cpython/Include/pymath.h
Sebastian Berg 7a3b03509e
gh-104263: Rely on Py_NAN and introduce Py_INFINITY (GH-104202)
This PR removes `_Py_dg_stdnan` and `_Py_dg_infinity` in favour of
using the standard `NAN` and `INFINITY` macros provided by C99.
This change has the side-effect of fixing a bug on MIPS where the
hard-coded value used by `_Py_dg_stdnan` gave a signalling NaN
rather than a quiet NaN.
---------

Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
2023-05-10 17:44:52 +01:00

62 lines
1.6 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)
// Py_INFINITY: Value that evaluates to a positive double infinity.
#ifndef Py_INFINITY
# define Py_INFINITY ((double)INFINITY)
#endif
/* Py_HUGE_VAL should always be the same as Py_INFINITY. But historically
* this was not reliable and Python did not require IEEE floats and C99
* conformity. Prefer Py_INFINITY for new code.
*/
#ifndef Py_HUGE_VAL
# define Py_HUGE_VAL HUGE_VAL
#endif
/* Py_NAN: Value that evaluates to a quiet Not-a-Number (NaN). The sign is
* undefined and normally not relevant, but e.g. fixed for float("nan").
*/
#if !defined(Py_NAN)
# define Py_NAN ((double)NAN)
#endif
#endif /* Py_PYMATH_H */