usr/src/lib/libm/common/complex/cacoshl.c

   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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  27  * Use is subject to license terms.
  28  */
  29
  30 #pragma weak __cacoshl = cacoshl
  31
  32 #include "libm.h"       /* fabsl/isnanl/isinfl/signbitl */
  33 #include "complex_wrapper.h"
  34 #include "longdouble.h"
  35
  36 /* INDENT OFF */
  37 /*
  38  * ldcomplex cacoshl(ldcomplex z);
  39  *      cacosh z = +-i cacos z .
  40  * In order to make conj(cacosh(z))=cacosh(conj(z)),
  41  * we define
  42  *      cacosh z = sign(Im(z))*i cacos z .
  43  *
  44  */
  45 /* INDENT ON */
  46
  47 ldcomplex
  48 cacoshl(ldcomplex z) {
  49         ldcomplex w, ans;
  50         long double x, y;
  51
  52         w = cacosl(z);
  53         x = LD_RE(z);
  54         y = LD_IM(z);
  55         if (isnanl(y)) {
  56                 LD_IM(ans) = y + y;
  57                 if (isinfl(x))
  58                         LD_RE(ans) = fabsl(x);
  59                 else
  60                         LD_RE(ans) = y;
  61         } else if (signbitl(y) == 0) {
  62                 LD_RE(ans) = -LD_IM(w);
  63                 LD_IM(ans) = LD_RE(w);
  64         } else {
  65                 LD_RE(ans) = LD_IM(w);
  66                 LD_IM(ans) = -LD_RE(w);
  67         }
  68         return (ans);
  69 }