
# define Py_NAN ((double)NAN)
# endif
#endif
#endif /* Py_PYMATH_H */