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 cpow = __cpow
  31 
  32 /* INDENT OFF */
  33 /*
  34  * dcomplex cpow(dcomplex z);
  35  *
  36  * z**w analytically equivalent to
  37  *
  38  * cpow(z,w) = cexp(w clog(z))
  39  *
  40  * Let z = x+iy, w = u+iv.
  41  * Since
  42  *                        _________
  43  *                       / 2    2            -1   y
  44  *     log(x+iy) = log(\/ x  + y    ) + i tan   (---)
  45  *                                                x
  46  *
  47  *                  1       2    2         -1   y
  48  *               = --- log(x  + y ) + i tan   (---)
  49  *                  2                           x
  50  *                       u       2    2         -1  y

  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 __cpow = cpow
  31 
  32 /* INDENT OFF */
  33 /*
  34  * dcomplex cpow(dcomplex z);
  35  *
  36  * z**w analytically equivalent to
  37  *
  38  * cpow(z,w) = cexp(w clog(z))
  39  *
  40  * Let z = x+iy, w = u+iv.
  41  * Since
  42  *                        _________
  43  *                       / 2    2            -1   y
  44  *     log(x+iy) = log(\/ x  + y    ) + i tan   (---)
  45  *                                                x
  46  *
  47  *                  1       2    2         -1   y
  48  *               = --- log(x  + y ) + i tan   (---)
  49  *                  2                           x
  50  *                       u       2    2         -1  y