1#ifndef Py_PYMATH_H 2#define Py_PYMATH_H 3 4#include "pyconfig.h" /* include for defines */ 5 6/************************************************************************** 7Symbols and macros to supply platform-independent interfaces to mathematical 8functions and constants 9**************************************************************************/ 10 11/* Python provides implementations for copysign, round and hypot in 12 * Python/pymath.c just in case your math library doesn't provide the 13 * functions. 14 * 15 *Note: PC/pyconfig.h defines copysign as _copysign 16 */ 17#ifndef HAVE_COPYSIGN 18extern double copysign(double, double); 19#endif 20 21#ifndef HAVE_ROUND 22extern double round(double); 23#endif 24 25#ifndef HAVE_HYPOT 26extern double hypot(double, double); 27#endif 28 29/* extra declarations */ 30#ifndef _MSC_VER 31#ifndef __STDC__ 32extern double fmod (double, double); 33extern double frexp (double, int *); 34extern double ldexp (double, int); 35extern double modf (double, double *); 36extern double pow(double, double); 37#endif /* __STDC__ */ 38#endif /* _MSC_VER */ 39 40#ifdef _OSF_SOURCE 41/* OSF1 5.1 doesn't make these available with XOPEN_SOURCE_EXTENDED defined */ 42extern int finite(double); 43extern double copysign(double, double); 44#endif 45 46/* High precision defintion of pi and e (Euler) 47 * The values are taken from libc6's math.h. 48 */ 49#ifndef Py_MATH_PIl 50#define Py_MATH_PIl 3.1415926535897932384626433832795029L 51#endif 52#ifndef Py_MATH_PI 53#define Py_MATH_PI 3.14159265358979323846 54#endif 55 56#ifndef Py_MATH_El 57#define Py_MATH_El 2.7182818284590452353602874713526625L 58#endif 59 60#ifndef Py_MATH_E 61#define Py_MATH_E 2.7182818284590452354 62#endif 63 64/* On x86, Py_FORCE_DOUBLE forces a floating-point number out of an x87 FPU 65 register and into a 64-bit memory location, rounding from extended 66 precision to double precision in the process. On other platforms it does 67 nothing. */ 68 69/* we take double rounding as evidence of x87 usage */ 70#ifndef Py_FORCE_DOUBLE 71# ifdef X87_DOUBLE_ROUNDING 72PyAPI_FUNC(double) _Py_force_double(double); 73# define Py_FORCE_DOUBLE(X) (_Py_force_double(X)) 74# else 75# define Py_FORCE_DOUBLE(X) (X) 76# endif 77#endif 78 79#ifdef HAVE_GCC_ASM_FOR_X87 80PyAPI_FUNC(unsigned short) _Py_get_387controlword(void); 81PyAPI_FUNC(void) _Py_set_387controlword(unsigned short); 82#endif 83 84/* Py_IS_NAN(X) 85 * Return 1 if float or double arg is a NaN, else 0. 86 * Caution: 87 * X is evaluated more than once. 88 * This may not work on all platforms. Each platform has *some* 89 * way to spell this, though -- override in pyconfig.h if you have 90 * a platform where it doesn't work. 91 * Note: PC/pyconfig.h defines Py_IS_NAN as _isnan 92 */ 93#ifndef Py_IS_NAN 94#if defined HAVE_DECL_ISNAN && HAVE_DECL_ISNAN == 1 95#define Py_IS_NAN(X) isnan(X) 96#else 97#define Py_IS_NAN(X) ((X) != (X)) 98#endif 99#endif 100 101/* Py_IS_INFINITY(X) 102 * Return 1 if float or double arg is an infinity, else 0. 103 * Caution: 104 * X is evaluated more than once. 105 * This implementation may set the underflow flag if |X| is very small; 106 * it really can't be implemented correctly (& easily) before C99. 107 * Override in pyconfig.h if you have a better spelling on your platform. 108 * Py_FORCE_DOUBLE is used to avoid getting false negatives from a 109 * non-infinite value v sitting in an 80-bit x87 register such that 110 * v becomes infinite when spilled from the register to 64-bit memory. 