1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  24  */
  25 
  26 /*
  27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 
  31 #pragma weak __ccos = ccos
  32 
  33 
  34 /*
  35  * dcomplex ccos(dcomplex z);
  36  *
  37  * z := x+iy; since ccos(iz) = cosh(z), we have
  38  * ccos(z)      = ccos((-1)*(-z)) = ccos(i*i*(-z))
  39  *              = ccosh(i*(-z)) = ccosh(i*(-x-yi))
  40  *              = ccosh(y-ix)
  41  */
  42 
  43 #include "libm.h"
  44 #include "complex_wrapper.h"
  45 
  46 dcomplex
  47 ccos(dcomplex z)
  48 {
  49         double x, y;
  50 
  51         x = D_RE(z);
  52         y = D_IM(z);
  53         D_RE(z) = y;
  54         D_IM(z) = -x;
  55         return (ccosh(z));
  56 }