Subversion Repositories openrisc_2011-10-31

/* @(#)w_hypot.c 5.1 93/09/24 */

/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunPro, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

/*

FUNCTION

        <<hypot>>, <<hypotf>>---distance from origin

INDEX

        hypot

INDEX

        hypotf

ANSI_SYNOPSIS

        #include <math.h>

        double hypot(double <[x]>, double <[y]>);

        float hypotf(float <[x]>, float <[y]>);

TRAD_SYNOPSIS

        double hypot(<[x]>, <[y]>)

        double <[x]>, <[y]>;

        float hypotf(<[x]>, <[y]>)

        float <[x]>, <[y]>;

DESCRIPTION

        <<hypot>> calculates the Euclidean distance

        @tex

        $\sqrt{x^2+y^2}$

        @end tex

        @ifnottex

        <<sqrt(<[x]>*<[x]> + <[y]>*<[y]>)>>

        @end ifnottex

        between the origin (0,0) and a point represented by the

        Cartesian coordinates (<[x]>,<[y]>).  <<hypotf>> differs only

        in the type of its arguments and result.

RETURNS

        Normally, the distance value is returned.  On overflow,

        <<hypot>> returns <<HUGE_VAL>> and sets <<errno>> to

        <<ERANGE>>.

        You can change the error treatment with <<matherr>>.

PORTABILITY

        <<hypot>> and <<hypotf>> are not ANSI C.  */

/*

 * wrapper hypot(x,y)

 */

#include "fdlibm.h"

#include <errno.h>

#ifndef _DOUBLE_IS_32BITS

#ifdef __STDC__

        double hypot(double x, double y)/* wrapper hypot */

#else

        double hypot(x,y)               /* wrapper hypot */

        double x,y;

#endif

{

#ifdef _IEEE_LIBM

        return __ieee754_hypot(x,y);

#else

        double z;

        struct exception exc;

        z = __ieee754_hypot(x,y);

        if(_LIB_VERSION == _IEEE_) return z;

        if((!finite(z))&&finite(x)&&finite(y)) {

            /* hypot(finite,finite) overflow */

#ifndef HUGE_VAL 

#define HUGE_VAL inf

            double inf = 0.0;

            SET_HIGH_WORD(inf,0x7ff00000);      /* set inf to infinite */

#endif

            exc.type = OVERFLOW;

            exc.name = "hypot";

            exc.err = 0;

            exc.arg1 = x;

            exc.arg2 = y;

            if (_LIB_VERSION == _SVID_)

               exc.retval = HUGE;

            else

               exc.retval = HUGE_VAL;

            if (_LIB_VERSION == _POSIX_)

               errno = ERANGE;

            else if (!matherr(&exc)) {

                errno = ERANGE;

            }

            if (exc.err != 0)

               errno = exc.err;

            return exc.retval;

        } else

            return z;

#endif

}

#endif /* defined(_DOUBLE_IS_32BITS) */