1 #ifndef Py_PYMATH_H 2 #define Py_PYMATH_H 3 4 #include "pyconfig.h" /* include for defines */ 5 6 /************************************************************************** 7 Symbols and macros to supply platform-independent interfaces to mathematical 8 functions 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 18 extern double copysign(double, double); 19 #endif 20 21 #ifndef HAVE_ROUND 22 extern double round(double); 23 #endif 24 25 #ifndef HAVE_HYPOT 26 extern double hypot(double, double); 27 #endif 28 29 /* extra declarations */ 30 #ifndef _MSC_VER 31 #ifndef __STDC__ 32 extern double fmod (double, double); 33 extern double frexp (double, int *); 34 extern double ldexp (double, int); 35 extern double modf (double, double *); 36 extern 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 */ 42 extern int finite(double); 43 extern double copysign(double, double); 44 #endif 45 46 /* High precision definition 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 72 PyAPI_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 80 PyAPI_FUNC(unsigned short) _Py_get_387controlword(void); 81 PyAPI_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 */ 113 #ifndef Py_IS_INFINITY 114 # if defined HAVE_DECL_ISINF && HAVE_DECL_ISINF == 1 115 # define Py_IS_INFINITY(X) isinf(X) 116 # else 117 # define Py_IS_INFINITY(X) ((X) && \ 118 (Py_FORCE_DOUBLE(X)*0.5 == Py_FORCE_DOUBLE(X))) 119 # endif 120 #endif 121 122 /* Py_IS_FINITE(X) 123 * Return 1 if float or double arg is neither infinite nor NAN, else 0. 124 * Some compilers (e.g. VisualStudio) have intrisics for this, so a special 125 * macro for this particular test is useful 126 * Note: PC/pyconfig.h defines Py_IS_FINITE as _finite 127 */ 128 #ifndef Py_IS_FINITE 129 #if defined HAVE_DECL_ISFINITE && HAVE_DECL_ISFINITE == 1 130 #define Py_IS_FINITE(X) isfinite(X) 131 #elif defined HAVE_FINITE 132 #define Py_IS_FINITE(X) finite(X) 133 #else 134 #define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X)) 135 #endif 136 #endif 137 138 /* HUGE_VAL is supposed to expand to a positive double infinity. Python 139 * uses Py_HUGE_VAL instead because some platforms are broken in this 140 * respect. We used to embed code in pyport.h to try to worm around that, 141 * but different platforms are broken in conflicting ways. If you're on 142 * a platform where HUGE_VAL is defined incorrectly, fiddle your Python 143 * config to #define Py_HUGE_VAL to something that works on your platform. 144 */ 145 #ifndef Py_HUGE_VAL 146 #define Py_HUGE_VAL HUGE_VAL 147 #endif 148 149 /* Py_NAN 150 * A value that evaluates to a NaN. On IEEE 754 platforms INF*0 or 151 * INF/INF works. Define Py_NO_NAN in pyconfig.h if your platform 152 * doesn't support NaNs. 153 */ 154 #if !defined(Py_NAN) && !defined(Py_NO_NAN) 155 #if !defined(__INTEL_COMPILER) 156 #define Py_NAN (Py_HUGE_VAL * 0.) 157 #else /* __INTEL_COMPILER */ 158 #if defined(ICC_NAN_STRICT) 159 #pragma float_control(push) 160 #pragma float_control(precise, on) 161 #pragma float_control(except, on) 162 #if defined(_MSC_VER) 163 __declspec(noinline) 164 #else /* Linux */ 165 __attribute__((noinline)) 166 #endif /* _MSC_VER */ __icc_nan()167 static double __icc_nan() 168 { 169 return sqrt(-1.0); 170 } 171 #pragma float_control (pop) 172 #define Py_NAN __icc_nan() 173 #else /* ICC_NAN_RELAXED as default for Intel Compiler */ 174 static union { unsigned char buf[8]; double __icc_nan; } __nan_store = {0,0,0,0,0,0,0xf8,0x7f}; 175 #define Py_NAN (__nan_store.__icc_nan) 176 #endif /* ICC_NAN_STRICT */ 177 #endif /* __INTEL_COMPILER */ 178 #endif 179 180 /* Py_OVERFLOWED(X) 181 * Return 1 iff a libm function overflowed. Set errno to 0 before calling 182 * a libm function, and invoke this macro after, passing the function 183 * result. 184 * Caution: 185 * This isn't reliable. C99 no longer requires libm to set errno under 186 * any exceptional condition, but does require +- HUGE_VAL return 187 * values on overflow. A 754 box *probably* maps HUGE_VAL to a 188 * double infinity, and we're cool if that's so, unless the input 189 * was an infinity and an infinity is the expected result. A C89 190 * system sets errno to ERANGE, so we check for that too. We're 191 * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or 192 * if the returned result is a NaN, or if a C89 box returns HUGE_VAL 193 * in non-overflow cases. 194 * X is evaluated more than once. 195 * Some platforms have better way to spell this, so expect some #ifdef'ery. 196 * 197 * OpenBSD uses 'isinf()' because a compiler bug on that platform causes 198 * the longer macro version to be mis-compiled. This isn't optimal, and 199 * should be removed once a newer compiler is available on that platform. 200 * The system that had the failure was running OpenBSD 3.2 on Intel, with 201 * gcc 2.95.3. 202 * 203 * According to Tim's checkin, the FreeBSD systems use isinf() to work 204 * around a FPE bug on that platform. 205 */ 206 #if defined(__FreeBSD__) || defined(__OpenBSD__) 207 #define Py_OVERFLOWED(X) isinf(X) 208 #else 209 #define Py_OVERFLOWED(X) ((X) != 0.0 && (errno == ERANGE || \ 210 (X) == Py_HUGE_VAL || \ 211 (X) == -Py_HUGE_VAL)) 212 #endif 213 214 #endif /* Py_PYMATH_H */ 215