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/* @(#)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) */
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