| 1 | #ifndef Py_PYMATH_H
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| 2 | #define Py_PYMATH_H
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| 3 |
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| 4 | #include "pyconfig.h" /* include for defines */
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| 5 |
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| 6 | /**************************************************************************
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| 7 | Symbols and macros to supply platform-independent interfaces to mathematical
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| 8 | functions and constants
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| 9 | **************************************************************************/
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| 10 |
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| 11 | /* Python provides implementations for copysign, round and hypot in
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| 12 | * Python/pymath.c just in case your math library doesn't provide the
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| 13 | * functions.
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| 14 | *
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| 15 | *Note: PC/pyconfig.h defines copysign as _copysign
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| 16 | */
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| 17 | #ifndef HAVE_COPYSIGN
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| 18 | extern double copysign(double, double);
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| 19 | #endif
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| 20 |
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| 21 | #ifndef HAVE_ROUND
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| 22 | extern double round(double);
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| 23 | #endif
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| 24 |
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| 25 | #ifndef HAVE_HYPOT
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| 26 | extern double hypot(double, double);
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| 27 | #endif
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| 28 |
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| 29 | /* extra declarations */
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| 30 | #ifndef _MSC_VER
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| 31 | #ifndef __STDC__
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| 32 | extern double fmod (double, double);
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| 33 | extern double frexp (double, int *);
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| 34 | extern double ldexp (double, int);
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| 35 | extern double modf (double, double *);
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| 36 | extern double pow(double, double);
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| 37 | #endif /* __STDC__ */
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| 38 | #endif /* _MSC_VER */
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| 39 |
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| 40 | #ifdef _OSF_SOURCE
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| 41 | /* OSF1 5.1 doesn't make these available with XOPEN_SOURCE_EXTENDED defined */
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| 42 | extern int finite(double);
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| 43 | extern double copysign(double, double);
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| 44 | #endif
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| 45 |
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| 46 | /* High precision defintion of pi and e (Euler)
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| 47 | * The values are taken from libc6's math.h.
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| 48 | */
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| 49 | #ifndef Py_MATH_PIl
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| 50 | #define Py_MATH_PIl 3.1415926535897932384626433832795029L
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| 51 | #endif
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| 52 | #ifndef Py_MATH_PI
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| 53 | #define Py_MATH_PI 3.14159265358979323846
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| 54 | #endif
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| 55 |
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| 56 | #ifndef Py_MATH_El
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| 57 | #define Py_MATH_El 2.7182818284590452353602874713526625L
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| 58 | #endif
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| 59 |
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| 60 | #ifndef Py_MATH_E
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| 61 | #define Py_MATH_E 2.7182818284590452354
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| 62 | #endif
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| 63 |
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| 64 | /* On x86, Py_FORCE_DOUBLE forces a floating-point number out of an x87 FPU
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| 65 | register and into a 64-bit memory location, rounding from extended
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| 66 | precision to double precision in the process. On other platforms it does
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| 67 | nothing. */
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| 68 |
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| 69 | /* we take double rounding as evidence of x87 usage */
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| 70 | #ifndef Py_FORCE_DOUBLE
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| 71 | # ifdef X87_DOUBLE_ROUNDING
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| 72 | PyAPI_FUNC(double) _Py_force_double(double);
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| 73 | # define Py_FORCE_DOUBLE(X) (_Py_force_double(X))
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| 74 | # else
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| 75 | # define Py_FORCE_DOUBLE(X) (X)
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| 76 | # endif
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| 77 | #endif
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| 78 |
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| 79 | #ifdef HAVE_GCC_ASM_FOR_X87
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| 80 | PyAPI_FUNC(unsigned short) _Py_get_387controlword(void);
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| 81 | PyAPI_FUNC(void) _Py_set_387controlword(unsigned short);
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| 82 | #endif
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| 83 |
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| 84 | /* Py_IS_NAN(X)
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| 85 | * Return 1 if float or double arg is a NaN, else 0.
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| 86 | * Caution:
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| 87 | * X is evaluated more than once.
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| 88 | * This may not work on all platforms. Each platform has *some*
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| 89 | * way to spell this, though -- override in pyconfig.h if you have
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| 90 | * a platform where it doesn't work.
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| 91 | * Note: PC/pyconfig.h defines Py_IS_NAN as _isnan
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| 92 | */
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| 93 | #ifndef Py_IS_NAN
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| 94 | #if defined HAVE_DECL_ISNAN && HAVE_DECL_ISNAN == 1
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| 95 | #define Py_IS_NAN(X) isnan(X)
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| 96 | #else
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| 97 | #define Py_IS_NAN(X) ((X) != (X))
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| 98 | #endif
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| 99 | #endif
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| 100 |
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| 101 | /* Py_IS_INFINITY(X)
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| 102 | * Return 1 if float or double arg is an infinity, else 0.
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| 103 | * Caution:
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| 104 | * X is evaluated more than once.
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| 105 | * This implementation may set the underflow flag if |X| is very small;
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| 106 | * it really can't be implemented correctly (& easily) before C99.
