math.h

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                           !isunordered(__x,__y) && (__x >= __y);}))
#define isless(x,y) \
          (__extension__ ({__typeof__(x) __x = (x); __typeof__(y) __y = (y); \
                           !isunordered(__x,__y) && (__x < __y);}))
#define islessequal(x,y) \
          (__extension__ ({__typeof__(x) __x = (x); __typeof__(y) __y = (y); \
                           !isunordered(__x,__y) && (__x <= __y);}))
#define islessgreater(x,y) \
          (__extension__ ({__typeof__(x) __x = (x); __typeof__(y) __y = (y); \
                           !isunordered(__x,__y) && (__x < __y || __x > __y);}))

#define isunordered(x,y) \
          (__extension__ ({__typeof__(x) __x = (x); __typeof__(y) __y = (y); \
                           fpclassify(__x) == FP_NAN || fpclassify(__y) == FP_NAN;}))

/*=========================================================================*/
/* Other non-ANSI standard functions                                       */

#ifndef CYGSYM_LIBM_NO_XOPEN_SVID_NAMESPACE_POLLUTION
# ifdef __cplusplus
__externC int matherr( struct __math_exception * );  // User-overridable error handling - see
# else                                               // <pkgconf/libm.h> for a discussion
__externC int matherr( struct exception * );
# endif
#endif


// FIXME: from here needs to be documented and mentioned as non-ISO
// Arc Hyperbolic trigonometric functions

__externC double
acosh( double );                  // Arc hyperbolic cos i.e. inverse cosh

__externC double
asinh( double );                  // Arc hyperbolic sin i.e. inverse sinh

__externC double
atanh( double );                  // Arc hyperbolic tan i.e. inverse tanh

// Error functions

__externC double                  // Error function, such that
erf( double );                    // erf(x) = 2/sqrt(pi) * integral from
                                  // 0 to x of e**(-t**2) dt

__externC double                  // Complementary error function - simply
erfc( double );                   // 1.0 - erf(x)

// Gamma functions

__externC double                  // Logarithm of the absolute value of the
lgamma( double );                 // gamma function of the argument. The
                                  // integer signgam is used to store the
                                  // sign of the gamma function of the arg

__externC double
lgamma_r( double, int * );        // Re-entrant version of the above, where
                                  // the user passes the location of signgam
                                  // as the second argument

__externC double                  // Identical to lgamma()!
gamma( double );                  // The reasons for this are historical,
                                  // and may be changed in future standards
                                  //
                                  // To get the real gamma function, you should
                                  // use: l=lgamma(x); g=signgam*exp(l);
                                  //
                                  // Do not just do signgam*exp(lgamma(x))
                                  // as lgamma() modifies signgam

__externC double
gamma_r( double, int * );         // Identical to lgamma_r(). See above.


// Bessel functions

__externC double                  // Zero-th order Bessel function of the
j0( double );                     // first kind at the ordinate of the argument

__externC double                  // First-order Bessel function of the
j1( double );                     // first kind at the ordinate of the argument

__externC double                  // Bessel function of the first kind of the
jn( int, double );                // order of the first argument at the
                                  // ordinate of the second argument

__externC double                  // Zero-th order Bessel function of the
y0( double );                     // second kind at the ordinate of the
                                  // argument

__externC double                  // First-order Bessel function of the
y1( double );                     // second kind at the ordinate of the
                                  // argument

__externC double                  // Bessel function of the second kind of the
yn( int, double );                // order of the first argument at the
                                  // ordinate of the second argument

// scalb*()

__externC double                    // scalbn(x,n) returns x*(2**n)
scalbn( double, int );

#ifdef CYGFUN_LIBM_SVID3_scalb

__externC double
scalb( double, double );          // as above except n is a floating point arg

#else
__externC double
scalb( double, int );             // as scalbn()

#endif // ifdef CYGFUN_LIBM_SVID3_scalb

// And the rest

__externC double
cbrt( double );                   // Cube Root

__externC double                  // hypotenuse function, defined such that:
hypot( double, double );          // hypot(x,y)==sqrt(x**2 + y**2)

__externC int                       // whether the argument is NaN
isnan( double );

__externC int
finite( double );                 // whether the argument is finite

__externC double                  // logb returns the binary exponent of its
logb( double );                   // argument as an integral value
                                  // This is not recommended - use ilogb
                                  // instead

__externC int                     // As for logb, but has the more correct
ilogb( double );                  // return value type of int


__externC double                  // nextafter(x,y) returns the next
nextafter( double, double );      // representable floating point number
                                  // adjacent to x in the direction of y
                                  // i.e. the next greater FP if y>x, the next
                                  // less FP if y<x, or just x if y==x

__externC double                  // remainder(x,y) returns the remainder
remainder( double, double );      // when x is divided by y

__externC double                  // IEEE Test Vector
significand( double );            // significand(x) computes:
                                  //   scalb(x, (double) -ilogb(x))
                                 
//===========================================================================
// Non-standard functions

__externC double                  // copysign(x,y) returns a number with
copysign ( double, double );      // the absolute value of x and the sign of y