111 * Note: PC/pyconfig.h defines Py_IS_INFINITY as _isinf 112 * FIXME: PC/pyconfig.h defines Py_IS_INFINITY as (!_finite(X) && !_isnan(X)) 113 * so that above note isn't correct !!! 114 */ 115#ifndef Py_IS_INFINITY 116# if defined HAVE_DECL_ISINF && HAVE_DECL_ISINF == 1 117# define Py_IS_INFINITY(X) isinf(X) 118# else 119# define Py_IS_INFINITY(X) ((X) && \ 120 (Py_FORCE_DOUBLE(X)*0.5 == Py_FORCE_DOUBLE(X))) 121# endif 122#endif 123 124/* Py_IS_FINITE(X) 125 * Return 1 if float or double arg is neither infinite nor NAN, else 0. 126 * Some compilers (e.g. VisualStudio) have intrisics for this, so a special 127 * macro for this particular test is useful 128 * Note: PC/pyconfig.h defines Py_IS_FINITE as _finite 129 */ 130#ifndef Py_IS_FINITE 131#if defined HAVE_DECL_ISFINITE && HAVE_DECL_ISFINITE == 1 132#define Py_IS_FINITE(X) isfinite(X) 133#elif defined HAVE_FINITE 134#define Py_IS_FINITE(X) finite(X) 135#else 136#define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X)) 137#endif 138#endif 139 140/* HUGE_VAL is supposed to expand to a positive double infinity. Python 141 * uses Py_HUGE_VAL instead because some platforms are broken in this 142 * respect. We used to embed code in pyport.h to try to worm around that, 143 * but different platforms are broken in conflicting ways. If you're on 144 * a platform where HUGE_VAL is defined incorrectly, fiddle your Python 145 * config to #define Py_HUGE_VAL to something that works on your platform. 146 */ 147#ifndef Py_HUGE_VAL 148#define Py_HUGE_VAL HUGE_VAL 149#endif 150 151/* Py_NAN 152 * A value that evaluates to a NaN. On IEEE 754 platforms INF*0 or 153 * INF/INF works. Define Py_NO_NAN in pyconfig.h if your platform 154 * doesn't support NaNs. 155 */ 156#if !defined(Py_NAN) && !defined(Py_NO_NAN) 157#define Py_NAN (Py_HUGE_VAL * 0.) 158#endif 159 160/* Py_OVERFLOWED(X) 161 * Return 1 iff a libm function overflowed. Set errno to 0 before calling 162 * a libm function, and invoke this macro after, passing the function 163 * result. 164 * Caution: 165 * This isn't reliable. C99 no longer requires libm to set errno under 166 * any exceptional condition, but does require +- HUGE_VAL return 167 * values on overflow. A 754 box *probably* maps HUGE_VAL to a 168 * double infinity, and we're cool if that's so, unless the input 169 * was an infinity and an infinity is the expected result. A C89 170 * system sets errno to ERANGE, so we check for that too. We're 171 * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or 172 * if the returned result is a NaN, or if a C89 box returns HUGE_VAL 173 * in non-overflow cases. 174 * X is evaluated more than once. 175 * Some platforms have better way to spell this, so expect some #ifdef'ery. 176 * 177 * OpenBSD uses 'isinf()' because a compiler bug on that platform causes 178 * the longer macro version to be mis-compiled. This isn't optimal, and 179 * should be removed once a newer compiler is available on that platform. 180 * The system that had the failure was running OpenBSD 3.2 on Intel, with 181 * gcc 2.95.3. 182 * 183 * According to Tim's checkin, the FreeBSD systems use isinf() to work 184 * around a FPE bug on that platform. 185 */ 186#if defined(__FreeBSD__) || defined(__OpenBSD__) 187#define Py_OVERFLOWED(X) isinf(X) 188#else 189#define Py_OVERFLOWED(X) ((X) != 0.0 && (errno == ERANGE || \ 190 (X) == Py_HUGE_VAL || \ 191 (X) == -Py_HUGE_VAL)) 192#endif 193 194#endif /* Py_PYMATH_H */ 195