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| 107 | * Override in pyconfig.h if you have a better spelling on your platform.
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| 108 | * Py_FORCE_DOUBLE is used to avoid getting false negatives from a
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| 109 | * non-infinite value v sitting in an 80-bit x87 register such that
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| 110 | * v becomes infinite when spilled from the register to 64-bit memory.
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| 111 | * Note: PC/pyconfig.h defines Py_IS_INFINITY as _isinf
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| 112 | */
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| 113 | #ifndef Py_IS_INFINITY
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| 114 | # if defined HAVE_DECL_ISINF && HAVE_DECL_ISINF == 1
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| 115 | # define Py_IS_INFINITY(X) isinf(X)
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| 116 | # else
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| 117 | # define Py_IS_INFINITY(X) ((X) && \
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| 118 | (Py_FORCE_DOUBLE(X)*0.5 == Py_FORCE_DOUBLE(X)))
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| 119 | # endif
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| 120 | #endif
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| 121 |
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| 122 | /* Py_IS_FINITE(X)
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| 123 | * Return 1 if float or double arg is neither infinite nor NAN, else 0.
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| 124 | * Some compilers (e.g. VisualStudio) have intrisics for this, so a special
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| 125 | * macro for this particular test is useful
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| 126 | * Note: PC/pyconfig.h defines Py_IS_FINITE as _finite
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| 127 | */
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| 128 | #ifndef Py_IS_FINITE
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| 129 | #if defined HAVE_DECL_ISFINITE && HAVE_DECL_ISFINITE == 1
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| 130 | #define Py_IS_FINITE(X) isfinite(X)
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| 131 | #elif defined HAVE_FINITE
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| 132 | #define Py_IS_FINITE(X) finite(X)
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| 133 | #else
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| 134 | #define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X))
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| 135 | #endif
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| 136 | #endif
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| 137 |
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| 138 | /* HUGE_VAL is supposed to expand to a positive double infinity. Python
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| 139 | * uses Py_HUGE_VAL instead because some platforms are broken in this
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| 140 | * respect. We used to embed code in pyport.h to try to worm around that,
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| 141 | * but different platforms are broken in conflicting ways. If you're on
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| 142 | * a platform where HUGE_VAL is defined incorrectly, fiddle your Python
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| 143 | * config to #define Py_HUGE_VAL to something that works on your platform.
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| 144 | */
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| 145 | #ifndef Py_HUGE_VAL
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| 146 | #define Py_HUGE_VAL HUGE_VAL
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| 147 | #endif
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| 148 |
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| 149 | /* Py_NAN
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| 150 | * A value that evaluates to a NaN. On IEEE 754 platforms INF*0 or
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| 151 | * INF/INF works. Define Py_NO_NAN in pyconfig.h if your platform
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| 152 | * doesn't support NaNs.
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| 153 | */
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| 154 | #if !defined(Py_NAN) && !defined(Py_NO_NAN)
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| 155 | #define Py_NAN (Py_HUGE_VAL * 0.)
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| 156 | #endif
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| 157 |
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| 158 | /* Py_OVERFLOWED(X)
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| 159 | * Return 1 iff a libm function overflowed. Set errno to 0 before calling
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| 160 | * a libm function, and invoke this macro after, passing the function
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| 161 | * result.
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| 162 | * Caution:
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| 163 | * This isn't reliable. C99 no longer requires libm to set errno under
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| 164 | * any exceptional condition, but does require +- HUGE_VAL return
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| 165 | * values on overflow. A 754 box *probably* maps HUGE_VAL to a
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| 166 | * double infinity, and we're cool if that's so, unless the input
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| 167 | * was an infinity and an infinity is the expected result. A C89
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| 168 | * system sets errno to ERANGE, so we check for that too. We're
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| 169 | * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or
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| 170 | * if the returned result is a NaN, or if a C89 box returns HUGE_VAL
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| 171 | * in non-overflow cases.
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| 172 | * X is evaluated more than once.
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| 173 | * Some platforms have better way to spell this, so expect some #ifdef'ery.
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| 174 | *
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| 175 | * OpenBSD uses 'isinf()' because a compiler bug on that platform causes
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| 176 | * the longer macro version to be mis-compiled. This isn't optimal, and
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| 177 | * should be removed once a newer compiler is available on that platform.
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| 178 | * The system that had the failure was running OpenBSD 3.2 on Intel, with
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| 179 | * gcc 2.95.3.
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| 180 | *
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| 181 | * According to Tim's checkin, the FreeBSD systems use isinf() to work
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| 182 | * around a FPE bug on that platform.
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| 183 | */
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| 184 | #if defined(__FreeBSD__) || defined(__OpenBSD__)
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| 185 | #define Py_OVERFLOWED(X) isinf(X)
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| 186 | #else
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| 187 | #define Py_OVERFLOWED(X) ((X) != 0.0 && (errno == ERANGE || \
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| 188 | (X) == Py_HUGE_VAL || \
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| 189 | (X) == -Py_HUGE_VAL))
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| 190 | #endif
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| 191 |
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| 192 | #endif /* Py_PYMATH_H */
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