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 cacos = __cacos
  31 
  32 /* INDENT OFF */
  33 /*
  34  * dcomplex cacos(dcomplex z);
  35  *
  36  * Alogrithm
  37  * (based on T.E.Hull, Thomas F. Fairgrieve and Ping Tak Peter Tang's
  38  * paper "Implementing the Complex Arcsine and Arccosine Functins Using
  39  * Exception Handling", ACM TOMS, Vol 23, pp 299-335)
  40  *
  41  * The principal value of complex inverse cosine function cacos(z),
  42  * where z = x+iy, can be defined by
  43  *
  44  *      cacos(z) = acos(B) - i sign(y) log (A + sqrt(A*A-1)),
  45  *
  46  * where the log function is the natural log, and
  47  *             ____________           ____________
  48  *       1    /     2    2      1    /     2    2
  49  *  A = ---  / (x+1)  + y   +  ---  / (x-1)  + y
  50  *       2 \/                   2 \/

  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 __cacos = cacos
  31 
  32 /* INDENT OFF */
  33 /*
  34  * dcomplex cacos(dcomplex z);
  35  *
  36  * Alogrithm
  37  * (based on T.E.Hull, Thomas F. Fairgrieve and Ping Tak Peter Tang's
  38  * paper "Implementing the Complex Arcsine and Arccosine Functins Using
  39  * Exception Handling", ACM TOMS, Vol 23, pp 299-335)
  40  *
  41  * The principal value of complex inverse cosine function cacos(z),
  42  * where z = x+iy, can be defined by
  43  *
  44  *      cacos(z) = acos(B) - i sign(y) log (A + sqrt(A*A-1)),
  45  *
  46  * where the log function is the natural log, and
  47  *             ____________           ____________
  48  *       1    /     2    2      1    /     2    2
  49  *  A = ---  / (x+1)  + y   +  ---  / (x-1)  + y
  50  *       2 \/                   2 \/