__externC double                  // rounds to an integer according to the
rint( double );                   // current rounding mode


// BSD functions

__externC double                  // expm1(x) returns the equivalent of
expm1( double );                  // (exp(x) - 1) but more accurately when
                                  // x tends to zero

__externC double                  // log1p(x) returns the equivalent of
log1p( double );                  // log(1+x) but more accurately when
                                  // x tends to zero

/* New from newlib: */
#ifdef __cplusplus
extern "C" {
#endif
extern double infinity(void);
extern double nan(const char *);
extern int isinf(double);
extern double exp2 (double);
extern double scalbln (double, long int);
extern double tgamma(double);
extern double nearbyint(double);
extern long int lrint( double );
extern double round( double );
extern long int lround( double );
extern double trunc( double );
extern double remquo( double, double, int * );
extern double fdim( double, double );
extern double fmax( double, double );
extern double fmin( double, double );
extern double fma( double, double, double );
extern void sincos( double, double *, double * );
#define log2(x) (log (x) / M_LOG2_E)
// cabs() is not defined here as it conflicts with C99.
extern double drem( double, double );

#endif /* ! defined (__STRICT_ANSI__) */

#if !defined(__STRICT_ANSI__) || defined(__cplusplus)

/* Single precision versions of ANSI functions.  */

extern float atanf( float );
extern float cosf( float );
extern float sinf( float );
extern float tanf( float );
extern float tanhf( float );
extern float frexpf( float, int * );
extern float modff( float, float * );
extern float ceilf( float );
extern float fabsf( float );
extern float floorf( float );
extern float acosf( float );
extern float asinf( float );
extern float atan2f( float, float );
extern float coshf( float );
extern float sinhf( float );
extern float expf( float );
extern float ldexpf( float, int );
extern float logf( float );
extern float log10f( float );
extern float powf( float, float );
extern float sqrtf( float );
extern float fmodf( float, float );

#endif /* !defined(__STRICT_ANSI__) || defined(__cplusplus) */

#ifndef __STRICT_ANSI__

/* Other single precision functions.  */

extern float exp2f( float );
extern float scalblnf( float, long int );
extern float tgammaf( float );
extern float nearbyintf( float );
extern long int lrintf( float );
extern float roundf( float );
extern long int lroundf( float );
extern float truncf( float );
extern float remquof( float, float, int * );
extern float copysignf( float, float );
extern float fdimf( float, float );
extern float fmaxf( float, float );
extern float fminf( float, float );
extern float fmaf( float, float, float );

extern float infinityf( void );
extern float nanf( const char * );
extern int isnanf( float );
extern int isinff( float );
extern int finitef( float );
extern float copysignf( float, float );
extern int ilogbf( float );

extern float asinhf( float );
extern float cbrtf( float );
extern float nextafterf( float, float );
extern float rintf( float );
extern float scalbnf( float, int );
extern float log1pf( float );
extern float expm1f( float );
extern void sincosf( float, float *, float * );

extern float acoshf( float );
extern float atanhf( float );
extern float remainderf( float, float );
extern float gammaf( float );
extern float gammaf_r( float, int * );
extern float lgammaf( float );
extern float lgammaf_r( float, int * );
extern float erff( float );
extern float erfcf( float );
extern float y0f( float );
extern float y1f( float );
extern float ynf( int, float );
extern float j0f( float );
extern float j1f( float );
extern float jnf( int, float );
#define log2f(x) (logf (x) / (float) M_LOG2_E)
extern float hypotf( float, float );

#ifdef NOTYETFIXME
extern float cabsf();
#endif
extern float dremf( float, float );

/* Useful constants.  */

#define MAXFLOAT        3.40282347e+38F

#define M_E             2.7182818284590452354
#define M_LOG2E         1.4426950408889634074
#define M_LOG10E        0.43429448190325182765
#define M_LN2           0.69314718055994530942
#define M_LN10          2.30258509299404568402
#define M_PI            3.14159265358979323846
#define M_TWOPI         (M_PI * 2.0)
#define M_PI_2          1.57079632679489661923
#define M_PI_4          0.78539816339744830962
#define M_3PI_4         2.3561944901923448370E0
#define M_SQRTPI        1.77245385090551602792981
#define M_1_PI          0.31830988618379067154
#define M_2_PI          0.63661977236758134308
#define M_2_SQRTPI      1.12837916709551257390
#define M_SQRT2         1.41421356237309504880
#define M_SQRT1_2       0.70710678118654752440
#define M_LN2LO         1.9082149292705877000E-10
#define M_LN2HI         6.9314718036912381649E-1
#define M_SQRT3         1.73205080756887719000
#define M_IVLN10        0.43429448190325182765 /* 1 / log(10) */
#define M_LOG2_E        0.693147180559945309417
#define M_INVLN2        1.4426950408889633870E0  /* 1 / log(2) */

#ifdef __cplusplus
} // extern "C"
#endif

#endif // ifndef __STRICT_ANSI__

#endif // CYGONCE_LIBM_MATH_H multiple inclusion protection

// EOF math.h