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/* @(#)w_asin.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
<<asin>>, <<asinf>>---arc sine
INDEX
asin
INDEX
asinf
SYNOPSIS
#include <math.h>
double asin(double <[x]>);
float asinf(float <[x]>);
DESCRIPTION
<<asin>> computes the inverse sine (arc sine) of the argument <[x]>.
Arguments to <<asin>> must be in the range @minus{}1 to 1.
<<asinf>> is identical to <<asin>>, other than taking and
returning floats.
You can modify error handling for these routines using <<matherr>>.
RETURNS
@ifnottex
<<asin>> returns values in radians, in the range of -pi/2 to pi/2.
@end ifnottex
@tex
<<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$.
@end tex
If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>>
return NaN (not a number), set the global variable <<errno>> to
<<EDOM>>, and issue a <<DOMAIN error>> message.
You can change this error treatment using <<matherr>>.
QUICKREF
ansi svid posix rentrant
asin y,y,y,m
asinf n,n,n,m
MATHREF
asin, -1<=arg<=1, asin(arg),,,
asin, NAN, arg,EDOM, DOMAIN
MATHREF
asinf, -1<=arg<=1, asin(arg),,,
asinf, NAN, arg,EDOM, DOMAIN
*/
/*
* wrapper asin(x)
*/
#include "fdlibm.h"
#include <errno.h>
#ifndef _DOUBLE_IS_32BITS
#ifdef __STDC__
double asin(double x) /* wrapper asin */
#else
double asin(x) /* wrapper asin */
double x;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_asin(x);
#else
double z;
struct exception exc;
z = __ieee754_asin(x);
if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
if(fabs(x)>1.0) {
/* asin(|x|>1) */
exc.type = DOMAIN;
exc.name = "asin";
exc.err = 0;
exc.arg1 = exc.arg2 = x;
exc.retval = nan("");
if(_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
errno = EDOM;
}
if (exc.err != 0)
errno = exc.err;
return exc.retval;
} else
return z;
#endif
}
#endif /* defined(_DOUBLE_IS_32BITS) */
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