cpython/Include/pymath.h
Victor Stinner 194a9526d8
bpo-45440: Require math.h isinf() to build (GH-28894)
Building Python now requires a C99 <math.h> header file providing
isinf(), isnan() and isfinite() functions.

Remove the Py_FORCE_DOUBLE() macro. It was used by the
Py_IS_INFINITY() macro.

Changes:

* Remove Py_IS_NAN(), Py_IS_INFINITY() and Py_IS_FINITE()
  in PC/pyconfig.h.
* Remove the _Py_force_double() function.
* configure no longer checks if math.h defines isinf(), isnan() and
  isfinite().
2021-10-13 23:27:50 +02:00

80 lines
2.4 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
* A value that evaluates to a NaN. On IEEE 754 platforms INF*0 or
* INF/INF works. Define Py_NO_NAN in pyconfig.h if your platform
* doesn't support NaNs.
*/
#if !defined(Py_NAN) && !defined(Py_NO_NAN)
# if !defined(__INTEL_COMPILER)
# define Py_NAN (Py_HUGE_VAL * 0.)
# else /* __INTEL_COMPILER */
# if defined(ICC_NAN_STRICT)
#pragma float_control(push)
#pragma float_control(precise, on)
#pragma float_control(except, on)
Py_NO_INLINE static double __icc_nan()
{
return sqrt(-1.0);
}
#pragma float_control (pop)
# define Py_NAN __icc_nan()
# else /* ICC_NAN_RELAXED as default for Intel Compiler */
static const union { unsigned char buf[8]; double __icc_nan; } __nan_store = {0,0,0,0,0,0,0xf8,0x7f};
# define Py_NAN (__nan_store.__icc_nan)
# endif /* ICC_NAN_STRICT */
# endif /* __INTEL_COMPILER */
#endif
#endif /* Py_PYMATH_H */