cacosh.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak cacosh = __cacosh
/* INDENT OFF */
/*
* dcomplex cacosh(dcomplex z);
* cacosh z = +-i cacos z .
* In order to make conj(cacosh(z))=cacosh(conj(z)),
* we define
* cacosh z = sign(Im(z))*i cacos z .
*
*/
/* INDENT ON */
#include "libm.h" /* fabs/isnan/isinf/signbit */
#include "complex_wrapper.h"
/* need to work on special cases according to spec */
dcomplex
cacosh(dcomplex z) {
dcomplex w, ans;
double x, y;
w = cacos(z);
x = D_RE(z);
y = D_IM(z);
if (isnan(y)) {
D_IM(ans) = y + y;
if (isinf(x))
D_RE(ans) = fabs(x);
else
D_RE(ans) = y;
} else if (signbit(y) == 0) {
D_RE(ans) = -D_IM(w);
D_IM(ans) = D_RE(w);
} else {
D_RE(ans) = D_IM(w);
D_IM(ans) = -D_RE(w);
}
return (ans);
}