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#ifndef CYGONCE_LIBM_MATH_H

#define CYGONCE_LIBM_MATH_H

//===========================================================================

//

//      math.h

//

//      Standard mathematical functions conforming to ANSI and other standards

//

//===========================================================================

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// -------------------------------------------

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//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   jlarmour

// Contributors:  jlarmour

// Date:        1998-02-13

// Purpose:     

// Description: Standard mathematical functions. These can be

//              configured to conform to ANSI section 7.5. There are also

//              a number of extensions conforming to IEEE-754 and behaviours

//              compatible with other standards

// Usage:       #include <math.h>

//

//####DESCRIPTIONEND####

//

//===========================================================================

// CONFIGURATION

#include <pkgconf/libm.h>   // Configuration header

// Include the Math library?

#ifdef CYGPKG_LIBM     

// INCLUDES

#include <cyg/infra/cyg_type.h>    // Common type definitions and support

#include <float.h>                 // Properties of FP representation on this

                                   // platform

#include <sys/ieeefp.h>            // Cyg_libm_ieee_double_shape_type

// CONSTANT DEFINITIONS

// HUGE_VAL is a positive double (not necessarily representable as a float)

// representing infinity as specified in ANSI 7.5. cyg_libm_infinity is

// defined further down

#define HUGE_VAL        (cyg_libm_infinity.value)

#ifndef CYGSYM_LIBM_NO_XOPEN_SVID_NAMESPACE_POLLUTION

// HUGE is defined in System V Interface Definition 3 (SVID3) as the largest

// finite single precision number

#define HUGE            FLT_MAX    // from float.h

// Values used in the type field of struct exception below

#define DOMAIN          1

#define SING            2

#define OVERFLOW        3

#define UNDERFLOW       4

#define TLOSS           5

#define PLOSS           6

// TYPE DEFINITIONS

// Things required to support matherr() ( see comments in <pkgconf/libm.h>)

struct exception {

    int type;       // One of DOMAIN, SING, OVERFLOW, UNDERFLOW, TLOSS, PLOSS

    char *name;     // Name of the function generating the exception

    double arg1;    // First argument to the function

    double arg2;    // Second argument to the function

    double retval;  // Value to be returned - can be altered by matherr()

};

#endif // ifndef CYGSYM_LIBM_NO_XOPEN_SVID_NAMESPACE_POLLUTION

// GLOBALS

externC const Cyg_libm_ieee_double_shape_type cyg_libm_infinity;

//===========================================================================

// FUNCTION PROTOTYPES

// Functions not part of a standard

// This retrieves a pointer to the current compatibility mode of the Math

// library. See <pkgconf/libm.h> for the definition of Cyg_libm_compat_t

#ifdef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

externC Cyg_libm_compat_t

cyg_libm_get_compat_mode( void );

externC Cyg_libm_compat_t

cyg_libm_set_compat_mode( Cyg_libm_compat_t );

#else

externC Cyg_libm_compat_t cygvar_libm_compat_mode;

// Defined as static inline as it is unlikely that anyone wants to take the

// address of these functions.

//

// This returns the current compatibility mode

static inline Cyg_libm_compat_t

cyg_libm_get_compat_mode( void )

{

    return cygvar_libm_compat_mode;

}

// This sets the compatibility mode, and returns the previous mode

static inline Cyg_libm_compat_t

cyg_libm_set_compat_mode( Cyg_libm_compat_t math_compat_mode)

{

    Cyg_libm_compat_t oldmode;

    oldmode = cygvar_libm_compat_mode;

    cygvar_libm_compat_mode = math_compat_mode;

    return oldmode;

}

#endif // ifdef CYGSEM_LIBM_THREAD_SAFE_COMPAT_MODE

#ifdef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

// FIXME: these need to be documented and signgam mentioned as non-ISO

// This returns the address of the signgam variable used by the gamma*() and

// lgamma*() functions

externC int *

cyg_libm_get_signgam_p( void );

#define signgam (*cyg_libm_get_signgam_p())

#else

externC int signgam;

#endif // ifdef CYGSEM_LIBM_THREAD_SAFE_GAMMA_FUNCTIONS

//===========================================================================

// Standard ANSI functions. Angles are always in radians

// Trigonometric functions - ANSI 7.5.2

externC double

acos( double );            // arc cosine i.e. inverse cos

externC double

asin( double );            // arc sine i.e. inverse sin

externC double

atan( double );            // arc tan i.e. inverse tan

externC double

atan2( double, double );   // arc tan of (first arg/second arg) using signs

                           // of args to determine quadrant

externC double

cos( double );             // cosine

externC double

sin( double );             // sine

externC double

tan( double );             // tangent

// Hyperbolic functions - ANSI 7.5.3

externC double

cosh( double );            // hyperbolic cosine

externC double

sinh( double );            // hyperbolic sine

externC double

tanh( double );            // hyperbolic tangent

// Exponential and Logarithmic Functions - ANSI 7.5.4

externC double

exp( double );             // exponent

externC double

frexp( double, int * );    // break number into normalized fraction (returned)

                           // and integral power of 2 (second arg)

externC double

ldexp( double, int );      // multiples number by integral power of 2 

externC double

log( double );             // natural logarithm

externC double

log10( double );           // base ten logarithm

externC double

modf( double, double * );  // break number into integral and fractional

                           // parts, each of which has same sign as arg.

                           // It returns signed fractional part, and

                           // puts integral part in second arg

// Power Functions - ANSI 7.5.5

externC double

pow( double, double );     // (1st arg) to the power of (2nd arg)

externC double

sqrt( double );            // square root

// Nearest integer, absolute value and remainder functions - ANSI 7.5.6

externC double

ceil( double );            // smallest integer >= arg

externC double

fabs( double );            // absolute value

externC double

floor( double );           // largest integer <= arg

externC double

fmod( double, double );    // remainder of (1st arg)/(2nd arg)

//===========================================================================

// Other standard functions

#ifndef CYGSYM_LIBM_NO_XOPEN_SVID_NAMESPACE_POLLUTION

externC int

matherr( struct exception * );    // User-overridable error handling - see

#endif                            // <pkgconf/libm.h> for a discussion

// 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

#endif // ifdef CYGPKG_LIBM     

#endif // CYGONCE_LIBM_MATH_H multiple inclusion protection

// EOF math.h