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 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
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 */
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 */
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