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54842e4311
Building Python now requires a C99 <math.h> header file providing a NAN constant, or the __builtin_nan() built-in function. If a platform does not support Not-a-Number (NaN), the Py_NO_NAN macro can be defined in the pyconfig.h file.
69 lines
2.0 KiB
C
69 lines
2.0 KiB
C
// Symbols and macros to supply platform-independent interfaces to mathematical
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// functions and constants.
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#ifndef Py_PYMATH_H
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#define Py_PYMATH_H
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/* High precision definition of pi and e (Euler)
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* The values are taken from libc6's math.h.
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*/
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#ifndef Py_MATH_PIl
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#define Py_MATH_PIl 3.1415926535897932384626433832795029L
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#endif
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#ifndef Py_MATH_PI
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#define Py_MATH_PI 3.14159265358979323846
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#endif
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#ifndef Py_MATH_El
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#define Py_MATH_El 2.7182818284590452353602874713526625L
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#endif
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#ifndef Py_MATH_E
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#define Py_MATH_E 2.7182818284590452354
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#endif
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/* Tau (2pi) to 40 digits, taken from tauday.com/tau-digits. */
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#ifndef Py_MATH_TAU
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#define Py_MATH_TAU 6.2831853071795864769252867665590057683943L
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#endif
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// Py_IS_NAN(X)
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// Return 1 if float or double arg is a NaN, else 0.
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#define Py_IS_NAN(X) isnan(X)
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// Py_IS_INFINITY(X)
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// Return 1 if float or double arg is an infinity, else 0.
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#define Py_IS_INFINITY(X) isinf(X)
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// Py_IS_FINITE(X)
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// Return 1 if float or double arg is neither infinite nor NAN, else 0.
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#define Py_IS_FINITE(X) isfinite(X)
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/* HUGE_VAL is supposed to expand to a positive double infinity. Python
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* uses Py_HUGE_VAL instead because some platforms are broken in this
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* respect. We used to embed code in pyport.h to try to worm around that,
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* but different platforms are broken in conflicting ways. If you're on
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* a platform where HUGE_VAL is defined incorrectly, fiddle your Python
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* config to #define Py_HUGE_VAL to something that works on your platform.
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*/
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#ifndef Py_HUGE_VAL
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# define Py_HUGE_VAL HUGE_VAL
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#endif
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/* Py_NAN
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* A value that evaluates to a quiet Not-a-Number (NaN).
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* Define Py_NO_NAN in pyconfig.h if your platform doesn't support NaNs.
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*/
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#if !defined(Py_NAN) && !defined(Py_NO_NAN)
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# if _Py__has_builtin(__builtin_nan)
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// Built-in implementation of the ISO C99 function nan(): quiet NaN.
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# define Py_NAN (__builtin_nan(""))
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#else
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// Use C99 NAN constant: quiet Not-A-Number.
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// NAN is a float, Py_NAN is a double: cast to double.
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# define Py_NAN ((double)NAN)
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# endif
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#endif
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#endif /* Py_PYMATH_H */
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